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The use of different firefighting methods influences how fast a fire is extinguished and how fast the temperature drops in the area affected by the fire. These differences may also influence the formation of harmful pollutants during firefighting of an accidental fire. The aim was to study occurrence of brominated dibenzo- p -dioxins and furans (PBDD/Fs) in gas and soot during five fire scenarios resembling a small apartment fire and where different firefighting methods were used. Samples of gas and soot were taken both during the buildup of the fire and during the subsequent extinguishing of the fire while using different firefighting methods (nozzle, compressed air foam system, cutting extinguisher) and an extinguishing additive. New containers equipped with identical sets of combustible material were used for the five tests. The use of different firefighting methods and extinguishing additive induced variations in concentration and congener profiles of detected PBDD/Fs. The concentration range of ∑ PBDD/Fs in gas was 4020–18,700 pg/m 3 , and in soot 76–4092 pg/m 2 . PBDFs were the predominant congeners and 1,2,3,4,6,7,8-HpBDF was the most abundant congener. Chlorinated dibenzo- p -dioxins and furans (PCDD/Fs) were also monitored. The PBDD/Fs contributed with in average 97% to the total (PCDD/Fs plus PBDD/Fs) toxic equivalents, in soot and gas. During extinguishing, the shorter time the temperature was around 300 °C, the lower occurrence of PBDD/Fs. In the study the firefighting methods showed a difference in how effectively they induced a temperature decrease below 300 °C in the fire zone during quenching, where cutting extinguishing using additive and the compressed air foam system showed the fastest drop in temperature. [ABSTRACT FROM AUTHOR]

Perfluorooctane sulfonic acid (PFOS) and 3,3′,4,4′,5-pentachlorobiphenyl (PCB126) are persistent organic pollutants of high concern because of their environmental persistence, bioaccumulation and toxic properties. Besides, the amphiphilic properties of fluorinated compounds such as PFOS and perfluorohexanoic acid (PFHxA) suggest a role in increasing cell membrane permeability and solubilizing chemicals. The present study aimed at investigating whether PFOS and PFHxA are capable of modifying the activation of PCB126 toxicity-related pathways. For this purpose, zebrafish embryos were exposed in semi-static conditions to 7.5 μg/L of PCB126 alone, in the presence of 25 mg/L of PFOS, 15.7 mg/L of PFHxA or in the presence of both PFOS and PFHxA. Quantitative PCR was performed on embryos aged from 24 h post fertilization (hpf) to 96 hpf to investigate expression changes of genes involved in metabolism of xenobiotics ( ahr2 , cyp1a ), oxidative stress ( gpx1a , tp53 ), lipids metabolism ( acaa2 , osbpl1a ), and epigenetic mechanisms ( dnmt1 , dnmt3ba ). Cyp1a and ahr2 expression were significantly induced by the presence of PCB126. However, after 72 and 78 h of exposure, induction of cyp1a expression was significantly lower when embryos were co-exposed to PCB126 + PFOS + PFHxA when compared to PCB126-exposed embryos. Significant upregulation of gpx1a occurred after exposure to PCB126 + PFHxA and to PCB126 + PFOS + PFHxA at 30 and 48 hpf. Besides, embryos appeared more sensitive to PCB126 + PFOS + PFHxA at 78 hpf: acaa2 and osbpl1a were significantly downregulated; dnmt1 was significantly upregulated. While presented as environmentally safe, PFHxA demonstrated that it could affect gene expression patterns in zebrafish embryos when combined to PFOS and PCB126, suggesting that such mixture may increase PCB126 toxicity. This is of particular relevance since PFHxA is persistent and still being ejected into the environment. Moreover, it provides additional information as to the importance to integrate mixture effects of chemicals in risk assessment and biomonitoring frameworks. [ABSTRACT FROM AUTHOR]

Human exposure to perfluorooctanoic acid (PFOA) and other per- and polyfluoroalkyl substances (PFASs) is ongoing and in some cases increasing, despite efforts made to reduce emissions. The role of precursor compounds such as polyfluorinated phosphate esters (PAPs) has received increasing attention, but there are knowledge gaps regarding their occurrence and impact on human exposure. In this study, mono-, di-, and triPAPs, perfluorinated alkyl acids (PFAAs), saturated, and unsaturated fluorotelomer carboxylic acids (FTCA/FTUCAs), perfluoroalkane sulfonamides, and sulfonamidethanols (FOSA/FOSEs), and one fluorotelomer sulfonic acid (FTSA)) were compared in household dust samples from Canada, the Faroe Islands, Sweden, Greece, Spain, Nepal, Japan, and Australia. Mono-, di-, and triPAPs, including several diPAP homologues, were frequently detected in dust from all countries, revealing an ubiquitous spread in private households from diverse geographic areas, with significant differences between countries. The median levels of monoPAPs and diPAPs ranged from 3.7 ng/g to 1 023 ng/g and 3.6 ng/g to 692 ng/g, respectively, with the lowest levels found in Nepal and the highest in Japan. The levels of PAPs exceeded those of the other PFAS classes. These findings reveal the importance of PAPs as a source of PFAS exposure worldwide. [ABSTRACT FROM AUTHOR]

