Article pubs.acs.org/est
Detections of Commercial Fluorosurfactants in Hong Kong Marine Environment and Human Blood: A Pilot Study Eva I. H. Loi,† Leo W. Y. Yeung,‡ Scott A. Mabury,‡ and Paul K. S. Lam*,† †
State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Hong Kong SAR, China ‡ Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada S Supporting Information *
ABSTRACT: 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.
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INTRODUCTION Over the last two decades, there has been increasing discussion in scientific and public health studies concerning the occurrence, fate and transport, and potential adverse effects of perfluoroalkyl and polyfluoroalkyl substances (PFASs). The two most well-studied PFASs are perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) because of not only their ubiquitous occurrences in the environment,1,2 and even in human serum3 and in breast milk,4 but also their potential adverse effects toward human health.5 The production of PFOS has ceased substantially since 3M voluntarily phased-out its production of perfluorooctane sulfonyl fluoride (POSF)-based materials in 2000−2002,6 and the use of PFOS and its related precursors is currently regulated under the Stockholm Convention since 2009. In 2006, eight major fluoropolymer and fluorotelomer manufacturers participated in a global PFOA Stewardship program.7 The goals of the program were to achieve a 95% reduction of PFOA together with precursor chemicals and higher homologue chemicals from the year 2000 baseline in emissions to all media by 2010; and to have a complete elimination of these chemicals in emission and products by 2015. Therefore, the environmental concentrations © 2013 American Chemical Society
of PFOS and PFOA are expected to decline. However, although recent studies show a decline in PFOS in human blood starting from the year 2000, PFOA elimination was relatively slow, and some higher homologue chemicals (e.g., perfluorononanoate (PFNA), perfluorodecanoate (PFDA)) did not decline but showed an increase.8−10 Several hypotheses have been proposed to explain these observed trends, including human exposure via an indirect source,11 residuals in commercial products,12 and intake of tainted food grown in contaminated soil.13−15 Recent studies demonstrate the occurrence of a new class of PFASs in human serum,8,16,17 wastewater treatment plant sludge, and paper fibers.16 These are the polyfluoroalkyl phosphate diesters (diPAPs), having two polyfluoroalkyl chains attached to a phosphate headgroup. These compounds are commercially used as greaseproofing agents in food contact papers, and are also marketed for other applications, such as Received: Revised: Accepted: Published: 4677
September 19, 2012 March 19, 2013 March 24, 2013 March 25, 2013 dx.doi.org/10.1021/es303805k | Environ. Sci. Technol. 2013, 47, 4677−4685
Environmental Science & Technology
Article
Figure 1. PFAS pollution map of surface water samples in Hong Kong. * indicates
