Summary

New research by University of Rhode Island professor Jamie Ross focuses on the neurobehavioral effects and inflammatory responses of exposure to microplastics, as well as the accumulation of microplastics in tissues, including the brain. Her team found that the infiltration of microplastics in the body was as common as in the environment, leading to behavioral changes, especially in older test subjects.

Background

Plastics—especially microplastics—are among the most pervasive pollutants on Earth, entering air, water systems and food chains around the world. While the ubiquity of microplastics in the environment is well known, as is their negative impact on marine life, few studies have investigated potential health effects in mammals, prompting professor Jamie Ross to conduct new research.

Ross and her team focused on the neurobehavioral effects and inflammatory responses of exposure to microplastics, as well as the accumulation of microplastics in tissues, including the brain. They found that the infiltration of microplastics in the body was as common as in the environment, leading to behavioral changes, especially in older test subjects.

"Current research suggests that these microplastics are transmitted throughout the environment and may accumulate in human tissues; however, research on the health effects of microplastics, particularly in mammals, remains very limited," Ross said, who is an assistant professor of biomedical and pharmaceutical sciences at the Ryan Institute for Neuroscience and the School of Pharmacy. "This prompted our team to explore the biological and cognitive consequences of exposure to microplastics."

Research Process

Ross's team, including research assistant professor Giuseppe Copotelli, biomedical and pharmaceutical sciences graduate student Lauren Gaspar and interdisciplinary neuroscience program graduate student Sydney Bateman, exposed young and old mice to different levels of drinking water over a three-week period. They found that microplastic exposure caused both behavioral changes and changes in immune markers in liver and brain tissue. The study mice began to move and behave strangely, exhibiting behaviors similar to those seen in humans with dementia. This result has even more profound implications in older animals.

"For us, it was striking. The dose of these microplastics was not high, but in a very short period of time, we saw these changes," Ross said. "No one really understands the life cycle of these microplastics in the human body, so part of the question we want to address is what happens as we age. Are you more susceptible to systemic inflammation from these microplastics as you age? Can your body get rid of them easily? Do your cells respond differently to these toxins?"

To understand the physiological systems that may drive these behavioral changes, Ross's team investigated how widespread microplastic exposure is in the body, dissecting several major tissues, including the brain, liver, kidneys, gastrointestinal tract, heart, spleen and lungs. The researchers found that these particles had begun to bioaccumulate in every organ, including the brain, as well as in body waste.

"Given that in this study microplastics were taken orally in drinking water, it is always possible that microplastics could be detected in the gastrointestinal tract, a major part of the digestive system, or in tissues such as the liver and kidneys," Ross said. "However, microplastics detected in tissues such as the heart and lungs suggest that microplastics are moving beyond the digestive system and may be making their way to the systemic circulation." The brain-blood barrier should be impermeable. It's a protective mechanism against viruses and bacteria, yet these particles can get in there. It's actually deep in the brain tissue.”

The findings revealed that infiltration of the brain may also lead to a reduction in glial fibrillary acidic protein (GFAP), a protein that supports many cellular processes in the brain. "Reductions in GFAP have been linked to the early stages of several neurodegenerative diseases, including mouse models of Alzheimer's disease, as well as depression," Ross said. "We were very surprised to find that microplastics can induce changes in GFAP signaling."

Future Plan

She plans to investigate this finding further in future work. "We want to understand how plastic alters the brain's ability to maintain its own homeostasis, or how exposure to plastic can lead to neurological disorders and diseases, such as Alzheimer's disease," she said.

About the Author

Collected by Matexcel. Matexcel can provide microplastic testing services by using qualitative analysis equipment to determine the type of microplastics (MPs), quantitative analysis equipment to determine the quantity, content, etc., and also analyzing the chemical substances adhering to the surface of the microplastics.