Untargeted metabolic profiling of body fluids in experimental animals and humans exposed to chemicals may reveal early signs of toxicity and indicate toxicity pathways. Avian embryos develop separately from their mothers, which gives unique possibilities to study effects of chemicals during embryo development with minimal confounding factors from the mother. In this study we explored blood plasma and allantoic fluid from chicken embryos as matrices for revealing metabolic changes caused by exposure to chemicals during embryonic development. Embryos were exposed via egg injection on day 7 to the environmental pollutant perfluorooctanoic acid (PFOA), and effects on the metabolic profile on day 12 were compared with those caused by GW7647 and rosiglitazone, which are selective agonists to peroxisome-proliferator activated receptor α (PPARα) and PPARγ, respectively. Analysis of the metabolite concentrations from allantoic fluid by Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) showed clear separation between the embryos exposed to GW7647, rosiglitazone, and vehicle control, respectively. In blood plasma only GW7647 caused a significant effect on the metabolic profile. PFOA induced embryo mortality and increased relative liver weight at the highest dose. Sublethal doses of PFOA did not significantly affect the metabolic profile in either matrix, although single metabolites appeared to be altered. Neonatal mortality by PFOA in the mouse has been suggested to be mediated via activation of PPARα. However, we found no similarity in the metabolite profile of chicken embryos exposed to PFOA with those of embryos exposed to PPAR agonists. This indicates that PFOA does not activate PPAR pathways in our model at concentrations in eggs and embryos well above those found in wild birds. The present study suggests that allantoic fluid and plasma from chicken embryos are useful and complementary matrices for exploring effects on the metabolic profile resulting from chemical exposure during embryonic development. [ABSTRACT FROM AUTHOR]

Side-chain fluorinated polymers are speculated to be potential precursors to other non-polymeric aliphatic per- and polyfluoroalkyl acids (PFAAs). Limited knowledge of environmental occurrence of this compound class is partly due to lack of structural information and authentic standards. In this study, two novel fluorinated compounds, suspected to be side-chain fluorinated copolymers used in two commercial technical mixtures (Scotchgard™ Pre-2002 formulation and Scotchgard™ Post-2002 formulation) were analyzed and characterized in order to provide information to facilitate detection and quantification. The commercial mixtures were analyzed using tandem mass spectrometry and high-resolution mass spectrometry; besides already reported C4- and C8-fluoroalkylsulfonamido (FASA) side-chains, a proposed structure was determined for the perfluorooctane (C8) sulfonamide-urethane copolymer in the Pre-2002 formulation. Structural isomers were also observed for C4- and C8-FASA-based copolymers. Total fluorine analysis revealed that the Scotchgard™ Pre-2002 Formulation contained a fluorine content of 0.5% and 1.8% for the Scotchgard™ Post-2002 Formulation. The equivalent FASA side-chain content was determined to be 0.8% for Pre-2002 and 3.1% for Post-2002. Both C4- and C8-FASA-based copolymers underwent hydrolysis and oxidation and were transformed to their respective perfluoroalkyl side chain, which suggest that transformation products can be analyzed for example after total oxidizable precursor (TOP) assay. Both compounds were shown to strongly sorb to sediment particles, which also gives indications about their environmental fate and transport pathways. [Display omitted] • A perfluorooctane (C8) sulfonamide-urethane copolymer structure is presented for the Scotchgard pre-2002 formulation. • Fluorinated side-chain equivalents should be used to quantify fluorinated side-chain copolymers of unknown structure. • Both side-chain fluorinated copolymers (C4 and C8-based) underwent oxidation, and their transformation products are presented. • The findings emphasize the importance of quantifying structural isomers, both for the copolymers and the oxidation products. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFASs) are a class of compounds with unique chemical properties that have been shown useful in a wide variety of applications because they provide materials with reduced surface tension and exceptional non-stick properties. PFASs are commonly found in impregnation materials, coatings of papers and textiles, fire-fighting foams, pesticides, and cleaning agents. The potential for human exposure to PFASs is high because of their widespread distribution. The aim of this study was to investigate levels of PFASs in men and women from Sweden and to assess the influence of gender and parity among women. Levels of 13 PFASs were determined in plasma samples collected during 2001–2004 from 1016 (507 women) 70 year-old participants from the population-based Prospective Study of the Vasculature in Uppsala Seniors (PIVUS). The PFASs studied were nine perfluorinated carboxylic acids (PFCAs), four perfluorinated sulfonic acids (PFSAs) and perfluorooctane sulfonamide (PFOSA). In addition, structural isomers of perfluorooctane sulfonic acid (PFOS) were determined in a subset of 398 individuals. The detection rates were high and the majority of the studied compounds were detected in more than 75% of the participants. Levels of the selected analytes were found to be similar to other studies of non-occupationally exposed populations. Gender differences were observed in levels of PFHpA which was higher in men, while PFHxS was higher in women. Parity among women was shown to have a minor effect on PFAS concentrations and we found primi- and multiparous women to have slightly lower levels of PFUnDA when compared to nulliparous women. [ABSTRACT FROM AUTHOR]

