Brazilian scientists have discovered microplastics in the brain tissues of deceased individuals, as detailed in a new study released on Monday in the JAMA Network Open journal. This research contributes to the growing body of evidence that microplastics are pervasive across various organs, the bloodstream, and even arterial plaques.
The focus of this study was the olfactory bulb, a brain region integral to processing smell sensations, located above each nasal cavity and linked by the olfactory nerve. Concerns have been raised about the olfactory pathway potentially serving as a conduit for microplastics entering the brain, beyond just the olfactory bulb.
Dr. Thais Mauad, the study’s lead author and an associate professor of pathology at the University of São Paulo Medical School, stated, “Previous findings have demonstrated that air pollution can access the brain and that particles have been located in the olfactory bulb, suggesting it as a likely initial point of entry for microplastics into the brain.”
In their analysis, Mauad’s team examined olfactory bulb samples from 15 cadavers, aged between 33 and 100, and detected microplastics in eight of these samples. These plastics ranged from 5.5 to 26.4 micrometers in size, with polypropylene being the most common type found.
Matthew Campen, a toxicologist at the University of New Mexico, remarked on the uniqueness of finding microplastics in the olfactory bulb but noted it was expected given their widespread presence in the body. He speculated that the samples might also contain numerous nanoplastics, much smaller in size, potentially penetrating the brain through other means like the bloodstream.
While the study highlights the presence of microplastics in the olfactory bulb, it remains uncertain whether these particles can travel to brain areas involved in cognition. The potential for microplastics and other small particles to bypass the blood-brain barrier—a protective membrane surrounding the brain—is an ongoing area of research.
The implications of microplastics on human health are still largely derived from animal studies, which suggest possible cognitive impacts and inflammation from exposure. This research adds another layer to the understanding of environmental pollutants’ effects on human health, especially concerning neurological conditions like dementia, which have been associated with exposure to air pollution.
