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• How to Write a Literature Review | Guide, Examples, & Templates

How to Write a Literature Review | Guide, Examples, & Templates

Published on January 2, 2023 by Shona McCombes . Revised on September 11, 2023.

What is a literature review? A literature review is a survey of scholarly sources on a specific topic. It provides an overview of current knowledge, allowing you to identify relevant theories, methods, and gaps in the existing research that you can later apply to your paper, thesis, or dissertation topic .

There are five key steps to writing a literature review:

• Search for relevant literature
• Evaluate sources
• Identify themes, debates, and gaps
• Outline the structure
• Write your literature review

A good literature review doesn’t just summarize sources—it analyzes, synthesizes , and critically evaluates to give a clear picture of the state of knowledge on the subject.

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Table of contents

What is the purpose of a literature review, examples of literature reviews, step 1 – search for relevant literature, step 2 – evaluate and select sources, step 3 – identify themes, debates, and gaps, step 4 – outline your literature review’s structure, step 5 – write your literature review, free lecture slides, other interesting articles, frequently asked questions, introduction.

• Quick Run-through
• Step 1 & 2

When you write a thesis , dissertation , or research paper , you will likely have to conduct a literature review to situate your research within existing knowledge. The literature review gives you a chance to:

• Demonstrate your familiarity with the topic and its scholarly context
• Develop a theoretical framework and methodology for your research
• Position your work in relation to other researchers and theorists
• Show how your research addresses a gap or contributes to a debate
• Evaluate the current state of research and demonstrate your knowledge of the scholarly debates around your topic.

Writing literature reviews is a particularly important skill if you want to apply for graduate school or pursue a career in research. We’ve written a step-by-step guide that you can follow below.

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Writing literature reviews can be quite challenging! A good starting point could be to look at some examples, depending on what kind of literature review you’d like to write.

• Example literature review #1: “Why Do People Migrate? A Review of the Theoretical Literature” ( Theoretical literature review about the development of economic migration theory from the 1950s to today.)
• Example literature review #2: “Literature review as a research methodology: An overview and guidelines” ( Methodological literature review about interdisciplinary knowledge acquisition and production.)
• Example literature review #3: “The Use of Technology in English Language Learning: A Literature Review” ( Thematic literature review about the effects of technology on language acquisition.)
• Example literature review #4: “Learners’ Listening Comprehension Difficulties in English Language Learning: A Literature Review” ( Chronological literature review about how the concept of listening skills has changed over time.)

You can also check out our templates with literature review examples and sample outlines at the links below.

Download Word doc Download Google doc

Before you begin searching for literature, you need a clearly defined topic .

If you are writing the literature review section of a dissertation or research paper, you will search for literature related to your research problem and questions .

Make a list of keywords

Start by creating a list of keywords related to your research question. Include each of the key concepts or variables you’re interested in, and list any synonyms and related terms. You can add to this list as you discover new keywords in the process of your literature search.

• Social media, Facebook, Instagram, Twitter, Snapchat, TikTok
• Body image, self-perception, self-esteem, mental health
• Generation Z, teenagers, adolescents, youth

Search for relevant sources

Use your keywords to begin searching for sources. Some useful databases to search for journals and articles include:

• Your university’s library catalogue
• Google Scholar
• Project Muse (humanities and social sciences)
• Medline (life sciences and biomedicine)
• EconLit (economics)
• Inspec (physics, engineering and computer science)

You can also use boolean operators to help narrow down your search.

Make sure to read the abstract to find out whether an article is relevant to your question. When you find a useful book or article, you can check the bibliography to find other relevant sources.

You likely won’t be able to read absolutely everything that has been written on your topic, so it will be necessary to evaluate which sources are most relevant to your research question.

For each publication, ask yourself:

• What question or problem is the author addressing?
• What are the key concepts and how are they defined?
• What are the key theories, models, and methods?
• Does the research use established frameworks or take an innovative approach?
• What are the results and conclusions of the study?
• How does the publication relate to other literature in the field? Does it confirm, add to, or challenge established knowledge?
• What are the strengths and weaknesses of the research?

Make sure the sources you use are credible , and make sure you read any landmark studies and major theories in your field of research.

You can use our template to summarize and evaluate sources you’re thinking about using. Click on either button below to download.

Take notes and cite your sources

As you read, you should also begin the writing process. Take notes that you can later incorporate into the text of your literature review.

It is important to keep track of your sources with citations to avoid plagiarism . It can be helpful to make an annotated bibliography , where you compile full citation information and write a paragraph of summary and analysis for each source. This helps you remember what you read and saves time later in the process.

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To begin organizing your literature review’s argument and structure, be sure you understand the connections and relationships between the sources you’ve read. Based on your reading and notes, you can look for:

• Trends and patterns (in theory, method or results): do certain approaches become more or less popular over time?
• Themes: what questions or concepts recur across the literature?
• Debates, conflicts and contradictions: where do sources disagree?
• Pivotal publications: are there any influential theories or studies that changed the direction of the field?
• Gaps: what is missing from the literature? Are there weaknesses that need to be addressed?

This step will help you work out the structure of your literature review and (if applicable) show how your own research will contribute to existing knowledge.

• Most research has focused on young women.
• There is an increasing interest in the visual aspects of social media.
• But there is still a lack of robust research on highly visual platforms like Instagram and Snapchat—this is a gap that you could address in your own research.

There are various approaches to organizing the body of a literature review. Depending on the length of your literature review, you can combine several of these strategies (for example, your overall structure might be thematic, but each theme is discussed chronologically).

Chronological

The simplest approach is to trace the development of the topic over time. However, if you choose this strategy, be careful to avoid simply listing and summarizing sources in order.

Try to analyze patterns, turning points and key debates that have shaped the direction of the field. Give your interpretation of how and why certain developments occurred.

If you have found some recurring central themes, you can organize your literature review into subsections that address different aspects of the topic.

For example, if you are reviewing literature about inequalities in migrant health outcomes, key themes might include healthcare policy, language barriers, cultural attitudes, legal status, and economic access.

Methodological

If you draw your sources from different disciplines or fields that use a variety of research methods , you might want to compare the results and conclusions that emerge from different approaches. For example:

• Look at what results have emerged in qualitative versus quantitative research
• Discuss how the topic has been approached by empirical versus theoretical scholarship
• Divide the literature into sociological, historical, and cultural sources

Theoretical

A literature review is often the foundation for a theoretical framework . You can use it to discuss various theories, models, and definitions of key concepts.

You might argue for the relevance of a specific theoretical approach, or combine various theoretical concepts to create a framework for your research.

Like any other academic text , your literature review should have an introduction , a main body, and a conclusion . What you include in each depends on the objective of your literature review.

The introduction should clearly establish the focus and purpose of the literature review.

Depending on the length of your literature review, you might want to divide the body into subsections. You can use a subheading for each theme, time period, or methodological approach.

As you write, you can follow these tips:

• Summarize and synthesize: give an overview of the main points of each source and combine them into a coherent whole
• Analyze and interpret: don’t just paraphrase other researchers — add your own interpretations where possible, discussing the significance of findings in relation to the literature as a whole
• Critically evaluate: mention the strengths and weaknesses of your sources
• Write in well-structured paragraphs: use transition words and topic sentences to draw connections, comparisons and contrasts

In the conclusion, you should summarize the key findings you have taken from the literature and emphasize their significance.

When you’ve finished writing and revising your literature review, don’t forget to proofread thoroughly before submitting. Not a language expert? Check out Scribbr’s professional proofreading services !

This article has been adapted into lecture slides that you can use to teach your students about writing a literature review.

Scribbr slides are free to use, customize, and distribute for educational purposes.

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If you want to know more about the research process , methodology , research bias , or statistics , make sure to check out some of our other articles with explanations and examples.

• Sampling methods
• Simple random sampling
• Stratified sampling
• Cluster sampling
• Likert scales
• Reproducibility

 Statistics

• Null hypothesis
• Statistical power
• Probability distribution
• Effect size
• Poisson distribution

Research bias

• Optimism bias
• Cognitive bias
• Implicit bias
• Hawthorne effect
• Anchoring bias
• Explicit bias

A literature review is a survey of scholarly sources (such as books, journal articles, and theses) related to a specific topic or research question .

It is often written as part of a thesis, dissertation , or research paper , in order to situate your work in relation to existing knowledge.

There are several reasons to conduct a literature review at the beginning of a research project:

• To familiarize yourself with the current state of knowledge on your topic
• To ensure that you’re not just repeating what others have already done
• To identify gaps in knowledge and unresolved problems that your research can address
• To develop your theoretical framework and methodology
• To provide an overview of the key findings and debates on the topic

Writing the literature review shows your reader how your work relates to existing research and what new insights it will contribute.

The literature review usually comes near the beginning of your thesis or dissertation . After the introduction , it grounds your research in a scholarly field and leads directly to your theoretical framework or methodology .

A literature review is a survey of credible sources on a topic, often used in dissertations , theses, and research papers . Literature reviews give an overview of knowledge on a subject, helping you identify relevant theories and methods, as well as gaps in existing research. Literature reviews are set up similarly to other  academic texts , with an introduction , a main body, and a conclusion .

An  annotated bibliography is a list of  source references that has a short description (called an annotation ) for each of the sources. It is often assigned as part of the research process for a  paper .  

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7 Writing a Literature Review

Hundreds of original investigation research articles on health science topics are published each year. It is becoming harder and harder to keep on top of all new findings in a topic area and – more importantly – to work out how they all fit together to determine our current understanding of a topic. This is where literature reviews come in.

In this chapter, we explain what a literature review is and outline the stages involved in writing one. We also provide practical tips on how to communicate the results of a review of current literature on a topic in the format of a literature review.

7.1 What is a literature review?

Literature reviews provide a synthesis and evaluation  of the existing literature on a particular topic with the aim of gaining a new, deeper understanding of the topic.

Published literature reviews are typically written by scientists who are experts in that particular area of science. Usually, they will be widely published as authors of their own original work, making them highly qualified to author a literature review.

However, literature reviews are still subject to peer review before being published. Literature reviews provide an important bridge between the expert scientific community and many other communities, such as science journalists, teachers, and medical and allied health professionals. When the most up-to-date knowledge reaches such audiences, it is more likely that this information will find its way to the general public. When this happens, – the ultimate good of science can be realised.

A literature review is structured differently from an original research article. It is developed based on themes, rather than stages of the scientific method.

In the article Ten simple rules for writing a literature review , Marco Pautasso explains the importance of literature reviews:

Literature reviews are in great demand in most scientific fields. Their need stems from the ever-increasing output of scientific publications. For example, compared to 1991, in 2008 three, eight, and forty times more papers were indexed in Web of Science on malaria, obesity, and biodiversity, respectively. Given such mountains of papers, scientists cannot be expected to examine in detail every single new paper relevant to their interests. Thus, it is both advantageous and necessary to rely on regular summaries of the recent literature. Although recognition for scientists mainly comes from primary research, timely literature reviews can lead to new synthetic insights and are often widely read. For such summaries to be useful, however, they need to be compiled in a professional way (Pautasso, 2013, para. 1).

An example of a literature review is shown in Figure 7.1.

Video 7.1: What is a literature review? [2 mins, 11 secs]

Watch this video created by Steely Library at Northern Kentucky Library called ‘ What is a literature review? Note: Closed captions are available by clicking on the CC button below.

Examples of published literature reviews

• Strength training alone, exercise therapy alone, and exercise therapy with passive manual mobilisation each reduce pain and disability in people with knee osteoarthritis: a systematic review
• Traveler’s diarrhea: a clinical review
• Cultural concepts of distress and psychiatric disorders: literature review and research recommendations for global mental health epidemiology

7.2 Steps of writing a literature review

Writing a literature review is a very challenging task. Figure 7.2 summarises the steps of writing a literature review. Depending on why you are writing your literature review, you may be given a topic area, or may choose a topic that particularly interests you or is related to a research project that you wish to undertake.

Chapter 6 provides instructions on finding scientific literature that would form the basis for your literature review.

Once you have your topic and have accessed the literature, the next stages (analysis, synthesis and evaluation) are challenging. Next, we look at these important cognitive skills student scientists will need to develop and employ to successfully write a literature review, and provide some guidance for navigating these stages.

Analysis, synthesis and evaluation

Analysis, synthesis and evaluation are three essential skills required by scientists  and you will need to develop these skills if you are to write a good literature review ( Figure 7.3 ). These important cognitive skills are discussed in more detail in Chapter 9.

The first step in writing a literature review is to analyse the original investigation research papers that you have gathered related to your topic.

Analysis requires examining the papers methodically and in detail, so you can understand and interpret aspects of the study described in each research article.

An analysis grid is a simple tool you can use to help with the careful examination and breakdown of each paper. This tool will allow you to create a concise summary of each research paper; see Table 7.1 for an example of  an analysis grid. When filling in the grid, the aim is to draw out key aspects of each research paper. Use a different row for each paper, and a different column for each aspect of the paper ( Tables 7.2 and 7.3 show how completed analysis grid may look).

Before completing your own grid, look at these examples and note the types of information that have been included, as well as the level of detail. Completing an analysis grid with a sufficient level of detail will help you to complete the synthesis and evaluation stages effectively. This grid will allow you to more easily observe similarities and differences across the findings of the research papers and to identify possible explanations (e.g., differences in methodologies employed) for observed differences between the findings of different research papers.

Table 7.1: Example of an analysis grid

Table 7.3: Sample filled-in analysis grid for research article by Ping and colleagues

Source: Ping, WC, Keong, CC & Bandyopadhyay, A 2010, ‘Effects of acute supplementation of caffeine on cardiorespiratory responses during endurance running in a hot and humid climate’, Indian Journal of Medical Research, vol. 132, pp. 36–41. Used under a CC-BY-NC-SA licence.

Step two of writing a literature review is synthesis.

Synthesis describes combining separate components or elements to form a connected whole.

You will use the results of your analysis to find themes to build your literature review around. Each of the themes identified will become a subheading within the body of your literature review.

A good place to start when identifying themes is with the dependent variables (results/findings) that were investigated in the research studies.

Because all of the research articles you are incorporating into your literature review are related to your topic, it is likely that they have similar study designs and have measured similar dependent variables. Review the ‘Results’ column of your analysis grid. You may like to collate the common themes in a synthesis grid (see, for example Table 7.4 ).

Step three of writing a literature review is evaluation, which can only be done after carefully analysing your research papers and synthesising the common themes (findings).

During the evaluation stage, you are making judgements on the themes presented in the research articles that you have read. This includes providing physiological explanations for the findings. It may be useful to refer to the discussion section of published original investigation research papers, or another literature review, where the authors may mention tested or hypothetical physiological mechanisms that may explain their findings.

When the findings of the investigations related to a particular theme are inconsistent (e.g., one study shows that caffeine effects performance and another study shows that caffeine had no effect on performance) you should attempt to provide explanations of why the results differ, including physiological explanations. A good place to start is by comparing the methodologies to determine if there are any differences that may explain the differences in the findings (see the ‘Experimental design’ column of your analysis grid). An example of evaluation is shown in the examples that follow in this section, under ‘Running performance’ and ‘RPE ratings’.

When the findings of the papers related to a particular theme are consistent (e.g., caffeine had no effect on oxygen uptake in both studies) an evaluation should include an explanation of why the results are similar. Once again, include physiological explanations. It is still a good idea to compare methodologies as a background to the evaluation. An example of evaluation is shown in the following under ‘Oxygen consumption’.

7.3 Writing your literature review

Once you have completed the analysis, and synthesis grids and written your evaluation of the research papers , you can combine synthesis and evaluation information to create a paragraph for a literature review ( Figure 7.4 ).

The following paragraphs are an example of combining the outcome of the synthesis and evaluation stages to produce a paragraph for a literature review.

Note that this is an example using only two papers – most literature reviews would be presenting information on many more papers than this ( (e.g., 106 papers in the review article by Bain and colleagues discussed later in this chapter). However, the same principle applies regardless of the number of papers reviewed.

The next part of this chapter looks at the each section of a literature review and explains how to write them by referring to a review article that was published in Frontiers in Physiology and shown in Figure 7.1. Each section from the published article is annotated to highlight important features of the format of the review article, and identifies the synthesis and evaluation information.

In the examination of each review article section we will point out examples of how the authors have presented certain information and where they display application of important cognitive processes; we will use the colour code shown below:

This should be one paragraph that accurately reflects the contents of the review article.

Introduction

The introduction should establish the context and importance of the review

Body of literature review

The reference section provides a list of the references that you cited in the body of your review article. The format will depend on the journal of publication as each journal has their own specific referencing format.

It is important to accurately cite references in research papers to acknowledge your sources and ensure credit is appropriately given to authors of work you have referred to. An accurate and comprehensive reference list also shows your readers that you are well-read in your topic area and are aware of the key papers that provide the context to your research.

It is important to keep track of your resources and to reference them consistently in the format required by the publication in which your work will appear. Most scientists will use reference management software to store details of all of the journal articles (and other sources) they use while writing their review article. This software also automates the process of adding in-text references and creating a reference list. In the review article by Bain et al. (2014) used as an example in this chapter, the reference list contains 106 items, so you can imagine how much help referencing software would be. Chapter 5 shows you how to use EndNote, one example of reference management software.

Click the drop down below to review the terms learned from this chapter.

Copyright note:

• The quotation from Pautasso, M 2013, ‘Ten simple rules for writing a literature review’, PLoS Computational Biology is use under a CC-BY licence. 
• Content from the annotated article and tables are based on Schubert, MM, Astorino, TA & Azevedo, JJL 2013, ‘The effects of caffeinated ‘energy shots’ on time trial performance’, Nutrients, vol. 5, no. 6, pp. 2062–2075 (used under a CC-BY 3.0 licence ) and P ing, WC, Keong , CC & Bandyopadhyay, A 2010, ‘Effects of acute supplementation of caffeine on cardiorespiratory responses during endurance running in a hot and humid climate’, Indian Journal of Medical Research, vol. 132, pp. 36–41 (used under a CC-BY-NC-SA 4.0 licence ). 

Bain, A.R., Morrison, S.A., & Ainslie, P.N. (2014). Cerebral oxygenation and hyperthermia. Frontiers in Physiology, 5 , 92.

Pautasso, M. (2013). Ten simple rules for writing a literature review. PLoS Computational Biology, 9 (7), e1003149.

How To Do Science Copyright © 2022 by University of Southern Queensland is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License , except where otherwise noted.

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Writing a Literature Review

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A literature review is a document or section of a document that collects key sources on a topic and discusses those sources in conversation with each other (also called synthesis ). The lit review is an important genre in many disciplines, not just literature (i.e., the study of works of literature such as novels and plays). When we say “literature review” or refer to “the literature,” we are talking about the research ( scholarship ) in a given field. You will often see the terms “the research,” “the scholarship,” and “the literature” used mostly interchangeably.

Where, when, and why would I write a lit review?

There are a number of different situations where you might write a literature review, each with slightly different expectations; different disciplines, too, have field-specific expectations for what a literature review is and does. For instance, in the humanities, authors might include more overt argumentation and interpretation of source material in their literature reviews, whereas in the sciences, authors are more likely to report study designs and results in their literature reviews; these differences reflect these disciplines’ purposes and conventions in scholarship. You should always look at examples from your own discipline and talk to professors or mentors in your field to be sure you understand your discipline’s conventions, for literature reviews as well as for any other genre.

