A new U.S. coastal analysis links elevated ocean microplastic concentrations to increased chronic disease prevalence, raising new questions about how environmental pollution relates to cardiovascular and metabolic health.
Study: Association between marine microplastic concentrations and prevalence of stroke and chronic diseases. Image credit: Spice Footage / Shutterstock
In a recent study published in the journal npj cardiovascular healthresearchers investigated ocean microplastic concentrations across coastal regions of the United States (US).
Marine microplastics and cardiovascular background
Plastic pollution is associated with destruction of ecosystems and human health. Microplastics and nanoplastics (MNPs) are widespread in the environment and have emerged as potential risk factors for cardiovascular disease (CVD). MNPs have also been detected in food, air, and water. Estimates suggest that humans ingest or inhale millions of MNP particles during their lifetime.
In vitro analyzes suggest that MNPs may trigger pathophysiological pathways associated with CVD development and provide preliminary human evidence demonstrating a potential pathological role for MNPs in the cardiovascular system. Several studies have also documented the presence of MNPs in ex vivo cardiovascular samples.
US Coastal Microplastic Research Design
In the current study, researchers investigated the association between microplastic (MP) concentrations and chronic disease prevalence across coastal regions of the United States. The research team obtained data on environmental MP levels from 1972 to 2019 from the National Oceanic and Atmospheric Administration’s (NOAA) National Centers for Environmental Information (NCEI) database.
Additionally, the prevalence of diabetes, cancer, stroke, and hypertension were obtained from the Centers for Disease Control and Prevention’s (CDC) Population-Level Analysis and Area Estimates (PLACES) database. Environmental and sociodemographic variables included social vulnerability index (SVI), household income, air pollution levels, demographics, and employment rates.
The dataset consisted of 709 coastal census tracts, grouped into five categories of MP concentrations: very low, low, moderate, high, and very high. This study included census tracts with at least one MP sampling point within 200 meters of the tract’s coastal boundary. The association between MP levels and disease prevalence was assessed using correlation tests.
Analysis of variance was used to examine differences in disease rates between MP concentration groups. Additionally, 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, uninsured rate, and fine particulate matter <2.5 μm (PM2.5).
Additionally, the team trained an extreme gradient boosting (XGBoost) model based on all environmental and socioeconomic characteristics to predict stroke prevalence at the census tract level. Model performance was evaluated using the coefficient of determination (R2) and root mean square error (RMSE). The contribution of features was quantified using Shapley additive description (SHAP) values.
Stroke and chronic disease findings
Census tracts with elevated MP concentrations showed increased prevalence of stroke, hypertension, and diabetes. Specifically, stroke prevalence is reported to be higher in areas with very high MP than in areas with very low MP, but the manuscript contains inconsistent stroke prevalence values between the results text and Table 1. The proportion of black residents and socially vulnerable residents generally increased with increasing MP levels. Similarly, some environmental variables, such as light pollution and proximity to traffic, increased with higher MP concentrations, whereas PM2.5 showed a less consistent pattern across categories.
The normalized vegetation difference index and median household income decreased with increasing MP level. Specifically, areas with high MP levels overlapped with areas with several indicators of environmental and socio-economic disadvantage, low household income, and high proportions of uninsured residents. MP concentrations were correlated with stroke, diabetes, and hypertension. Census tracts with increased MP exposure had significant increases in the prevalence of chronic diseases. Cancer showed a different pattern, and the authors noted a negative association that warrants further investigation.
Specifically, the prevalence of stroke, diabetes, and hypertension increased from 1.02, 1.04, and 1.03 in areas with moderate MP exposure to 1.21, 1.17, and 1.10, respectively, in areas with very high MP exposure. The XGBoost model showed reasonable performance in predicting stroke incidence, achieving R2 0.73 and RMSE 0.44. MP exposure was a significant predictor of stroke incidence, along with PM2.5, median household income, and transportation proximity, but socio-economic factors dominated in the overall model.
Microplastic exposure and public health impact
Taken together, MP pollution may be associated with increased prevalence of stroke, hypertension, and diabetes. The prevalence increased with increasing MP concentration. MP concentration also emerged as an important predictor of stroke prevalence. However, because this analysis used aggregate census tract-level data, it is not possible to establish individual-level risks or causal relationships, and the potential for ecological fallacy remains. This study has some limitations. The MP measurements were collected over many years prior to 2019, whereas the covariate and disease data are from the 2019 dataset, potentially leading to misclassification of exposure.
Additionally, only coastal areas, which constitute a small percentage of the total census tract, were surveyed. Substantial overlap with other pollutants and socio-economic factors also makes it difficult to establish a direct causal relationship. Understanding how environmental contaminants, including pollutants, contribute to non-communicable diseases is critical for developing regulatory policies and public health interventions. Further research is needed to elucidate the causal mechanisms and inform interventions to reduce MP exposure and its adverse health effects.
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Reference magazines:
- Ponnana SR, Shamsa EH, Chen Z et al. (2026). Associations between marine microplastic concentrations and the prevalence of stroke and chronic diseases. npj cardiovascular health. Doi: 10.1038/s44325-026-00133-6, https://www.nature.com/articles/s44325-026-00133-6
