Scientists studying human tissue samples have made a discovery that has prompted researchers to use the phrase "medical emergency": microscopic plastic particles are accumulating in the human brain at concentrations far higher than anywhere else in the body, the levels are rising rapidly, and the people with the highest concentrations are those diagnosed with dementia.
An international research team from the University of New Mexico, the University of Ottawa, Technische Universität Dresden, and King's College London published findings on May 5, 2026 in the journal Brain Health, reporting that microplastic particles were found in human brain tissue at concentrations 7 to 30 times higher than in the liver or kidneys. The team analyzed tissue samples collected from human donors between 2016 and 2024 and found a 50 percent increase in the plastic burden in brains sampled in 2024 compared to those from 2016. The highest concentrations of microplastics were found in tissue donors who had been diagnosed with dementia during their lifetimes. Polyethylene — the same plastic used in food packaging and beverage bottles — was the predominant plastic type found, present in nanoscale, shard-like fragments.