A literature review can be a part of a research paper or scholarly article, usually falling after the introduction and before the research methods sections. In these cases, the lit review just needs to cover scholarship that is important to the issue you are writing about; sometimes it will also cover key sources that informed your research methodology.

Lit reviews can also be standalone pieces, either as assignments in a class or as publications. In a class, a lit review may be assigned to help students familiarize themselves with a topic and with scholarship in their field, get an idea of the other researchers working on the topic they’re interested in, find gaps in existing research in order to propose new projects, and/or develop a theoretical framework and methodology for later research. As a publication, a lit review usually is meant to help make other scholars’ lives easier by collecting and summarizing, synthesizing, and analyzing existing research on a topic. This can be especially helpful for students or scholars getting into a new research area, or for directing an entire community of scholars toward questions that have not yet been answered.

What are the parts of a lit review?

Most lit reviews use a basic introduction-body-conclusion structure; if your lit review is part of a larger paper, the introduction and conclusion pieces may be just a few sentences while you focus most of your attention on the body. If your lit review is a standalone piece, the introduction and conclusion take up more space and give you a place to discuss your goals, research methods, and conclusions separately from where you discuss the literature itself.

Introduction:

• An introductory paragraph that explains what your working topic and thesis is
• A forecast of key topics or texts that will appear in the review
• Potentially, a description of how you found sources and how you analyzed them for inclusion and discussion in the review (more often found in published, standalone literature reviews than in lit review sections in an article or research paper)
• Summarize and synthesize: Give an overview of the main points of each source and combine them into a coherent whole
• Analyze and interpret: Don’t just paraphrase other researchers – add your own interpretations where possible, discussing the significance of findings in relation to the literature as a whole
• Critically Evaluate: Mention the strengths and weaknesses of your sources
• Write in well-structured paragraphs: Use transition words and topic sentence to draw connections, comparisons, and contrasts.

Conclusion:

• Summarize the key findings you have taken from the literature and emphasize their significance
• Connect it back to your primary research question

How should I organize my lit review?

Lit reviews can take many different organizational patterns depending on what you are trying to accomplish with the review. Here are some examples:

• Chronological : The simplest approach is to trace the development of the topic over time, which helps familiarize the audience with the topic (for instance if you are introducing something that is not commonly known in your field). If you choose this strategy, be careful to avoid simply listing and summarizing sources in order. Try to analyze the patterns, turning points, and key debates that have shaped the direction of the field. Give your interpretation of how and why certain developments occurred (as mentioned previously, this may not be appropriate in your discipline — check with a teacher or mentor if you’re unsure).
• Thematic : If you have found some recurring central themes that you will continue working with throughout your piece, you can organize your literature review into subsections that address different aspects of the topic. For example, if you are reviewing literature about women and religion, key themes can include the role of women in churches and the religious attitude towards women.
• Qualitative versus quantitative research
• Empirical versus theoretical scholarship
• Divide the research by sociological, historical, or cultural sources
• Theoretical : In many humanities articles, the literature review is the foundation for the theoretical framework. You can use it to discuss various theories, models, and definitions of key concepts. You can argue for the relevance of a specific theoretical approach or combine various theorical concepts to create a framework for your research.

What are some strategies or tips I can use while writing my lit review?

Any lit review is only as good as the research it discusses; make sure your sources are well-chosen and your research is thorough. Don’t be afraid to do more research if you discover a new thread as you’re writing. More info on the research process is available in our "Conducting Research" resources .

As you’re doing your research, create an annotated bibliography ( see our page on the this type of document ). Much of the information used in an annotated bibliography can be used also in a literature review, so you’ll be not only partially drafting your lit review as you research, but also developing your sense of the larger conversation going on among scholars, professionals, and any other stakeholders in your topic.

Usually you will need to synthesize research rather than just summarizing it. This means drawing connections between sources to create a picture of the scholarly conversation on a topic over time. Many student writers struggle to synthesize because they feel they don’t have anything to add to the scholars they are citing; here are some strategies to help you:

• It often helps to remember that the point of these kinds of syntheses is to show your readers how you understand your research, to help them read the rest of your paper.
• Writing teachers often say synthesis is like hosting a dinner party: imagine all your sources are together in a room, discussing your topic. What are they saying to each other?
• Look at the in-text citations in each paragraph. Are you citing just one source for each paragraph? This usually indicates summary only. When you have multiple sources cited in a paragraph, you are more likely to be synthesizing them (not always, but often
• Read more about synthesis here.

The most interesting literature reviews are often written as arguments (again, as mentioned at the beginning of the page, this is discipline-specific and doesn’t work for all situations). Often, the literature review is where you can establish your research as filling a particular gap or as relevant in a particular way. You have some chance to do this in your introduction in an article, but the literature review section gives a more extended opportunity to establish the conversation in the way you would like your readers to see it. You can choose the intellectual lineage you would like to be part of and whose definitions matter most to your thinking (mostly humanities-specific, but this goes for sciences as well). In addressing these points, you argue for your place in the conversation, which tends to make the lit review more compelling than a simple reporting of other sources.

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What is a literature review?

A literature review is an integrated analysis -- not just a summary-- of scholarly writings and other relevant evidence related directly to your research question.  That is, it represents a synthesis of the evidence that provides background information on your topic and shows a association between the evidence and your research question.

A literature review may be a stand alone work or the introduction to a larger research paper, depending on the assignment.  Rely heavily on the guidelines your instructor has given you.

Why is it important?

A literature review is important because it:

• Explains the background of research on a topic.
• Demonstrates why a topic is significant to a subject area.
• Discovers relationships between research studies/ideas.
• Identifies major themes, concepts, and researchers on a topic.
• Identifies critical gaps and points of disagreement.
• Discusses further research questions that logically come out of the previous studies.

APA7 Style resources

APA Style Blog - for those harder to find answers

1. Choose a topic. Define your research question.

Your literature review should be guided by your central research question.  The literature represents background and research developments related to a specific research question, interpreted and analyzed by you in a synthesized way.

• Make sure your research question is not too broad or too narrow.  Is it manageable?
• Begin writing down terms that are related to your question. These will be useful for searches later.
• If you have the opportunity, discuss your topic with your professor and your class mates.

2. Decide on the scope of your review

How many studies do you need to look at? How comprehensive should it be? How many years should it cover? 

• This may depend on your assignment.  How many sources does the assignment require?

3. Select the databases you will use to conduct your searches.

Make a list of the databases you will search. 

Where to find databases:

• use the tabs on this guide
• Find other databases in the Nursing Information Resources web page
• More on the Medical Library web page
• ... and more on the Yale University Library web page

4. Conduct your searches to find the evidence. Keep track of your searches.

• Use the key words in your question, as well as synonyms for those words, as terms in your search. Use the database tutorials for help.
• Save the searches in the databases. This saves time when you want to redo, or modify, the searches. It is also helpful to use as a guide is the searches are not finding any useful results.
• Review the abstracts of research studies carefully. This will save you time.
• Use the bibliographies and references of research studies you find to locate others.
• Check with your professor, or a subject expert in the field, if you are missing any key works in the field.
• Ask your librarian for help at any time.
• Use a citation manager, such as EndNote as the repository for your citations. See the EndNote tutorials for help.

Review the literature

Some questions to help you analyze the research:

• What was the research question of the study you are reviewing? What were the authors trying to discover?
• Was the research funded by a source that could influence the findings?
• What were the research methodologies? Analyze its literature review, the samples and variables used, the results, and the conclusions.
• Does the research seem to be complete? Could it have been conducted more soundly? What further questions does it raise?
• If there are conflicting studies, why do you think that is?
• How are the authors viewed in the field? Has this study been cited? If so, how has it been analyzed?

Tips: 

• Review the abstracts carefully.  
• Keep careful notes so that you may track your thought processes during the research process.
• Create a matrix of the studies for easy analysis, and synthesis, across all of the studies.
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How-to conduct a systematic literature review: A quick guide for computer science research

Angela carrera-rivera.

a Faculty of Engineering, Mondragon University

William Ochoa

Felix larrinaga.

b Design Innovation Center(DBZ), Mondragon University

Associated Data

• No data was used for the research described in the article.

Performing a literature review is a critical first step in research to understanding the state-of-the-art and identifying gaps and challenges in the field. A systematic literature review is a method which sets out a series of steps to methodically organize the review. In this paper, we present a guide designed for researchers and in particular early-stage researchers in the computer-science field. The contribution of the article is the following:

• • Clearly defined strategies to follow for a systematic literature review in computer science research, and
• • Algorithmic method to tackle a systematic literature review.

Graphical abstract

Specifications table

Method details

A Systematic Literature Review (SLR) is a research methodology to collect, identify, and critically analyze the available research studies (e.g., articles, conference proceedings, books, dissertations) through a systematic procedure [12] . An SLR updates the reader with current literature about a subject [6] . The goal is to review critical points of current knowledge on a topic about research questions to suggest areas for further examination [5] . Defining an “Initial Idea” or interest in a subject to be studied is the first step before starting the SLR. An early search of the relevant literature can help determine whether the topic is too broad to adequately cover in the time frame and whether it is necessary to narrow the focus. Reading some articles can assist in setting the direction for a formal review., and formulating a potential research question (e.g., how is semantics involved in Industry 4.0?) can further facilitate this process. Once the focus has been established, an SLR can be undertaken to find more specific studies related to the variables in this question. Although there are multiple approaches for performing an SLR ( [5] , [26] , [27] ), this work aims to provide a step-by-step and practical guide while citing useful examples for computer-science research. The methodology presented in this paper comprises two main phases: “Planning” described in section 2, and “Conducting” described in section 3, following the depiction of the graphical abstract.

Defining the protocol is the first step of an SLR since it describes the procedures involved in the review and acts as a log of the activities to be performed. Obtaining opinions from peers while developing the protocol, is encouraged to ensure the review's consistency and validity, and helps identify when modifications are necessary [20] . One final goal of the protocol is to ensure the replicability of the review.

Define PICOC and synonyms

The PICOC (Population, Intervention, Comparison, Outcome, and Context) criteria break down the SLR's objectives into searchable keywords and help formulate research questions [ 27 ]. PICOC is widely used in the medical and social sciences fields to encourage researchers to consider the components of the research questions [14] . Kitchenham & Charters [6] compiled the list of PICOC elements and their corresponding terms in computer science, as presented in Table 1 , which includes keywords derived from the PICOC elements. From that point on, it is essential to think of synonyms or “alike” terms that later can be used for building queries in the selected digital libraries. For instance, the keyword “context awareness” can also be linked to “context-aware”.

Planning Step 1 “Defining PICOC keywords and synonyms”.

Formulate research questions

Clearly defined research question(s) are the key elements which set the focus for study identification and data extraction [21] . These questions are formulated based on the PICOC criteria as presented in the example in Table 2 (PICOC keywords are underlined).

Research questions examples.

Select digital library sources

The validity of a study will depend on the proper selection of a database since it must adequately cover the area under investigation [19] . The Web of Science (WoS) is an international and multidisciplinary tool for accessing literature in science, technology, biomedicine, and other disciplines. Scopus is a database that today indexes 40,562 peer-reviewed journals, compared to 24,831 for WoS. Thus, Scopus is currently the largest existing multidisciplinary database. However, it may also be necessary to include sources relevant to computer science, such as EI Compendex, IEEE Xplore, and ACM. Table 3 compares the area of expertise of a selection of databases.

Planning Step 3 “Select digital libraries”. Description of digital libraries in computer science and software engineering.

Define inclusion and exclusion criteria

Authors should define the inclusion and exclusion criteria before conducting the review to prevent bias, although these can be adjusted later, if necessary. The selection of primary studies will depend on these criteria. Articles are included or excluded in this first selection based on abstract and primary bibliographic data. When unsure, the article is skimmed to further decide the relevance for the review. Table 4 sets out some criteria types with descriptions and examples.

Planning Step 4 “Define inclusion and exclusion criteria”. Examples of criteria type.

Define the Quality Assessment (QA) checklist

Assessing the quality of an article requires an artifact which describes how to perform a detailed assessment. A typical quality assessment is a checklist that contains multiple factors to evaluate. A numerical scale is used to assess the criteria and quantify the QA [22] . Zhou et al. [25] presented a detailed description of assessment criteria in software engineering, classified into four main aspects of study quality: Reporting, Rigor, Credibility, and Relevance. Each of these criteria can be evaluated using, for instance, a Likert-type scale [17] , as shown in Table 5 . It is essential to select the same scale for all criteria established on the quality assessment.

Planning Step 5 “Define QA assessment checklist”. Examples of QA scales and questions.

Define the “Data Extraction” form

The data extraction form represents the information necessary to answer the research questions established for the review. Synthesizing the articles is a crucial step when conducting research. Ramesh et al. [15] presented a classification scheme for computer science research, based on topics, research methods, and levels of analysis that can be used to categorize the articles selected. Classification methods and fields to consider when conducting a review are presented in Table 6 .

Planning Step 6 “Define data extraction form”. Examples of fields.

The data extraction must be relevant to the research questions, and the relationship to each of the questions should be included in the form. Kitchenham & Charters [6] presented more pertinent data that can be captured, such as conclusions, recommendations, strengths, and weaknesses. Although the data extraction form can be updated if more information is needed, this should be treated with caution since it can be time-consuming. It can therefore be helpful to first have a general background in the research topic to determine better data extraction criteria.

After defining the protocol, conducting the review requires following each of the steps previously described. Using tools can help simplify the performance of this task. Standard tools such as Excel or Google sheets allow multiple researchers to work collaboratively. Another online tool specifically designed for performing SLRs is Parsif.al 1 . This tool allows researchers, especially in the context of software engineering, to define goals and objectives, import articles using BibTeX files, eliminate duplicates, define selection criteria, and generate reports.

Build digital library search strings

Search strings are built considering the PICOC elements and synonyms to execute the search in each database library. A search string should separate the synonyms with the boolean operator OR. In comparison, the PICOC elements are separated with parentheses and the boolean operator AND. An example is presented next:

(“Smart Manufacturing” OR “Digital Manufacturing” OR “Smart Factory”) AND (“Business Process Management” OR “BPEL” OR “BPM” OR “BPMN”) AND (“Semantic Web” OR “Ontology” OR “Semantic” OR “Semantic Web Service”) AND (“Framework” OR “Extension” OR “Plugin” OR “Tool”

Gather studies

Databases that feature advanced searches enable researchers to perform search queries based on titles, abstracts, and keywords, as well as for years or areas of research. Fig. 1 presents the example of an advanced search in Scopus, using titles, abstracts, and keywords (TITLE-ABS-KEY). Most of the databases allow the use of logical operators (i.e., AND, OR). In the example, the search is for “BIG DATA” and “USER EXPERIENCE” or “UX” as a synonym.

Example of Advanced search on Scopus.

In general, bibliometric data of articles can be exported from the databases as a comma-separated-value file (CSV) or BibTeX file, which is helpful for data extraction and quantitative and qualitative analysis. In addition, researchers should take advantage of reference-management software such as Zotero, Mendeley, Endnote, or Jabref, which import bibliographic information onto the software easily.

Study Selection and Refinement

The first step in this stage is to identify any duplicates that appear in the different searches in the selected databases. Some automatic procedures, tools like Excel formulas, or programming languages (i.e., Python) can be convenient here.

In the second step, articles are included or excluded according to the selection criteria, mainly by reading titles and abstracts. Finally, the quality is assessed using the predefined scale. Fig. 2 shows an example of an article QA evaluation in Parsif.al, using a simple scale. In this scenario, the scoring procedure is the following YES= 1, PARTIALLY= 0.5, and NO or UNKNOWN = 0 . A cut-off score should be defined to filter those articles that do not pass the QA. The QA will require a light review of the full text of the article.

Performing quality assessment (QA) in Parsif.al.

Data extraction

Those articles that pass the study selection are then thoroughly and critically read. Next, the researcher completes the information required using the “data extraction” form, as illustrated in Fig. 3 , in this scenario using Parsif.al tool.

Example of data extraction form using Parsif.al.

The information required (study characteristics and findings) from each included study must be acquired and documented through careful reading. Data extraction is valuable, especially if the data requires manipulation or assumptions and inferences. Thus, information can be synthesized from the extracted data for qualitative or quantitative analysis [16] . This documentation supports clarity, precise reporting, and the ability to scrutinize and replicate the examination.

Analysis and Report

The analysis phase examines the synthesized data and extracts meaningful information from the selected articles [10] . There are two main goals in this phase.

The first goal is to analyze the literature in terms of leading authors, journals, countries, and organizations. Furthermore, it helps identify correlations among topic s . Even when not mandatory, this activity can be constructive for researchers to position their work, find trends, and find collaboration opportunities. Next, data from the selected articles can be analyzed using bibliometric analysis (BA). BA summarizes large amounts of bibliometric data to present the state of intellectual structure and emerging trends in a topic or field of research [4] . Table 7 sets out some of the most common bibliometric analysis representations.

Techniques for bibliometric analysis and examples.

Several tools can perform this type of analysis, such as Excel and Google Sheets for statistical graphs or using programming languages such as Python that has available multiple  data visualization libraries (i.e. Matplotlib, Seaborn). Cluster maps based on bibliographic data(i.e keywords, authors) can be developed in VosViewer which makes it easy to identify clusters of related items [18] . In Fig. 4 , node size is representative of the number of papers related to the keyword, and lines represent the links among keyword terms.

[1] Keyword co-relationship analysis using clusterization in vos viewer.

This second and most important goal is to answer the formulated research questions, which should include a quantitative and qualitative analysis. The quantitative analysis can make use of data categorized, labelled, or coded in the extraction form (see Section 1.6). This data can be transformed into numerical values to perform statistical analysis. One of the most widely employed method is frequency analysis, which shows the recurrence of an event, and can also represent the percental distribution of the population (i.e., percentage by technology type, frequency of use of different frameworks, etc.). Q ualitative analysis includes the narration of the results, the discussion indicating the way forward in future research work, and inferring a conclusion.

Finally, the literature review report should state the protocol to ensure others researchers can replicate the process and understand how the analysis was performed. In the protocol, it is essential to present the inclusion and exclusion criteria, quality assessment, and rationality beyond these aspects.

The presentation and reporting of results will depend on the structure of the review given by the researchers conducting the SLR, there is no one answer. This structure should tie the studies together into key themes, characteristics, or subgroups [ 28 ].

SLR can be an extensive and demanding task, however the results are beneficial in providing a comprehensive overview of the available evidence on a given topic. For this reason, researchers should keep in mind that the entire process of the SLR is tailored to answer the research question(s). This article has detailed a practical guide with the essential steps to conducting an SLR in the context of computer science and software engineering while citing multiple helpful examples and tools. It is envisaged that this method will assist researchers, and particularly early-stage researchers, in following an algorithmic approach to fulfill this task. Finally, a quick checklist is presented in Appendix A as a companion of this article.

CRediT author statement

Angela Carrera-Rivera: Conceptualization, Methodology, Writing-Original. William Ochoa-Agurto : Methodology, Writing-Original. Felix Larrinaga : Reviewing and Supervision Ganix Lasa: Reviewing and Supervision.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

Funding : This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant No. 814078.

Carrera-Rivera, A., Larrinaga, F., & Lasa, G. (2022). Context-awareness for the design of Smart-product service systems: Literature review. Computers in Industry, 142, 103730.

