The World Health Organization reviewed the evidence on human exposure to micro- and nanoplastics through food, water and air, and on what is known about their effects.
It concluded that exposure is widespread but that limited data provide little evidence that micro- and nanoplastics have adverse effects in humans. At the same time it recommended that measures be taken to reduce exposure, and called for better measurement methods and more research.
The report is useful for balance: it represents the official, conservative scientific position and reminds readers that finding plastic in the body is not the same as proving harm.
It was published before several major later studies, including the 2024 NEJM artery-plaque study and the 2025–2026 brain studies, so its conclusions do not reflect the most recent evidence.