A new study, published 3 February 2025 in Nature Medicine, analysed levels of microplastics and nanoplastics (“MNP” or “MNPs”) in tissue from postmortems between 1997 and 2024.
Results
The study found a rising trend in MNP contamination of human brain tissue, as well as liver and kidney. Furthermore, when examining brain samples taken from 2024 and 2016 autopsies, the 2024 samples showed a 50% increase in MNP concentrations compared to 2016 samples. The predominant type of plastic found in the study was polyethylene — the most widely produced plastic in the world, commonly used in plastic bags and packaging. The report further noted that MNP concentrations were not influenced by age, sex, ethnicity, or cause of death.
Since large-scale production of plastics began to accelerate after the second world war, environmental concentrations of MNPs have increased exponentially. The authors therefore suggest that rapidly increasing environmental levels of MNPs may similarly lead to higher maximum concentrations within the body.
Health Implications of Microplastics
Although previous studies have linked MNPs to various health issues, the extent to which MNPs cause harm to humans is currently unclear. This is because scientists do not yet have a clear understanding of how MNPs spread throughout the body, as well as how much of them accumulate. As such, it can be difficult to properly interpret the results of controlled exposure studies (experiments where participants or test subjects are exposed to MNPs in a regulated setting to study their effects). Essentially, without knowing where and how much MNPs accumulate in the body, it’s hard to draw accurate conclusions from these studies.
Microplastics have previously been found in other parts of the human body, including but not limited to, the lungs, intestine, and placenta.
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