1 https://parsif.al/

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Organizing Your Social Sciences Research Paper

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A literature review surveys prior research published in books, scholarly articles, and any other sources relevant to a particular issue, area of research, or theory, and by so doing, provides a description, summary, and critical evaluation of these works in relation to the research problem being investigated. Literature reviews are designed to provide an overview of sources you have used in researching a particular topic and to demonstrate to your readers how your research fits within existing scholarship about the topic.

Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper . Fourth edition. Thousand Oaks, CA: SAGE, 2014.

Importance of a Good Literature Review

A literature review may consist of simply a summary of key sources, but in the social sciences, a literature review usually has an organizational pattern and combines both summary and synthesis, often within specific conceptual categories . A summary is a recap of the important information of the source, but a synthesis is a re-organization, or a reshuffling, of that information in a way that informs how you are planning to investigate a research problem. The analytical features of a literature review might:

• Give a new interpretation of old material or combine new with old interpretations,
• Trace the intellectual progression of the field, including major debates,
• Depending on the situation, evaluate the sources and advise the reader on the most pertinent or relevant research, or
• Usually in the conclusion of a literature review, identify where gaps exist in how a problem has been researched to date.

Given this, the purpose of a literature review is to:

• Place each work in the context of its contribution to understanding the research problem being studied.
• Describe the relationship of each work to the others under consideration.
• Identify new ways to interpret prior research.
• Reveal any gaps that exist in the literature.
• Resolve conflicts amongst seemingly contradictory previous studies.
• Identify areas of prior scholarship to prevent duplication of effort.
• Point the way in fulfilling a need for additional research.
• Locate your own research within the context of existing literature [very important].

Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper. 2nd ed. Thousand Oaks, CA: Sage, 2005; Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination . Thousand Oaks, CA: Sage Publications, 1998; Jesson, Jill. Doing Your Literature Review: Traditional and Systematic Techniques . Los Angeles, CA: SAGE, 2011; Knopf, Jeffrey W. "Doing a Literature Review." PS: Political Science and Politics 39 (January 2006): 127-132; Ridley, Diana. The Literature Review: A Step-by-Step Guide for Students . 2nd ed. Los Angeles, CA: SAGE, 2012.

Types of Literature Reviews

It is important to think of knowledge in a given field as consisting of three layers. First, there are the primary studies that researchers conduct and publish. Second are the reviews of those studies that summarize and offer new interpretations built from and often extending beyond the primary studies. Third, there are the perceptions, conclusions, opinion, and interpretations that are shared informally among scholars that become part of the body of epistemological traditions within the field.

In composing a literature review, it is important to note that it is often this third layer of knowledge that is cited as "true" even though it often has only a loose relationship to the primary studies and secondary literature reviews. Given this, while literature reviews are designed to provide an overview and synthesis of pertinent sources you have explored, there are a number of approaches you could adopt depending upon the type of analysis underpinning your study.

Argumentative Review This form examines literature selectively in order to support or refute an argument, deeply embedded assumption, or philosophical problem already established in the literature. The purpose is to develop a body of literature that establishes a contrarian viewpoint. Given the value-laden nature of some social science research [e.g., educational reform; immigration control], argumentative approaches to analyzing the literature can be a legitimate and important form of discourse. However, note that they can also introduce problems of bias when they are used to make summary claims of the sort found in systematic reviews [see below].

Integrative Review Considered a form of research that reviews, critiques, and synthesizes representative literature on a topic in an integrated way such that new frameworks and perspectives on the topic are generated. The body of literature includes all studies that address related or identical hypotheses or research problems. A well-done integrative review meets the same standards as primary research in regard to clarity, rigor, and replication. This is the most common form of review in the social sciences.

Historical Review Few things rest in isolation from historical precedent. Historical literature reviews focus on examining research throughout a period of time, often starting with the first time an issue, concept, theory, phenomena emerged in the literature, then tracing its evolution within the scholarship of a discipline. The purpose is to place research in a historical context to show familiarity with state-of-the-art developments and to identify the likely directions for future research.

Methodological Review A review does not always focus on what someone said [findings], but how they came about saying what they say [method of analysis]. Reviewing methods of analysis provides a framework of understanding at different levels [i.e. those of theory, substantive fields, research approaches, and data collection and analysis techniques], how researchers draw upon a wide variety of knowledge ranging from the conceptual level to practical documents for use in fieldwork in the areas of ontological and epistemological consideration, quantitative and qualitative integration, sampling, interviewing, data collection, and data analysis. This approach helps highlight ethical issues which you should be aware of and consider as you go through your own study.

Systematic Review This form consists of an overview of existing evidence pertinent to a clearly formulated research question, which uses pre-specified and standardized methods to identify and critically appraise relevant research, and to collect, report, and analyze data from the studies that are included in the review. The goal is to deliberately document, critically evaluate, and summarize scientifically all of the research about a clearly defined research problem . Typically it focuses on a very specific empirical question, often posed in a cause-and-effect form, such as "To what extent does A contribute to B?" This type of literature review is primarily applied to examining prior research studies in clinical medicine and allied health fields, but it is increasingly being used in the social sciences.

Theoretical Review The purpose of this form is to examine the corpus of theory that has accumulated in regard to an issue, concept, theory, phenomena. The theoretical literature review helps to establish what theories already exist, the relationships between them, to what degree the existing theories have been investigated, and to develop new hypotheses to be tested. Often this form is used to help establish a lack of appropriate theories or reveal that current theories are inadequate for explaining new or emerging research problems. The unit of analysis can focus on a theoretical concept or a whole theory or framework.

NOTE: Most often the literature review will incorporate some combination of types. For example, a review that examines literature supporting or refuting an argument, assumption, or philosophical problem related to the research problem will also need to include writing supported by sources that establish the history of these arguments in the literature.

Baumeister, Roy F. and Mark R. Leary. "Writing Narrative Literature Reviews."  Review of General Psychology 1 (September 1997): 311-320; Mark R. Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper . 2nd ed. Thousand Oaks, CA: Sage, 2005; Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination . Thousand Oaks, CA: Sage Publications, 1998; Kennedy, Mary M. "Defining a Literature." Educational Researcher 36 (April 2007): 139-147; Petticrew, Mark and Helen Roberts. Systematic Reviews in the Social Sciences: A Practical Guide . Malden, MA: Blackwell Publishers, 2006; Torracro, Richard. "Writing Integrative Literature Reviews: Guidelines and Examples." Human Resource Development Review 4 (September 2005): 356-367; Rocco, Tonette S. and Maria S. Plakhotnik. "Literature Reviews, Conceptual Frameworks, and Theoretical Frameworks: Terms, Functions, and Distinctions." Human Ressource Development Review 8 (March 2008): 120-130; Sutton, Anthea. Systematic Approaches to a Successful Literature Review . Los Angeles, CA: Sage Publications, 2016.

Structure and Writing Style

I.  Thinking About Your Literature Review

The structure of a literature review should include the following in support of understanding the research problem :

• An overview of the subject, issue, or theory under consideration, along with the objectives of the literature review,
• Division of works under review into themes or categories [e.g. works that support a particular position, those against, and those offering alternative approaches entirely],
• An explanation of how each work is similar to and how it varies from the others,
• Conclusions as to which pieces are best considered in their argument, are most convincing of their opinions, and make the greatest contribution to the understanding and development of their area of research.

The critical evaluation of each work should consider :

• Provenance -- what are the author's credentials? Are the author's arguments supported by evidence [e.g. primary historical material, case studies, narratives, statistics, recent scientific findings]?
• Methodology -- were the techniques used to identify, gather, and analyze the data appropriate to addressing the research problem? Was the sample size appropriate? Were the results effectively interpreted and reported?
• Objectivity -- is the author's perspective even-handed or prejudicial? Is contrary data considered or is certain pertinent information ignored to prove the author's point?
• Persuasiveness -- which of the author's theses are most convincing or least convincing?
• Validity -- are the author's arguments and conclusions convincing? Does the work ultimately contribute in any significant way to an understanding of the subject?

II.  Development of the Literature Review

Four Basic Stages of Writing 1.  Problem formulation -- which topic or field is being examined and what are its component issues? 2.  Literature search -- finding materials relevant to the subject being explored. 3.  Data evaluation -- determining which literature makes a significant contribution to the understanding of the topic. 4.  Analysis and interpretation -- discussing the findings and conclusions of pertinent literature.

Consider the following issues before writing the literature review: Clarify If your assignment is not specific about what form your literature review should take, seek clarification from your professor by asking these questions: 1.  Roughly how many sources would be appropriate to include? 2.  What types of sources should I review (books, journal articles, websites; scholarly versus popular sources)? 3.  Should I summarize, synthesize, or critique sources by discussing a common theme or issue? 4.  Should I evaluate the sources in any way beyond evaluating how they relate to understanding the research problem? 5.  Should I provide subheadings and other background information, such as definitions and/or a history? Find Models Use the exercise of reviewing the literature to examine how authors in your discipline or area of interest have composed their literature review sections. Read them to get a sense of the types of themes you might want to look for in your own research or to identify ways to organize your final review. The bibliography or reference section of sources you've already read, such as required readings in the course syllabus, are also excellent entry points into your own research. Narrow the Topic The narrower your topic, the easier it will be to limit the number of sources you need to read in order to obtain a good survey of relevant resources. Your professor will probably not expect you to read everything that's available about the topic, but you'll make the act of reviewing easier if you first limit scope of the research problem. A good strategy is to begin by searching the USC Libraries Catalog for recent books about the topic and review the table of contents for chapters that focuses on specific issues. You can also review the indexes of books to find references to specific issues that can serve as the focus of your research. For example, a book surveying the history of the Israeli-Palestinian conflict may include a chapter on the role Egypt has played in mediating the conflict, or look in the index for the pages where Egypt is mentioned in the text. Consider Whether Your Sources are Current Some disciplines require that you use information that is as current as possible. This is particularly true in disciplines in medicine and the sciences where research conducted becomes obsolete very quickly as new discoveries are made. However, when writing a review in the social sciences, a survey of the history of the literature may be required. In other words, a complete understanding the research problem requires you to deliberately examine how knowledge and perspectives have changed over time. Sort through other current bibliographies or literature reviews in the field to get a sense of what your discipline expects. You can also use this method to explore what is considered by scholars to be a "hot topic" and what is not.

III.  Ways to Organize Your Literature Review

Chronology of Events If your review follows the chronological method, you could write about the materials according to when they were published. This approach should only be followed if a clear path of research building on previous research can be identified and that these trends follow a clear chronological order of development. For example, a literature review that focuses on continuing research about the emergence of German economic power after the fall of the Soviet Union. By Publication Order your sources by publication chronology, then, only if the order demonstrates a more important trend. For instance, you could order a review of literature on environmental studies of brown fields if the progression revealed, for example, a change in the soil collection practices of the researchers who wrote and/or conducted the studies. Thematic [“conceptual categories”] A thematic literature review is the most common approach to summarizing prior research in the social and behavioral sciences. Thematic reviews are organized around a topic or issue, rather than the progression of time, although the progression of time may still be incorporated into a thematic review. For example, a review of the Internet’s impact on American presidential politics could focus on the development of online political satire. While the study focuses on one topic, the Internet’s impact on American presidential politics, it would still be organized chronologically reflecting technological developments in media. The difference in this example between a "chronological" and a "thematic" approach is what is emphasized the most: themes related to the role of the Internet in presidential politics. Note that more authentic thematic reviews tend to break away from chronological order. A review organized in this manner would shift between time periods within each section according to the point being made. Methodological A methodological approach focuses on the methods utilized by the researcher. For the Internet in American presidential politics project, one methodological approach would be to look at cultural differences between the portrayal of American presidents on American, British, and French websites. Or the review might focus on the fundraising impact of the Internet on a particular political party. A methodological scope will influence either the types of documents in the review or the way in which these documents are discussed.

Other Sections of Your Literature Review Once you've decided on the organizational method for your literature review, the sections you need to include in the paper should be easy to figure out because they arise from your organizational strategy. In other words, a chronological review would have subsections for each vital time period; a thematic review would have subtopics based upon factors that relate to the theme or issue. However, sometimes you may need to add additional sections that are necessary for your study, but do not fit in the organizational strategy of the body. What other sections you include in the body is up to you. However, only include what is necessary for the reader to locate your study within the larger scholarship about the research problem.

Here are examples of other sections, usually in the form of a single paragraph, you may need to include depending on the type of review you write:

• Current Situation : Information necessary to understand the current topic or focus of the literature review.
• Sources Used : Describes the methods and resources [e.g., databases] you used to identify the literature you reviewed.
• History : The chronological progression of the field, the research literature, or an idea that is necessary to understand the literature review, if the body of the literature review is not already a chronology.
• Selection Methods : Criteria you used to select (and perhaps exclude) sources in your literature review. For instance, you might explain that your review includes only peer-reviewed [i.e., scholarly] sources.
• Standards : Description of the way in which you present your information.
• Questions for Further Research : What questions about the field has the review sparked? How will you further your research as a result of the review?

IV.  Writing Your Literature Review

Once you've settled on how to organize your literature review, you're ready to write each section. When writing your review, keep in mind these issues.

Use Evidence A literature review section is, in this sense, just like any other academic research paper. Your interpretation of the available sources must be backed up with evidence [citations] that demonstrates that what you are saying is valid. Be Selective Select only the most important points in each source to highlight in the review. The type of information you choose to mention should relate directly to the research problem, whether it is thematic, methodological, or chronological. Related items that provide additional information, but that are not key to understanding the research problem, can be included in a list of further readings . Use Quotes Sparingly Some short quotes are appropriate if you want to emphasize a point, or if what an author stated cannot be easily paraphrased. Sometimes you may need to quote certain terminology that was coined by the author, is not common knowledge, or taken directly from the study. Do not use extensive quotes as a substitute for using your own words in reviewing the literature. Summarize and Synthesize Remember to summarize and synthesize your sources within each thematic paragraph as well as throughout the review. Recapitulate important features of a research study, but then synthesize it by rephrasing the study's significance and relating it to your own work and the work of others. Keep Your Own Voice While the literature review presents others' ideas, your voice [the writer's] should remain front and center. For example, weave references to other sources into what you are writing but maintain your own voice by starting and ending the paragraph with your own ideas and wording. Use Caution When Paraphrasing When paraphrasing a source that is not your own, be sure to represent the author's information or opinions accurately and in your own words. Even when paraphrasing an author’s work, you still must provide a citation to that work.

V.  Common Mistakes to Avoid

These are the most common mistakes made in reviewing social science research literature.

• Sources in your literature review do not clearly relate to the research problem;
• You do not take sufficient time to define and identify the most relevant sources to use in the literature review related to the research problem;
• Relies exclusively on secondary analytical sources rather than including relevant primary research studies or data;
• Uncritically accepts another researcher's findings and interpretations as valid, rather than examining critically all aspects of the research design and analysis;
• Does not describe the search procedures that were used in identifying the literature to review;
• Reports isolated statistical results rather than synthesizing them in chi-squared or meta-analytic methods; and,
• Only includes research that validates assumptions and does not consider contrary findings and alternative interpretations found in the literature.

Cook, Kathleen E. and Elise Murowchick. “Do Literature Review Skills Transfer from One Course to Another?” Psychology Learning and Teaching 13 (March 2014): 3-11; Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper . 2nd ed. Thousand Oaks, CA: Sage, 2005; Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination . Thousand Oaks, CA: Sage Publications, 1998; Jesson, Jill. Doing Your Literature Review: Traditional and Systematic Techniques . London: SAGE, 2011; Literature Review Handout. Online Writing Center. Liberty University; Literature Reviews. The Writing Center. University of North Carolina; Onwuegbuzie, Anthony J. and Rebecca Frels. Seven Steps to a Comprehensive Literature Review: A Multimodal and Cultural Approach . Los Angeles, CA: SAGE, 2016; Ridley, Diana. The Literature Review: A Step-by-Step Guide for Students . 2nd ed. Los Angeles, CA: SAGE, 2012; Randolph, Justus J. “A Guide to Writing the Dissertation Literature Review." Practical Assessment, Research, and Evaluation. vol. 14, June 2009; Sutton, Anthea. Systematic Approaches to a Successful Literature Review . Los Angeles, CA: Sage Publications, 2016; Taylor, Dena. The Literature Review: A Few Tips On Conducting It. University College Writing Centre. University of Toronto; Writing a Literature Review. Academic Skills Centre. University of Canberra.

Writing Tip

Break Out of Your Disciplinary Box!

Thinking interdisciplinarily about a research problem can be a rewarding exercise in applying new ideas, theories, or concepts to an old problem. For example, what might cultural anthropologists say about the continuing conflict in the Middle East? In what ways might geographers view the need for better distribution of social service agencies in large cities than how social workers might study the issue? You don’t want to substitute a thorough review of core research literature in your discipline for studies conducted in other fields of study. However, particularly in the social sciences, thinking about research problems from multiple vectors is a key strategy for finding new solutions to a problem or gaining a new perspective. Consult with a librarian about identifying research databases in other disciplines; almost every field of study has at least one comprehensive database devoted to indexing its research literature.

Frodeman, Robert. The Oxford Handbook of Interdisciplinarity . New York: Oxford University Press, 2010.

Another Writing Tip

Don't Just Review for Content!

While conducting a review of the literature, maximize the time you devote to writing this part of your paper by thinking broadly about what you should be looking for and evaluating. Review not just what scholars are saying, but how are they saying it. Some questions to ask:

• How are they organizing their ideas?
• What methods have they used to study the problem?
• What theories have been used to explain, predict, or understand their research problem?
• What sources have they cited to support their conclusions?
• How have they used non-textual elements [e.g., charts, graphs, figures, etc.] to illustrate key points?

When you begin to write your literature review section, you'll be glad you dug deeper into how the research was designed and constructed because it establishes a means for developing more substantial analysis and interpretation of the research problem.

Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination . Thousand Oaks, CA: Sage Publications, 1 998.

Yet Another Writing Tip

When Do I Know I Can Stop Looking and Move On?

Here are several strategies you can utilize to assess whether you've thoroughly reviewed the literature:

• Look for repeating patterns in the research findings . If the same thing is being said, just by different people, then this likely demonstrates that the research problem has hit a conceptual dead end. At this point consider: Does your study extend current research?  Does it forge a new path? Or, does is merely add more of the same thing being said?
• Look at sources the authors cite to in their work . If you begin to see the same researchers cited again and again, then this is often an indication that no new ideas have been generated to address the research problem.
• Search Google Scholar to identify who has subsequently cited leading scholars already identified in your literature review [see next sub-tab]. This is called citation tracking and there are a number of sources that can help you identify who has cited whom, particularly scholars from outside of your discipline. Here again, if the same authors are being cited again and again, this may indicate no new literature has been written on the topic.

Onwuegbuzie, Anthony J. and Rebecca Frels. Seven Steps to a Comprehensive Literature Review: A Multimodal and Cultural Approach . Los Angeles, CA: Sage, 2016; Sutton, Anthea. Systematic Approaches to a Successful Literature Review . Los Angeles, CA: Sage Publications, 2016.

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How to Conduct a Literature Review (Health Sciences and Beyond)

What is a literature review, traditional (narrative) literature review, integrative literature review, systematic reviews, meta-analysis, scoping review.

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• Systematic Reviews by Roy Brown Last Updated Oct 17, 2023 968 views this year
• Write a Literature Review by John Glover Last Updated Jul 26, 2024 4856 views this year

A literature review provides an overview of what's been written about a specific topic. There are many different types of literature reviews. They vary in terms of comprehensiveness, types of study included, and purpose. 

