Ocean plastics linked to disability risks for coastal residents 

Tiny plastic particles in coastal waters may be linked to higher rates of disabilities that affect thinking, movement, and self-care, according to a preliminary investigation. 

This research examined regions with elevated levels of marine microplastics and observed a greater prevalence of functional limitations in local populations, though the study does not prove a direct cause-and-effect relationship.

Ocean plastics and coastal communities

The researchers focused on microscopic fragments of plastic less than 5 millimeters across – referred to as microplastics – which can form when plastic trash breaks apart or can originate in personal care products, food wrappers, and discarded fishing materials. 

The experts assessed whether people living in coastal counties with higher levels of these particles in nearby waters also had a higher prevalence of impairments in memory, thinking, mobility, and day-to-day self-care tasks.

“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,” said study co-author Dr. Sarju Ganatra of the Lahey Hospital and Medical Center.

“Our study found that in coastal communities with higher levels of microplastics in the water, there were higher rates of disabilities that can affect a person’s life in many ways through thinking and memory, movement and their ability to take care of themselves and live independently.”

However, the authors caution that their findings only suggest an association, not necessarily causation.

How the research was conducted

In total, 218 coastal counties across 22 U.S. states were included. The scientists gathered information on marine microplastic concentrations in ocean surface waters adjacent to these counties, sorting the locations into four main categories: low, medium, high, and very high. 

The lower bound included zero to 0.005 pieces of plastic per cubic meter, and the higher tiers reached up to or beyond 10 pieces per cubic meter – sometimes more than a thousand pieces per cubic meter on average.

Next, the team examined data on disabilities among residents in four functional domains: memory/thinking, mobility, self-care, and independent living. 

Ocean plastics and disability risks

Self-care disabilities might mean difficulties bathing or dressing, while independent living disabilities could involve challenges such as shopping, managing money, or using transportation.

The researchers found that in counties with the highest levels of ocean plastics, the average prevalence of memory and thinking disabilities was 15.2%, compared to 13.9% in counties with the lowest levels. Similarly, mobility disabilities in high-level counties averaged 14.1%, whereas low-level counties came in at 12.3%. 

For self-care disabilities, the average was 4.2% in high-exposure counties compared to 3.6% at the low end. Independent living impairments stood at 8.5% in the highest category versus 7.7% in the lowest group.

After accounting for variables such as heart disease, stroke, depression, air pollution, and differences in wealth, they calculated that areas with very high microplastic concentrations showed a 9% higher rate of memory and thinking disability, 6% higher mobility disability, 16% higher self-care disability, and 8% higher independent living disability compared to the lowest-exposure counties.

“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.”

Complex distribution of ocean plastics

According to the investigators, ocean circulation patterns, local waste management practices, industrial activities, and population density all influence how plastic accumulates. 

“The amount of plastic in different areas can vary due to ocean currents, which can carry and concentrate plastic in certain regions. Other factors, like population density, local waste management, and industrial activities, may also play a role,” Ganatra explained.

The reasons are complex and likely involve multiple environmental- and human-related factors working together, but this relationship needs further investigation to be fully understood.” 

Microplastics and community health

The study offers a snapshot in time, highlighting that a key limitation was the lack of longitudinal tracking to see whether rising or falling marine microplastic levels coincide with changes in community health over extended periods. 

Nonetheless, the results open a door to more exploration of how small-scale pollutants might have large-scale effects on population health, especially in regions most exposed to marine pollution.

While the link between microplastic levels and disabilities remains tentative, the findings point to a potential intersection of environmental science and neurological well-being. 

Researchers hope that further work on both sides – studying how plastic behaves in coastal ecosystems, and how human health outcomes might shift – could offer clearer answers in the years ahead.

This preliminary study was released on February 25, 2025, and will be presented at the American Academy of Neurology’s 77th Annual Meeting, set to take place April 5–9, 2025. 

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