Fluorinated surfactant-based aqueous film-forming foams (AFFFs) are made up of per- and polyfluorinated alkyl substances (PFAS) and are used to extinguish fires involving highly flammable liquids. The use of perfluorooctanesulfonic acid (PFOS) and other perfluoroalkyl acids (PFAAs) in some AFFF formulations has been linked to substantial environmental contamination. Recent studies have identified a large number of novel and infrequently reported fluorinated surfactants in different AFFF formulations. In this study, a strategy based on a case-control approach using quadrupole time-of-flight tandem mass spectrometry (QTOF-MS/MS) and advanced statistical methods has been used to extract and identify known and unknown PFAS in human serum associated with AFFF-exposed firefighters. Two target sulfonic acids [PFOS and perfluorohexanesulfonic acid (PFHxS)], three non-target acids [perfluoropentanesulfonic acid (PFPeS), perfluoroheptanesulfonic acid (PFHpS), and perfluorononanesulfonic acid (PFNS)], and four unknown sulfonic acids (Cl-PFOS, ketone-PFOS, ether-PFHxS, and Cl-PFHxS) were exclusively or significantly more frequently detected at higher levels in firefighters compared to controls. The application of this strategy has allowed for identification of previously unreported fluorinated chemicals in a timely and cost-efficient way. [ABSTRACT FROM AUTHOR]

Temporal trends of perfluoroalkyl substances (PFASs) have been determined in the blood samples from several countries globally including a female population in Sweden recently, yet little is known about the time trends in the blood levels of these compounds in Swedish male populations over recent years. In this study, the fourteen target PFASs consisted of four perfluorosulfonates (PFSAs) and ten perfluorocarboxylates (PFCAs) in the whole blood samples, collected from 153 Swedish elderly men during the period between 2008 and 2010, were analyzed via ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). As the dominant PFASs contaminants in the blood samples, perfluorooctane sulfonate (PFOS) showed the highest geometric mean (GM) at 8.5 ng/mL, ranging from 1.7 to 29 ng/mL, while blood perfluorooctanoic acid (PFOA) contained the GM of 1.8 ng/mL, ranging from 0.35 to 6.4 ng/mL. Both the levels of these two compounds were lower than those determined in the blood samples of Swedish elderly populations derived from the late 1990s. According to the temporal trend analysis, over the three years, the blood levels of PFOS in Swedish male populations declined 16 % per annum, while those of perfluoroundecanoic acid (PFUnDA) increased 6.1 % per annum, which were consistent with those reported previously for the populations from other countries. [ABSTRACT FROM AUTHOR]

Abstract: Perfluorinated alkyl acids (PFAAs) are emerging environmental contaminants. Possible health effects for humans include increased risk for cancer but the knowledge is limited. In this study serum concentrations of certain perfluorinated sulfonates (PFHxS and PFOS) and carboxylates (PFOA, PFNA, PFDA, PFUnDA) were analyzed among 201 cases with prostate cancer and 186 population based control subjects. All blood samples were collected during 2007–2011 and no case had been treated with radio- or chemotherapy before enrolment in the study. The blood concentrations did not differ statistically significant between cases and controls except for PFDA with higher concentration among the cases (p=0.03). Analyses based on Gleason score and prostate specific antigen (PSA) level did not change the results. Heredity was a risk factor for prostate cancer yielding odds ratio (OR)=1.8, 95% confidence interval (CI)=1.01–3.1. The analyzed PFAAs yielded statistically significant higher ORs in cases with a first degree relative reporting prostate cancer, e.g., PFOA gave OR=2.6, 95% CI=1.2–6.0 and PFOS gave OR=2.7, 95% CI=1.04–6.8. The results showed a higher risk for prostate cancer in cases with heredity as a risk factor. In further studies interaction between gene and environment should be considered. [Copyright &y& Elsevier]

Highlights: [•] A method for rapid analysis of PFAS including structural PFOS isomers was developed. [•] The method successfully combines 96-well plate column-switching UPLC–MS/MS. [•] The method was sensitive, accurate, precise, and robust after validation studies. [•] The method was successfully applied to plasma samples for an epidemiological study. [•] Structural PFOS isomers were successfully quantified in all human serum samples. [ABSTRACT FROM AUTHOR]

Abstract: Levels of perfluorocarboxylates (PFCAs) in biological compartments have been known for some time but their transport routes and distribution patterns are not properly elucidated. The opinions diverge whether the exposure of the general population occurs indirect through precursors or direct via PFCAs. Previous results showed that ski wax technicians are exposed to levels up to 92 000ng/m3 of 8:2 fluorotelomer alcohol (FTOH) via air and have elevated blood levels of PFCAs. Blood samples were collected in 2007–2011 and analyzed for C4–C18 PFCAs, 6:2, 8:2 and 10:2 unsaturated fluorotelomer acids (FTUCAs) and 3:3, 5:3 and 7:3 fluorotelomer acids (FTCAs) using UPLC–MS/MS. Perfluorooctanoic acid (PFOA) was detected in levels ranging from 1.90 to 628ng/mL whole blood (wb). Metabolic intermediates 5:3 and 7:3 FTCA were detected in all samples at levels up to 6.1 and 3.9ng/mL wb. 6:2, 8:2 and 10:2 FTUCAs showed maximum levels of 0.07, 0.64 and 0.11ng/mL wb. Also, for the first time levels of PFHxDA and PFOcDA were detected in the human blood at mean concentrations up to 4.22ng/mL wb and 4.25ng/mL wb respectively. The aim of this study was to determine concentrations of PFCAs and FTOH metabolites in blood from ski wax technicians. [Copyright &y& Elsevier]

