Exposure to Perfluoroalkyl Substances and Mortality for COVID-19: A Spatial Ecological Analysis in the Veneto Region (Italy).

Dolores Catelan,Dario Gregori,Tony Fletcher,Gisella Pitter,Annibale Biggeri,Filippo Da Re,Cristina Canova,Francesca Russo

doi:10.3390/ijerph18052734

Abstract

Background: In the context of the COVID-19 pandemic, there is interest in assessing if per- and polyfluoroalkyl substances (PFAS) exposures are associated with any increased risk of COVID-19 or its severity, given the evidence of immunosuppression by some PFAS. The objective of this paper is to evaluate at the ecological level if a large area (Red Zone) of the Veneto Region, where residents were exposed for decades to drinking water contaminated by PFAS, showed higher mortality for COVID-19 than the rest of the region. Methods: We fitted a Bayesian ecological regression model with spatially and not spatially structured random components on COVID-19 mortality at the municipality level (period between 21 February and 15 April 2020). The model included education score, background all-cause mortality (for the years 2015–2019), and an indicator for the Red Zone. The two random components are intended to adjust for potential hidden confounders. Results: The COVID-19 crude mortality rate ratio for the Red Zone was 1.55 (90% Confidence Interval 1.25; 1.92). From the Bayesian ecological regression model adjusted for education level and baseline all-cause mortality, the rate ratio for the Red Zone was 1.60 (90% Credibility Interval 0.94; 2.51). Conclusion: In conclusion, we observed a higher mortality risk for COVID-19 in a population heavily exposed to PFAS, which was possibly explained by PFAS immunosuppression, bioaccumulation in lung tissue, or pre-existing disease being related to PFAS.

Highlights

More than four thousands polyfluoroalkyl substances (PFAS) are classified by OECD; among them, perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and perfluorohexanesulfonic acid (PFHxS), which are slowly eliminated by the
The objective of this paper is to evaluate at the ecological level if the geographical distribution of mortality for COVID-19 is associated with PFAS exposure in the Veneto
We observed a higher mortality risk for COVID-19 in a population heavily exposed to PFAS compared to the resident population in the other municipalities of the Veneto region

Summary

Introduction

Per- and polyfluoroalkyl substances (PFAS) are a group of man-made organic chemicals with both hydrophilic and hydrophobic functionalities. They are persistent environmental contaminants because of their resistance to biodegradation, photooxidation, direct photolysis, and hydrolysis [1]. PFAS have been manufactured since the 1940s and widely used in a variety of consumer and industrial products such as carpeting, clothing, upholstery, food paper wrappings, fire-fighting foams, and in processes such as PTFE polymer production and metal plating [2]. More than four thousands PFAS are classified by OECD; among them, perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and perfluorohexanesulfonic acid (PFHxS), which are slowly eliminated by the

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