@article {Lioemed-2017-104651, author = {Ying Li and Tony Fletcher and Daniel Mucs and Kristin Scott and Christian H Lindh and Pia Tallving and Kristina Jakobsson}, title = {Half-lives of PFOS, PFHxS and PFOA after end of exposure to contaminated drinking water}, elocation-id = {oemed-2017-104651}, year = {2017}, doi = {10.1136/oemed-2017-104651}, publisher = {BMJ Publishing Group Ltd}, abstract = {Background Municipal drinking water contaminated with perfluorinated alkyl acids had been distributed to one-third of households in Ronneby, Sweden. The source was firefighting foam used in a nearby airfield since the mid-1980s. Clean water was provided from 16 December 2013.Objective To determine the rates of decline in serum perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), and their corresponding half-lives.Methods Up to seven blood samples were collected between June 2014 and September 2016 from 106 participants (age 4{\textendash}84 years, 53\% female).Results Median initial serum concentrations were PFHxS, 277 ng/mL (range 12{\textendash}1660); PFOS, 345 ng/mL (range 24{\textendash}1500); and PFOA, 18 ng/mL (range 2.4{\textendash}92). The covariate-adjusted average rates of decrease in serum were PFHxS, 13\% per year (95\% CI 12\% to 15\%); PFOS, 20\% per year (95\% CI 19\% to 22\%); and PFOA, 26\% per year (95\% CI 24\% to 28\%). The observed data are consistent with a first-order elimination model. The mean estimated half-life was 5.3 years (95\% CI 4.6 to 6.0) for PFHxS, 3.4 years (95\% CI 3.1 to 3.7) for PFOS and 2.7 years (95\% CI 2.5 to 2.9) for PFOA. The interindividual variation of half-life was around threefold when comparing the 5th and 95th percentiles. There was a marked sex difference with more rapid elimination in women for PFHxS and PFOS, but only marginally for PFOA.Conclusions The estimated half-life for PFHxS was considerably longer than for PFOS and PFOA. For PFHxS and PFOS, the average half-life is shorter than the previously published estimates. For PFOA the half-life is in line with the range of published estimates.}, issn = {1351-0711}, URL = {https://oem.bmj.com/content/early/2017/11/13/oemed-2017-104651}, eprint = {https://oem.bmj.com/content/early/2017/11/13/oemed-2017-104651.full.pdf}, journal = {Occupational and Environmental Medicine} }