Abstract: Temporal variations in concentrations of perfluorinated carboxylic acids (PFCAs) and sulfonic acids (PFSAs), including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) structural isomers, were examined in livers of pilot whale (Globicephala melas), ringed seal (Phoca hisida), minke whale (Balaenoptera acutorostrata), harbor porpoise (Phocoena phocoena), hooded seal (Cystophora cristata), Atlantic white-sided dolphin (Lagenorhynchus acutus) and in muscle tissue of fin whales (Balaenoptera physalus). The sampling spanned over 20years (1984–2009) and covered a large geographical area of the North Atlantic and West Greenland. Liver and muscle samples were homogenized, extracted with acetonitrile, cleaned up using hexane and solid phase extraction (SPE), and analyzed by liquid chromatography with negative electrospray tandem mass spectrometry (LC-MS/MS). In general, the levels of the long-chained PFCAs (C9–C12) increased whereas the levels of PFOS remained steady over the studied period. The PFOS isomer pattern in pilot whale liver was relatively constant over the sampling years. However, in ringed seals there seemed to be a decrease in linear PFOS (L-PFOS) with time, going from 91% in 1984 to 83% in 2006. [Copyright &y& Elsevier]

Levels of perfluorinated carboxylates (PFCAs) in different environmental and biological compartments have been known for some time, but the routes of exposure still remain unclear. The opinions are divergent whether the exposure to general populations occurs mainly indirect through precursor compounds or direct via PFCAs. Previous results showed elevated blood levels of PFCAs in ski wax technicians compared to a general population. The objective of this follow-up study was to determine concentrations of PFCAs, perfluorosulfonates (PFSAs), and fluorotelomer alcohols (FTOHs), precursor compounds that are known to degrade to PFCAs, in air collected in the breathing zone of ski wax technicians during work. We collected air samples by using ISOLUTE ENV+ cartridges connected to portable air pumps with an air flow of 2.0 L min-1. PFCAs C5-C11 and PFSAs C4, C6, C8, and C10 were analyzed using LC- MS/MS and FTOHs 6:2, 8:2, and 10:2 with GC-MS/MS. The results show daily inhalation exposure of 8:2 FTOH in μg/m³ air which is up to 800 times higher than levels of PFOA with individual levels ranging between 830-255000 ng/m³ air. This suggests internal exposure of PFOA through biotransformation of 8:2 FTOH to PFOA and PFNA in humans. [ABSTRACT FROM AUTHOR]

A time trend study focusing on ski waxing technicians' exposure to perfluorinated chemicals (PFCs) from fluorinated wax fumes was performed in 2001/2008. Levels of eight perfluorocarboxylates and three perfluorosulfonates ware analyzed in monthly blood samples from eight technicians. Samples ware collected before the ski season, i.e., preseason, then at four FIS World Cup competitions in cross country skiing, and finally during an unexposed 5-month postseason period. The perfluorinated carboxylates perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodacanoic acid (PFDA), and perfluoroundecanoic acid(PFUnDA) bioaccumulate, and continued exposure may contribute to elevated levels in ski technicians compared to the general population. The wax technicians' median blood level of PFOA is 112 ng/mL compared to 2.5 ng/mL in the general Swedish population. A significant correlation wan found between number of working years and levels of perfluorocarhoxylates. The PFOA levels in three technicians with "low" initial levels of PFOA (<10.0 ng/mL in preseason blood) increased by 254, 134, and 120%, whereas five technicians with "high" initial levels (>100 ng/mL in preseason sample) were at steady state. PFHxA is suggested to have a short half-life in humans relative the other perfluorocarboxylates. The levels of perfluorosulfonates were unaffected by the wax exposure. [ABSTRACT FROM AUTHOR]

Daily dietary intake of perfluorinated chemicals (PFCs) in relation to serum levels was assessed by determination of nine PFCs including perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in matched daily diet duplicates and serum samples. Diet and serum were collected in year 2004 from 20 women in Osaka and Miyagi, Japan. Only PFOS and PFOA were detected in the diet samples and no significant difference between cities was seen. After adjusted by water content, diet concentration of PFOA was significantly higher in Osaka. The median daily intake calculated using the measured diet concentrations was 1.47 ng PFOS/kg b.w. and 1.28 ng PFOA/kg b.w. for Osaka, and 1.08 ng PFOS/kg b.w. and 0.72 ng PFOA/kg b.w. for Miyagi. A significant difference between cities was seen for the serum concentrations with median of 31 ng/mL PFOS and PFOA in Osaka, compared to 14 ng/mL PFOS and 4.6 ng/mL PFOA in Miyagi. Carboxylates such as perfluorononanoic acid (PFNA) and perfluoroundecanoic acid (PFUnDA) were also detected in serum at median levels 6.9 ng/mL and 3.2 ng/mL (Osaka), and 2.8 ng/mL and 5.1 ng/mL (Miyagi). Based on one-compartment model under steady state, dietary intake of PFOS and PFOA accounted for only 22.4% and 23.7% of serum levels in Osaka females, and in contrast 92.5% and 110.6% in Miyagi females, respectively. [Copyright &y& Elsevier]

