Tiny pieces of plastic in the ocean could mean an increased risk for disabilities in coastal residents who live nearby, according to a new preliminary study released this month.
The study, which will be publicly presented at the American Academy of Neurology's annual meeting in April, found an association -- not causation -- between high levels of marine microplastics and disabilities, but researchers are nonetheless alarmed by their findings.
"The environment can play a crucial role in our health, and factors such as pollution may impact a person's risk of developing cognitive decline and other neurological disabilities," Dr. Sarju Ganatra, of Lahey Hospital and Medical Center in Burlington, said in a statement about the study.
Microplastics in the ocean, which never fully decompose, are fragments of plastic less than 5 millimeters in size. They're from broken-down plastic trash or products such as beads in face scrubs and cosmetics, fishing nets, food wrappers and take-out containers.
They can be ingested or absorbed by marine life, a possible threat to humans who eat fish and shellfish.
Environmental experts say microplastics are everywhere.
Study researchers looked at microplastic levels in the ocean for 218 coastal counties across 22 U.S. states, and then compared those levels to the amount of disability among nearby residents in the following categories: memory and thinking, mobility, self-care and independent living.
The study found counties with the highest levels of microplastics in the ocean nearby had higher percentages of residents with disabilities: 9% higher for disability in memory and thinking, 6% for disability in mobility, 16% for disability in self-care, and 8% for disability in independent living, compared to counties with the lowest levels.
"These findings provide insights into how marine microplastics might affect brain health," Ganatra said. "More research is needed to explore this connection further and examine the overall public health implications of microplastic pollution."
The amount of microplastics in different areas can vary due to ocean currents, Ganatra added, ultimately carrying and concentrating plastics in certain regions. In 2019, for example, researchers found samples from the busy waterways of Boston Harbor had a high concentration of particles compared to those from the open ocean.
Salt marshes on Cape Cod and in New Bedford have been found to act as "sinks" when capturing microplastics, depositing them deep below the surface.
Factors such as population density, local waste management and industrial activities also play a role in the distribution of microplastics, Ganatra said.
Researchers noted a limitation of the study was that it was a snapshot in time, rather than a review of coastal residents and marine microplastic levels over time.