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Benskin J.P.,AXYS Analytical Services Ltd. | Benskin J.P.,Canadian Department of Fisheries and Oceans | Li B.,University of British Columbia | Ikonomou M.G.,Canadian Department of Fisheries and Oceans | And 2 more authors.
Environmental Science and Technology | Year: 2012

Concentrations and isomer profiles for 24 per- and polyfluoroalkyl substances (PFASs) were monitored over 5 months (February-June, 2010) in municipal landfill leachate. These data were used to assess the role of perfluoroalkyl acid (PFAA) precursor degradation on changes in PFAA concentrations over time. The influence of total organic carbon, total suspended solids, pH, electrical conductivity (EC), leachate flow rates, and meteorological data (precipitation, air temperature) on leachate PFAS concentrations was also investigated. Perfluoropentanoate and perfluorohexanoate were typically the dominant PFASs in leachate, except for March-April, when concentrations of perfluorooctane sulfonate, perfluorooctanoate, and numerous PFAA-precursors (i.e., (N-alkyl) perfluorooctane sulfonamides and fluorotelomer carboxylic acids) increased by a factor of 2-10 (∼4 μg/L to ∼36 μg/L ∑PFASs). During this time, isomer profiles of PFOA became increasingly dominated by the linear isomer, likely from transformation of linear, telomer-manufactured precursors. While ∑PFAA-precursors accounted for up to 71% of ∑PFASs (molar basis) in leachate from this site, leachate from a second landfill displayed only low concentrations of precursors (<1% of ∑PFASs). Overall, degradation of PFAA-precursors and changes in leachate pH, EC, and 24-h precipitation were important factors controlling PFAS occurrence in leachate. Finally, 8.5-25 kg/yr (mean 16 kg/yr) of ∑PFASs was estimated to leave the landfill via leachate for subsequent treatment at a wastewater treatment plant. © 2012 American Chemical Society.


Beesoon S.,University of Alberta | Genuis S.J.,University of Alberta | Benskin J.P.,University of Alberta | Benskin J.P.,AXYS Analytical Services Ltd. | Martin J.W.,University of Alberta
Environmental Science and Technology | Year: 2012

Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are normally the dominant perfluoroalkyl substances (PFASs) in human serum, but here a Canadian family of seven was identified with particularly high exposure to perfluorohexanesulfonate (PFHxS). Disproportionately high serum PFHxS concentrations (range 27.5-423 ng/mL) and moderately high PFOS (range 15.2-108 ng/mL) and PFOA (range 2.40-9.23 ng/mL) concentrations were detected in the family members, with all three chemicals being highest in the youngest children. We therefore sought to identify the source(s) and pathway(s) of this unusual exposure, and to study the excretion of PFASs for this family. Serum, urine, and stool were sampled from family members, carpet, dust, and air were sampled in the home, and a questionnaire was administered. Over 15 years, the family's household carpets were treated 8 times with Scotchgard formulations. Elevated concentrations of PFHxS were detected in household dust (2780 ng/g dust) and in family room carpet (2880 ng/g carpet), and the primary mode of excretion for the major PFASs was through urine. The high PFHxS and moderately high PFOS concentrations in serum and household samples are consistent with the known PFAS content of certain Scotchgard formulations, and exposure was likely through dust ingestion and/or inhalation. © 2012 American Chemical Society.


Sutton R.,San Francisco Estuary Institute | Sedlak M.D.,San Francisco Estuary Institute | Yee D.,San Francisco Estuary Institute | Davis J.A.,San Francisco Estuary Institute | And 3 more authors.
Environmental Science and Technology | Year: 2015

California has implemented unique consumer product flammability standards. Polybrominated diphenyl ether (PBDE) flame retardants were once widely incorporated into products to meet these standards, but concerns regarding toxicity and accumulation in humans and biota led to nationwide phase-outs and state bans. A decade of PBDE monitoring in San Francisco Bay has resulted in a data set that covers periods during and after PBDE use and consists of hundreds of measurements of water, sediment, and biota. While PBDEs remain widely detected in biota, levels have declined by nearly half in sport fish and 74-95% in bivalves and bird eggs. Concentrations of BDE-47 in sediment have dropped by over one-third from 2002 to 2012; in water, a decline is not yet evident. The dominant congener in sediment, DecaBDE component BDE-209, showed no temporal trend. U.S. production of DecaBDE ended in 2013; future monitoring may reveal declines. Overall, the data indicate that reduced production can result in relatively rapid reductions in the concentrations of some hydrophobic contaminants in biota and sediment, particularly when implemented after only a few decades of heavy use. Recent changes to California's flammability standards may lessen the use of other flame retardants and similarly reduce Bay contamination. (Graph Presented). © 2014 American Chemical Society.


