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

Background: Per- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants with emerging environmental and regulatory concerns. Objectives: This 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. Methods: We estimated PFAS groundwater concentrations for every ZIP code tabulated area (ZCTA) in California counties where 25 percent or more of the population 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. Results: Results 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). Discussion: This small increment in the incidence rate would produce an additional 1,700 new cases of hypertension each year in the study population. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This research was conducted with intramural EPA funds. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: UNC Institutional Review Board I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All exposure data and analytical code will be posted after the manuscript is accepted. Health data is considered sensitive and cannot be posted publicly.