The other pages in this guide will cover some basic steps to consider when conducting a traditional health sciences literature review. See below for a quick look at some of the more popular types of literature reviews.

For additional information on a variety of review methods, the following article provides an excellent overview.

Grant MJ, Booth A. A typology of reviews: an analysis of 14 review types and associated methodologies. Health Info Libr J. 2009 Jun;26(2):91-108. doi: 10.1111/j.1471-1842.2009.00848.x. Review. PubMed PMID: 19490148.

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Reviewing the Literature: Why do it?

• Personal: To familiarize yourself with a new area of research, to get an overview of a topic, so you don't want to miss something important, etc.
• Required writing for a journal article, thesis or dissertation, grant application, etc.

Literature reviews vary; there are many ways to write a literature review based on discipline, material type, and other factors.

Background:

• Literature Reviews - UNC Writing Center
• Literature Reviews: An Overview for Graduate Students  - What is a literature review? What purpose does it serve in research? What should you expect when writing one? - NCSU Video

Where to get help (there are lots of websites, blogs , articles,  and books on this topic) :

• The Center for writing and Communicating Ideas (CWCI)
• (these are non-STEM examples: dissertation guidance , journal guidelines )
• How to prepare a scientific doctoral dissertation based on research articles (2012)
• Writing a graduate thesis or dissertation (2016)
• The good paper : a handbook for writing papers in higher education (2015)
• Proposals that work : a guide for planning dissertations and grant proposals (2014)
• Theses and dissertations : a guide to planning, research, and writing (2008)
• Talk to your professors, advisors, mentors, peers, etc. for advice

READ related material and pay attention to how others write their literature reviews:

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Scientific Research and Communication — Science Literature Reviews

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What is a literature review in the sciences?

To answer this question, please read the following content excerpted from the UCLA Undergraduate Science Journal guidelines .   Also, if you scroll down this page there is a link to a recorded webinar about science literature reviews. I have also included some links to books about engineering and STEM literature reviews at the bottom of this page.

Guide to Writing a Review Article: What is a Literature Review?

A literature review addresses a specific topic by evaluating research that others have done on it. As an author, you will weave your review article around a certain thesis or problem you wish to address, evaluate the quality and the meaning of the studies done before, and arrives at a conclusion about the problem based on the studies evaluated.

A literature review is not a summary and it is not a list. The author cannot simply cite the studies that have been done and the results that have been obtained. If you describe past research without evaluating it, then your “review” is little more than a book report. A literature review must be a synthesis of the results of your search, organized around your chosen theme.

The article should be your evaluation of the literature and of the issue at stake. This is a challenging piece of work. You must:

1. Organize information and relate it to your thesis or research question

2. Synthesize results into a summary of what is and isn’t known

3. Identify contradictions, inconsistencies, and gaps in the research

4. Identify and analyze controversy when it appears in the literature

5. Develop questions for further research

6. Draw conclusions based on your evaluation of the studies presented

Literature Review vs. Research Article

A literature review surveys research done by others in a particular area. You will read and evaluate studies done by others, instead of conducting a new study yourself. Research articles, on the other hand, present research that you have conducted yourself. A research article should contain enough background information and literature evaluation to shed light on your study, but the ultimate purpose of the paper is to report research done by you.

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• UCLA Undergraduate Science Journal guidelines Click on the "Guide to Scientific Writing" link.

Below is a recorded webinar led by the science and engineering librarians from Western Michigan State University on science literature reviews:

Here is another video on literature reviews by Associate Professor Cecile Badenhorst of Memorial University of Newfoundland.  Dr. Badenhorst uses examples from research in the field of education, but the theoretical components she introduces are of interest to science students as well.

• How to Write a Scientific Literature Review from University of Michigan Libraries
• Engineering Literature Reviews Guide from University of Arizona

Books on Literature Reviews

Literature Review Examples

• White Paper - Literature Review on Kinematic Properties of Road Users for Use on Safety-Related Models for Automated Driving Systems
• A sensor ontology literature review
• Literature review of fuel processing: hydrogen as fuel
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What is a Literature Review? How to Write It (with Examples)

A literature review is a critical analysis and synthesis of existing research on a particular topic. It provides an overview of the current state of knowledge, identifies gaps, and highlights key findings in the literature. 1 The purpose of a literature review is to situate your own research within the context of existing scholarship, demonstrating your understanding of the topic and showing how your work contributes to the ongoing conversation in the field. Learning how to write a literature review is a critical tool for successful research. Your ability to summarize and synthesize prior research pertaining to a certain topic demonstrates your grasp on the topic of study, and assists in the learning process. 

Table of Contents

What is the purpose of literature review , a. habitat loss and species extinction: , b. range shifts and phenological changes: , c. ocean acidification and coral reefs: , d. adaptive strategies and conservation efforts: .

• Choose a Topic and Define the Research Question: 
• Decide on the Scope of Your Review: 
• Select Databases for Searches: 
• Conduct Searches and Keep Track: 
• Review the Literature: 
• Organize and Write Your Literature Review: 
• How to write a literature review faster with Paperpal? 

Frequently asked questions 

What is a literature review .

A well-conducted literature review demonstrates the researcher’s familiarity with the existing literature, establishes the context for their own research, and contributes to scholarly conversations on the topic. One of the purposes of a literature review is also to help researchers avoid duplicating previous work and ensure that their research is informed by and builds upon the existing body of knowledge.

A literature review serves several important purposes within academic and research contexts. Here are some key objectives and functions of a literature review: 2  

1. Contextualizing the Research Problem: The literature review provides a background and context for the research problem under investigation. It helps to situate the study within the existing body of knowledge. 

2. Identifying Gaps in Knowledge: By identifying gaps, contradictions, or areas requiring further research, the researcher can shape the research question and justify the significance of the study. This is crucial for ensuring that the new research contributes something novel to the field.

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3. Understanding Theoretical and Conceptual Frameworks: Literature reviews help researchers gain an understanding of the theoretical and conceptual frameworks used in previous studies. This aids in the development of a theoretical framework for the current research. 

4. Providing Methodological Insights: Another purpose of literature reviews is that it allows researchers to learn about the methodologies employed in previous studies. This can help in choosing appropriate research methods for the current study and avoiding pitfalls that others may have encountered. 

5. Establishing Credibility: A well-conducted literature review demonstrates the researcher’s familiarity with existing scholarship, establishing their credibility and expertise in the field. It also helps in building a solid foundation for the new research. 

6. Informing Hypotheses or Research Questions: The literature review guides the formulation of hypotheses or research questions by highlighting relevant findings and areas of uncertainty in existing literature. 

Literature review example 

Let’s delve deeper with a literature review example: Let’s say your literature review is about the impact of climate change on biodiversity. You might format your literature review into sections such as the effects of climate change on habitat loss and species extinction, phenological changes, and marine biodiversity. Each section would then summarize and analyze relevant studies in those areas, highlighting key findings and identifying gaps in the research. The review would conclude by emphasizing the need for further research on specific aspects of the relationship between climate change and biodiversity. The following literature review template provides a glimpse into the recommended literature review structure and content, demonstrating how research findings are organized around specific themes within a broader topic. 

Literature Review on Climate Change Impacts on Biodiversity:  

Climate change is a global phenomenon with far-reaching consequences, including significant impacts on biodiversity. This literature review synthesizes key findings from various studies: 

Climate change-induced alterations in temperature and precipitation patterns contribute to habitat loss, affecting numerous species (Thomas et al., 2004). The review discusses how these changes increase the risk of extinction, particularly for species with specific habitat requirements. 

Observations of range shifts and changes in the timing of biological events (phenology) are documented in response to changing climatic conditions (Parmesan & Yohe, 2003). These shifts affect ecosystems and may lead to mismatches between species and their resources. 

The review explores the impact of climate change on marine biodiversity, emphasizing ocean acidification’s threat to coral reefs (Hoegh-Guldberg et al., 2007). Changes in pH levels negatively affect coral calcification, disrupting the delicate balance of marine ecosystems. 

Recognizing the urgency of the situation, the literature review discusses various adaptive strategies adopted by species and conservation efforts aimed at mitigating the impacts of climate change on biodiversity (Hannah et al., 2007). It emphasizes the importance of interdisciplinary approaches for effective conservation planning. 

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How to write a good literature review 

Writing a literature review involves summarizing and synthesizing existing research on a particular topic. A good literature review format should include the following elements. 

Introduction: The introduction sets the stage for your literature review, providing context and introducing the main focus of your review. 

• Opening Statement: Begin with a general statement about the broader topic and its significance in the field. 
• Scope and Purpose: Clearly define the scope of your literature review. Explain the specific research question or objective you aim to address. 
• Organizational Framework: Briefly outline the structure of your literature review, indicating how you will categorize and discuss the existing research. 
• Significance of the Study: Highlight why your literature review is important and how it contributes to the understanding of the chosen topic. 
• Thesis Statement: Conclude the introduction with a concise thesis statement that outlines the main argument or perspective you will develop in the body of the literature review. 

Body: The body of the literature review is where you provide a comprehensive analysis of existing literature, grouping studies based on themes, methodologies, or other relevant criteria. 

• Organize by Theme or Concept: Group studies that share common themes, concepts, or methodologies. Discuss each theme or concept in detail, summarizing key findings and identifying gaps or areas of disagreement. 
• Critical Analysis: Evaluate the strengths and weaknesses of each study. Discuss the methodologies used, the quality of evidence, and the overall contribution of each work to the understanding of the topic. 
• Synthesis of Findings: Synthesize the information from different studies to highlight trends, patterns, or areas of consensus in the literature. 
• Identification of Gaps: Discuss any gaps or limitations in the existing research and explain how your review contributes to filling these gaps. 
• Transition between Sections: Provide smooth transitions between different themes or concepts to maintain the flow of your literature review. 

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Conclusion: The conclusion of your literature review should summarize the main findings, highlight the contributions of the review, and suggest avenues for future research. 

• Summary of Key Findings: Recap the main findings from the literature and restate how they contribute to your research question or objective. 
• Contributions to the Field: Discuss the overall contribution of your literature review to the existing knowledge in the field. 
• Implications and Applications: Explore the practical implications of the findings and suggest how they might impact future research or practice. 
• Recommendations for Future Research: Identify areas that require further investigation and propose potential directions for future research in the field. 
• Final Thoughts: Conclude with a final reflection on the importance of your literature review and its relevance to the broader academic community. 

Conducting a literature review 

Conducting a literature review is an essential step in research that involves reviewing and analyzing existing literature on a specific topic. It’s important to know how to do a literature review effectively, so here are the steps to follow: 1  

Choose a Topic and Define the Research Question:  

• Select a topic that is relevant to your field of study. 
• Clearly define your research question or objective. Determine what specific aspect of the topic do you want to explore? 

Decide on the Scope of Your Review:  

• Determine the timeframe for your literature review. Are you focusing on recent developments, or do you want a historical overview? 
• Consider the geographical scope. Is your review global, or are you focusing on a specific region? 
• Define the inclusion and exclusion criteria. What types of sources will you include? Are there specific types of studies or publications you will exclude? 

Select Databases for Searches:  

• Identify relevant databases for your field. Examples include PubMed, IEEE Xplore, Scopus, Web of Science, and Google Scholar. 
• Consider searching in library catalogs, institutional repositories, and specialized databases related to your topic. 

Conduct Searches and Keep Track:  

• Develop a systematic search strategy using keywords, Boolean operators (AND, OR, NOT), and other search techniques. 
• Record and document your search strategy for transparency and replicability. 
• Keep track of the articles, including publication details, abstracts, and links. Use citation management tools like EndNote, Zotero, or Mendeley to organize your references. 

Review the Literature:  

• Evaluate the relevance and quality of each source. Consider the methodology, sample size, and results of studies. 
• Organize the literature by themes or key concepts. Identify patterns, trends, and gaps in the existing research. 
• Summarize key findings and arguments from each source. Compare and contrast different perspectives. 
• Identify areas where there is a consensus in the literature and where there are conflicting opinions. 
• Provide critical analysis and synthesis of the literature. What are the strengths and weaknesses of existing research? 

Organize and Write Your Literature Review:  

• Literature review outline should be based on themes, chronological order, or methodological approaches. 
• Write a clear and coherent narrative that synthesizes the information gathered. 
• Use proper citations for each source and ensure consistency in your citation style (APA, MLA, Chicago, etc.). 
• Conclude your literature review by summarizing key findings, identifying gaps, and suggesting areas for future research. 

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How to write a literature review faster with Paperpal?  

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The literature review sample and detailed advice on writing and conducting a review will help you produce a well-structured report. But remember that a good literature review is an ongoing process, and it may be necessary to revisit and update it as your research progresses. By combining effortless research with an easy citation process, Paperpal Research streamlines the literature review process and empowers you to write faster and with more confidence. Try Paperpal Research now and see for yourself.  

A literature review is a critical and comprehensive analysis of existing literature (published and unpublished works) on a specific topic or research question and provides a synthesis of the current state of knowledge in a particular field. A well-conducted literature review is crucial for researchers to build upon existing knowledge, avoid duplication of efforts, and contribute to the advancement of their field. It also helps researchers situate their work within a broader context and facilitates the development of a sound theoretical and conceptual framework for their studies.

Literature review is a crucial component of research writing, providing a solid background for a research paper’s investigation. The aim is to keep professionals up to date by providing an understanding of ongoing developments within a specific field, including research methods, and experimental techniques used in that field, and present that knowledge in the form of a written report. Also, the depth and breadth of the literature review emphasizes the credibility of the scholar in his or her field.  

Before writing a literature review, it’s essential to undertake several preparatory steps to ensure that your review is well-researched, organized, and focused. This includes choosing a topic of general interest to you and doing exploratory research on that topic, writing an annotated bibliography, and noting major points, especially those that relate to the position you have taken on the topic. 

Literature reviews and academic research papers are essential components of scholarly work but serve different purposes within the academic realm. 3 A literature review aims to provide a foundation for understanding the current state of research on a particular topic, identify gaps or controversies, and lay the groundwork for future research. Therefore, it draws heavily from existing academic sources, including books, journal articles, and other scholarly publications. In contrast, an academic research paper aims to present new knowledge, contribute to the academic discourse, and advance the understanding of a specific research question. Therefore, it involves a mix of existing literature (in the introduction and literature review sections) and original data or findings obtained through research methods. 

Literature reviews are essential components of academic and research papers, and various strategies can be employed to conduct them effectively. If you want to know how to write a literature review for a research paper, here are four common approaches that are often used by researchers.  Chronological Review: This strategy involves organizing the literature based on the chronological order of publication. It helps to trace the development of a topic over time, showing how ideas, theories, and research have evolved.  Thematic Review: Thematic reviews focus on identifying and analyzing themes or topics that cut across different studies. Instead of organizing the literature chronologically, it is grouped by key themes or concepts, allowing for a comprehensive exploration of various aspects of the topic.  Methodological Review: This strategy involves organizing the literature based on the research methods employed in different studies. It helps to highlight the strengths and weaknesses of various methodologies and allows the reader to evaluate the reliability and validity of the research findings.  Theoretical Review: A theoretical review examines the literature based on the theoretical frameworks used in different studies. This approach helps to identify the key theories that have been applied to the topic and assess their contributions to the understanding of the subject.  It’s important to note that these strategies are not mutually exclusive, and a literature review may combine elements of more than one approach. The choice of strategy depends on the research question, the nature of the literature available, and the goals of the review. Additionally, other strategies, such as integrative reviews or systematic reviews, may be employed depending on the specific requirements of the research.

The literature review format can vary depending on the specific publication guidelines. However, there are some common elements and structures that are often followed. Here is a general guideline for the format of a literature review:  Introduction:   Provide an overview of the topic.  Define the scope and purpose of the literature review.  State the research question or objective.  Body:   Organize the literature by themes, concepts, or chronology.  Critically analyze and evaluate each source.  Discuss the strengths and weaknesses of the studies.  Highlight any methodological limitations or biases.  Identify patterns, connections, or contradictions in the existing research.  Conclusion:   Summarize the key points discussed in the literature review.  Highlight the research gap.  Address the research question or objective stated in the introduction.  Highlight the contributions of the review and suggest directions for future research.

Both annotated bibliographies and literature reviews involve the examination of scholarly sources. While annotated bibliographies focus on individual sources with brief annotations, literature reviews provide a more in-depth, integrated, and comprehensive analysis of existing literature on a specific topic. The key differences are as follows: 

References 

• Denney, A. S., & Tewksbury, R. (2013). How to write a literature review.  Journal of criminal justice education ,  24 (2), 218-234. 
• Pan, M. L. (2016).  Preparing literature reviews: Qualitative and quantitative approaches . Taylor & Francis. 
• Cantero, C. (2019). How to write a literature review.  San José State University Writing Center . 

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How to write a good scientific review article

Affiliation.

• 1 The FEBS Journal Editorial Office, Cambridge, UK.
• PMID: 35792782
• DOI: 10.1111/febs.16565

Literature reviews are valuable resources for the scientific community. With research accelerating at an unprecedented speed in recent years and more and more original papers being published, review articles have become increasingly important as a means to keep up to date with developments in a particular area of research. A good review article provides readers with an in-depth understanding of a field and highlights key gaps and challenges to address with future research. Writing a review article also helps to expand the writer's knowledge of their specialist area and to develop their analytical and communication skills, amongst other benefits. Thus, the importance of building review-writing into a scientific career cannot be overstated. In this instalment of The FEBS Journal's Words of Advice series, I provide detailed guidance on planning and writing an informative and engaging literature review.

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How to Write a Good Scientific Literature Review

Nowadays, there is a huge demand for scientific literature reviews as they are especially appreciated by scholars or researchers when designing their research proposals. While finding information is less of a problem to them, discerning which paper or publication has enough quality has become one of the biggest issues. Literature reviews narrow the current knowledge on a certain field and examine the latest publications’ strengths and weaknesses. This way, they are priceless tools not only for those who are starting their research, but also for all those interested in recent publications. To be useful, literature reviews must be written in a professional way with a clear structure. The amount of work needed to write a scientific literature review must be considered before starting one since the tasks required can overwhelm many if the working method is not the best.

Designing and Writing a Scientific Literature Review

Writing a scientific review implies both researching for relevant academic content and writing , however, writing without having a clear objective is a common mistake. Sometimes, studying the situation and defining the work’s system is so important and takes equally as much time as that required in writing the final result. Therefore, we suggest that you divide your path into three steps.

Define goals and a structure

Think about your target and narrow down your topic. If you don’t choose a well-defined topic, you can find yourself dealing with a wide subject and plenty of publications about it. Remember that researchers usually deal with really specific fields of study.

It is time to be a critic and locate only pertinent publications. While researching for content consider publications that were written 3 years ago at the most. Write notes and summarize the content of each paper as that will help you in the next step.

Time to write

Check some literature review examples to decide how to start writing a good literature review . When your goals and structure are defined, begin writing without forgetting your target at any moment.

Related: Conducting a literature survey? Wish to learn more about scientific misconduct? Check out this resourceful infographic.

Here you have a to-do list to help you write your review :

• A scientific literature review usually includes a title, abstract, index, introduction, corpus, bibliography, and appendices (if needed).
• Present the problem clearly.
• Mention the paper’s methodology, research methods, analysis, instruments, etc.
• Present literature review examples that can help you express your ideas.
• Remember to cite accurately.
• Limit your bias
• While summarizing also identify strengths and weaknesses as this is critical.

