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Bioaccumulation of microplastics in decedent human brains
Nihart AJ, Garcia MA, El Hayek E, Liu R, Olewine M, Kingston JD, Castillo EF, Gullapalli RR et al.. Nature medicine, 2025-02-03
Topic: Brain proteins, microglia and lab models
Rising global concentrations of environmental microplastics and nanoplastics (MNPs) drive concerns for human exposure and health outcomes. Complementary methods for the robust detection of tissue MNPs, including pyrolysis gas chromatography-mass spectrometry, attenuated total reflectance-Fourier transform infrared spectroscopy and electron microscopy with energy-dispersive spectroscopy, confirm the presence of MNPs in human kidney, liver and brain. MNPs in these organs primarily consist of polyethylene, with lesser but significant concentrations of other polymers. Brain tissues harbor higher proportions of polyethylene compared to the composition of the plastics in liver or kidney, and electron microscopy verified the nature of the isolated brain MNPs, which present largely as nanoscale shard-like fragments. Plastic concentrations in these decedent tissues were not influenced by age, sex, race/ethnicity or cause of death; the time of death (2016 versus 2024) was a significant factor, with increasing MNP concentrations over time in both liver and brain samples (P = 0.01). Finally, even greater accumulation of MNPs was observed in a cohort of decedent brains with documented dementia diagnosis, with notable deposition in cerebrovascular walls and immune cells. These results highlight a critical need to better understand the routes of exposure, uptake and clearance pathways and potential health consequences of plastics in human tissues, particularly in the brain.
Key findings
- MNPs in these organs primarily consist of polyethylene, with lesser but significant concentrations of other polymers.
- Brain tissues harbor higher proportions of polyethylene compared to the composition of the plastics in liver or kidney, and electron microscopy verified the nature of the isolated brain MNPs, which present largely as nanoscale shard-like fragments.
- Plastic concentrations in these decedent tissues were not influenced by age, sex, race/ethnicity or cause of death; the time of death (2016 versus 2024) was a significant factor, with increasing MNP concentrations over time in both liver and brain samples (P = 0.01).
- These results highlight a critical need to better understand the routes of exposure, uptake and clearance pathways and potential health consequences of plastics in human tissues, particularly in the brain.
Why it matters
This study detected microplastics and nanoplastics in human kidney, liver, and brain tissue, with higher concentrations in brains and even greater accumulation in decedent brains with a documented dementia diagnosis. It does not test any treatment, cure or prevention for Alzheimer's disease, and the authors call for more research into exposure, uptake and clearance pathways.
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Study details
- Evidence strengthModerate
How this study scored 64/100
Published in a top-tier journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 10 / 10 | Tier 1 — top-tier general journal (Nature medicine) |
| Journal's citation record | 4 / 4 | Nature Medicine: journal h-index 763 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 4 / 5 | 2025 — within 3 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 6 / 7 | Cited 934 times (OpenAlex, 2026-10-10) |
| Citations per year | 5 / 5 | 311.3 citations a year over 3 year(s) since 2025 |
| Impact for its field and year | 6 / 6 | Cited 208.2× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 1 / 6 | Cited by 1 other studies in this library |
| Still being cited | 4 / 4 | Cited 934 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Matthew J. Campen: h-index 52 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | Duke University: institution h-index 1,541 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 5 institution(s) in 2 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 39901044) |
| Free to read | 2 / 2 | Free to read |
| Total | 64 / 100 | — |
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Read the original
- DOI: 10.1038/s41591-024-03453-1
- PubMed: 39901044
- Original source →
- Free full text: Nature Medicine →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
APA 7th
Nihart, A. J., Garcia, M. A., El Hayek, E., Liu, R., Olewine, M., Kingston, J. D., et al. (2025). Bioaccumulation of microplastics in decedent human brains. Nature medicine. https://doi.org/10.1038/s41591-024-03453-1
Vancouver
Nihart AJ, Garcia MA, El Hayek E, Liu R, Olewine M, Kingston JD, et al. Bioaccumulation of microplastics in decedent human brains. Nature medicine. 2025. doi:10.1038/s41591-024-03453-1. PMID: 39901044.
BibTeX
@article{nihart2025-39901044,
author = {Nihart, A. J. and Garcia, M. A. and El Hayek, E. and Liu, R. and Olewine, M. and Kingston, J. D. and Castillo, E. F. and Gullapalli, R. R. and others},
title = {{Bioaccumulation of microplastics in decedent human brains}},
journal = {Nature medicine},
year = {2025},
doi = {10.1038/s41591-024-03453-1},
pmid = {39901044},
url = {https://doi.org/10.1038/s41591-024-03453-1}
}
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