ReCent Medical News

Microplastics: From headlines to health risk

March 2026

Image: Соня Монштейн- stock.adobe.com

This article examines the growing body of evidence showing that microplastics are widespread in our environment and are increasingly recognised as a concern for human health. Drawing on recent studies, the article explores what is currently known, where evidence remains limited or overstated, and why microplastics are viewed as an emerging risk that continues to be monitored.

Microplastics have been hitting the headlines with some attention-grabbing claims suggesting that we ingest a credit card’s worth of plastic a week, raising questions about the possible impacts on our health.[1] Since publication, this claim has been challenged by some members of the scientific community; it came from a blog citing a scientific paper, but the paper itself made no such claim. The study’s author later clarified that even at the highest levels measured, inhaling that amount of plastic would take thousands of years, underscoring the importance of sharing accurate information about health risks.[2]

While such a claim can be misleading, microplastic contaminants in all environmental compartments may have significant effects on human health. The potentially serious long-term consequences represent the greatest risk.

What are microplastics, or nanoplastics?

Microplastics are small pieces of plastic with a diameter of less than 5 mm. Nanoplastics are a subset of microplastics, defined as plastic particles that measure between 1 nanometer and 1 micrometer (0.001 millimeters). Microplastic particles originate from the fragmentation of large plastic litter or from direct environmental emissions. Most of the particles are not biodegradable and have lifespans of >100 years.[3]

Image: Pcess609 - stock.adobe.com

How do microplastics impact us and our environment?

Microplastics have been found in:

Environments: deep oceans, mountain peaks like Everest.
Food and soil: fish and the soil we use to grow our fruit and vegetables.
Everyday products: cosmetics, clothing, kitchen utensils, children’s toys.
Other materials: cars, construction, medical devices.
Human tissues: organs, bloodstream, placenta, and even meconium (first stool of newborn).

They can cross the blood/brain barrier in humans, and while the liver can remove some of them, they are also present in other tissues and can’t be excreted.

A health lens on an emerging risk

The study of microplastics began about a decade ago, primarily into their impact on the environment, as less than 10% of plastic is recycled.[4] Studies on how human health might be impacted are relatively new, few, or small in size. However, here are what some studies have shown initially:

Heart disease

A 2024 study of 257 patients found that the presence of microplastics was associated with a roughly quadrupled risk of heart attack, stroke or death. However, large, long‑term human studies are still needed before stating they definitively cause heart disease.[5]

Microplastics alone do not appear to cause furring of the arteries, however, they may exacerbate pre-existing risks by provoking an inflammatory response.[5]

Irritable bowel syndrome

A small study in 2021 observed that there was a much higher amount of microplastics in the stool samples of people who were diagnosed with IBS. We do not know whether this is down to what they were consuming, or that their bodies are less able to break the particles down effectively. More research is required[6]

Reproductive system

Years ago, a human study showed that urinary phthalate metabolites are associated with decreased serum testosterone in men, women, and children. Animal studies have observed that microplastics consistently damage reproductive organs, disrupt hormones, reduce sperm and egg quality, lower fertility, due to inflammation and endocrine disruption.[7] In humans, particles are clearly present in reproductive tissues, and early data link them to subfertility, but more studies are needed.[8]

Bioaccumulation in the brain

A recent trial at the University of New Mexico found that brain tissue samples from autopsies conducted eight years apart (2016-2024) had around 60% higher levels of microplastics.[9]

Microplastics have also been linked to neurodevelopmental disorders, however, the studies are too weak to draw any conclusions.

A recent news report has claimed that some studies into microplastics are exaggerated or incorrect. The main issues are:[10]

Plastics are everywhere so they can contaminate samples in laboratories.
There is debate as to whether fat might give false positives for polyethylene.
Many studies have been in animals, which do not always translate well to humans, human risk is suspected but not yet fully quantified.
It can’t be trialled because you can’t deliberately overload people with microplastics.

"I noticed the link between microplastics and disease in humans when I was researching the rise of cancer in people under 50 last year.[11] Right now, we don’t know the impact on human health, but it’s caused me to review plastic use in my household and do our bit for the environment too. This is what I’ve done to reduce mine and my family’s exposure to microplastics."

Kate Baldry, Underwriting Research & Systems Developer, Hannover Re UK Life Branch

Personal reflections of the author

Reflecting on her own research, Kate explains how this awareness has prompted practical changes at home to reduce everyday exposure to microplastics. She has replaced plastic bottles with stainless steel alternatives and reduced the use of plastic utensils and containers, particularly when heating food, opting instead for ceramic or glass. She now favours loose-leaf tea and ground coffee over teabags and plastic pods.

Beyond the kitchen, she chooses clothing made from natural fibres to limit the release of synthetic microfibres and has increased fibre intake to support digestive health and the elimination of ingested particles.

Plastics are cheap, mouldable and undeniably useful in everyday life. However, there has been little regulation, and we’re left with landfill problems, hazards to the environment and potentially our health.