Scholars and researchers are usually the best candidates to write scientific literature reviews, not only because they are experts in a certain field, but also because they know the exigencies and needs that researchers have while writing research proposals or looking for information among thousands of academic papers. Therefore, considering your experience as a researcher can help you understand how to write a scientific literature review.

Have you faced challenges while drafting your first literature review? How do you think can these tips help you in acing your next literature review? Let us know in the comments section below! You can also visit our  Q&A forum  for frequently asked questions related to copyrights answered by our team that comprises eminent researchers and publication experts.

Thank you for your information. It adds knowledge on critical review being a first time to do it, it helps a lot.

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• Getting Started

Literature Reviews: Getting Started

What is a literature review.

A literature review is an overview of the available research for a specific scholarly topic. Literature reviews summarize existing research to answer a review question, provide context for new research, or identify important gaps in the existing body of literature.

An incredible amount of academic literature is published each year; by some estimates nearly three million articles .

Sorting through and reviewing that literature can be complicated, so this Research Guide provides a structured approach to make the process more manageable.

THIS GUIDE IS AN OVERVIEW OF THE LITERATURE REVIEW PROCESS:

• Getting Started (asking a research question | defining scope)
• Choosing a Type of Review
• Searching the Literature
• Organizing the Literature
• Writing the Literature Review (analyzing | synthesizing)

A  literature search  is a systematic search of the scholarly sources in a particular discipline. A  literature review   is the analysis, critical evaluation and synthesis of the results of that search. During this process you will move from a review  of  the literature to a review  for   your research.   Your synthesis of the literature is your unique contribution to research.

WHO IS THIS RESEARCH GUIDE FOR?

— those new to reviewing the literature

— those that need a refresher or a deeper understanding of writing literature reviews

You may need to do a literature review as a part of a course assignment, a capstone project, a master's thesis, a dissertation, or as part of a journal article. No matter the context, a literature review is an essential part of the research process. 

Literature Review Process

Purpose of a Literature Review

What is the purpose of a literature review.

A literature review is typically performed for a specific reason. Even when assigned as an assignment, the goal of the literature review will be one or more of the following:

• To communicate a project's novelty by identifying a research gap

• An overview of research issues , methodologies or results relevant to field
• To explore the  volume and types of available studies
• To establish familiarity with current research before carrying out a new project
• To resolve conflicts amongst contradictory previous studies

Reviewing the literature helps you understand a research topic and develop your own perspective.

A LITERATURE REVIEW IS NOT :

• An annotated bibliography – which is a list of annotated citations to books, articles and documents that includes a brief description and evaluation for each entry
• A literary review – which is a critical discussion of the merits and weaknesses of a literary work
• A book review – which is a critical discussion of the merits and weaknesses of a particular book

Attribution

Thanks to Librarian Jamie Niehof at the University of Michigan for providing permission to reuse and remix this Literature Reviews guide.

Workshop Materials

• Materials from OSU Literature Review Workshop
• Last Updated: Sep 23, 2024 11:11 AM
• URL: https://info.library.okstate.edu/literaturereviews

Education: Lit Review + Methods

• Getting Started
• News and Data Sources
• Children's Literature
• Lit Review + Methods
• Praxis Prep
• Need help? Off campus?

What is a Literature Review?

A literature review is a comprehensive and up-to-date overview of the principal research about the topic being studied. Your literature review should contain the following information:

• The most pertinent studies and important past and current research and practices in the field
• An overview of sources you have explored while researching a particular topic
• An explanation to your readers as to how your research fits within a larger field of study.

The review helps form the intellectual framework for the study.

17 - what is a literature review  from  Joshua Vossler  on  Vimeo .

Why do a Literature Review?

At its core, a literature provides a summary of existing knowledge on a subject or topic and identifies areas where research is lacking: missing information, incomplete studies or studies that draw conflicting conclusions, or perhaps even outdated methods of research.

This can be especially helpful if you intend to conduct research of your own on this topic; by explaining where the previous studies have fallen short or leave openings for further examination, you provide a strong foundation and justification for the research project you intend to embark on.

Literature reviews can stand on their own as an article or assignment for a class, or they can serve as an introduction to a larger work, such as an article describing a study or even a book. They can also vary in granularity: a literature review in the beginning of an article might only summarize the largest or most influential studies, while an academic literature review will not only describe the research so far but look for common themes, analyze the quality of the research, and explain gaps where further research is needed.

Elements of a Successful Literature Review

When preparing your literature review, keep these questions in mind:

• What is your literature review about?
• Why are you studying this topic?
• How will you organize your sources?  (You could group them by themes or subtopics, or perhaps keep them in chronological order. The way you present your sources is important, so make sure you think hard about this!)
• What are the major themes/subtopics that you discovered when reading your sources?
• Where could more research be done to increase our understanding of this topic?

For each individual source, be prepared to analyze:

• Who were the key researchers and what are their qualifications?
• How was the research conducted?
• The similarities and differences between this source and the others in your literature review
• How this source contributes to greater understanding of the topic as a whole
• Any questions you have about the research done, which could identify opportunities for further study

When preparing your literature review, examine these elements and determine which ones would be best for your paper. (Tip: If you're not sure which parts of the literature review to include, ask your professor!)

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• Last Updated: Sep 25, 2024 11:33 AM
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Research in the Biological and Life Sciences: A Guide for Cornell Researchers: Literature Reviews

• Books and Dissertations
• Databases and Journals
• Locating Theses
• Resource Not at Cornell?
• Citing Sources
• Staying Current
• Measuring your research impact
• Plagiarism and Copyright
• Data Management
• Literature Reviews
• Evidence Synthesis and Systematic Reviews
• Writing an Honors Thesis
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• Research Help

What is a Literature Review?

A literature review is a body of text that aims to review the critical points of current knowledge on a particular topic. Most often associated with science-oriented literature, such as a thesis, the literature review usually proceeds a research proposal, methodology and results section. Its ultimate goals is to bring the reader up to date with current literature on a topic and forms that basis for another goal, such as the justification for future research in the area. (retrieved from  http://en.wikipedia.org/wiki/Literature_review )

Writing a Literature Review

The literature review is the section of your paper in which you cite and briefly review the related research studies that have been conducted. In this space, you will describe the foundation on which  your  research will be/is built. You will:

• discuss the work of others
• evaluate their methods and findings
• identify any gaps in their research
• state how  your  research is different

The literature review should be selective and should group the cited studies in some logical fashion.

If you need some additional assistance writing your literature review, the Knight Institute for Writing in the Disciplines offers a  Graduate Writing Service .

Demystifying the Literature Review

For more information, visit our guide devoted to " Demystifying the Literature Review " which includes:

• guide to conducting a literature review,
• a recorded 1.5 hour workshop covering the steps of a literature review, a checklist for drafting your topic and search terms, citation management software for organizing your results, and database searching.

Online Resources

• A Guide to Library Research at Cornell University
• Literature Reviews: An Overview for Graduate Students North Carolina State University 
• The Literature Review: A Few Tips on Conducting Written by Dena Taylor, Director, Health Sciences Writing Centre, and Margaret Procter, Coordinator, Writing Support, University of Toronto
• How to Write a Literature Review University Library, University of California, Santa Cruz
• Review of Literature The Writing Center, University of Wisconsin-Madison

Print Resources

• << Previous: Writing
• Next: Evidence Synthesis and Systematic Reviews >>
• Last Updated: Oct 25, 2023 11:28 AM
• URL: https://guides.library.cornell.edu/bio

SOC 200 - Sims: How to Write a Lit Review

• What are Literature Reviews?
• How to Write a Lit Review
• How to Choose a Topic
• Finding the Literature

How to write a literature review

Below are the steps you should follow when crafting a lit review for your class assignment.

• It's preferable if you can select a topic that you find interesting, because this will make the work seem less like work. 
• It's also important to select a topic that many researchers have already explored. This way, you'll actually have "literature" to "review."
• Sometimes, doing a very general search and reading other literature reviews can reveal a topic or avenue of research to you. 
• It's important to gain an understanding of your topic's research history, in order to properly comprehend how and why the current (emerging) research exists.
• One trick is to look at the References (aka Bibliographies aka Works Cited pages) of any especially relevant articles, in order to expand your search for those same sources. This is because there is often overlap between works, and if you're paying attention, one source can point you to several others.
• One method is to start with the most recently-published research and then use their citations to identify older research, allowing you to piece together a timeline and work backwards. 
• Chronologically : discuss the literature in order of its writing/publication. This will demonstrate a change in trends over time, and/or detail a history of controversy in the field, and/or illustrate developments in the field.
• Thematically : group your sources by subject or theme. This will show the variety of angels from which your topic has been studied. This method works well if you are trying to identify a sub-topic that has so far been overlooked by other researchers.
• Methodologically : group your sources by methodology. For example, divide the literature into categories like qualitative versus quantitative, or by population or geographical region, etc. 
• Theoretically : group your sources by theoretical lens. Your textbook should have a section(s) dedicated to the various theories in your field. If you're unsure, you should ask your professor.
• Are there disagreements on some issues, and consensus on others?
• How does this impact the path of research and discovery?
• Many articles will have a Limitations section, or a Discussion section, wherein suggestions are provided for next steps to further the research.
• These are goldmines for helping you see a possible outlook of the situation. 
• Identifying any gaps in the literature that are of a particular interest to your research goals will help you justify why your own research should be performed. 
• Be selective about which points from the source you use. The information should be the most important and the most relevant. 
• Use direct quotes sparingly, and don't rely too heavily on summaries and paraphrasing. You should be drawing conclusions about how the literature relates to your own analysis or the other literature. 
• Synthesize your sources. The goal is not to make a list of summaries, but to show how the sources relate to one another and to your own analysis. 
• At the end, make suggestions for future research. What subjects, populations, methodologies, or theoretical lenses warrant further exploration? What common flaws or biases did you identify that could be corrected in future studies? 
• Common citation styles for sociology classes include APA and ASA.

Understanding how a literature review is structured will help you as you craft your own. 

Below is information and example articles that you should review, in order to comprehend why they are written a certain way.

Below are some very good examples of Literature Reviews:

Cyberbullying: How Physical Intimidation Influences the Way People are Bullied

Use of Propofol and Emergence Agitation in Children

Eternity and Immortality in Spinoza's 'Ethics'

As you read these, take note of the sections that comprise the main structure of each one:

• Introduction 
• Summarize sources
• Synthesize sources

Below are some articles that provide very good examples of an "Introduction" section, which includes a "Review of the Literature."

• Sometimes, there is both an Introduction section, and a separate Review of the Literature section (oftentimes, it simply depends on the publication)

Krimm, H., & Lund, E. (2021). Efficacy of online learning modules for teaching dialogic reading strategies and phonemic awareness.  Language, Speech & Hearing Services in Schools,  52 (4), 1020-1030.  https://doi.org/10.1044/2021_LSHSS-21-00011

Melfsen, S., Jans, T., Romanos, M., & Walitza, S. (2022). Emotion regulation in selective mutism: A comparison group study in children and adolescents with selective mutism.  Journal of Psychiatric Research,  151 , 710-715.  https://doi.org/10.1016/j.jpsychires.2022.05.040

Citation Resources

• MU Library's Citing Sources page
• Purdue OWL's APA Guide
• APA Citation Style - Quick Guide
• Purdue OWL's ASA Guide
• ASA Citation Style - Quick Tips

Suggested Reading

• How to: Conduct a Lit Review (from Central Michigan University)
• Purdue OWL Writing Lab's Advice for Writing a Lit Review

How to Read a Scholarly Article

 read:.

• Things to consider when reading a scholarly article This helpful guide, from Meriam Library at California State University in Chico, explains what a scholarly article is and provides tips for reading them.

  Watch:

• How to read a scholarly article (YouTube) This tutorial, from Western University, quickly and efficiently describes how to read a scholarly article.
• << Previous: What are Literature Reviews?
• Next: How to Choose a Topic >>
• Last Updated: Sep 25, 2024 2:23 PM
• URL: https://libguides.marshall.edu/soc200-sims

Environmental Science

• Literature Review
• Environmental Science Major
• Primary Sources & Original Research vs. Review Articles
• Find Articles
• Getting Started in Biological Research
• Finding Empirical & Scholarly Articles
• Citing Sources This link opens in a new window
• General Biology
• Environmental Biology
• Evolutionary Biology
• Cellular & Molecular Biology
• Microbiology
• Health & Medicine
• Anatomy & Physiology

Planning your Literature Review

While planning your review, in addition to finding and analyzing the reviews in dissertations, you might ask yourself questions such as the following:

What is my central question or issue that the literature can help define?

What is already known about the topic?

Is the scope of the literature being reviewed wide or narrow enough?

Is there a conflict or debate in the literature?

What connections can be made between the texts being reviewed?

What sort of literature should be reviewed? Historical? Theoretical? Methodological? Quantitative? Qualitative?

What criteria should be used to evaluate the literature being reviewed?

How will reviewing the literature justify the topic I plan to investigate?

From: Writing the successful thesis and dissertation: entering the conversation , by Irene L. Clark

source: Kent State University's Literature Reviews Libguide

Organizing the Review

Categorizing the Literature

When categorizing the writings in the review, the researcher might consider

• the methodology employed;
• the quality of the findings or conclusions;
• the document’s major strengths and weaknesses;
• any other pivotal information.

He/She might consider such questions as:

• what beliefs are expressed?
• Is there an ideological stance?
• What is being described? Is it comprehensive or narrow?
• Are the results generalizable?

Remember that you are relating other studies to your study. How do the studies in your lit. review relate to your thesis? How are the other studies related to each other?

From http://libguides.redlands.edu/content.php?pid=32380&sid=239161

Literature Review -Created by North Carolina State University Libraries

Watch this video for more information about writing a literature review.

• Writing a Literature Review

What is a Literature Review?

A literature review is a comprehensive and up-to-date overview of the principal research about the topic being studied.

The aim of a literature review is to show "that the writer has studied existing work in the field with insight" (Haywood and Wragg, 1982). It is not enough merely to show what others in your field have discovered. You need to view the work of others with insight to review critically. An effective review analyses and synthesizes material, and it should meet the following requirements: (Caulley, 1992)

• Compare and contrast different authors' views on an issue
• Group authors who draw similar conclusions,
• Criticise aspects of methodology,
• Note areas in which authors are in disagreement,
• Highlight exemplary studies,
• Identify patterns or trends in the literature
• Highlight gaps in and omissions in previous research or questions left unanswered
• Show how your study relates to previous studies,
• Show how your study relates to the literature in general,
• Conclude by summarising what the literature says.

A literature review has a number of purposes. It enables you to:

• Set the background on what has been researched on a topic.
• Show why a topic is significant to a subject area.
• Discover relationships between ideas.
• Identify major themes & concepts.
• Identify critical gaps & points of disagreement.
• Help the researcher turn a network of articles into a coherent view of the literature.

Source: University of Melbourne's Literature Review Libguide

Literature Review Samples

• Otterbein's Institutional Repository You can browse by collection and then department and student scholarship. Look up samples of literature reviews in theses and dissertations.
• OhioLink's ETD Browse by institution and look up samples of literature review in the students' theses and dissertations
• << Previous: Environmental Science Major
• Next: Primary Sources & Original Research vs. Review Articles >>
• Last Updated: Aug 22, 2024 4:53 PM
• URL: https://otterbein.libguides.com/environmental

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• Review Article
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• Published: 17 September 2024

Evidence for widespread human exposure to food contact chemicals

• Birgit Geueke   ORCID: orcid.org/0000-0002-0749-3982 1 ,
• Lindsey V. Parkinson   ORCID: orcid.org/0000-0002-6219-0546 1 ,
• Ksenia J. Groh   ORCID: orcid.org/0000-0002-3778-4721 2 ,
• Christopher D. Kassotis   ORCID: orcid.org/0000-0002-0990-2428 3 ,
• Maricel V. Maffini   ORCID: orcid.org/0000-0002-3853-9461 4 ,
• Olwenn V. Martin   ORCID: orcid.org/0000-0003-2724-7882 5 ,
• Lisa Zimmermann   ORCID: orcid.org/0000-0001-6801-6859 1 ,
• Martin Scheringer   ORCID: orcid.org/0000-0002-0809-7826 6 , 7 &
• Jane Muncke   ORCID: orcid.org/0000-0002-6942-0594 1  

Journal of Exposure Science & Environmental Epidemiology ( 2024 ) Cite this article

8705 Accesses

1454 Altmetric

Metrics details

Over 1800 food contact chemicals (FCCs) are known to migrate from food contact articles used to store, process, package, and serve foodstuffs. Many of these FCCs have hazard properties of concern, and still others have never been tested for toxicity. Humans are known to be exposed to FCCs via foods, but the full extent of human exposure to all FCCs is unknown.

To close this important knowledge gap, we conducted a systematic overview of FCCs that have been monitored and detected in human biomonitoring studies according to a previously published protocol.

We first compared the more than 14,000 known FCCs to five biomonitoring programs and three metabolome/exposome databases. In a second step, we prioritized FCCs that have been frequently detected in food contact materials and systematically mapped the available evidence for their presence in humans.

For 25% of the known FCCs (3601), we found evidence for their presence in humans. This includes 194 FCCs from human biomonitoring programs, with 80 of these having hazard properties of high concern. Of the 3528 FCCs included in metabolome/exposome databases, most are from the Blood Exposome Database. We found evidence for the presence in humans for 63 of the 175 prioritized FCCs included in the systematic evidence map, and 59 of the prioritized FCCs lack hazard data.

Significance

Notwithstanding that there are also other sources of exposure for many FCCs, these data will help to prioritize FCCs of concern by linking information on migration and biomonitoring. Our results on FCCs monitored in humans are available as an interactive dashboard (FCChumon) to enable policymakers, public health researchers, and food industry decision-makers to make food contact materials and articles safer, reduce human exposure to hazardous FCCs and improve public health.

Impact statement

We present systematically compiled evidence on human exposure to 3601 food contact chemicals (FCCs) and highlight FCCs that are of concern because of their known hazard properties. Further, we identify relevant data gaps for FCCs found in food contact materials and foods. This article improves the understanding of food contact materials’ contribution to chemical exposure for the human population and highlights opportunities for improving public health.

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Introduction.

Humans are exposed to synthetic chemicals from food, drugs, household and personal care products, and environmental pollutants. Some of these chemicals have been associated with the increasing prevalence of non-communicable diseases [ 1 , 2 , 3 ]. Food packaging and other food contact articles (FCAs), such as tableware and food processing equipment, contribute to the human chemical burden via oral exposure, because food contact chemicals (FCCs) migrate from different food contact materials (FCMs) into foodstuffs and are then ingested [ 4 , 5 , 6 , 7 , 8 ].

For individual FCCs, such as bisphenol A (BPA) and several phthalates, the contribution of chemical migration from FCMs to human exposure has been studied in detail, taking into account that other exposure sources exist [ 9 , 10 , 11 , 12 ]. BPA is banned in some food contact applications, such as baby bottles, in many parts of the world, but is still regularly measured in FCMs (e.g [ 13 , 14 , 15 ].). Currently, a complete ban on BPA in FCMs is proposed by the European Commission [ 16 ]. However, hundreds of FCCs have been shown to migrate from FCMs into foods, and thousands of FCCs have been extracted from FCMs [ 5 ]. In total, over 12,000 FCCs could be intentionally used during the manufacturing of different types of FCMs [ 17 ] and even more chemicals could be present in FCMs as non-intentionally added substances (NIAS) that are introduced or formed during manufacture or use [ 5 , 18 , 19 ].

