Abstract  We analyzed food market basket samples obtained in Sweden from 1999, 2005, and 2010 for perfluoroalkyl acids (PFAAs) and a range of precursor compounds. Perfluorooctane sulfonic acid (PFOS) precursors were detected in all food year pools with the highest concentrations in 1999. Six polyfluoroalkyl phosphate diesters (diPAPs, 4:2/6:2, 6:2/6:2, 6:2/8:2, 8:2/8:2, 6:2/10:2, and 10:2/10:2) were detected in the year pools with the highest ∑diPAP concentrations in 1999 and 2005. All precursors were predominantly found in meat, fish, and/or eggs based on analysis of individual food groups from 1999. Based on year pools, PFOS precursors contributed between 4 and 1% as an indirect source to total dietary PFOS intakes between 1999 and 2010. Perfluorohexanoic acid (PFHxA) exposure originated entirely from diPAPs, whereas for perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA), diPAPs contributed between 1 and 19% to total exposure. The lowest precursor contributions were generally seen in food samples from 2010.

Abstract  Concentrations (including isomer patterns) and temporal changes (1997-2012) of perfluoroalkyl acids (PFAAs) and selected perfluorooctane sulfonate (PFOS) and perfluoroalkyl carboxylic acid (PFCA) precursors were determined in serum samples from Swedish women. Perfluorooctane sulfonamide (FOSA) and perfluorooctane sulfonamidoacetic acid (FOSAA), as well as its N-methyl and N-ethyl derivatives (MeFOSAA and EtFOSAA) were consistently detected. Highest PFOS precursor concentrations were found for EtFOSAA (before year 2000) or MeFOSAA and FOSAA (after 2000). Disappearance half-lives for all PFOS precursors were shorter compared to PFOS. 4:2/6:2 and 6:2/6:2 polyfluoroalkyl phosphate diesters (diPAPs) were detected in <60% of the samples, whereas 6:2/8:2 and 8:2/8:2 diPAPs were detected in >60% of the samples, but showed no significant change in concentrations over time. Linear and sum-branched isomers were quantified separately for three PFAAs and three precursors. Significant changes between 1997 and 2012 in the % linear isomer were observed for PFOA and FOSA (increase) and PFOS (decrease).

Abstract  Microbial transformation of polyfluoroalkyl phosphate esters (PAPs) into perfluorocarboxylic acids (PFCAs) has recently been confirmed to occur in activated sludge and soil. However, there lacks quantitative information about the half-lives of the PAPs and their significance as the precursors to PFCAs. In the present study, the biotransformation of 6:2 and 8:2 diPAP in aerobic soil was investigated in semi-dynamics reactors using improved sample preparation methods. To develop an efficient extraction method for PAPs, six different extraction solvents were compared, and the phenomenon of solvent-enhanced hydrolysis was investigated. It was found that adding acetic acid could enhance the recoveries of the diPAPs and inhibit undesirable hydrolysis during solvent extraction of soil. However 6:2 and 8:2 monoPAPs, which are the first breakdown products from diPAPs, were found to be unstable in the six solvents tested and quickly hydrolyzed to form fluorotelomer alcohols. Therefore reliable measurement of the monoPAPs from a live soil was not achievable. The apparent DT50 values of 6:2 diPAP and 8:2 diPAP biotransformation were estimated to be 12 and > 1000 days, respectively, using a double first-order in parallel model. At the end of incubation of day 112, the major degradation products of 6:2 diPAP were 5:3 fluorotelomer carboxylic acid (5:3 acid, 9.3% by mole), perfluoropentanoic acid (PFPeA, 6.4%) and perfluorohexanoic acid (PFHxA, 6.0%). The primary product of 8:2 diPAP was perfluorooctanoic acid (PFOA, 2.1%). The approximately linear relationship between the half-lives of eleven polyfluoroalkyl and perfluoroalkyl substances (PFASs, including 6:2 and 8:2 diPAPs) that biotransform in aerobic soils and their molecular weights suggested that the molecular weight is a good indicator of the general stability of low-molecular-weight PFAS-based compounds in aerobic soils.