Abstract: Perfluorinated chemicals (PFCs) are analyzed in laboratories worldwide to determine human blood levels and exposure pathways. The development of the analytical technique has been rapid in the last 10 years, and prerequisites for accurate and precise determination of PFCs in human blood at low ng/g concentrations are today readily available. The main contributing factors are the improved LC–MS instrumentations, the increased availability of native and mass labeled PFC standards, and new column materials available for chromatographic separations. The results of the first international interlaboratory study (ILS) in 2005 on PFCs revealed relatively better analytical results for human blood analyses when compared to analyses of a number of environmental matrices. The representative accuracy for the analyses of PFCs in human matrixes reported in recent years was established in the second human serum ILS in 2006. Interlaboratory standard deviations for the two human serum samples one low level concentration and one medium level concentration were found to be 12% and 16% for PFOS, respectively, and 47% and 21% for PFOA, respectively. Reported detections for all PFCs followed a frequency of PFOS>PFOA>PFHxS>PFNA>PFDA≫PFDoA≫PFDS≫PFHxA. Due to the small number of reported values for the other perfluorosulfonates and perfluorocarboxylates, standard deviations were not established. [Copyright &y& Elsevier]

Although fluorotelomer alcohols (FTOHs) have been detected in various environmental matrices worldwide, no studies have been conducted to evaluate their concentrations in surface water or precipitation. Therefore, we developed a sensitive and reliable method to analyze various environmental aqueous samples for the presence of trace levels of 6:2 FTOH, 8:2 FTOH, 10:2 FTOH, 8:2 FTOAcr and 8:2 FTOMethacr FTOlefin using gas-chromatography/mass-spectrometry. The recoveries obtained using this method ranged from 57.8% to 78.2% and the detection limits were 0.5, 0.2, 0.2, 0.05 and 0.1ngL−1 for 6:2 FTOH, 8:2 FTOH, 10:2 FTOH, 8:2 FTOAcr and 8:2 FTOMethacr, respectively. Liquid and suspended phases of the examined samples were analyzed. The analysis revealed presence of telomer alcohols from the liquid phase only. Of the FTOHs evaluated, 6:2 FTOH and 8:2 FTOMethacr FTOlefin were not found in any of the environmental samples. The average concentrations of 8:2 FTOH, 10:2 FTOH and 8:2 FTOAcr of the precipitation samples were 1.97, 0.82 and 0.21ngL−1, respectively. In surface water samples, the highest concentrations of 8:2 FTOH, 10:2 FTOH and 8:2 FTOAcr were 3.38, 4.06 and 0.16ngL−1, which were observed in samples from the Daini-Neyagawa, Yamato and Kanzaki rivers, respectively. The total concentration of FTOHs in wastewater treatment plant effluents (23.2ngL−1) was much higher than that of surface water (10.8ngL−1). Taken together, the results of this study indicate that FTOHs released into the air contaminate rain and that those released from water disposal sites contaminate surface water. [Copyright &y& Elsevier]

Abstract: Human serum and plasma from Sweden (n =17), the United Kingdom (the UK) (n =13) and Australia (n =40) were analyzed by high performance liquid chromatography coupled to mass spectrometry. The objective was to identify different perfluorooctane sulfonate (PFOS) isomers. Similar isomer patterns typical for the electrochemical fluorination (ECF) process were found for all samples. The linear PFOS (L-PFOS) was the major isomer found (58–70%) followed by the monosubstituted PFOS isomers 1/6-CF3-PFOS (18–22%) and 3/4/5-CF3-PFOS (13–18%). Disubstituted isomers were also detected. The percentage of L-PFOS found in the serum and plasma samples was lower compared to a standard PFOS product (76–79%). The pattern of PFOS isomers in human serum and plasma may be suggestive concerning potential isomeric discrimination since PFOS is only produced by ECF. Possibilities for such isomer discrimination are discussed. Significant higher content of L-PFOS (68%) in Swedish samples compared to Australia and the UK (59%) was also found, which may suggest differences in exposure sources for humans. [Copyright &y& Elsevier]

BACKGROUND: Only limited data exist on lactation as an exposure source of persistent perfluorinated chemicals (PFCs) for children. OBJECTIVES: We studied occurrence and levels of PFCs in human milk in relation to maternal serum together with the temporal trend in milk levels between 1996 and 2004 in Sweden. Matched, individual human milk and serum samples from 12 primiparous women in Sweden were analyzed together with composite milk samples (25-90 women/year) from 1996 to 2004. RESULTS: Eight PFCs were detected in the serum samples, and five of them were also above the detection limits in the milk samples. Perfluorooctanesulfonate (PFOS) and perfluorohexanesulfonate (PFHxS) were detected in all milk samples at mean concentrations of 0.201 ng/mL and 0.085 ng/mL, respectively. Perfluorooctanesulfonamide (PFOSA), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were detected less frequently. DISCUSSION: The total PFC concentration in maternal serum was 32 ng/mL, and the corresponding milk concentration was 0.34 ng/mL. The PFOS milk level was on average 1% of the corresponding serum level. There was a strong association between increasing serum concentration and increasing milk concentration for PFOS (r² = 0.7) and PFHxS (r² = 0.8). PFOS and PFHxS levels in composite milk samples were relatively unchanged between 1996 and 2004, with a total variation of 20 and 32% coefficient of variation, respectively. CONCLUSION: The calculated total amount of PFCs transferred by lactation to a breast-fed infant in this study was approximately 200 ng/day. Lactation is a considerable source of exposure for infants, and reference concentrations for hazard assessments are needed. [ABSTRACT FROM AUTHOR]

