A new cross-sectional study of 218 U.S. coastal counties found significant associations between higher marine microplastic levels and increased prevalence of neurologic disabilities, according to findings presented at the American Academy of Neurology 2025 Annual Meeting.
Study investigators from Lahey Hospital & Medical Center and collaborating institutions reported that counties with very high marine microplastic levels (MMLs) had significantly higher rates of cognitive (prevalence ratio [PR] = 1.09), mobility (PR = 1.06), self-care (PR = 1.16), and independent living disabilities (PR = 1.08) compared with counties with low MMLs.
The mean prevalence of cognitive disability was 15.2% in very high–MML counties vs 13.9% in low–MML counties, the researchers reported in their American Academy of Neurology presentation. Mobility disability affected 14.1% vs 12.3%, self-care disability affected 4.2% vs 3.6%, and independent living disability affected 8.5% vs 7.7%, respectively (P < .001 for all comparisons).
Methods
The researchers used population-weighted quasi-Poisson regression modeling across three analytic models to examine the association between MMLs and the prevalence of disabilities. Outcomes included cognitive function, mobility, self-care, and independent living ability.
The cross-sectional analysis evaluated existing population-level disability data across coastal U.S. counties stratified by levels of marine microplastic pollution. Models controlled for potential confounding variables.
Background
Micro- and nanoplastics (MNPs) are increasingly recognized as environmental risk factors that potentially contribute to cognitive decline. However, the population-level relationship between marine microplastic exposure and neurologic disabilities has not been well characterized.
The study researchers aimed to address this knowledge gap by investigating proposed mechanisms that link MNP exposure to adverse neurologic outcomes and quantifying associated disability prevalence in affected communities.
Public Health Implications
Although the findings demonstrate statistically significant associations between marine microplastic pollution and increased neurologic disability prevalence, further research is needed to clarify the causal mechanisms and broader public health implications.
The study was conducted by investigators from Lahey Hospital & Medical Center; Cleveland Clinic; Houston Methodist DeBakey Heart & Vascular Center; Harvard T.H. Chan School of Public Health; Columbia University Mailman School of Public Health; University Hospitals Cleveland Medical Center; and Houston Methodist Hospital.
Disclosures are available through the American Academy of Neurology.
