Microplastics Found in Human Brain Tissue, Study Reveals

Microplastics, which have already been found in human lungs, ancient rocks, and bottled water, are now being detected in the brain, according to the new study.

An international group of scientists examined the olfactory bulbs—the regions of the brain that process smell—of 15 deceased individuals and discovered microplastics in eight of them.

While previous research had identified microplastics in brain blood clots, this is the first published study confirming their presence in actual brain tissue. Another similar study is currently undergoing peer review.

"While microplastics have been detected in various human tissues, their presence in the human brain has not been documented, raising important questions about potential neurotoxic effects and the mechanisms by which microplastics might reach brain tissues," the researchers wrote in their paper.

The team found that particles and fibers were the most prevalent shapes, with polypropylene being the most common polymer. Polypropylene, one of the most widely used plastics, is found in packaging, car parts, and medical devices. The microplastic particles ranged in size from 5.5 to 26.4 micrometers—less than a quarter the width of a human hair.

Previous studies have shown that air pollution particles can travel up the olfactory pathway. This new research suggests microplastics could follow the same route to the brain, passing through tiny openings in the cribriform plate, located just beneath the olfactory bulb.

"The identification of microplastics in the nose and now in the olfactory bulb, along with the vulnerable anatomical pathways, reinforces the notion that the olfactory pathway is an important entry site for exogenous particles to the brain," the researchers added.

Despite efforts to reduce plastic use and develop biodegradable alternatives, global plastic production has doubled in the past two decades, and microplastics continue to infiltrate the environment and human tissues.

The full extent of the damage microplastics might cause to human health is still unclear, but it is likely that increasing concentrations of synthetic materials in the brain pose significant risks. Some studies suggest potential neuron damage and a heightened risk of neurological disorders.

A potential link between air pollution and cognitive issues has already been established, and if microplastics are also entering through the nasal passages, they could exacerbate these health concerns.

"Some neurodegenerative diseases, such as Parkinson's disease, seem to have a connection with nasal abnormalities as initial symptoms," the researchers noted.