Abstract: In order to evaluate blood levels of some perfluorinated chemicals (PFCs) and compare them to current levels of classical persistent organic pollutants (POPs) whole blood samples from Sweden were analyzed with respect to 12 PFCs, 37 polychlorinated biphenyls (PCBs), p,p′-dichlorodiphenyl-dichloroethylene (DDE), hexachlorobenzene (HCB), six chlordanes and three polybrominated diphenyl ethers (PBDEs). The median concentration, on whole blood basis, of the sum of PFCs was 20–50 times higher compared to the sum of PCBs and p,p′-DDE, 300–450 times higher than HCB, sum of chlordanes and sum of PBDEs. Estimations of the total body amount of PFCs and lipophilic POPs point at similar body burdens. While levels of for example PCBs and PBDEs are normalized to the lipid content of blood, there is no such general procedure for PFCs in blood. The distributions of a number of perfluorinated compounds between whole blood and plasma were therefore studied. Plasma concentrations were higher than whole blood concentrations for four perfluoroalkylated acids with plasma/whole blood ratios between 1.1 and 1.4, whereas the ratio for perflurooctanesulfonamide (PFOSA) was considerably lower (0.2). This suggests that the comparison of levels of PFCs determined in plasma with levels determined in whole blood should be made with caution. We also conclude that Swedish residents are exposed to a large number of PFCs to the same extent as in USA, Japan, Colombia and the few other countries from which data is available today. [Copyright &y& Elsevier]

Pooled serum samples from 3802 Australian residents were analyzed for four perfluoroalkylsulfonates, seven perfluoroalkylcarboxylates, and perfluorooctanesulfonamide (PFOSA). Serum was collected from men and women of five different age groups and from rural and urban regions in Australia. The highest mean concentration was obtained for perfluorooctane sulfonate (PFOS, 20.8 ng/mL) followed by perfluorooctanoic acid (PFOA, 7.6 ng/mL), perfluorohexane sulfonate (PFHxS, 6.2 ng/mL), perfluorononanoic acid (PFNA, 1.1 ng/mL), and PFOSA (0.71 ng/mL). Additional four PFCs were detected in 5-18% of the samples at concentrations near the detection limits (0.1–0.5 ng/mL). An increase in PFOS concentration with increasing age in both regions and genders was observed. The male pool levels of some of the age groups compared to females were higher for PFOS, PFOA, and PFHxS. In contrast, PFNA concentrations were higher in the female pools. No substantial difference was found in levels of PFCs between the urban and rural regions. The levels are equal or higher than previously reported serum levels in Europe and Asia but lower compared to the U.S.A. These results suggest that emissions from production in the Northern Hemisphere are of less importance for human exposure. [ABSTRACT FROM AUTHOR]

Since the detection of per- and polyfluoroalkyl substances (PFAS) in humans and different environmental media in the last two decades, this substance group has attracted a lot of attention as well as increasing concerns. The fluorine mass balance approach, by comparing the levels of targeted PFAS after conversion to fluorine equivalents with those of extractable organic fluorine (EOF), showed the presence of unidentified organofluorine in different environmental samples. Out of the thousands of PFAS in existence, only a very small fraction is included in routine analysis. In recent years, liquid chromatography coupled with tandem-mass spectrometry (LC-MS/MS) has demonstrated the ability to analytically cover a wide spectrum of PFAS. In contrast, conventional extraction methods developed 10 to 15 years ago were only evaluated for a limited number of PFAS. The aim of the present study was to evaluate the advantages and disadvantages of three different extraction methods, adapted from the literatures without further optimization (ion-pair liquid-liquid extraction, solid-phase extraction (SPE), using hydrophilic-lipophilic (HLB) or weak anion exchange (WAX) sorbents), for human biomonitoring of 61 PFAS in serum and placental tissue samples. In addition, levels of EOF were compared among these extraction methods via spiked samples. Results showed that performance, in terms of recovery, differed between the extraction methods for different PFAS; different extraction methods resulted in different EOF concentrations indicating that the choice of extraction method is important for target PFAS and EOF analysis. Results of maternal serum samples, analyzed in two different laboratories using two different extraction methods, showed an accordance of 107.6% (± 21.3); the detected perfluoroalkyl acids (PFAAs) in maternal and cord serum samples were in the range of 0.076 to 2.9 ng/mL. Graphical abstract [ABSTRACT FROM AUTHOR]

