Science
Understanding the Science on Microplastics
Providing clear analyses of peer-reviewed microplastics research, which evaluates study methods, results, and limitations to help readers interpret what the evidence shows — and what it doesn’t. Research on microplastics is advancing rapidly, and continued study is essential to better understand potential microplastics exposures and risks. At the same time, producing reliable answers requires high-quality research. Too many studies share common limitations, and when preliminary or low-quality findings are reported without appropriate context, unnecessary concerns can rise.
Challenges in microplastics research:
No standardized or validated methods. Studying microplastics is a relatively new area of scientific inquiry, and in many cases, verifiable methods are still being established. For example, some analytical approaches lack validation or can misidentify biological materials as plastics, greatly affecting results.
Small sample sizes. Many studies that have garnered media attention are based on very few samples, which makes it difficult to draw broad or reliable conclusions.
Contamination and/or lack of control groups. Without strict controls in laboratory settings, samples can be contaminated during collection or analysis. Additionally, studies should include blank or control samples (empty samples run through the same analytical process) to measure background contamination. This helps determine whether detected particles come from the sample itself or from the testing process.
Unrealistic exposure scenarios. Laboratory studies sometimes use doses or exposure routes far above real-world conditions, limiting relevance to human health.
Research Findings
Microplastics and Chemical Exposure: The Hype v. the Science
Microplastics are small particles of plastic that may contain trace amounts of additives such as stabilizers, plasticizers, pigments, or flame retardants. In addition, some chemicals present in the surrounding environment may “stick” (i.e., adsorb) to the surface of the microplastics as well as any other organic particle (e.g., soil).
Microplastics and Infertility: What the Science Shows and What It Doesn’t
Do microplastics cause infertility? This question has gained increasing attention as studies report microscopic plastics in human tissues, including reproductive organs. While these findings have raised understandable concerns about infertility and reproductive risks…
Are Food Packaging Plastics a Major Source of Microplastics in Food?
While food-contact materials can release microplastics under certain conditions, Europe’s food safety authority concludes that current data are too limited and inconsistent to quantify dietary exposure or assess human health risks.
Do Microplastics Cause Heart Disease? What a Widely Reported Study Actually Found
A 2024 study in Italy examined artery plaque from patients undergoing surgery and asserted the presence of microplastics was associated with subsequent cardiovascular events.
Do Microplastics Reach the Lungs? What the Evidence and Pulmonary Science Say
A 2022 study by Jenner et al. claimed to find microplastics in human lung tissue, but key issues, including particle size, contamination, and a very small sample, undermine its reliability.
What They’re Saying
Food and Drug Administration
Current scientific evidence does not demonstrate that levels of microplastics or nanoplastics detected in foods pose a risk to human health.
German Federal Institute for Risk Assessment
The current state of knowledge suggests that the risk to consumers from microplastics is relatively low, given that the majority of particles do not become bioavailable, and the overall quantities taken up are likely insufficient to trigger health effects.
European Food Safety Authority
Despite the large number of publications investigating the release of MNP [micro- and nanoplastics) from FCM [food contact materials], the available evidence concerning the characteristics and quantities of released MNP from FCM remains limited. Many publications are affected by methodological shortcomings in test conditions, in sample preparation, and by deficiencies in the reliability of analytical data, with the consequence of frequent misidentification and miscounting.
World Health Organization
Based on the limited evidence available, chemicals and microbial pathogens associated with microplastics in drinking-water pose a low concern for human health.
Microplastics 101
What are microplastics and how do they form?
Microplastics are tiny plastic particles—typically less than 5 millimeters in size—that can result from the breakdown of larger plastic products over time or be intentionally added to products for specific functions. They can form through wear, use, and improper disposal, which is why reducing waste and improving recovery systems is critical.
What are the main sources of microplastics in the environment?
The main sources of microplastics are tire wear particles, synthetic fibers from textiles, degradation of unmanaged waste, and flaking paint from roads and buildings. These products can release fragments into the environment through everyday activities like driving, washing clothes, and weathering. While estimates vary as to the amount each source contributes, tire wear and synthetic fibers from textiles are thought to be the largest contributors of microplastics entering the environment.
Are microplastics harmful to human health?
To date there is no conclusive evidence microplastics are harmful to human health. This has been reaffirmed by multiple health authorities including the World Health Organization in two reports on drinking water, and on inhalation and ingestion, the U.S. Food and Drug Administration, and the German Federal Institute for Risk Assessment. At the same time, continued research using validated methods, stronger study design, and standardized measurement approaches is important to close remaining data gaps and better understand potential exposures and risks.