What we learned about microplastics in 2025

Researchers reported microplastics were found accumulating in human brains, with samples from 2024 showing higher concentrations than samples from 2016 and analyses back to 1997 indicating newer samples had more microplastics.

Researchers reported several notable findings about microplastics in 2025. Earlier studies had detected microplastics in testicles, kidneys, the liver, the placenta, and in a newborn's first stool. Last year, a team at the University of New Mexico examined cadaver brains to assess whether tiny particles crossed the blood-brain barrier. They reported plastics were entering and accumulating in brain tissue, and analyses of samples back to 1997 showed newer samples had higher concentrations. Key findings: - Microplastics had previously been detected in testicles, kidneys, the liver, the placenta, and a newborn's first stool. - A University of New Mexico study of cadaver brains reported plastics entering and accumulating in brain tissue. - Brains of people who died in 2024 had significantly higher concentrations than brains from people who died in 2016. - Analysis of samples back to 1997 showed newer samples contained more microplastics. - Researchers reported no correlation between the amount of microplastics and the age of the person at death. Summary: Researchers reported microplastics are entering and accumulating in human brain tissue and that levels were higher in recent samples than in older ones. Undetermined at this time.