Nature, 11 February 2025

Your brain is full of microplastics: are they harming you?

Plastics have infiltrated every recess of the planet, including your lungs, kidneys and other sensitive organs. Scientists are scrambling to understand their effects on health.

A sliver of human brain in a small vial starts to melt as lye is added to it. Over the next few days, the caustic chemical will break down the neurons and blood vessels within, leaving behind a grisly slurry containing thousands of tiny plastic particles.

Toxicologist Matthew Campen has been using this method to isolate and track the microplastics — and their smaller counterparts, nanoplastics — found in human kidneys, livers and especially brains. Campen, who is at the University of New Mexico in Albuquerque, estimates that he can isolate about 10 grams of plastics from a donated human brain; that’s about the weight of an unused crayon.