Scientists investigating the possible health effects of microplastics have revealed some alarming early results in experiments with mice.
Researchers at the University of Rhode Island found that when old and young rodents drank microscopic pieces of plastic suspended in water over a period of three weeks, it affected every organ in the tiny mammal’s body, including the brain. We found traces of contaminants accumulating.
The presence of these microplastics was also accompanied by behavioral changes resembling human dementia and changes in immune markers in the liver and brain.
“For us, this was shocking. These weren’t high-dose microplastics, but we saw these changes in such a short period of time.” explain Neuroscientist Jamie Ross.
“No one really understands the life cycle of these microplastics in the body, so part of what we want to address is the question of what happens as we age. Are you more susceptible to systemic inflammation from these microplastics as you build up your cells? react differently to toxins in
Although the results may not directly translate to humans, studies involving such animal models are an important first step in clinical research.
Scientists recently discovered that microplastics hide in the human intestine, circulate in the bloodstream, collect deep in the lungs, and even penetrate the placenta.
In 2021, toxicologists warned that future research urgently needed to address the effects of these pollutants on our health, especially now that avoiding exposure has become nearly impossible. .
In a recent experiment, both old and young mice were given water treated with fluorescent polystyrene microplastics.
Some mice were also given regular drinking water as a control.
During the 3-week study, mouse behavior was periodically assessed during open field tests to encourage exploratory behavior. They also conducted a light-dark preference test based on rodents’ natural aversion to bright areas.
Compared with controls, mice that drank microplastic-contaminated water for three weeks exhibited marked behavioral changes, especially in older mice.
At the end of three weeks, red fluorescent microplastic particles were found in every type of tissue the team examined, including the brain, liver, kidneys, gastrointestinal tract, heart, spleen and lungs. Plastic was also found in mouse poop and urine.
The fact that contaminants were detected outside the digestive system suggests that contaminants undergo systemic circulation.
Their presence in the brain is of particular concern. This means that these potentially toxic pollutants can cross the immune barrier that separates the central nervous system from the rest of the body’s bloodstream and can cause neurocognitive problems. is showing.
The findings join another study earlier this year that found microplastics in the brains of mice just two hours after eating a contaminated meal.
In 2022,similar research They also found that ingested polystyrene microplastics can accumulate in the brains of mice, causing inflammation and impairing memory. However, this study did not identify any behavioral changes in mice during open field testing.
Despite the discrepancy between the results, Ross and colleagues argue that it is now clear that polystyrene microplastics can reach the mammalian brain and have harmful effects after absorption.
Their recent study found that a protein called GFAP, which supports brain cells, was reduced in abundance after ingestion of microplastics.
“Decreases in GFAP are associated with early stages of some neurodegenerative diseases, including mouse models of Alzheimer’s disease, and with depression.” To tell Loss.
“We were very surprised to see that microplastics can induce changes in GFAP signaling.”
Ross plans to explore these changes in future research.
This study International Journal of Molecular Science.