Fluorosurfactants in groundwater increase the incidence of chronic health conditions among California Medicare beneficiaries

BackgroundPer- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants with emerging environmental and regulatory concerns. ObjectivesThis study aimed to estimate the burden of PFAS exposures through ground water on the incidence of chronic health conditions among Medicare beneficiaries aged 65 years and older. MethodsWe estimated PFAS groundwater concentrations for every ZIP code tabulated area (ZCTA) in California counties where 25 percent or more of the populations drinking water was derived from groundwater. We calculated the annual incidence of non-cancer chronic health conditions among 1,696,247 Medicare beneficiaries aged 65 and older by residential ZCTA over the seven-year study period (2011-2017). A Poisson regression model was used to estimate associations between PFAS groundwater concentration and chronic condition incidence with an offset for the number of beneficiary-years at risk and adjusting for bias due to non-random sampling of wells, use of groundwater for drinking water, demographic characteristics, and lung cancer incidence as a control for smoking. ResultsResults suggest an association between a 10 ng/L increment in PFAS contaminated groundwater and chronic health conditions including hypertension (+1.15%, 95% confidence interval (CI) 1.01, 1.30), chronic kidney disease (+0.83%, 95% CI 0.68, 0.99) and cataracts (+1.50%, 95% CI 1.35, 1.66). DiscussionThis small increment in the incidence rate would produce an additional 1,700 new cases of hypertension each year in the study population.