Many FCCs are of concern for human health because they have hazard properties such as carcinogenicity, mutagenicity, and reprotoxicity (CMR), endocrine disrupting properties, bioaccumulation potential, and/or persistence [ 17 , 20 , 21 ]. In addition, toxicity data are often incomplete or missing, which means that safe use cannot be assessed [ 17 , 22 , 23 ]. Therefore, reducing exposure to known hazardous FCCs and assessing untested FCCs can contribute to the prevention of non-communicable diseases that are associated with chemical exposures [ 24 , 25 ].

The challenges in regulating FCMs and managing the health risks associated with FCCs are diverse and legislation often does not keep up with the latest scientific understanding [ 26 , 27 ]. Publicly available evidence on intentionally used FCCs and their known hazards is available in our earlier work where we compiled the Food Contact Chemicals Database (FCCdb) [ 17 ]. The FCCdb gives an overview of all chemicals that are known to be used in the manufacture of FCMs. Further, we systematically mapped data on migrating and extractable FCCs, and our Database on Migrating and Extractable Food Contact Chemicals (FCCmigex) provides evidence for FCCs that have been detected in extracts of FCMs and/or their migrates into food and food simulants, indicating the potential for human exposure [ 5 ]. Only 30% of the chemicals present in FCMs are listed in the FCCdb, based on information from the most recent update of the FCCmigex database [ 28 ]. This indicates that the non-listed FCCs are either NIAS or have been intentionally used although they are not recorded in any of the FCCdb’s sources. Even though it is well-established that chemicals migrating from FCMs contribute to human exposure, the presence of FCCs in human samples has not yet been systematically assessed.

Here, we provide a systematic overview of FCCs that have been monitored and detected in humans by including information from biomonitoring programs, metabolome and exposome databases, and the primary scientific literature. We detailed our approach in a previously published protocol [ 29 ]. The resulting Database on Food Contact Chemicals Monitored in Humans (FCChumon) is a publicly available tool integrating empirical data on FCCs in human samples, and it complements the FCCdb and FCCmigex databases. Our goal is to provide scientific evidence that supports advancing global FCM regulations and the safety assessments of FCCs.

Overview of the two-step approach

The evidence for FCCs that have been monitored and detected in human samples was compiled according to a protocol initially registered on Zenodo in September 2022 and updated in April 2023 [ 29 ]. We followed the structure of a Population-Outcome (PO) question:

Question: Which known FCCs have been monitored in the human body?

Population (P): Human samples, such as blood, urine, hair, and breast milk, from people of any age, gender, or ethnicity

Outcome (O): Any result describing the monitoring/detection of a known FCC or its metabolite

As detailed in the protocol and further specified below, we applied a stepwise approach and referred to biomonitoring programs, databases on the human exposome and metabolome, and the primary scientific literature to map the evidence for FCCs’ presence in humans. Briefly, in step 1, FCCs included in the FCCdb and the FCCmigex databases were matched to the chemicals listed in biomonitoring programs and metabolome and exposome databases (Fig.  1 ). During protocol development, we found that thousands of FCCs were neither included in the selected metabolome/exposome databases nor in biomonitoring programs, while the primary scientific literature reported the monitoring of some of these FCCs in human samples. In step 2, we therefore applied the methodology of a systematic evidence map to obtain relevant information from the scientific literature. FCCs not found in any of the sources consulted in step 1 were prioritized based on their presence in FCMs, according to evidence from FCCmigex. These prioritized FCCs were included in the systematic evidence mapping performed in step 2 to understand their presence in human samples.

We compared known FCCs to biomonitoring programs and metabolome/exposome databases (step 1) and systematically mapped the evidence for presence of additional, priority FCCs in humans (step 2). The results of steps 1 and step 2 (red boxes) comprise the Database of Food Contact Chemicals Monitored in Humans (FCChumon).

Information sources for chemical comparisons

Together, the FCCdb and the FCCmigex databases presently consist of 14,402 known FCCs with assigned CAS Registry Numbers (Fig.  1 ). The FCCdb is an inventory for FCCs that are potentially used in the manufacture of FCMs and FCAs [ 17 ]. It currently contains 12,285 distinct FCCs of which 11,593 have a CAS Registry Number. The FCCmigex database systematically maps scientific evidence of FCCs that have been measured in FCMs and FCAs [ 5 , 28 ]. The most recent version of the FCCmigex database contains 4262 chemicals with a CAS Registry Number, of which 3995 FCCs have been detected at least once in an FCM migrate or extract. Each FCCmigex database entry is linked to the reference from which it was generated and provides information about the FCC, what type of FCA and which FCM(s) were tested, details about the experimental set-up, and whether the FCC was detected or not. Chemicals that have been targeted but never detected in FCMs, and that are not in the FCCdb, are not included in this study.

In the first step, we consulted five biomonitoring programs that encompass different ranges of chemicals and provide wide geographic coverage, namely the National Health and Nutrition Examination Survey (NHANES) of the US [ 30 ], the Canadian Health Measures Survey (CHMS) [ 31 ], the Human Biomonitoring for Europe project (HBM4EU) [ 32 , 33 ], the Korean National Environmental Health Survey (KoNEHS) [ 34 ], and Biomonitoring California [ 35 ]. Further, three metabolome/exposome databases were used to identify FCCs that have been monitored in humans: the Human Metabolome Database (HMDB) [ 36 , 37 ]; the Blood Exposome Database [ 38 , 39 ], and the Exposome Explorer [ 40 , 41 ]. In addition to these sources, in the second step we systematically searched the primary scientific literature for human biomonitoring data on specific FCCs, using bibliographic databases (PubMed, Web of Science Core Collection (WoS), ScienceDirect, and CAS SciFinder n ).

Data processing and comparisons (step 1)

All known FCCs with CAS Registry Numbers were included in the comparisons of step 1, regardless of whether the CAS Registry Number indicates a specific structure or a chemical mixture. If available, additional chemical identifiers, such as INChI Keys and SMILES, were retrieved from the collections of FCCs associated with lists S77 and S112 from the NORMAN Suspect List Exchange [ 42 , 43 , 44 ].

In step 1A, information on chemicals that are part of any of the biomonitoring programs was downloaded from the respective sources. We also collected information on whether a chemical has been ‘monitored but never detected’ or ‘monitored and detected’. If it was stated in the biomonitoring programs that the analyte was a metabolite of a specific parent compound, we paired the metabolite and the parent compound for comparison with the known FCCs. For example, the analyte mono-ethyl phthalate (CAS 863029-89-4) is listed as a metabolite of di-ethyl phthalate (CAS 84-66-2) in NHANES, and we used both CAS Registry Numbers in the comparisons to the known FCCs. In this way, we ensured that FCCs were identified in the biomonitoring programs regardless of whether detection in human samples was reported for parent compounds or their metabolites. We manually added CAS Registry Numbers to chemicals missing these identifiers in the biomonitoring lists to enable their comparisons to the FCCs.

In step 1B, the data set ‘biomarkers’ was downloaded from the Exposome Explorer, and the full content of the Blood Exposome Database was retrieved. From the HMDB, all chemicals were included that were labeled by metabolite status as ‘detected and quantified’, ‘detected but not quantified’, and ‘expected but not quantified’. The metabolome/exposome databases do not systematically report links between parent compounds and metabolites. We used these chemical lists from the metabolome/exposome databases without any further editing.

Based on their CAS Registry Numbers, InChI Keys, or SMILES identifiers, FCCs were then compared to the chemical lists retrieved from the biomonitoring programs and metabolome/exposome databases. These comparisons were performed by means of Python (v3.10.8) pandas package (v1.5.3).

Systematic evidence mapping (step 2)

Prioritization and grouping of fccs.

In step 2, we focused on the FCCs that were not found in any of the sources of step 1, i.e., all FCCs, or their metabolites, that have never been included in a biomonitoring program (regardless of whether they have been detected or not) and all FCCs that did not generate any match in the metabolome/exposome databases. These FCCs not monitored in any of the sources of step 1 were candidates for the systematic evidence mapping in step 2. For this step, we prioritized FCCs that have at least five database entries in the FCCmigex, reporting their detection in migrates and/or extracts of FCMs. To verify the absence of any prioritized chemicals in step 1, we also searched the HMDB for the chemical names that are used in the FCCmigex database and in Norman SLE.

For further data analysis and interpretation, prioritized FCCs were assigned to chemical groups based on functional categories and/or chemical structures. During grouping, we referred to the primary literature included in this systematic evidence map and in the FCCmigex database to understand the function and/or chemical features of an FCC. Additionally, we used the tool Classyfire [ 45 ], the Plastics Additives Handbook [ 46 ], and expert knowledge to group FCCs based on their applications in FCMs and/or chemical features, such as functional groups and structural properties.

Literature searches and screening

For each of the prioritized FCCs, individual literature searches were performed. For PubMed, WoS, and ScienceDirect, search strategies included the chemical name as used in the FCCdb or the FCCmigex, and generic search terms related to human biomonitoring (e.g., human, blood, urine, biomonitoring) that were connected by the Boolean operator OR. Searches in CAS SciFinder n used CAS Registry Numbers instead of chemical names. Search strings and settings were slightly adapted depending on the requirements of each database. The searches were not restricted by publication date or language and included all literature published by February 2023. Full details on search strings, applied filters, and settings have been published previously [ 29 ].

Individual literature searches were stored in separate Endnote files, from which duplicates were removed. All individual libraries were uploaded into the online evidence synthesis tool Cadima [ 47 ], where further duplicates were deleted. The references were then screened in a two-level process, beginning with title-and-abstract screening and followed by full-text screening. During the screening, the eligibility criteria specified in the protocol were applied to all prioritized FCCs that were analyzed in the respective reference [ 29 ]. In brief, studies were considered eligible and included in the systematic evidence map if the analyzed sample originated from a human specimen (e.g., urine, blood, and breast milk) and at least one prioritized FCC was analyzed. Ten percent of the references were independently screened by two reviewers in parallel at title-and-abstract and full-text levels, and disagreements were resolved bilaterally. Reasons for exclusion were recorded during full-text screening.

Data extraction

Eligible studies were used to collect information on whether FCCs have been monitored in human samples and if they have been detected. Details on the sample type and analytical approaches were part of the data extraction process (see Supplementary Information). The process was based on the data extraction software tool SciExtract [ 5 ] which allowed us to use precoded options to systematically compile the data. SciExtract was also used to organize and manage the workflow and to store the extracted data.

Hazard mapping

For FCCs included in the biomonitoring programs (step 1A) and those prioritized in step 2, we compiled the hazard properties according to human-health-related criteria described in the EU’s Chemicals Strategy for Sustainability (CSS) [ 48 ]. The CSS seeks to ban the most harmful chemicals from consumer products, including FCMs, and defines chemicals as ‘most harmful’ to human health if they are carcinogenic, mutagenic or toxic to reproduction (CMR) or exhibit specific target organ toxicity (STOT). Hazards associated with endocrine-disrupting properties, persistence, bioaccumulation, and mobility of a chemical are also mentioned in the CSS but were not included in this analysis. We consulted the European Chemicals Agency’s (ECHA) Classification and Labelling Inventory aligned with the Globally Harmonized System (GHS) for chemical classification and labeling [ 49 ] and referred to GHS-aligned classifications by the Japanese Government [ 50 ] for identifying human health-related hazards. Following the GHS criteria for classification and labeling, we identified chemicals as ‘high concern’ if they exhibit CMR properties belonging to categories 1A and 1B (known and presumed CMR, respectively) and/or have been classified as STOT category 1 after repeated exposure (RE) (Fig.  S1 ). Chemicals of ‘medium concern’ were those suspected to have CMR and/or STOT RE properties, as indicated by their classifications in category 2. Chemicals that have been classified based on other concerns, such as aquatic toxicity or skin sensitization, were marked as ‘other concern’. FCCs with data in at least one hazard category and without any classification were labeled as ‘not classified’. FCCs that were not included in the hazard inventories, or for which no data were available in any hazard category, were labelled with ‘no hazard data’.

Overall evidence for the presence of FCCs in humans

For a total of 3601 (or 25%) of the 14,402 known FCCs, we found evidence for their presence in human samples (Fig.  2 ). Of these, 194 FCCs have been detected in biomonitoring programs, and 3528 FCCs are listed in metabolome/exposome databases, with an overlap of 184 FCCs found in both types of sources. The total of 3601 FCCs also includes 63 out of 175 prioritized FCCs that have been detected in humans according to the results of the systematic evidence map (step 2).

Schematic representation of the FCCs monitored and detected in biomonitoring programs and/or listed in metabolome/exposome databases (step 1) and additional FCCs detected in humans, based on evidence from the scientific literature for a set of prioritized FCCs (step 2).

Based on the results of this stepwise approach, we set up the FCChumon database, which is provided as an interactive tool that is freely available, searchable, and linking to the relevant sources ( https://www.foodpackagingforum.org/fcchumon ).

Analysis of biomonitoring programs and metabolome/exposome databases

In step 1, we identified 3538 FCCs that have been detected in humans, which can be divided into 1883, 863, and 792 FCCs that are included only in the FCCdb, only in the FCCmigex, and in both databases, respectively (Fig.  3 , lower panel). These numbers indicate that 23% of the FCCs in the FCCdb and 41% of the FCCs in the FCCmigex are listed in at least one of the sources in Step 1. Sixty-seven percent of FCCs that are listed in both FCC databases have evidence of presence in humans.

The upper panel illustrates the FCCs from the FCCdb (green outline), the FCCmigex (yellow outline), and their overlap. The left part of the middle panel shows the number of known FCCs that have been detected in biomonitoring programs and, in brackets, the total number of monitored FCCs. The right part of the middle panel displays the FCCs that are listed in metabolome/exposome databases. FCCs that have been detected in humans are indicated by the orange filling of the respective areas; white areas represent FCCs without any evidence of the presence in humans and the FCCs that have been monitored but not detected. The figure in the lower panel is the result of the overall comparison of the known FCCs with all sources of step 1.

Of the 265 FCCs monitored in at least one of the five biomonitoring programs, 194 FCCs (or their metabolites) have been detected in human samples, and 71 FCCs (or their metabolites) have been monitored but not detected in any of the biomonitoring programs (Fig.  3 , middle panel; Table  S1 ). The most extensive national program, NHANES, has monitored over 400 different chemicals in human samples since 1999, and 154 of these are FCCs (Figure S2). We also found 84, 66, 66, and 25 FCCs with evidence for the presence in humans in the biomonitoring programs CHMS, HBM4EU, Biomonitoring California, and KoNEHS, respectively. One hundred and twenty-four FCCs have only been monitored in a single biomonitoring program, and 55 of these have not been detected, whereas 13 FCCs have been included across all five programs, of which 8 have been detected in all programs (Figure S3; Table  S1 ).

The overlap of known FCCs with metabolome/exposome databases is much larger than the overlap with biomonitoring programs: of the three metabolome/exposome databases, the Blood Exposome Database includes the highest number of FCCs (2918 FCCs), followed by the HMDB (2211 FCCs) and the Exposome Explorer (253 FCCs) (Fig.  3 , middle panel; Figure S4). The HMDB lists 367, 1072, and 772 FCCs that are labelled as “detected and quantified”, “detected but not quantified”, and “expected but not quantified”, respectively, according to the classification system of the database (Figure S5) [ 36 ].

Sixty-one out of the 71 FCCs that have been monitored but not detected in biomonitoring programs are listed in at least one of the metabolome/exposome databases. This means that only 10 FCCs fall under the category “monitored but not detected” in step 1 (Fig.  2 ).

Systematic evidence mapping of prioritized FCCs

In step 1 we show that 75% of the known FCCs are not listed in any of the biomonitoring programs or metabolome/exposome databases. However, for some of these FCCs, scoping searches resulted in additional evidence from the primary literature. Therefore, we decided to systematically map the evidence for 175 FCCs which we prioritized based on the number of FCCmigex database entries that report their detection in FCMs.

In this systematic approach, we found 3152 scientific studies for 147 out of the 175 prioritized FCCs (Figure S6) and considered 251 and 159 studies eligible after title-and abstract and full-text screening, respectively. These studies refer to 68 FCCs – for the other 107 FCCs, no studies fulfilled the eligibility criteria.

Of the 68 FCCs for which scientific studies were found, 63 have been detected in human samples and five have been monitored, but not detected, i.e., Irganox 1330 (CAS 1709-70-2), 2,6-(1,1-dimethylethyl)phenol (CAS 128-39-2), phenyl-bis-(2,4,6-trimethylbenzoyl) phosphinoxid (CAS 162881-26-7), 2,5-bis(5-tert-butyl-2-benzoxazolyl) thiophene (CAS 7128-64-5), and Tinuvin 622 (CAS 65447-77-0) (Fig.  4A ). The detected chemicals have been detected in urine (28 FCCs), serum (20), blood (13), and plasma (12) (Fig.  4B ). FCCs have also been found in breast milk (13) and samples taken from umbilical cords (18) and placentas (6). One hundred and thirteen studies have used targeted analyses, whereas 47 studies have used non-targeted approaches (Fig.  4C ), and only one study has applied both methods [ 51 ]. The vast majority of FCCs have been detected directly, i.e. as parent compounds, in human samples (Fig.  4D ), while antioxidant 1098 (CAS 23128-74-7) and Irganox 1035 (CAS 4148-35-9) have been putatively identified based on an unspecific common metabolite in one study [ 52 ].

A Numbers of FCCs with and without evidence from the primary scientific literature indicating their presence in humans. B Types of human samples in which the 63 FCCs have been detected (multiple sample types possible). C Types of applied analytical methods per study and per detected FCC. D Numbers of FCCs that have been analyzed directly (as parent compound) or as specific or unspecific metabolite.

FCCs monitored in humans

Fccs detected in biomonitoring programs.

Among the 235 FCCs present in FCMs that have been included in human biomonitoring programs, there are 51 volatile organic compounds (VOCs), 29 per- and polyfluoroalkyl substances (PFAS), 25 pesticides, 23 metals, 23 dioxin-like compounds, 20 flame retardants, and 19 phthalates and their alternatives (Fig.  5A , right panel; Table  S1 ). Phthalates and alternative plasticizers, and metals are frequently detected FCCs in FCMs and have also been often found in humans (Fig.  5A , bar charts). Furthermore, PFAS, VOCs, and phenolic compounds, including bisphenols, parabens, and benzophenones, have been frequently monitored and detected in FCMs and in humans. In contrast, for dioxin-like compounds, pesticides, flame retardants, polyaromatic hydrocarbons (PAHs), amines, and perchlorate there is less evidence for their presence in FCMs. Interestingly, 71 of the 95 FCCs belonging to these six groups would not be expected to be present in FCMs, since they are not included in the FCCdb (Table  S1 ). The evidence for presence of FCCs in FCMs varies widely between but also within chemical groups. For example, the VOC styrene (CAS 100-42-5) has been listed 99 times as “detected in FCMs” in the FCCmigex database, while 16 other VOCs found in humans have been listed less than ten times each (Table  S1 ). The presence of styrene, or its metabolites, in humans has been shown by NHANES, CHMS, and KoNEHS, but there is no evidence for 18 of the 51 VOCs from any of the five biomonitoring programs.

