Scientists in Brazil found microplastics in the brain tissue of corpses, according to a new study published Monday in journal JAMA Network Open. Research in recent years has found microplastics in almost every organ of the body, as well as in the bloodstream, something that can clog arteries.
Whether these ubiquitous pollutants can reach the human brain has been a primary concern of scientists. So the latest research looked at a part of the brain called the olfactory bulb, which processes information about smell. Humans have two olfactory bulbs, one above each nasal cavity. The olfactory bulb and nasal cavity are connected by the olfactory nerve.
Some researchers are concerned that the olfactory tract may also be an entry point for microplastics that enter the brain, beyond the olfactory bulb. "Previous human and animal studies have shown that air pollution reaches the brain and particles have been found in the olfactory bulb, so we think the olfactory bulb is probably one of the first places for microplastics to reach the brain." said study lead author Dr. Thais Mauad, associate professor of pathology at Sao Paulo Medical School, Brazil.
Mauad and her team took olfactory bulb tissue samples from 15 cadavers between the ages of 33 and 100. Samples from eight of the corpses contained microplastics (tiny pieces of plastic ranged from 5,5 micrometers to 26,4 micrometers in size). In total, the researchers found 16 plastic fibers and particles in the tissues. The smallest were thinner than the diameter of a human red blood cell, which is about 8 micrometers.
The most common type of plastic scientists discovered was polypropylene, followed by polyamide, nylon, and polyethylene vinyl acetate.