Exposure to microplastics could be a piece to the puzzle of finding out what causes brain aging disorders such as Alzheimer’s disease.
Professor of biomedical and pharmaceutical sciences Jaime Ross studies how environmental factors can contribute to brain health and brain aging disorders.
In her studies, Ross exposed healthy mice to microplastics through their water supply. Ross’ team also looked in the tissues of the rodents to see where microplastics could be found.
“Every tissue where we looked virtually we found them and, to our dismay, we found them in the brain,” Ross said. “They really shouldn’t be getting into the brain because there is something called a blood-brain barrier that’s supposed to protect such small particles from getting into the brain.”
By looking at Alzheimer’s studies, Ross hopes to understand if there is any overlap between microplastic exposure and Alzheimer’s risk factors being triggered.
30% of dementia cases could have been altered if modifiable life factors had been addressed, according to Ross. These factors can be physiological, like sleep hygiene, vitamins and minerals consumption and diet, or they can be environmental, such as an individual’s exposure to pollutants and the climate they live in.
“Now we find microplastics in almost every tissue of the body where they’ve looked,” Ross said. “It seems to be everywhere.”
Scientists still aren’t sure the extent to which humans are exposed to microplastics, according to Ross. For this reason, it was difficult for Ross to determine the level and length of microplastic exposure. Ultimately, she and her team settled on three weeks of exposure and three different dosing amounts for the rodents, according to Ross.
“I honestly didn’t think we were going to find anything,” Ross said. “I thought that this would be a good pilot study to work out all the kinks of how to expose the mice and that we would need to expose the mice for much longer periods of time.”
However, once the team began observing the behavior of the mice, they found more unnatural behaviors in them. Ross explained that mice tend to stick to the edges of a chamber because it is safer for them than out in the middle. However, after this experiment, the older mice began spending more time in the center of the chamber.
While it is hard to officially determine that the rodents are experiencing a cognitive disease such as Alzheimer’s, Ross said that the mice exhibited behaviors seen in people with cognitive illnesses. This included a loss of protective natural instincts and doing things that they wouldn’t naturally do.
One reason Ross believes it took “so long” for these studies to emerge is because microplastics are so hard to work with.
“These different plastics come in different shaped fragments so they are almost like snowflakes when you think about it,” Ross said.
Microplastics are also very small; the largest ones Ross worked with in her study were two micrometers. Ross also worked with nanoplastics for her research.
“Nanoplastics can get so small that they can float in the air,” Ross said. “They can be as small as the size of a virus.”
Ross hopes that her research will inform policy makers about the impacts of microplastics.
Professor of Oceanography J.P. Walsh is another URI professor studying the effects of microplastics. He researches how microplastics affect marine environments and biology.
“I think what we really need to move to in society is to be a little more focused on our plastic and not just producing less, which would be a nice goal, but really being smart about what we produce, how it’s going to be reused and where it’s going to end up in the environment,” Walsh said.
As more research is done on the impact of microplastics on the human body, both Ross and Walsh hope more policy is made to reduce these effects.