High exposure to perfluorinated compounds in drinking water and thyroid disease. A cohort study from Ronneby, Sweden
By Eva M. Andersson, Kristin Scott, YiYi Xu, Ying Li, Daniel S. Olsson, Tony Fletcher, and Kristina Jakobsson
Environmental Research
July 15, 2019
DOI: 10.1016/j.envres.2019.108540
Abstract
Per- and polyfluoroalkyl substances (PFAS) are extremely persistent manmade substances. Apart from exposure through food and indoor air and dust, humans can be exposed through drinking water if the surface or groundwater is contaminated. In 2013 very high levels of PFOS and PFHxS were found in the drinking water from one of the two waterworks supplying the municipality of Ronneby, Sweden.
A cohort was formed, including all individuals who had lived at least one year in Ronneby during the period 1980–2013 (ñ63,000). Each year, addresses that got their drinking water from the contaminated water works were identified. Through the Swedish personal identity number, each individual was linked to registers providing diagnoses and prescriptions for hyper- and hypothyroidism.
In total, 16,150 individuals had ever been exposed. The hazard ratios did not indicate any excess risk of hyperthyroidism among those with contaminated water. For hypothyroidism, the risk of being prescribed medication was significantly increased among women with exposure during the mid part of the study period (but not men). However, the association with period of exposure was non-monotonic, so the significance is considered to be a chance finding. Our research was limited by the relatively simple exposure assessment.
Highlights
• High serum PFOS and PFHxS from fire fighting foam drinking water contamination.
• Thyroid disease in the general population studied 1985 to 2013.
• Linkage to national patient and prescription registers.
• No association between PFAS in drinking water and hyperthyroidism.
• Increased risk of hypothyroidism medication in one sub-group probably due to chance.
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