A 235 FCCs detected in FCMs and included in biomonitoring programs (step 1A). B 175 FCCs prioritized based on their detection in FCMs and their absence in step 1 (step 2). The yellow bar charts illustrate the evidence for the presence of FCC groups in FCMs, based on the sum of database entries from the FCCmigex that report the detection of FCCs in FCMs. The orange bar charts show the evidence of the presence of FCC groups in humans. In step 1A, this is based on the number of biomonitoring programs that have monitored individual FCCs in humans and the addition of these counts by group. In step 2, the orange bars represent the number of studies that have monitored at least one FCC of the respective group. The pie charts show how many FCCs per group have been monitored and detected at least once and how many FCCs have been monitored but not detected in any sample. For step 2, the pie charts also include the chemicals for which there is no evidence in the scientific literature.

FCCs included in the systematic evidence map

Among the 175 FCCs included in the systematic evidence map, there are 38 oligomers (mainly siloxane, polyamide, and polyethylene terephthalate (PET) derivatives), 15 antioxidants and degradation products, 14 photoinitiators, and 14 plasticizers (Fig.  5B , right panel; Table  S2 ).

For oligomers and antioxidants and their degradation products, 424 and 499 FCCmigex database entries, respectively, imply that FCMs play a role in human exposure to these chemical groups (Fig.  5B ). However, there is limited evidence for the presence of antioxidants and oligomers in humans, as indicated by 6 and 12 studies, respectively, reporting the detection of the chemicals of these groups. For only five out of 38 prioritized oligomers, we found evidence for their detection in humans: a PET cyclic trimer (CAS 7441-32-9), three cyclic siloxanes (D7, CAS 107-50-6; D8, CAS 556-68-3 and D9, CAS 556-71-8), and 1,6-dioxacyclododecane-7,12-dione (CAS 777-95-7) (Table  S2 ). With 209 FCCmigex database entries and 9 studies reporting detection in humans, photoinitiators are regularly found in FCMs, but less frequently monitored in humans. For the five BADGE derivatives BADGE·H 2 O, BADGE·2H 2 O, BADGE·HCl, BADGE·2HCl, and BADGE·H 2 O·HCl, 23 studies confirm the detection of at least one of these FCCs in humans. In addition, they have 65 database entries in the FCCmigex, confirming their regular detection in migrates and/or extracts from coated metal FCMs.

FCCs of concern

Of the 235 FCCs included in biomonitoring studies and with evidence for their presence in FCMs, 100 FCCs have hazard properties of high concern for human health, and 44 FCCs have hazard properties of medium concern, i.e., they are assigned to categories 1 and 2, respectively (Fig.  6A , Table  S1 ). Among the FCCs detected in humans are several category 1 A and 1B carcinogens, of which, e.g., styrene, benzophenone (CAS 119-61-9), formaldehyde (CAS 50-00-0), and cadmium (CAS 7440-43-9) have also been frequently found in FCMs. Dozens of FCCs are classified as toxic to reproduction, for example, nine phthalates, which are all classified as 1B reprotoxicants. Over 30 FCCs are mutagens (e.g., benzene (CAS 71-43-2), lead, cadmium, and cobalt), and many more exhibit specific target organ toxicity after repeated exposure (e.g., 4,4’-methylenedianiline (CAS 101-77-9) and perfluorooctanoic acid (CAS 335-67-1)). Seventy-seven FCCs have other concerns or have not been classified as hazardous based on the available data, and 14 do not have hazard data or are not listed.

A 235 FCCs detected in FCMs and included in biomonitoring programs. B 175 FCCs prioritized based on their detection in FCMs and their absence in step 1. On the left side of both Sankey diagrams, the number of FCCs monitored and detected in humans (red), monitored but not detected in humans (light gray), and without any evidence for the presence in humans (dark gray) are shown. On the right sides, the diagrams visualize the number of chemicals of high (red) and medium concern (yellow), chemicals of other concerns or not classified chemicals (light gray), and chemicals with no hazard data (dark gray). The thickness of connecting lines represents the numbers of chemicals that belong to a hazard category and their evidence for presence in humans. *Many hazard classifications lack information for specific hazard categories. This means that chemicals may be newly categorized or reassigned to other hazard categories when more information becomes available in the future.

Among the 175 FCCs included in the systematic evidence map, 5 and 13 FCCs are classified in categories 1 and 2, respectively, resulting in high and medium concern for CMR and/or STOT RE properties (Fig.  6B , Table  S2 ). Di-n-octylisophthalate (CAS 137-89-3), 2-benzyl-2-(dimethylamino)-4-morpholino-butyrophenone (CAS 119313-12-1), ethyl-4-dimethylaminobenzoate (CAS 10287-53-3), and medium-chain chlorinated paraffins (CAS 85535-85-9) are reproductive toxicants of high concern (category 1B) and have been detected in FCMs and in humans. For the category 1B carcinogen 2,4’-methylenedianiline (CAS 1208-52-2), however, we found no evidence concerning its presence in humans. Ninety-eight FCCs are allocated to other hazard categories or have not been classified, and 59 FCCs are not listed in the hazard inventories, indicating a lack of data for these chemicals. Based on this evidence map, 49 FCCs without hazard data have also never been targeted in human samples, but they are known to migrate so the implications of the probable human exposure from these FCCs are unknown. Among these are 29 oligomers that have been mainly detected in PA, PET, and siloxane FCMs.

Relevance of this study

There is evidence of human exposure for at least 3601 (or 25%) of the known FCCs (Fig.  1 ). While other exposure sources (than FCMs) exist for FCCs, it is likely that humans are exposed to more FCCs than reported here, as we only searched the scientific literature for a small subset of chemicals. The novel database on FCCs monitored in humans (FCChumon) lends itself to integration with our previously published database of chemicals present in/migrating from specific FCMs (FCCmigex) [ 5 ], thereby enabling hypothesis-driven research for closing pertinent knowledge gaps on human exposure to chemicals originating from FCMs. Together, these databases can also be used as information sources for elucidating FCCs’ health impacts and highlighting other priority research needs.

Parent compounds vs. metabolites

For the exposure assessment of chemicals with well-known metabolic fate in humans, such as phthalates and certain VOCs, metabolites instead of their parent compounds are monitored [ 53 , 54 ]. We considered this aspect when comparing FCCs to chemicals from the biomonitoring programs and when analyzing the primary literature. Various tools could support identifying FCC metabolites by predicting chemical biotransformation [ 55 , 56 ], but they are associated with large scientific uncertainty, as shown, e.g., for the metabolism of agrochemicals in rats [ 57 ] or for 15 structurally different groups of flame retardants [ 58 ]. Given the high number of FCCs included in this study, we did not attempt to systematically predict potential metabolites and only considered information on specific metabolites if it was readily available in the biomonitoring programs. Only one unspecific metabolite was identified in the systematic evidence map, indicating potential exposure to two antioxidants [ 52 ].

Focus on chemical groups

FCMs are a well-known and relevant exposure source for phthalates and their alternatives, metals, VOCs, and phenolic compounds. These chemicals are regularly monitored and detected in human biomonitoring programs and frequently found in FCMs (Fig.  5A ), and there is ample evidence for their migration, e.g. [ 17 , 59 , 60 , 61 ]. There is also evidence for the presence of PFAS in humans and in FCMs. Although most PFAS have never been authorized for food contact use [ 62 ], the contribution of food packaging to human exposure has been mapped [ 63 ]. Dioxin-like compounds, many pesticides, and flame retardants are not intentionally added FCCs, but they may be present in FCMs because they are introduced or formed during FCM use, manufacture, and recycling, as their detection in FCMs shows [ 64 , 65 , 66 ]. FCMs may therefore contribute to human exposure to FCCs intentionally used in the manufacture of FCMs, various types of NIAS, and illicitly added chemicals. Yet, for most FCCs, comprehensive assessments of the relative contribution of FCMs to human body burden are missing.

Antioxidants are of special interest because many are high-production volume chemicals that are widely used in plastic food packaging [ 67 ] and robust evidence for their presence in FCMs exists (Fig.  5B , Table  S2 ). Important groups of antioxidants are sterically hindered phenols and phosphite antioxidants that are very common in FCMs, e.g., Irgafos 168 (CAS 31570-04-4), Irganox 1076 (CAS 2082-79-3), and Irganox 1010 (CAS 6683-19-8). However, neither of these substances is included in the biomonitoring programs and exposome/metabolome databases (step 1), and we found only limited evidence for their presence in humans in step 2 [ 52 , 68 , 69 ]. Major degradation products of these antioxidants, such as 2,4-di-tert-butylphenol (CAS 96-76-4), 2,6-di-tert-butylbenzoquinone (CAS 719-22-2), and tris(2,4-di-tert-butylphenyl)phosphate (CAS 95906-11-9), have been detected in humans in a few studies, but at high levels and with frequent detection in sampled populations [ 70 , 71 , 72 ]. These results show that the contribution of FCMs to human exposure to antioxidants and their degradation products has not yet received much attention. Such gaps need to be filled by better understanding the overall exposure to antioxidants and their metabolism in humans.

Oligomers are another group of FCCs requiring more attention. PET, PA, and siloxane oligomers are known side-products of polymerization, and they have been detected in extracts and migrates of FCMs. There is however only very limited evidence for their presence in humans, e.g. for PET oligomers [ 73 ]. This is likely due to the challenging chemical analysis of oligomers, especially in complex media, such as human samples, and the fact that chemical standards required for the identification and quantification of oligomers are rarely available [ 74 , 75 ]. BADGE and its derivatives are commonly observed side-products formed during the polymerization of epoxy resins [ 76 ]. Toxic effects, such as endocrine disruption, genotoxicity, and allergic reactions, have been linked to BADGE derivatives and epoxy resins, but information on their toxicity is still limited [ 77 ]. Seventeen BADGE derivatives have been detected in extracts or migrates of FCMs, and five of them have been found in humans. This illustrates that targeted analysis of structurally related chemicals is possible and should be prioritized, to close this important knowledge gap on human exposure to expected side-products of polymerization reactions [ 76 ].

Photoinitiators form a group of structurally diverse FCCs that are used in various FCMs, such as coatings, printing inks, and adhesives [ 78 ]. While there is substantial evidence for their presence in FCMs, their presence in human samples has not been extensively investigated. Liu and Mabury showed that 18 photoinitiators and their sulfoxidation products are present in human sera [ 79 ], and human exposure, environmental occurrence, and toxicity of 25 photoinitiators have recently been reviewed [ 78 ]. According to the FCCmigex and FCChumon databases, several of these photoinitiators have been detected in FCMs and there is evidence for human exposure. Among these, benzophenone (CAS 119-61-9) is the most frequently detected photoinitiator in FCMs. Since benzophenone is a presumed carcinogen (class 1B, Table  S1 ) as well as a suspected endocrine disruptor [ 80 ], exposure via FCMs should be prevented.

Limitations affecting data interpretation

The sources used for the compilation of the FCChumon data vary with respect to the chemical space, curation level, and details provided. In general, we consider data collected in biomonitoring programs (Step 1A) as having a high level of confidence because they are usually derived from a representative population by following strict analytical standards and guidelines [ 81 ]. However, only a limited number of several hundred chemicals is monitored in these programs. We also rate the results of step 2 with a high level of confidence because they were generated by the robust approach of a systematic evidence map (including data extraction by a trained team of scientists but excluding the quality rating of each included study [ 29 ]). Conversely, the metabolome/exposome databases contain many thousands of different chemicals that have been assembled by different means, also including automated approaches [ 36 , 38 ]. The matches between the known FCCs and these databases may therefore require further review before being used in future assessments (e.g., by checking the “metabolite status” integrated in the HMDB).

Some of the FCCs listed in the FCCdb and FCCmigex consist of chemical mixtures of, e.g., polymeric molecules, stereoisomers, or structural isomers. Converting the CAS Registry Number of such mixtures into other identifiers was not always possible and could therefore result in some FCCs not being found in some sources of step 1. For example, short-chain chlorinated paraffins (SCCPs, CAS 85535-84-8) and medium-chain chlorinated paraffins (MCCPs, CAS 85535-85-9) do not have any identifiers other than CAS and were not matched in step 1, but we found ample evidence for the presence of these mixtures in humans in step 2, because they have been monitored regularly and the chemical names are reported in a standardized manner in the primary literature e.g. [ 82 , 83 , 84 ]. Nonylphenol (CAS 25154-52-3) is another example of a mixture of undefined stereoisomers and structural isomers that was not found in step 1 but prioritized in step 2. However, due to the listing of more defined nonylphenol isomers in the FCC databases as well as the metabolome/exposome databases, we decided to exclude this technical mixture from the systematic evidence map. These examples show that searches for (alternative) names and/or identifiers were helpful during the systematic evidence map and may be recommended for users of the FCChumon database.

Implications for assessing and managing FCCs

The data presented here lend support to the possible contribution of FCMs towards human exposure to FCCs. Since there are various FCCs with hazard properties of concern among the chemicals detected in humans and FCMs, their use in FCMs should be restricted to minimize human exposure. This is now recognized and currently under discussion for a few of these chemicals, including PFAS [ 85 , 86 ], BPA [ 10 , 16 ] and phthalates [ 87 ]. However, it does not mean that the remaining FCCs can be considered safe, as shown, e.g., by the absence of biomonitoring and hazard data for 107 (61%) and 59 (34%), respectively, of the 175 FCCs included in step 2. Importantly, even for chemicals where hazard data have been submitted to authorities there are significant data gaps for one or more hazard categories, as has been demonstrated for certain PFAS [ 62 , 88 ]. For FCCs migrating into foods, such related hazard data gaps need to be filled with high priority to characterize risk on human health [ 89 ]. This is especially urgent for intentionally added FCCs found at high levels in humans, such as antioxidants and photoinitiators, and expected NIAS, such as oligomers and BADGE derivatives.

In summary, this study systematically maps 3601 chemicals from different FCAs (food packaging, tableware, etc.) for which there is evidence for human exposure, and for 10,786 FCCs, no evidence could be provided at all. Only 15 FCCs have been monitored but have never been detected in humans. Based on two subsets totalling 410 FCCs, this study further identifies 105 FCCs of high concern due to their hazard properties and highlights the many data gaps related to hazards and human health risks. We make these data accessible in the user-friendly, freely accessible FCChumon dashboard, which complements our previously published FCCmigex dashboard on extractable and migrating FCCs. In combination, FCChumon and FCCmigex enable the prioritization of FCCs requiring more detailed investigations, either because they are frequently found in FCMs, despite having only little or no information on their presence in humans, or because they are measured in humans but lack hazard information. Furthermore, this evidence base supports policy and decision-making and highlights the urgent need to ban the most hazardous chemicals shown to migrate from food packaging and other types of FCAs into foods, to protect human health.

Data availability

The data are publicly and freely available as interactive dashboard that is based on Microsoft PowerBI under the following link ( https://www.foodpackagingforum.org/fcchumon ). The references that were included in the systematic evidence map (step 2) are also provided under this link.

WHO. Human biomonitoring: Facts and figures. Copenhagen: WHO Regional Office for Europe. 2015.

Choi J, Mørck TA, Joas A, Knudsen LE. Major national human biomonitoring programs in chemical exposure assessment. AIMS Environ Sci. 2015;2:782–802.

Article   Google Scholar  

Landrigan PJ, Fuller R, Acosta NJR, Adeyi O, Arnold R, Basu N, et al. The Lancet Commission on pollution and health. Lancet. 2018;391:462–512.

Article   PubMed   Google Scholar  

Grob K, Biedermann M, Scherbaum E, Roth M, Rieger K. Food contamination with organic materials in perspective: packaging materials as the largest and least controlled source? A view focusing on the European situation. Crit Rev Food Sci Nutr. 2006;46:529–35.

Article   CAS   PubMed   Google Scholar  

Geueke B, Groh KJ, Maffini MV, Martin OV, Boucher JM, Chiang Y-T, et al. Systematic evidence on migrating and extractable food contact chemicals: Most chemicals detected in food contact materials are not listed for use. Crit Rev Food Sci Nutr. 2022;63:9425–35.

Jeddi MZ, Boon PE, Cubadda F, Hoogenboom R, Mol H, Verhagen H, et al. A vision on the ‘foodture’ role of dietary exposure sciences in the interplay between food safety and nutrition. Trends Food Sci Tech. 2022;120:288–300.

Article   CAS   Google Scholar  

Barnes KA, Sinclair CR, Watson DH, (eds.). Chemical migration and food contact materials. Woodhead Publishing, 2007.

Hahladakis JN, Velis CA, Weber R, Iacovidou E, Purnell P. An overview of chemical additives present in plastics: Migration, release, fate and environmental impact during their use, disposal and recycling. J Hazard Mater. 2018;344:179–99.

Wang Y, Zhu H, Kannan K. A review of biomonitoring of phthalate exposures. Toxics. 2019;7:21.

Article   PubMed   PubMed Central   Google Scholar  

EFSA CEP Panel. Re-evaluation of the risks to public health related to the presence of bisphenol A (BPA) in foodstuffs. EFSA J. 2023;21:e06857.

Google Scholar  

EFSA CEP Panel. Update of the risk assessment of di-butylphthalate (DBP), butyl-benzyl-phthalate (BBP), bis(2-ethylhexyl)phthalate (DEHP), di-isononylphthalate (DINP) and di-isodecylphthalate (DIDP) for use in food contact materials. EFSA J. 2019;17:e05838.

HBM4EU. Substance report - Bisphenols. 2022. https://www.hbm4eu.eu/wp-content/uploads/2022/07/Bisphenols_Substance-report.pdf . Accessed 7 February 2024.

Banaderakhshan R, Kemp P, Breul L, Steinbichl P, Hartmann C, Fürhacker M. Bisphenol A and its alternatives in Austrian thermal paper receipts, and the migration from reusable plastic drinking bottles into water and artificial saliva using UHPLC-MS/MS. Chemosphere. 2022;286:131842.

Siddique S, Zhang G, Coleman K, Kubwabo C. Investigation of the migration of bisphenols from baby bottles and sippy cups. Curr Res Food Sci. 2021;4:619–26.

Article   CAS   PubMed   PubMed Central   Google Scholar  

Marchiandi J, Alghamdi W, Dagnino S, Green MP, Clarke BO. Exposure to endocrine disrupting chemicals from beverage packaging materials and risk assessment for consumers. J Hazard Mater. 2024;465:133314.

EC. Draft regulation on the use of BPA and other bisphenols in FCMs. 2024. https://ec.europa.eu/transparency/comitology-register/core/api/integration/ers/400274/097818/1/attachment . Accessed 16 July 2024.

Groh KJ, Geueke B, Martin O, Maffini M, Muncke J. Overview of intentionally used food contact chemicals and their hazards. Environ Int. 2021;150:106225.

Nerín C, Bourdoux S, Faust B, Gude T, Lesueur C, Simat T, et al. Guidance in selecting analytical techniques for identification and quantification of non-intentionally added substances (NIAS) in food contact materials (FCMS). Food Addit Contam A. 2022;39:620–43.

Geueke B. Dossier - Non-intentionally added substances. 2018. https://www.foodpackagingforum.org/fpf-2016/wp-content/uploads/2018/06/FPF_Dossier03_NIAS_2nd-edition.pdf . Accessed 7 February 2024.