Ultra-short-chain perfluoroalkyl acids have recently gained attention due to increasing environmental concentrations being observed. The most well-known ultra-short-chain perfluoroalkyl acid is trifluoroacetic acid (TFA) which has been studied since the 1990s. Potential sources and the fate of ultra-short-chain perfluoroalkyl acids other than TFA are not well studied and data reporting their environmental occurrence is scarce. The analytical determination of ultra-short-chain perfluoroalkyl acids is challenging due to their high polarity resulting in low retention using reversed-phase liquid chromatography. Furthermore, recent studies have reported varying extraction recoveries in water samples depending on the water matrix and different methods have been suggested to increase the extraction recovery. The present review gives an overview of the currently used analytical methods and summarizes the findings regarding potential analytical challenges. In addition, the current state of knowledge regarding TFA and other ultra-short-chain perfluoroalkyl acids, namely perfluoropropanoic acid, trifluoromethane sulfonic acid, perfluoroethane sulfonic acid, and perfluoropropane sulfonic acid‚ are reviewed. Both known and potential sources as well as environmental concentrations are summarized and discussed together with their fate and the environmental and human implications. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl acids (PFAAs) are ubiquitous environmental contaminants and eggs and nestlings of raptors and fish-eating birds often contain high levels of PFAAs. We studied developmental effects of a mixture of ten PFAAs by exposing chicken embryos to 0.5 or 3 μg/g egg of each compound in the mixture. Histological changes of the thyroid gland were noted at both doses and increased expression of mRNA coding for type III deiodinase was found at 0.5 μg/g egg. Serum concentrations of the free fraction of thyroid hormones (T3 and T4) were reduced by the PFAA mixture at 3 µg/g egg, which is in line with a decreased synthesis and increased turnover of thyroid hormones as indicated by our histological findings and the decreased mRNA expression of type III deiodinase. The relative weight of the bursa of Fabricius increased at a dose of 3 μg/g egg in females. The bursa is the site of B-cell development in birds and is crucial for the avian adaptive immune system. Analysis of plasma and liver concentrations of the mixture components showed differences depending on chain length and functional group. Our results highlight the vulnerability of the thyroid hormone and immune systems to PFAAs. [ABSTRACT FROM AUTHOR]

Background While it is known that perfluoroalkyl substances (PFASs) induce liver toxicity in experimental studies, the evidence of an association in humans is inconsistent. Objective The main aim of the present study was to examine the association of PFAS concentrations and markers of liver function using panel data. Methods We investigated 1002 individuals from Sweden (50% women) at ages 70, 75 and 80 in 2001–2014. Eight PFASs were measured in plasma using isotope dilution ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS). Bilirubin and hepatic enzymes alanine aminotransferase (ALT), alkaline phosphatase (ALP), and γ-glutamyltransferase (GGT) were determined in serum using an immunoassay methodology. Mixed-effects linear regression models were used to examine the relationship between the changes in markers of liver function and changes in PFAS levels. Results The changes in majority of PFAS concentrations were positively associated with the changes in activity of ALT, ALP, and GGT and inversely associated with the changes in circulating bilirubin after adjustment for gender and the time-updated covariates LDL- and HDL-cholesterol, serum triglycerides, BMI, statin use, smoking, fasting glucose levels and correction for multiple testing. For example, changes in perfluorononanoic acid (PFNA) were associated with the changes liver function markers β BILIRUBIN  = −1.56, 95% confidence interval (CI) −1.93 to −1.19, β ALT  = 0.04, 95% CI 0.03–0.06, and β ALP  = 0.11, 95% CI 0.06–0.15. Conclusion Our longitudinal assessment established associations between changes in markers of liver function and changes in plasma PFAS concentrations. These findings suggest a relationship between low-dose background PFAS exposure and altered liver function in the general population. [ABSTRACT FROM AUTHOR]

Abstract: This study investigates the influence of biological and environmental factors on the concentrations of perfluoroalkyl acids (PFAAs) in a top predator; the American mink. Perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS) and perfluoroalkyl carboxylates (PFCAs) with C8–C13 perfluorinated carbon chains were analyzed in livers from wild male mink liver (n =101) from four areas in Sweden representing two inland environments (rural and highly anthropogenic, respectively) and two different coastal environments. Mean PFOS concentrations were 1250ng/g wet weight and some mink from the urban inland area had among the highest PFOS concentrations ever recorded in mink (up to 21 800ng/g wet weight). PFBS was detected in 89% of the samples, but in low concentrations (mean 0.6ng/g ww). There were significant differences in PFAA concentrations between the geographical areas (p<0.001–0.01). Age, body condition and body weight did not influence the concentrations significantly, but there was a seasonal influence on the concentrations of perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnDA) (p<0.01 and p<0.05, respectively), with lower concentrations in autumn samples than in samples taken in the winter and spring. It is thus recommended to take possible seasonal differences into account when using mink exposure data. The overall results suggest that the mink is a suitable sentinel species for assessing and monitoring environmental levels of PFAAs. [Copyright &y& Elsevier]

Abstract: Perfluoroalkyl acids (PFAAs) such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are developmental toxicants in various animal classes, including birds. Both compounds interact with peroxisome proliferator-activated receptors (PPARs), but it is not known whether activation of PPARs is involved in their embryo toxicity in birds. We exposed chicken embryos via egg injection at a late developmental stage to GW7647, a potent PPARα agonist in mammals, and to PFOS or PFOA. Mortality was induced by PFOS and PFOA but not by GW7647. Transcripts of a number of genes activated by PPARα agonists in mammals were analyzed in liver and kidney of 18-day-old embryos. Several of the genes were induced in both liver and kidney following exposure to GW7647. Treatment with PFOA resulted in induction of acyl-coenzyme A oxidase mRNA in liver, whereas none of the genes were significantly induced by PFOS treatment. No up-regulation of gene transcription was found in kidney following treatment with PFOS or PFOA. Principal component analysis showed that PFOA caused an mRNA expression pattern in liver more similar to the pattern induced by GW7647 than PFOS did. Our findings do not support that the embryo mortality by PFOS and PFOA in chicken embryos involves PPARα activation. [Copyright &y& Elsevier]

