Microplastics are ubiquitous, found both in the environment and in consumer goods, but certain precautions can help reduce exposure sources to protect human health from the serious risks they pose.
A study by Canadian and U.S. researchers (Fabiano et al., 2025) summarizes the scientific evidence on the health impact of microplastics and provides concrete guidance on how to protect oneself.
Microplastics in every human tissue, including the brain
A recent study published in Nature Medicine (Nihart et al., 2025) revealed that microplastics and nanoplastics (MNP) were found in the human brain, amounting to about a tablespoon. And that’s not all.
In the brains of deceased individuals diagnosed with dementia, the levels of these particles were 3 to 5 times higher. Brain tissues contained 7 to 30 times more MNP compared to other organs like the liver or kidneys. The microplastics found in the brain were mostly very small (less than 200 nanometers) and often composed of polyethylene.
It is unclear whether dementia facilitates the entry of these particles into the brain by weakening the blood-brain barrier or if the microplastics themselves cause inflammation and worsen neurodegeneration.
Exponential growth over half a century
A thought-provoking finding is that while the concentration of MNP did not seem to be influenced by factors such as age, sex, race, or cause of death, a 50% increase in the amount of these particles in brain tissues was observed between 2016 and 2024.
This increase aligns with the exponential rise in microplastics in the environment over the past 50 years.
It is estimated that 10 to 40 million tons of microplastics are released into the environment each year, and this figure is expected to double by 2040. These particles are now everywhere: from the ocean floor to mountain peaks, in the food we eat, the water we drink, and the air we breathe.
Health effects
Most evidence on the health effects of microplastic accumulation in the body currently comes from animal and cell culture studies, suggesting correlations with:
- Oxidative stress,
- Inflammation,
- Immune dysfunction,
- Metabolic alterations, and
- Carcinogenicity.
These effects can impact various organs and systems, including the respiratory, gastrointestinal, cardiovascular, nervous, and immune systems. For example, a study published in the New England Journal of Medicine (Marfella et al., 2024) found that people with carotid plaques containing microplastics had a higher risk of heart attack, stroke, or premature death. Additionally, in patients with inflammatory bowel disease (IBD), feces contained 50% more microplastics than those of healthy individuals.
How to reduce exposure to microplastics
Zeroing it is impossible, but reduce exposure to microplastics is possible with some strategies, the researchers explain with concrete examples.
1. Which water to drink
Switching from bottled water to tap water could reduce microplastic intake from 90,000 to 4,000 particles per year. Besides bottled water, significant dietary sources of microplastics include alcohol and seafood.
2. Containers for heating and storing food
Heating food in plastic containers, especially in the microwave, can release large amounts of microplastics and nanoplastics, up to 4.22 million and 2.11 billion particles per square centimeter, respectively, in just three minutes (Hussain et al., 2023).
Significant particle release also occurs with long-term food storage at room temperature or in the refrigerator in plastic containers.
“These plastics show toxic potential, with in vitro studies revealing up to 77% cell death in human kidney cells after prolonged exposure,” warn the study authors. It is therefore advisable to eliminate plastic and opt for glass or stainless steel containers for storing and heating food.
3. The hidden threat in tea
A study (Banaei et al., 2024) found that, despite being labeled as food-grade, plastic tea bags released 2.4 million microparticles (1–150 μm) and 14.7 billion submicrometer plastic particles (<1 μm).
4. Canned soups
A study (Carwile et al., 2011) showed a more than 1000% increase in urinary levels of bisphenol A (BPA) after five days of daily canned soup consumption. It is therefore suggested to limit canned food consumption and opt for non-plastic or BPA-free certified packaging.
5. Highly processed foods
Researchers cite a study (Milne et al., 2024) that compared the amount of microplastics in highly processed protein foods versus unprocessed ones. For example, ready-to-eat chicken nuggets contained 30 times more microplastics per gram than unprocessed chicken breasts due to industrial processing.
6. Microplastics in household air
A study (Allen et al., 2019) demonstrated how microplastics are transported by wind over long distances.
Outdoors or indoors (including homes and offices), inhalation is another source of exposure to microplastics that is difficult to reduce and estimated at up to 62,000 particles per year in adult males.
In these cases, a HEPA (High-Efficiency Particulate Air) filter can be useful: it removes up to 99.97% of airborne particles as small as 0.3 μm, including a significant amount of airborne microplastics.
The mystery of biological excretion
Once microplastics are in our bodies, how can we eliminate them? Currently, there is little evidence on effective methods.
Some studies suggest that sweating might facilitate the excretion of substances like BPA, a chemical compound used in plastic production that is released during degradation. However, it is still unclear if this applies to microplastics as well.
Conclusion
An encouraging finding is the lack of correlation between age and microplastic accumulation. This means that despite continuous environmental exposure, the body has mechanisms to eliminate these particles over time through sweat, urine, and feces.
In fish models, it takes about 70 days to eliminate 75% of accumulated brain microplastics. This suggests that both reduced input and increased output must be maintained for sufficiently long periods to see measurable changes.
Future research should prioritize defining clear exposure limits for microplastics and assessing long-term health consequences, as well as evaluating the effectiveness of various reduction and elimination strategies, conclude the study authors.
Marta Strinati
References
– Fabiano N, Luu B, Puder D. (2025). Human microplastic removal: what does the evidence tell us?. Brain Medicine. doi: 10.61373/bm025c.0020
– Marfella R, Prattichizzo F, Sardu C, Graciotti L, Fulgenzi G, Spadoni T, et al. (2024). Microplastics and nanoplastics in atheromas and cardiovascular events. N Engl J Med. 390(10):900–10. DOI: 10.1056/nejmoa2309822
– Hussain KA, Romanova S, Okur I, Zhang D, Kuebler J, Huang X, Wang B, Fernandez-Ballester L, Lu Y, Schubert M, Li Y. (2023). Assessing the Release of Microplastics and Nanoplastics from Plastic Containers and Reusable Food Pouches: Implications for Human Health. Environ Sci Technol. Jul 4;57(26):9782-9792. doi: 10.1021/acs.est.3c01942
– Carwile JL, Ye X, Zhou X, Calafat AM, Michels KB (2011). Canned soup consumption and urinary bisphenol A: a randomized crossover trial. JAMA. 306(20):2218–20. DOI: 10.1001/jama.2011.1721
– Milne MH, De Frond H, Rochman CM, Mallos NJ, Leonard GH, Baechler BR (2024). Exposure of U.S. adults to microplastics from commonly-consumed proteins. Environ Pollut. 343:123233. doi: 10.1016/j.envpol.2023.123233
– Steve Allen, Deonnie Allen et al. (2019). Atmospheric transport and deposition of microplastics in a remote mountain catchment. Nature Geoscience https://doi.org/10.1038/s41561-019-0335-5
– Kacprzak S, Tijing LD (2022). Microplastics in indoor environment: sources, mitigation and fate. J Environ Chem Eng. DOI: 10.1016/j.jece.2022.107359
Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".
