Bioaccumulation of microplastics in decedent human brains
Nihart AJ, Garcia MA, El Hayek E, et al. (2025). Nature Medicine.
What they found
Pyrolysis-GC/MS reported plastic, mostly polyethylene, in liver, kidney and brain. Median brain concentrations were 3,345 µg/g (2016) and 4,917 µg/g (2024), far above liver (433) and kidney (404) in 2024; concentrations rose between 2016 and 2024. Brains from 12 people with dementia had even higher levels.
Read this too
Author correction (31 March 2025) fixed duplicated supplementary images and incorrect scale bars; authors say spectra data were unaffected. Monikh et al. (Nature Medicine, Nov 2025) argued limited contamination controls and lack of validation may affect the reported concentrations; the authors replied acknowledging uncertainties, including possible lipid interference.
- Sample
- Autopsy liver, kidney and brain from about 20–28 decedents per timepoint (2016 and 2024), plus 12 brains with dementia
- What it can't tell you
- Autopsy samples, small groups, one region (New Mexico) for most samples. The dementia finding is an association; the authors state no causality is assumed, and dementia itself could change brain tissue or clearance. Brain is fatty, and lipids can be misread as polyethylene by Py-GC/MS. Contamination controls and validation were criticised in a published Matters Arising.
- Funding
- US National Institutes of Health (NIEHS, NIGMS, NIMHD and others); authors declare no competing interests
- Topics
- In the body, Health effects, Methods
- Checked against
- Abstract (PMID 39901044) and full text (PMC12003191): medians from results and Fig. 1; correction text (PMC12003150); Matters Arising and reply preview pages on nature.com