Abstract  A fast and sensitive method for simultaneous determination of 18 traditional and 6 alternative per- and polyfluoroalkyl substances (PFASs) using solid-liquid extraction (SLE), off-line clean-up using activated carbon and on-line solid phase extraction-ultrahigh performance liquid chromatography-time-of-flight-mass spectrometry (on-line SPE-UHPLC-TOF-MS) was developed. The extraction efficiency was studied and recoveries in range the 58-114% were obtained. Extraction and injection volumes were also optimized to 2mL and 400μL, respectively. The method was validated by spiking dust from a vacuum cleaner bag that had been found to contain low levels of the PFASs in focus. Low method detection limits (MDLs) and method quantification limits (MQLs) in the range 0.008-0.846ngg(-1) and 0.027-2.820ngg(-1) were obtained, respectively. For most of the PFASs, the accuracies were between 70 and 125% in the range from 2 to100ngg(-1) dust. Intra-day and inter-day precisions were in general well below 30%. Analysis of a Standard Reference Material (SRM 2585) showed high accordance with results obtained by other laboratories. Finally, the method was applied to seven indoor dust samples, and PFAS concentrations in the range 0.02-132ngg(-1) were found. The highest median concentrations were observed for some of the alternative PFASs, such as 6:2-diPAP (25ngg(-1)), 8:2-diPAP (49ngg(-1)), and PFOPA (23ngg(-1)), illustrating the importance of inclusion of new PFASs in the analytical methods.

Abstract  OBJECTIVE: To explore the level of perfluoroalkyl substances (PFASs) and their precursors in 18 market milk samples of China.

METHOD: The 18 milk samples were selected in 8 provinces of China, including Ningxia, Neimeng, Beijing, Tianjin, Hebei, Shanxi, Chongqing, and Guangdong. 8 PFASs and 11 PFAS precursors were measured by ultra-high performance liquid chromatography-tandem quadruple mass spectrometry (UPLC-MS/MS). The dietary exposure assessment was made.

RESULTS: Three PFASs were detected in milk samples which were PFOA, PFUdA, and PFOS. The numbers of detected samples were 5, 12, and 14, respectively. Their concentration ranges were < Limit of determination (LOD)-431.94 pg/ml, < LOD -15.95 pg/ml and < LOD -126.98 pg/ml, respectively. Three PFAS precursors were also found above the detection limits, namely, 4:2 FTS, 6:2 FTS, and 6:2 diPAP. Only one sample was detected 4:2 FTS at the concentration of 3.75 pg/ml. The detected samples of 6:2 FTS and 6:2 diPAP were 12 and 3. Their concentration ranges were < LOD -2.49 pg/ml and < LOD -24.56 pg/ml, respectively. The ranges estimated daily intake of PFOA and PFOS of the detected samples were 2.49 × 10⁻³-405.89 × 10⁻³ ng · kg⁻¹ · d⁻¹ and 36.10 × 10⁻³-119.32 × 10⁻³ ng · kg⁻¹ · d⁻¹.

CONCLUSION: Our results suggested that there were different contamination levels of PFASs and their precursors in the 18 market milk produced from different regions in china. The estimated daily intake of PFASs from the milk in our study were far below the tolerable daily intake set by European Union (PFOS: 150 ng · kg⁻¹ · d⁻¹, PFOA: 1 500 ng · kg⁻¹ · d⁻¹).

Abstract  BACKGROUND: Perfluorinated carboxylic acids (PFCAs) are ubiquitous in human sera worldwide. Biotransformation of the polyfluoroalkyl phosphate esters (PAPs) is a possible source of PFCA exposure, because PAPs are used in food-contact paper packaging and have been observed in human sera. OBJECTIVES: We determined pharmacokinetic parameters for the PAP monoesters (monoPAPs) and PAP diesters (diPAPs), as well as biotransformation yields to the PFCAs, using a rat model. METHODS: The animals were dosed intravenously or by oral gavage with a mixture of 4: 2, 6: 2, 8: 2, and 10: 2 monoPAP or diPAP chain lengths. Concentrations of the PAPs and PFCAs, as well as metabolic intermediates and phase II metabolites, were monitored over time in blood, urine, and feces. RESULTS: The diPAPs were bioavailable, with bioavailability decreasing as the chain length increased from 4 to 10 perfluorinated carbons. The monoPAPs were not absorbed from the gut; however, we found evidence to suggest phosphate-ester cleavage within the gut contents. We observed biotransformation to the PFCAs for both monoPAP and diPAP congeners. CONCLUSIONS: Using experimentally derived biotransformation yields, perfluoro-octanoic acid (PFOA) sera concentrations were predicted from the biotransformation of 8: 2 diPAP at concentrations observed in human serum. Because of the long human serum half-life of PFOA, biotransformation of diPAP even with low-level exposure could over time result in significant exposure to PFOA. Although humans are exposed directly to PFCAs in food and dust, the pharmacokinetic parameters determined here suggest that PAP exposure should be considered a significant indirect source of human PFCA contamination.