The EU has banned bisphenol A (BPA), which is a compound found in many plastics. BPA can bind to hormone receptors and cause endocrine disruption. This ban came into force in 2024, but it took 20 years of gathering data to make the substance illegal.[12]

Conclusion

With global plastic production having doubled since 2020 and projected to triple by 2060, microplastics are becoming an increasingly pervasive feature of our environment.[13]

While their long-term health impacts remain uncertain, and direct interventions at an individual underwriting level, or portfolio basis are currently limited, we actively track this as an emerging risk.

By tracking developments in research and exposure trends, we can better anticipate potential implications for mortality and critical illness experience, supporting our underwriting and portfolio strategy. Staying informed ensures that we provide clients with insight into emerging health risks and maintain confidence in our risk assessment. Contact us if you would like to discuss this topic further.

Author

Kate Baldry

Underwriting Research & Systems Developer

Hannover Re UK Life Branch

References

Mohammad S. Islam, Md. Mizanur Rahman, Puchanee Larpruenrudee, Akbar Arsalanloo, Hamidreza Mortazavy Beni, Md. Ariful Islam, YuanTong Gu, Emilie Sauret. How microplastics are transported and deposited in realistic upper airways?. Physics of Fluids 1 June 2023; 35 (6): 063319. Available from: https://doi.org/10.1063/5.0150703. Viewed: 15 January 2026
Leo Benedictus. You do not inhale a credit card’s worth of microplastic every week. March 2024. Available from: https://fullfact.org/health/credit-card-microplastic-week/. Viewed: 15 January 2026
Hannover Re Property & Casualty: Emerging Risks Insights – Microplastics: Effects on Health and the Environment. Available from: https://www.hannover-re.com/en/property-and-casualty/emerging-risks-insights/microplastics/. Viewed: 15 January 2026
Springer. 2025. Less than 10% of Global Plastics Manufactured from Recycled Materials, Findings Reveal. Phys.org, April 10, 2025. Available from: https://phys.org/news/202504globalplasticsrecycledmaterialsreveal.html. Viewed: 15 January 2026
Marfella R, Prattichizzo F, Sardu C, Fulgenzi G, Graciotti L, Spadoni T, et al. Microplastics and Nanoplastics in Atheromas and Cardiovascular Events. N Engl J Med. 2024 Mar 7;390(10):900 910. doi:10.1056/NEJMoa2309822. Available from: https://www.nejm.org/doi/full/10.1056/NEJMoa2309822. Viewed: 15 January 2026
Yan, Zehua, Yafei Liu, Ting Zhang, Faming Zhang, Hongqiang Ren, and Yan Zhang. 2022. “Analysis of Microplastics in Human Feces Reveals a Correlation between Fecal Microplastics and Inflammatory Bowel Disease Status.” Environmental Science & Technology 56, no. 1 (Dec 22): 414–421. Available from: https://doi.org/10.1021/acs.est.1c03924. Viewed: 15 January 2026
Inam, Ö. Impact of microplastics on female reproductive health: insights from animal and human experimental studies: a systematic review. Arch Gynecol Obstet 312, 77–92 (2025). Available from: https://doi.org/10.1007/s00404-024-07929-w. Viewed: 15 January 2026
Meeker JD, Ferguson KK. Urinary phthalate metabolites are associated with decreased serum testosterone in men, women, and children from NHANES 2011-2012. J Clin Endocrinol Metab. 2014 Nov;99(11):4346-52. doi: 10.1210/jc.2014-2555. Epub 2014 Aug 14. PMID: 25121464; PMCID: PMC4223430.
Haederle, Michael. 2025. UNM Researchers Find Alarmingly High Levels of Microplastics in Human Brains – and Concentrations Are Growing Over Time. UNM HSC Newsroom, February 28, 2025. Available from: https://hscnews.unm.edu/news/hsc-newsroom-post-microplastics-human-brains, Viewed: 15 January 2026
Carrington, Damian. ‘A Bombshell’: Doubt Cast on Discovery of Microplastics Throughout Human Body. The Guardian, 13 Jan. 2026. Available from: https://www.theguardian.com/environment/2026/jan/13/microplastics-human-body-doubt. Viewed: 15 January 2026
Hannover Re UK Life Branch. Colorectal cancer trends & insurance: Adapting to changing risks. Available from: https://life-and-health-uk.hannover-re.com/colorectal-cancer-trends-and-insurance/
Cimmino I, Fiory F, Perruolo G, Miele C, Beguinot F, Formisano P, Oriente F. Potential Mechanisms of Bisphenol A (BPA) Contributing to Human Disease. Int J Mol Sci. 2020 Aug 11;21(16):5761. doi: 10.3390/ijms21165761. PMID: 32796699; PMCID: PMC7460848. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC7460848/. Viewed: 15 January 2026
Organisation for Economic Co operation and Development. Global Plastic Waste Set to Almost Triple by 2060, Says OECD. OECD, 3 June 2022. Available from: https://www.oecd.org/en/about/news/pressreleases/2022/06/globalplasticwastesettoalmosttripleby2060.html. Viewed: 15 January 2026