A systematic scoping review of the environmental, food security and health impacts of food system plastics. 

While food system plastics impact the environment, food security and health, policies to tackle these impacts are themselves also likely to have broader consequences across domains. The results of this systematic review article reveal an imbalance in the literature, and the authors recommend addressing these gaps as well as fostering research from low-income countries.

Authors

Joe Yates,¹ Megan Deeney,¹ Heike B. Rolker,¹ Howard White,² Sofia Kalamatianou¹ and Suneetha Kadiyala¹

¹London School of Hygiene and Tropical Medicine, London, UK.

²The Campbell Collaboration, New Delhi, India.

Highlights

• Circular economy policies aimed at reducing food system plastics are likely to have broader consequences across domains.
• The scientific literature on food system plastics from 2000 to 2018 shows a fragmented and imbalanced picture, with most articles addressing intermediate impacts on food security/ economics or health at the production, processing, storage and distribution stages and few containing impacts at later stages or outcomes for the environment.
• There is very little causal evidence linking specific plastics used in the food system with specific human health conditions or outcomes.
• These results point at a mismatch between the public discourse around consumer-level plastics and research agendas.
• There is also a lack of research from low-income countries, and a lack of interlinking research across subsectors, types of plastics, uses and impacts, which is required by evidence-based policy and to evaluate trade-offs.

RESEARCH BRIEF

The use of plastics is widespread in food systems. For example, food and drink packaging accounts for 16% of all plastic produced globally in the last 70 years and single-use plastics continue to expand in food systems today.

Although circular economy policies seeking to mitigate the negative impacts of food systems plastics are commonplace, the scientific evidence of the broader effects of these policies on the environment, food security and health remain fragmented.

Study design and methods

Evidence-based decision making on food system plastics and the evaluation of potential trade-offs require systematic syntheses of the extent, range and nature of the evidence across food system sectors:

• Extent of evidence refers to the volume of research of different topics and regions;
• Range of evidence refers to the variety of plastic exposure-outcomes relationship;
• Nature of evidence refers to the characteristics of existing studies.

To address this need, this article presents a systematic scoping review of food system plastics across disciplines, including materials sciences, public health, agricultural sciences, food technology, nutrition, economics and environmental sciences.

With the aim of being comprehensive, the review also includes all the categories of common plastics employed in any stage of the food system (agricultural production, processing storage and distribution, retail, household consumption and waste disposal). Further, it divides impacts in three domains: human health, food security / economics and environment.

Results: Very few studies from low-income countries

The results of the analysis are organised as pertaining to: 1) the extent of evidence, 2) the range of evidence and 3) the nature of evidence, as defined in the previous section. In terms of the extent of evidence, the review found that almost all studies came from either high-income countries (48.3%) or middle-income countries (50.1%), but very few from low-income countries (1.6%). On the range of evidence, the results are further divided into three themes: impact categories, sectors, and types of relationships between plastic exposure and outcomes.

For impact categories, 75% of articles reviewed address outcomes which are relevant to food security or economics, almost half of the total focus on outcomes on a pathway towards human health, but only 8% contain outcomes for the environment.

“Evidence from low-income contexts is severely lacking and therefore urgently needed to ensure that circular economy policies in these settings can account for a range of context-specific beneficial and harmful outcomes for different domains.”

Results: Effects of agricultural plastics most commonly explored

When it comes to sectors, most studies cover agricultural production and processing, and storage and distribution, fewer cover retail and household consumption and only four focus on waste disposal.

Regarding the types of relationships, those more commonly explored in the literature are the effects of agricultural plastics on productivity and efficiency. Intermediate effects of plastics on human health and food security/ economics aspects, such as nutrient content and shelf-life of packaged food, are also common. Studies linking specific plastics to final impacts were found to be rare.

Finally, in relation to the nature of the evidence, the authors report that while most studies reviewed use experimental methods, only 1.4% of articles are meta-analyses, which are the most useful for policy-making.

Discussion: Mismatch between public discourse and research interests

There exist only a small number of studies quantitatively demonstrating environmental impacts of food system plastics and there are few studies covering plastics used in waste disposal across the food system.

The authors of this paper argue that these two facts reveal a mismatch between the public discourse around consumer-level plastics focusing on the environmental effects of the use of plastics and waste and the main research interests revealed by their review.

There is a concerning lack of research from low-income countries, and a lack of interlinking research across subsectors, types of plastics, uses and impacts. The authors suggest that both evidence from low-income countries and syntheses are urgently needed to advance context-appropriate evidence-based policies.

Further, they recommend addressing other research gaps unveiled by the review, such as the lack of research on on-farm plastic pollution, the effects of specific plastics and the causal relationships between food system plastics and concrete disease states.

“The extent, range and nature of this evidence highlights a mismatch between the prevailing discourse around consumer-level plastics and research agendas more focused on production, processing and storage economies.”

The full article is available here.

Watch a short and a longer video from the authors presenting the findings of the article: