Higher marine microplastics may signal greater stroke and chronic disease burden in coastal communities

By Tarun Sai LomteReviewed by Susha Cheriyedath, M.Sc.May 19 2026

A new U.S. coastal analysis links higher marine microplastic concentrations with increased chronic disease prevalence, raising new questions about how environmental pollution may intersect with cardiovascular and metabolic health.

Study: Marine microplastic concentration and associations with stroke and chronic disease prevalence. Image Credit: Spice Footage / Shutterstock

In a recent study published in the journal npj Cardiovascular Health, researchers investigated marine microplastic concentrations across coastal areas in the United States (US).

Marine Microplastics and Cardiovascular Background

Plastic pollution has been implicated in disrupting ecosystems and human health. Micro- and nano-plastics (MNPs) are widespread in the environment and have emerged as a potential risk factor for cardiovascular disease (CVD). MNPs have been detected in food, air, and water. Estimates indicate that humans ingest or inhale millions of MNP particles in their lifetime.

In vitro analyses suggest that MNPs may trigger pathophysiological pathways relevant to CVD development, with preliminary human evidence substantiating their potential pathological role in the cardiovascular system. Several studies have also documented the presence of MNPs in ex vivo cardiovascular samples.

US Coastal Microplastic Study Design

In the present study, researchers investigated associations between microplastic (MP) concentrations and chronic disease prevalence across US coastal areas. The team obtained data on environmental MP levels from 1972 to 2019 from the National Centers for Environmental Information (NCEI) database of the National Oceanic and Atmospheric Administration (NOAA).

Further, prevalence rates of diabetes, cancer, stroke, and high blood pressure were acquired from the Population Level Analysis and Community Estimates (PLACES) database of the Centers for Disease Control and Prevention (CDC). Environmental and sociodemographic variables included the social vulnerability index (SVI), household income, air pollution levels, population demographics, and employment rates.

The dataset comprised 709 coastal census tracts, grouped into five categories of MP concentrations: very low, low, medium, high, and very high. The study included census tracts with at least one MP sampling point within 200 meters of the tract’s coastal boundary. Associations between MP levels and disease prevalence were assessed using correlation tests.

Differences in disease rates across MP concentration groups were examined using analysis of variance. Further, Poisson regression models examined associations between census tract-level MP exposure categories and chronic disease prevalence, adjusting for age, sex, ethnicity/race, household income, SVI, percentage uninsured, and fine particulate matter < 2.5 µm (PM2.5).

In addition, the team trained an extreme gradient boosting (XGBoost) model on all environmental and socioeconomic features to predict census tract-level stroke prevalence. Model performance was assessed using the coefficient of determination (R2) and root mean squared error (RMSE). Feature contributions were quantified using Shapley additive explanation (SHAP) values.

Stroke and Chronic Disease Findings

Census tracts with elevated MP concentrations showed increased prevalence rates of stroke, high blood pressure, and diabetes. Specifically, the prevalence of stroke was reported as higher in very high-MP areas than in very low-MP areas, although the manuscript contains inconsistent stroke prevalence values between the results text and Table 1. The percentages of Black residents and of socially vulnerable residents generally increased with rising MP levels. Likewise, several environmental variables, including light pollution and proximity to traffic, were elevated with higher MP concentrations, whereas PM2.5 showed a less consistent pattern across categories.

The normalized difference vegetation index and median household income decreased with increasing MP levels. Notably, areas with higher MP levels overlapped with regions with several markers of environmental and socioeconomic disadvantage, lower household income, and higher rates of uninsured residents. MP concentrations were correlated with stroke, diabetes, and high blood pressure. Census tracts with elevated MP exposure had significantly increased prevalence of chronic conditions. Cancer showed a different pattern, with the authors noting a negative association that requires further exploration.

Specifically, the prevalence ratios for stroke, diabetes, and high blood pressure increased from 1.02, 1.04, and 1.03 in areas with medium MP exposure to 1.21, 1.17, and 1.10, respectively, in areas with very high MP exposure. The XGBoost model achieved an R2 of 0.73 and an RMSE of 0.44 in predicting stroke prevalence, showing reasonable performance. MP exposure was a meaningful predictor of stroke prevalence along with PM2.5, median household income, and traffic proximity, although socioeconomic factors dominated the model overall.

Microplastic Exposure and Public Health Implications

In sum, MP pollution may be linked to higher prevalence of stroke, high blood pressure, and diabetes. The prevalence ratios increased with rising MP concentrations. MP concentration also emerged as a key predictor of stroke prevalence. However, because the analysis used aggregated census tract-level data, it cannot establish individual-level risk or causality, and the ecological fallacy remains a possibility. The study has several limitations: MP measures were collected over many years before 2019, whereas covariate and disease data were sourced from 2019 datasets, potentially leading to exposure misclassification.

In addition, only coastal communities were examined, which constitute a small proportion of the overall census tracts. Substantial overlap with other pollutants and socioeconomic factors also makes it difficult to establish a direct causal association. Understanding how environmental pollutants, including MPs, contribute to non-communicable diseases is crucial to developing regulatory policies and public health interventions. Further research is required to determine causal mechanisms and inform interventions to decrease MP exposure and its adverse health effects.

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