The association between exposure to perfluoroalkyl substances in drinking water and osteoporotic fractures – a cohort from Ronneby, Sweden

Abstract

Background: For nearly 30 years, a waterworks in Ronneby, Sweden, unknowingly supplied drinking water contaminated with perfluoroalkyl substances (PFASs). These chemicals are still used in countless products, despite no natural degradation and a worldwide pollution. Amongst emerging evidence on adverse health effects are decreased bone mineral density (BMD). Fractures caused by low BMD are a growing problem, with a disease burden ranked higher than that of ischemic stroke. Aim and methods: This study aimed to provide an overall estimation of the association between the PFASs exposure in Ronneby and the risk of major osteoporotic fractures (MOFs), defined as fractures located in vertebrae, proximal humerus, distal forearm, or hip. Secondarily, all fractures were considered. With exposure assessment based on yearly residence during 1985-2013, and data on age, gender, education, and fractures registered in the Swedish National Patient Register, survival analyses were performed. Results: This registry cohort included 61,058 individuals. Amongst the 9,806 individuals classified as exposed, the risk of both MOFs and other fractures increased (hazard ratio 1.13 and 1.08 with 95% confidence interval 1.05-1.21 and 1.03-1.13 respectively). These results were consistent throughout most subgroup analyses; adjusting for educational level (only MOFs), men, individuals aged 50 years or more (only MOFs), individuals aged 49 years or less (only all fractures), later study period 2001-2013, proximal humeral fractures, distal forearm fractures, and hip fractures. Conclusions: This study is, to our knowledge, the first to associate PFASs exposure to increased fracture risk, and it may warrant an offer of follow-up to the PFASs exposed individuals of Ronneby. Furthermore, it supports a more extensive restriction of PFASs use.