Klosterhaus S.L.,San Francisco Estuary Institute | Grace R.,AXYS Analytical Services Ltd. | Hamilton M.C.,AXYS Analytical Services Ltd. | Yee D.,San Francisco Estuary Institute
Environment International | Year: 2013

Novel methods utilizing liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry were validated for low-level detection of 104 pharmaceuticals and personal care products ingredients (PPCPs) and four alkylphenols (APs) in environmental samples. The methods were applied to surface water, sediment, and mussel tissue samples collected from San Francisco Bay, CA, USA, an urban estuary that receives direct discharge from over forty municipal and industrial wastewater outfalls. Among the target PPCPs, 35% were detected in at least one sample, with 31, 10, and 17 compounds detected in water, sediment, and mussels, respectively. Maximum concentrations were 92. ng/L in water (valsartan), 33. ng/g dry weight (dw) in sediments (triclocarban), and 14. ng/g wet weight (ww) in mussels (N,N-diethyl-m-toluamide). Nonylphenol was detected in water (< 2-73. ng/L), sediments (22-86. ng/g dw), and mussels (< 0.04-95. ng/g ww), and nonylphenol mono- and diethoxylates were detected in sediments (< 1-40. ng/g dw) and mussels (< 5-192. ng/g ww). The concentrations of PPCPs and APs detected in the San Francisco Bay samples were generally at least an order of magnitude below concentrations expected to elicit toxic effects in aquatic organisms. This study represents the first reconnaissance of PPCPs in mussels living in an urban estuary and provides the first field-derived bioaccumulation factors (BAFs) for select compounds in aquatic organisms. © 2013 Elsevier Ltd.


Benskin J.P.,AXYS Analytical Services Ltd. | Benskin J.P.,Canadian Department of Fisheries and Oceans | Ikonomou M.G.,Canadian Department of Fisheries and Oceans | Gobas F.A.P.C.,Simon Fraser University | And 3 more authors.
Environmental Science and Technology | Year: 2013

Investigations into the biodegradation potential of perfluorooctane sulfonate (PFOS)-precursor candidates have focused on low molecular weight substances (e.g., N-ethyl perfluorooctane sulfonamido ethanol (EtFOSE)) in wastewater treatment plant sludge. Few data are available on PFOS-precursor biodegradation in other environmental compartments, and nothing is known about the stability of high-molecular-weight perfluorooctane sulfonamide-based substances such as the EtFOSE-based phosphate diester (SAmPAP diester) in any environmental compartment. In the present work, the biodegradation potential of SAmPAP diester and EtFOSE by bacteria in marine sediments was evaluated over 120 days at 4 and 25 C. At both temperatures, EtFOSE was transformed to a suite of products, including N-ethyl perfluorooctane sulfonamidoacetate, perfluorooctane sulfonamidoacetate, N-ethyl perfluorooctane sulfonamide, perfluorooctane sulfonamide, and perfluorooctane sulfonate. Transformation was significantly more rapid at 25 C (t1/2 = 44 ± 3.4 days; error represents standard error of the mean (SEM)) compared to 4 C (t1/2 = 160 ± 17 days), but much longer than previous biodegradation studies involving EtFOSE in sludge (t1/2 ∼0.7-4.2 days). In contrast, SAmPAP diester was highly recalcitrant to microbial degradation, with negligible loss and/or associated product formation observed after 120 days at both temperatures, and an estimated half-life of >380 days at 25 C (estimated using the lower bounds 95% confidence interval of the slope). We hypothesize that the hydrophobicity of SAmPAP diester reduces its bioavailability, thus limiting biotransformation by bacteria in sediments. The lengthy biodegradation half-life of EtFOSE and recalcitrant nature of SAmPAP diester in part explains the elevated concentrations of PFOS-precursors observed in urban marine sediments from Canada, Japan, and the U.S, over a decade after phase-out of their production and commercial application in these countries. © 2013 American Chemical Society.

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