Abstract  Perfluorinated carboxylic acids (PFCAs), including perfluorooctanoic acid (PFOA), are persistent organic pollutants that pose human health risks. However, sources of contamination and exposure pathways of PFCAs have not been explored. In this study, PFCA concentrations were quantified in personal care products. Among 24 samples that listed fluorinated compounds, such as polyfluoroalkyl phosphate esters (PAPs), in their international nomenclature of cosmetic ingredients (INCI) labels, 21 contained PFCAs (13 of 15 cosmetic samples, and 8 of 9 sunscreen samples). The concentrations of total PFCAs ranged from not detected to 5.9 mu g g(-1) for cosmetics and from not detected to 19 mu g g(-1) for sunscreens. We also investigated components of PFCAs in cosmetics and sunscreens. Commercially available compounding agents, mica and talc, which were treated with PAPs were analyzed and high concentrations of PFCAs were detected (total PFCAs 2.5 mu g g(-1) for talc treated with PAPs, 35.0 mu g g(-1) for mica treated with PAPs). To the best of our knowledge, this is the first report on contamination of end consumer products containing PAPs with high concentrations of PFCAs. (C) 2013 Elsevier Ltd. All rights reserved.

Abstract  Perfluorinated acids are detected in human blood world-wide, with increased levels observed in industrialized areas. The origin of this contamination is not well understood. A possible route of exposure, which has received little attention experimentally, is indirect exposure to perfluorinated acids through ingestion of chemicals applied to food contact paper packaging. The current investigation quantified the load of perfluorinated acids to Sprague-Dawley rats upon exposure to polyfluoroalkyl phosphate surfactants (PAPS), nonpolymeric fluorinated surfactants approved for application to food contact paper products. The animals were administered a single dose at 200 mg/kg by oral gavage of 8:2 fluorotelomer alcohol (8:2 FTOH) mono-phosphate (8:2 monoPAPS), or the corresponding di-phosphate (8:2 diPAPS), with blood taken over 15 days post-dosing to monitor uptake, biotransformation, and elimination. Upon completion of the time-course study the animals were redosed using an identical dosing procedure, with sacrifice and necropsy 24 h after the second dosing. Increased levels of perfluorooctanoic acid (PFOA), along with both 8:2 PAPS congeners, were observed in the blood of the dosed animals. In the 8:2 monoPAPS-dosed animals, 8:2 monoPAPS and PFOA blood concentrations peaked at 7900 +/- 1200 ng/g and 34 +/- 4 ng/g respectively. In the 8:2 diPAPS-dosed animals, 8:2 diPAPS peaked in concentration at 32 +/- 6 ng/g, and 8:2 monoPAPS and PFOA peaked at 900 +/- 200 ng/g and 3.8 +/- 0.3 ng/g, respectively. Several established polyfluorinated metabolites previously identified in 8:2 FTOH metabolism studies were also observed in the dosed animals. Consistent with other fluorinated contaminants, the tissue distributions showed increased levels of both PFOA and the 8:2 PAPS congeners in the liver relative to the other tissues measured. Previous investigations have found that PAPS can migrate into food from paper packaging. Here we link ingestion of PAPS with in vivo production of perfluorinated acids.

Abstract  The aim of this study was to assess the effectiveness of Perfluorotributylamine/Pluronic F-68 Stem-Emulsion (FC43se) against hyperacute rejection in rabbit-pig xenodiscordant transplantation in an ex-vivo lung model. Rabbits were divided into two groups. In Group 1 (control), after extraction, the lungs were connected directly to the experimental circuit as soon as possible. The lungs were then perfused with 100 ml of pig blood only. In Group 2 (FC(+) Group), after extraction, the lungs were connected to the same circuit as soon as possible. The lungs were then perfused with 10 ml of FC43se plus 90 ml of pig blood. The duration of perfusion was defined from when the perfusion started until the PAP reached 50 mmHg. Significant differences in survival were seen between Group 1 and Group 2: in Group 1, the survival time was 51.9 +/- 16.8 min, whereas in Group 2 the survival time was 76.9 +/- 12.4 min (p < 0.01). The wet-to-dry weight ratio after 30 min of perfusion in Group 2 was significantly lower than that of Group 1 and the mean pulmonary artery pressure of Group 2 at 35, 40 and 45 min after perfusion was significantly lower than that of Group 1. Histological examination revealed that FC43se suppressed the adhesion of leukocytes to the surfaces of endothelial cells, and also attenuated the intimal edematous changes accompanying leukocyte infiltration. Therefore, FC43se has a beneficial effect on suppressing hyperacute rejection in xenogeneic discordant lung transplantation.