To Örebro University

Previously, much of the perfluoroalkyl and polyfluoroalkyl substance (PFAS) research has focused on perfluoroalkyl carboxylates (PFCAs) or perfluoroalkane sulfonates (PFSAs). Recent studies indicate that known PFCAs and PFSAs accounted for 5-95% of the organofluorine (OF) in human and wild rat blood samples suggesting that a relatively large proportion of OF remained unknown. Until recently, some studies reported commercially available compounds such as polyfluoroalkyl phosphate diesters (diPAPs) and fluorotelomer sulfonates (FTSAs) in human blood and sludge samples. The present investigation is a pilot study aiming at surveying some newly identified PFASs such as diPAPs, FTSAs, and perfluorinated phosphinates (PFPiAs) in different environmental samples including surface water, sediment, sewage treatment plant influent and effluent, sludge, benthic worm, and human blood from Hong Kong. DiPAPs (6:2, 6:2/8:2, and 8:2) were detected in some of the samples at part-per-billion (ppb) levels in sludge, sub ppb levels in influent and effluent, sediment, worm, and human blood samples, and sub part-per-trillion (ppt) levels in surface waters. Sub ppt to ppb levels of 6:2 and 8:2 FTSAs were observed in worm, surface water, and human blood samples. PFPiAs were only observed in worm samples. The detected "new PFASs" accounted for a minor proportion (less than 5%) of the total PFASs in benthic worm and human blood, but up to 95% in sewage sludge samples from Hong Kong. This is the first report of commercial fluorosurfactants (PFPiAs, diPAPs, and FTSAs) in the samples from the environment and human blood in Hong Kong; further information on the distribution, fate, and transport of "new PFASs" in other Asian cities, as well as toxicity, is needed for further assessing the human exposure and risk.