While the fact that microplastics can make their way into our bodies is already known, but it is believed this is the first time they have been found in the brain.
The brains of 15 adults were examined at the São Paulo City Death Verification Service and microplastics were found in eight of them.
A total of 16 different synthetic polymer particles, ranging from 5.5 μm to 26.4 μm in size, were identified, with polypropylene being the most common. Polyamide (eg nylon), polyethylene and polyethylene vinyl acetate were also found.
These materials are commonly found in packaging and clothing.
The research was led by Professor Dr. Thais Mauad and Dr. Luis Fernando Amato-Lourenco from the University of Sao Paulo and Freie University Berlin.
Professor Mauad said: ‘Sixteen particles may not seem like a lot, but beware, they are relatively large particles, even if you call them microplastics. This means that there are almost certainly a lot of nanoplastics in our brains that are a thousand times smaller, but can invade and change cells. This is very disturbing.
‘This study finds that the olfactory pathway is a potential major entry route for plastic into the brain, meaning that breathing within indoor environments could be a major source of plastic pollution in the brain.
‘With much smaller nanoplastics entering the body with greater ease, the total level of plastic particles may be much higher. What is worrying is the capacity of such particles to be internalised by cells and alter how our bodies function.'
There is evidence to suggest that such particles can reach the brain, as black carbon particles have previously been found in various areas of the brain, including the olfactory bulbs.
The study was supported by Plastic Soup Foundation, a member of the Plastic Health Council, a group of leading scientists and campaigners, fighting to ensure a UN Global Plastics Treaty addresses the impact of plastic on human health.
Maria Westerbos, Founder of Plastic Soup Foundation & Co-Founder of the Plastic Health Council said: ‘Plastic has become as synonymous as air is to breathing. Time and time again scientists are peeling back the cover on plastics' dangerous effects on human health. There can be no further doubt.
‘The international community is only months away from the final Global Plastics Treaty negotiations, and yet policymakers are giving into the petrochemical giants. The international community cannot waste any more time, they must finally listen to science, once and for all.'
More than 500 million metric tonnes of plastic are produced every year and, of the 16,000 chemicals involved in the process, more than 4,000 are considered hazardous to human health and the environment.