Scientists find tiny plastic particles in human brain, new study says

Scientists have found microplastics in the olfactory bulb, a brain region that helps detect and process smells, according to a study published on Monday in “JAMA Network Open”.

The study analyzed tissue samples from 15 human cadavers, aged between 33 and 100. In eight of these, researchers identified microplastics, including particles made of polypropylene, polyamide, nylon, and polyethylene vinyl acetate.

Polypropylene, commonly used in clothing and packaging, was the most prevalent. Although nanoplastics—smaller particles about 1,000 times narrower than a human hair—weren’t studied, the microplastics found were significantly smaller than those found in other organs such as the liver or kidneys.

Researchers are concerned that microplastics may enter the brain through the olfactory pathway. Study co-author Luís Fernando Amato-Lourenço from the Free University of Berlin explained that once in the olfactory bulb, microplastics could migrate to other brain regions. However, the likelihood of this happening depends on particle size and shape, as well as the body’s defenses.

While it’s unclear whether microplastics can consistently reach the brain through the olfactory route, previous studies suggest that tiny airborne particles may sometimes move via the olfactory bulb.