KATHMANDU, Feb 6: A scientific study has shown that the presence of microplastics in the human brain is increasing and affecting its regular functions. The study, conducted by 21 scientists and published on Monday in the scientific journal Nature Medicine, found that microplastic pollution is continuously increasing, and its presence in the brain is several times higher compared to the liver and kidneys.
This study was conducted on human brain tissue after autopsies of people who died between 1997 and 2024. As plastic use has been increasing worldwide, numerous studies have shown a disturbing rise in the number of microplastics (plastic particles with a diameter of less than 5 millimeters) in the environment.
Currently, more than 300 million tons of plastic are produced worldwide annually. According to data from 2023, approximately 2.5 million tons of plastic are floating in the ocean. Plastic pollution in the ocean has increased tenfold compared to 2005.
The new study shows a significant increase in the presence of microplastics and even smaller-diameter nanoplastics in the 2024 samples compared to those observed in 2016. The study analyzed brain, liver, and kidney samples from 28 people who died in 2016 and 24 who died in 2024.
Similarly, higher levels of microplastic particles have been found in the brains of people with dementia. Research has shown that brain samples from dementia patients contain six times more microplastics than those from other individuals.
Previous studies have found these particles in human blood, breast milk, placenta, and bone marrow. Much more research is needed to determine the impact of this invisible challenge on human health. However, scientific evidence suggests a direct link to strokes and heart attacks.
“The increasing presence of micro- and nanoplastics in the environment calls for further study into neurological disorders and other effects on human health,” said researchers involved in the study, led by Professor Matthew Campen of the University of New Mexico in the US.
Generally, plastic bags, packaging, and other plastic items used in daily life break down and turn into microplastics. Similarly, dust from tires, paint, and marine fish are sources of microplastics.
Scientific studies have shown that microplastic pollution exists from the peak of Mount Everest to the deepest point of the ocean, the Mariana Trench. It is believed that these toxic particles enter the body through food, water, and breathing, reaching various parts of the body through the bloodstream.
To broaden the scope of the study, scientists analyzed brain tissue samples from people who died between 1997 and 2013 on the East Coast of the United States and found an increasing trend in brain microplastic pollution during this period.
The most common source of microplastics found in the study was polyethylene, a plastic used in plastic bags and food and beverage packaging. Another scientific study published last week found significant levels of microplastics in the placentas of premature babies.
Similarly, another study on the brains of mice found that microplastics blocked blood vessel flow and damaged the nervous system. However, since human cells are larger than those of mice, some scientists argue that the effect of microplastics on the blood vessels of the human brain may not be the same.
The study’s scope and sample size are limited to New Mexico and the East Coast of the US, so it needs to be expanded, according to other scientists who were not involved in the study.
“The 50 percent increase in microplastics in the human brain over the past eight years points to the increasing production and use of plastics. Therefore, it seems that technological innovations must be sought to prevent environmental pollution and reduce human risk,” Tamara Galloway, a professor at the University of Exeter in the UK, told The Guardian.