For the first time, traces of microplastics have been discovered in the brain - and scientists theorize that we are inhaling them.
Researchers found plastic fibers and particles in cadavers' nasal cavities and brains, believed to originate from clothing, bottles, and food packaging. The latest study was conducted in Sao Paulo, Brazil, using samples taken from the brains of 15 cadavers.
Scientists found traces of polypropylene in eight of the cadavers. as concerning increasing evidence suggests that plastic could play a significant role in early-onset cancer, as well as other illnesses.
Experts detected microplastics in human blood for the first time through a study over two years ago.
Thais Mauad, the lead researcher from the University of Sao Paulo, whose study was published in the Jama Network Open journal, stated: "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 internalized by cells and alter how our bodies function."
The microplastics were identified in the brain's olfactory bulb, which is located above the nasal cavity and processes smell information, according to Perth Now.
She added, "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."
Previously, researchers in the Netherlands analyzed blood samples from 22 anonymous donors and found plastic particles in 17 of them. Over 77 percent of the human bodies tested contained tiny particles of plastic pollution.
The original findings - published in the journal Environment International - are considered a "breakthrough result", according to co-author Professor Dick Vethaak.
But microplastics have been proven to cause damage to human cells in an isolated laboratory environment. Such pollution now contaminates the whole planet, with huge amounts of plastic waste dumped across the world, reaching all oceans and even the tallest mountains.
It is feared the plastic particles may become lodged in organs as they travel around the body, though the impact on health is as yet unknown.
Maria Westerbos of the Plastic Health Council urged policymakers to stop "giving in to the petrochemical giants" as final negotiations for a global plastics treaty approach.
The latest discovery has prompted scientists to warn about plastic's potential infiltration and alteration of our cells. Chemicals in plastic have been associated with cancer, heart disease, and poor fetal development.