Zimmermann L, Scheringer M, Geueke B, Boucher JM, Parkinson LV, Groh KJ, et al. Implementing the EU Chemicals Strategy for Sustainability: The case of food contact chemicals of concern. J Hazard Mater. 2022;437:129167.

vom Saal FS, Vandenberg LN. Update on the health effects of bisphenol A: Overwhelming evidence of harm. Endocrinology. 2020;162.

Neltner TG, Alger HM, Leonard JE, Maffini MV. Data gaps in toxicity testing of chemicals allowed in food in the United States. Reprod Toxicol. 2013;42:85–94.

Muncke J, Andersson A-M, Backhaus T, Belcher SM, Boucher JM, Carney Almroth B, et al. A vision for safer food contact materials: Public health concerns as drivers for improved testing. Environ Int. 2023;180:108161.

Balbus JM, Barouki R, Birnbaum LS, Etzel RA, Gluckman PD, Grandjean P, et al. Early-life prevention of non-communicable diseases. Lancet. 2013;381:3–4.

Muncke J, Myers JP, Scheringer M, Porta M. Food packaging and migration of food contact materials: will epidemiologists rise to the neotoxic challenge? J Epidemiol Commun H. 2014;68:592.

Simoneau C, Raffael B, Garbin S, Hoekstra E, Mieth A, Lopes J, et al. Non-harmonised food contact materials in the EU: Regulatory and market situation. Baseline study, final report. Publications Office of the European Union. 2016; JRC104198.

Muncke J, Backhaus T, Geueke B, Maffini MV, Martin OV, Myers JP, et al. Scientific challenges in the risk assessment of food contact materials. Environ Health Perspect. 2017;125:095001.

Food Packaging Forum. FCCmigex Database. 2023. https://www.foodpackagingforum.org/resources/fccmigex . Accessed 16 July 2024.

Geueke B, Parkinson LV, Dolenc J, Groh KJ, Kassotis CD, Maffini MV et al. Protocol for assessing the evidence of food contact chemicals monitored in humans. 2023; https://doi.org/10.5281/zenodo.7857837 .

National Center for Environmental Health, National Center for Health Statistics, National Health and Nutrition Examination Survey. Fourth national report on human exposure to environmental chemicals. Updated tables, March 2021, volume three: Analysis of pooled serum samples for select chemicals, NHANES 2005-16. 2021.

Health Canada. Sixth report on human biomonitoring of environmental chemicals in Canada. Minister of Health, Ottawa, ON. 2021. https://www.canada.ca/en/health-canada/services/environmental-workplace-health/reports-publications/environmental-contaminants/sixth-report-human-biomonitoring.html . Accessed 7 February 2023.

HBM4EU. EU HBM Dashboard. 2022. https://www.hbm4eu.eu/what-we-do/european-hbm-platform/eu-hbm-dashboard/ . Accessed 7 February 2023.

IPCHEM. Human Biomonitorin Data Module: HBM4EU-aggregated - HBM4EU aggregated workbook by VITO. 2022. https://ipchem.jrc.ec.europa.eu/#showmetadata/HBM4EUAGGREGATED . Accessed 7 February 2023.

Jung SK, Choi W, Kim SY, Hong S, Jeon HL, Joo Y, et al. Profile of environmental chemicals in the Korean population - Results of the Korean National Environmental Health Survey (KoNEHS) cycle 3, 2015-2017. Int J Environ Res Pub He. 2022;19:626.

Biomonitoring California. Chemicals biomonitored in California. 2022. https://biomonitoring.ca.gov/chemicals/chemicals-biomonitored-california . Accessed 7 February 2023.

Wishart DS, Guo A, Oler E, Wang F, Anjum A, Peters H, et al. HMDB 5.0: the Human Metabolome Database for 2022. Nucleic Acids Res. 2022;50:D622–31.

Wishart Research Group. The Human Metabolome Database. https://hmdb.ca/ . Accessed 7 February 2023.

Barupal DK, Fiehn O. Generating the Blood Exposome Database using a comprehensive text mining and database fusion approach. Environ Health Perspect. 2019;127:97008.

Barupal D, Fiehn O. Blood Exposome Database. https://bloodexposome.org/ . Accessed 9 February 2023.

Neveu V, Nicolas G, Salek RM, Wishart DS, Scalbert A. Exposome-Explorer 2.0: an update incorporating candidate dietary biomarkers and dietary associations with cancer risk. Nucleic Acids Res. 2019;48:D908–12.

PubMed Central   Google Scholar  

IARC. Exposome Explorer 3.0. 2021. http://exposome-explorer.iarc.fr/ . Accessed 9 February 2023.

Geueke B, Parkinson LV. S112 | FCCMIGEX | List of Migrating & Extractable Food Contact Chemicals (FCCmigex) by FPF. Zenodo. 2024. https://doi.org/10.5281/zenodo.10551195 .

Groh KJ, Geueke B, Chirsir P, Schymanski EL, Muncke J. S77 | FCCDB | Food Contact Chemicals Database v5.0. Zenodo. 2022. https://doi.org/10.5281/zenodo.7304977 .

Mohammed Taha H, Aalizadeh R, Alygizakis N, Antignac J-P, Arp HPH, Bade R, et al. The NORMAN Suspect List Exchange (NORMAN-SLE): facilitating European and worldwide collaboration on suspect screening in high resolution mass spectrometry. Environ Sci Eur. 2022;34:104.

Djoumbou Feunang Y, Eisner R, Knox C, Chepelev L, Hastings J, Owen G, et al. ClassyFire: automated chemical classification with a comprehensive, computable taxonomy. J Cheminform. 2016;8:61.

Zweifel H, Maier RD, Schiller M Plastics Additives Handbook. Carl Hanser Verlag: Munich, Germany, 2009.

Kohl C, McIntosh EJ, Unger S, Haddaway NR, Kecke S, Schiemann J, et al. Online tools supporting the conduct and reporting of systematic reviews and systematic maps: a case study on CADIMA and review of existing tools. Environ Evid. 2018;7:8.

EC. Chemicals Strategy for Sustainability, towards a toxic-free environment. COM(2020) 667 final. 2020.

ECHA. C&L Inventory. 2023. https://echa.europa.eu/information-on-chemicals/cl-inventory-database . Accessed 16 November 2023.

NITE. Chemical Management - GHS General Information. 2023. https://www.nite.go.jp/chem/english/ghs/ghs_index.html . Accessed 16 November 2023.

Tkalec Ž, Codling G, Tratnik JS, Mazej D, Klánová J, Horvat M, et al. Suspect and non-targeted screening-based human biomonitoring identified 74 biomarkers of exposure in urine of Slovenian children. Environ Pollut. 2022;313:120091.

Liu R, Mabury SA. Rat metabolism study suggests 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid as a potential urinary biomarker of human exposure to representative 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate antioxidants. Environ Sci Technol. 2021;55:14051–8.

Frederiksen H, Upners EN, Ljubicic ML, Fischer MB, Busch AS, Hagen CP, et al. Exposure to 15 phthalates and two substitutes (DEHTP and DINCH) assessed in trios of infants and their parents as well as longitudinally in infants exclusively breastfed and after the introduction of a mixed diet. Environ Int. 2022;161:107107.

Haines DA, Saravanabhavan G, Werry K, Khoury C. An overview of human biomonitoring of environmental chemicals in the Canadian Health Measures Survey: 2007-2019. Int J Hyg Environ Health. 2017;220:13–28.

de Bruyn Kops C, Šícho M, Mazzolari A, Kirchmair J. GLORYx: Prediction of the metabolites resulting from phase 1 and phase 2 biotransformations of xenobiotics. Chem Res Toxicol. 2021;34:286–99.

Mazzolari A, Scaccabarozzi A, Vistoli G, Pedretti A. MetaClass, a comprehensive classification system for predicting the occurrence of metabolic reactions based on the MetaQSAR database. Molecules. 2021;26:17.

Scholz VA, Stork C, Frericks M, Kirchmair J. Computational prediction of the metabolites of agrochemicals formed in rats. Sci Total Environ. 2023;895:11.

Kincaid B, Piechota P, Golden E, Maertens M, Hartung T, Maertens A. Using in silico tools to predict flame retardant metabolites for more informative exposomics-based approaches. Front Toxicol. 2023;5:16.

Rudel RA, Gray JM, Engel CL, Rawsthorne TW, Dodson RE, Ackerman JM, et al. Food packaging and bisphenol A and bis(2-ethyhexyl) phthalate exposure: findings from a dietary intervention. Environ Health Perspect. 2011;119:914–20.

Tang W, Hemm I, Eisenbrand G. Estimation of human exposure to styrene and ethylbenzene. Toxicology. 2000;144:39–50.

Stahl T, Falk S, Rohrbeck A, Georgii S, Herzog C, Wiegand A, et al. Migration of aluminum from food contact materials to food-a health risk for consumers? Part I of III: exposure to aluminum, release of aluminum, tolerable weekly intake (TWI), toxicological effects of aluminum, study design, and methods. Environ Sci Eur. 2017;29:19.

Phelps DW, Parkinson LV, Boucher JM, Muncke J, Geueke B. Per- and polyfluoroalkyl substances in food packaging: migration, toxicity, and management strategies. Environ Sci Technol. 2024;58:5670–84.

Holder C, DeLuca N, Luh J, Alexander P, Minucci JM, Vallero DA, et al. Systematic evidence mapping of potential exposure pathways for per- and polyfluoroalkyl substances based on measured occurrence in multiple media. Environ Sci Technol. 2023;57:5107–16.

Paseiro-Cerrato R, Ackerman L, de Jager L, Begley T. Brominated flame retardants (BFRs) in contaminated food contact articles: identification using DART-HRMS and GC-MS. Food Addit Contam A. 2021;38:350–9.

BEUC. Towards safe and sustainable food packaging - European consumer organisations call for action on single-use tableware made of alterantives to plastic. BEUC-X-2021-050. 2021.

Cramer G, Bolger M, Henry S, Lorentzen R. Usfda assessment of exposure to 2,3,7,8-TCDD and 2,3,7,8-TCDF from foods contacting bleached paper products. Chemosphere. 1991;23:1537–50.

Huang Y-Q, Zeng Y, Mai J-L, Huang Z-S, Guan Y-F, Chen S-J. Disposable plastic waste and associated antioxidants and plasticizers generated by online food delivery services in china: national mass inventories and environmental release. Environ Sci Technol. 2024; https://doi.org/10.1021/acs.est.3c06345 .

Cortéjade A, Buleté A, Prouteau L, Chatti S, Cren C, Vulliet E. Development and optimisation of home-made stir bar sorptive extraction for analysis of plastic additives: application in human urine. Anal Methods. 2017;9:3549–60.

Pouech C, Kiss A, Lafay F, Léonard D, Wiest L, Cren-Olivé C, et al. Human exposure assessment to a large set of polymer additives through the analysis of urine by solid phase extraction followed by ultra high performance liquid chromatography coupled to tandem mass spectrometry. J Chromatogr A. 2015;1423:111–23.

Liu R, Mabury SA. Unexpectedly high concentrations of 2,4-di-tert-butylphenol in human urine. Environ Pollut. 2019;252:1423–8.

Raman M, Ahmed I, Gillevet PM, Probert CS, Ratcliffe NM, Smith S, et al. Fecal microbiome and volatile organic compound metabolome in obese humans with nonalcoholic fatty liver disease. Clin Gastroenterol H. 2013;11:868–75.

Ibrahim B, Basanta M, Cadden P, Singh D, Douce D, Woodcock A, et al. Non-invasive phenotyping using exhaled volatile organic compounds in asthma. Thorax. 2011;66:804–9.

Diamantidou D, Mastrogianni O, Tsochatzis E, Theodoridis G, Raikos N, Gika H, et al. Liquid chromatography-mass spectrometry method for the determination of polyethylene terephthalate and polybutylene terephthalate cyclic oligomers in blood samples. Anal Bioanal Chem. 2022;414:1503–12.

Alberto Lopes J, Tsochatzis ED. Poly(ethylene terephthalate), poly(butylene terephthalate), and polystyrene oligomers: occurrence and analysis in food contact materials and food. J Agr Food Chem. 2023;71:2244–58.

Schreier VN, Appenzeller-Herzog C, Bruschweiler BJ, Geueke B, Wilks MF, Simat TJ, et al. Evaluating the food safety and risk assessment evidence-base of polyethylene terephthalate oligomers: Protocol for a systematic evidence map. Environ Int. 2022;167:107387.

Wang D, Zhao H, Fei X, Synder SA, Fang M, Liu M. A comprehensive review on the analytical method, occurrence, transformation and toxicity of a reactive pollutant: BADGE. Environ Int. 2021;155:106701.

Xue J, Liu Y, Yang D, Zhao Y, Cai Y, Zhang T, et al. A review of properties, production, human exposure, biomonitoring, toxicity, and regulation of bisphenol A diglycidyl ethers and novolac glycidyl ethers. J. Environ Chem Ecotoxicol. 2022;4:216–30.

Ji X, Liang J, Liu J, Shen J, Li Y, Wang Y, et al. Occurrence, fate, human exposure, and toxicity of commercial photoinitiators. Environ Sci Technol. 2023;57:11704–17.

Liu R, Mabury SA. First detection of photoinitiators and metabolites in human sera from United States donors. Environ Sci Technol. 2018;52:10089–96.

Lee J, Kim S, Park YJ, Moon H-B, Choi K. Thyroid hormone-disrupting potentials of major benzophenones in two cell lines (GH3 and FRTL-5) and embryo-larval zebrafish. Environ Sci Technol. 2018;52:8858–65.

Govarts E, Gilles L, Rodriguez Martin L, Santonen T, Apel P, Alvito P, et al. Harmonized human biomonitoring in European children, teenagers and adults: EU-wide exposure data of 11 chemical substance groups from the HBM4EU Aligned Studies (2014-2021). Int J Hyg Environ Health. 2023;249:114119.

Liu Y, Aamir M, Li M, Liu K, Hu Y, Liu N, et al. Prenatal and postnatal exposure risk assessment of chlorinated paraffins in mothers and neonates: Occurrence, congener profile, and transfer behavior. J Hazard Mater. 2020;395:122660.

Martínez C, Martínez Arroyo A, Barrientos Alemán D, Gavilán García A, Caba M, Calderón Garcidueñas AL, et al. Persistent organic compounds in human milk and evaluation of the effectiveness of the Stockholm convention in Mexico. Environ Adv. 2022;8:100190.

Xia D, Gao L-R, Zheng M-H, Li J-G, Zhang L, Wu Y-N, et al. Health risks posed to infants in rural China by exposure to short- and medium-chain chlorinated paraffins in breast milk. Environ Int. 2017;103:1–7.

ECHA. Annex XV. Restriction Report, Proposal for a restriction, Per and polyfluoroalkyl substances (PFASs). 2023. https://echa.europa.eu/documents/10162/1c480180-ece9-1bdd-1eb8-0f3f8e7c0c49 . Accessed 6 February 2024.

US FDA. FDA Announces PFAS Used in Grease-Proofing Agents for Food Packaging No Longer Being Sold in the U.S. 2024. https://www.fda.gov/food/cfsan-constituent-updates/fda-announces-pfas-used-grease-proofing-agents-food-packaging-no-longer-being-sold-us . Accessed 28 February 2024.

EFSA CEP Panel. Identification and prioritisation for risk assessment of phthalates, structurally similar substances and replacement substances potentially used as plasticisers in materials and articles intended to come into contact with food. EFSA Journal. 2022;20:e07231.

Rudin E, Glüge J, Scheringer M. Per- and polyfluoroalkyl substances (PFASs) registered under REACH-What can we learn from the submitted data and how important will mobility be in PFASs hazard assessment? Sci Total Environ. 2023;877:162618.

Pellizzari ED, Woodruff TJ, Boyles RR, Kannan K, Beamer PI, Buckley JP, et al. Identifying and prioritizing chemicals with uncertain burden of exposure: Opportunities for biomonitoring and health-related research. Environ Health Persp. 2019;127:126001.

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Acknowledgements

We thank all members of the FCCH project’s scientific advisory group for their contributions, especially John Peterson Myers, Katie Pelch, Rob Sargis, Emma Schymanski, and Martin Wagner. We thank Jozica Dolenc for help with the development of the literature search strategy and Frank Gwodsz and Christian Kohl for technical support during the compilation of the systematic evidence map.

This work was carried out as part of the FCCH project, which is funded by project-related funds from Adessium Foundation, MAVA Foundation, Stiftung Minerva, Sympany Stiftung, and the Food Packaging Forum’s own resources from unrestricted donations. All FPF funding sources are listed here: https://www.foodpackagingforum.org/about-us/funding .

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Birgit Geueke, Lindsey V. Parkinson, Lisa Zimmermann & Jane Muncke

Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Duebendorf, Switzerland

Ksenia J. Groh

Institute of Environmental Health Sciences and Department of Pharmacology, Wayne State University, Detroit, MI, USA

Christopher D. Kassotis

Independent Consultant, Frederick, MD, USA

Maricel V. Maffini

Department of Arts & Science, Plastic Waste Innovation Hub, University College London, London, UK

Olwenn V. Martin

RECETOX, Masaryk University, Brno, Czech Republic

Martin Scheringer

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Contributions

BG: Conceptualization, Literature screening, Data extraction, Visualization, Writing (original draft), Project administration; LVP: Data processing, Dashboard development, Writing (review & editing); LZ: Literature screening, Data extraction, Writing (review & editing); KJG: Conceptualization, Writing (review & editing); CK: Conceptualization, Writing (review & editing); MVM: Conceptualization, Writing (review & editing); OVM: Conceptualization, Writing (review & editing); MS: Data interpretation, Writing (review & editing); JM : Conceptualization, Data interpretation, Writing (review & editing), Funding acquisition. All authors reviewed the results and approved the final version of the manuscript.

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Correspondence to Birgit Geueke .

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Protocol for assessing the evidence of food contact chemicals monitored in humans, supplementary tables, rights and permissions.

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Geueke, B., Parkinson, L.V., Groh, K.J. et al. Evidence for widespread human exposure to food contact chemicals. J Expo Sci Environ Epidemiol (2024). https://doi.org/10.1038/s41370-024-00718-2

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Received : 08 May 2024

Revised : 23 August 2024

Accepted : 28 August 2024

Published : 17 September 2024

DOI : https://doi.org/10.1038/s41370-024-00718-2

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Computer Science > Cryptography and Security

Title: blockchain based information security and privacy protection: challenges and future directions using computational literature review.

Abstract: Blockchain technology is an emerging digital innovation that has gained immense popularity in enhancing individual security and privacy within Information Systems (IS). This surge in interest is reflected in the exponential increase in research articles published on blockchain technology, highlighting its growing significance in the digital landscape. However, the rapid proliferation of published research presents significant challenges for manual analysis and synthesis due to the vast volume of information. The complexity and breadth of topics, combined with the inherent limitations of human data processing capabilities, make it difficult to comprehensively analyze and draw meaningful insights from the literature. To this end, we adopted the Computational Literature Review (CLR) to analyze pertinent literature impact and topic modelling using the Latent Dirichlet Allocation (LDA) technique. We identified 10 topics related to security and privacy and provided a detailed description of each topic. From the critical analysis, we have observed several limitations, and several future directions are provided as an outcome of this review.

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