New research of the impact of microplastics on mice suggests that these small particles could induce behavioural changes.
Microplastics could be as widespread in the body as they are in the environment, according to a new study.
Researchers exposed mice to different levels of microplastics through drinking water and studied the impact of the plastics on organs and behaviour.
Microplastics are small plastic particles that are less than 5 mm long and come from larger plastic that has broken down, such as clothing, tyres and other items.
In the study published in the International Journal of Molecular Science, the authors found that the small plastic particles accumulated in every tissue they examined, including deep in the brain tissue.
“Given that in this study the microplastics were delivered orally via drinking water, detection in tissues such as the gastrointestinal tract, which is a major part of the digestive system, or in the liver and kidneys was always probable,” said study author Jaime Ross, a professor at the University of Rhode Island in the US, in a statement.
“The detection of microplastics in tissues such as the heart and lungs, however, suggests that the microplastics are going beyond the digestive system and likely undergoing systemic circulation”.
They also looked at the impact of microplastic exposure for three weeks on the behaviour of both younger and older mice.
Exposure to the plastics led to behavioural changes in the mice similar to dementia in humans, the researchers said, with older mice more heavily impacted.
“Nobody 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 you get older,” Ross said in a statement.
“Are you more susceptible to systemic inflammation from these microplastics as you age? Can your body get rid of them as easily? Do your cells respond differently to these toxins?”
They called for further research to determine how plastics can change the brain, as they found that microplastics could decrease a protein that impacts cell processes in the brain.
Microplastics already detected in human tissue
Microplastics have already been detected at alarming levels in the environment as plastic waste has increased in recent decades.
A 2019 study from scientists in Canada estimated that humans consume between 39,000 to 52,000 microplastic particles per year depending on age and sex.
This number could increase significantly depending on if the person drinks tap water or bottled water (which exposes them to more microplastics).
Research already suggests that these small plastic particles can accumulate in human organs.
“Overall, since human exposure to (microplastics) is inevitable due to their persistence and pervasiveness in the environment, it is essential to better understand their toxicity to limit their impact on human health,” wrote the authors of the new study.