Recent developments, improvements, and trends in the ultra-trace determination of per- and polyfluoroalkyl substances (PFASs) in environmental and human samples are highlighted and the remaining challenges and uncertainties are outlined and discussed. Understanding the analytical implications of such things as adsorption of PFASs to surfaces, effects of differing matrices, varying PFAS isomer response factors, potential bias effects of sampling, sample preparation, and analysis is critical to measuring highly fluorinated compounds at trace levels. These intricate analytical issues and the potential consequences of ignoring to deal with them correctly are discussed and documented with examples. Isomer-specific analysis and the development of robust multi-chemical methods are identified as topical trends in method development for an ever-increasing number of PFASs of environmental and human interest. Ultimately, the state-of-the-art of current analytical method accuracy is discussed on the basis of results from interlaboratory comparison studies. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

[Display omitted] • A case study using EOF as a screening tool for PFAS in human blood is presented. • The EOF level was 9 times higher in exposed people, 234 ng/mL F vs. 24.8 ng/mL F. • The UOF fraction was more than 2 times lower in the exposed group, 37% vs 84%. The ubiquitous occurrence of a few per- and polyfluoroalkyl substances (PFAS) in humans and the environment has been previously reported. However, the number of PFAS humans and the environment are potentially exposed to is much higher, making it difficult to investigate every sample in detail. More importantly, recent studies have shown an increasing fraction of potentially unknown PFAS in human samples. A screening tool for identifying samples of concern that may contain high PFAS levels, to be studied more thoroughly, is needed. This study presents a simplified workflow to detect elevated PFAS levels using extractable organofluorine (EOF) analysis. A fluorine mass balance analysis on samples with high EOF, targeting 63 PFAS, can then confirm the PFAS contamination. Whole blood samples from a cohort of individuals with historical drinking water contamination from firefighting foams (n = 20) in Ronneby (Sweden) and a control group (n = 9) with background exposure were used as a case study. The average EOF concentration in the Ronneby group was 234 ng/mL F (<107–592 ng/mL F) vs 24.8 ng/mL F (17.6–37.8 ng/mL F) in the control group. The large difference (statistically significant, p < 0.05) in the EOF levels between the exposed and control groups would have made it possible to identify samples with high PFAS exposure only using EOF data. This was confirmed by target analysis, which found an average ∑PFAS concentration of 346 ng/mL in the exposed group and 7.9 ng/mL in the control group. The limit of quantification for EOF analysis (up to 107 ng/mL F using 0.5 mL whole blood) did not allow for the detection of PFAS levels in low or sub parts per billion (ng/mL) concentrations, but the results indicate that EOF analysis is a suitable screening method sensitive enough to detect elevated/significant/exposure above background levels by known or unknown PFAS. [ABSTRACT FROM AUTHOR]

We synthesize current understanding of the magnitudes and methods for assessing human and wildlife exposures to poly‐ and perfluoroalkyl substances (PFAS). Most human exposure assessments have focused on 2 to 5 legacy PFAS, and wildlife assessments are typically limited to targeted PFAS (up to ~30 substances). However, shifts in chemical production are occurring rapidly, and targeted methods for detecting PFAS have not kept pace with these changes. Total fluorine measurements complemented by suspect screening using high‐resolution mass spectrometry are thus emerging as essential tools for PFAS exposure assessment. Such methods enable researchers to better understand contributions from precursor compounds that degrade into terminal perfluoroalkyl acids. Available data suggest that diet is the major human exposure pathway for some PFAS, but there is large variability across populations and PFAS compounds. Additional data on total fluorine in exposure media and the fraction of unidentified organofluorine are needed. Drinking water has been established as the major exposure source in contaminated communities. As water supplies are remediated, for the general population, exposures from dust, personal care products, indoor environments, and other sources may be more important. A major challenge for exposure assessments is the lack of statistically representative population surveys. For wildlife, bioaccumulation processes differ substantially between PFAS and neutral lipophilic organic compounds, prompting a reevaluation of traditional bioaccumulation metrics. There is evidence that both phospholipids and proteins are important for the tissue partitioning and accumulation of PFAS. New mechanistic models for PFAS bioaccumulation are being developed that will assist in wildlife risk evaluations. Environ Toxicol Chem 2021;40:631–657. © 2020 SETAC [ABSTRACT FROM AUTHOR]

Background: Lipoproteins at aberrant levels are known to play a role in cardiovascular disease. The metabolite of the insecticide dichlorodiphenyltrichloroethane (DDT), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), physically associates with lipids and accumulates in adipose tissue. Little is known about which lipoproteins associate with p,p'-DDE. An association between p,p'-DDE exposure and altered levels of circulating lipids was assessed in a large human cohort using a detailed analysis of lipoprotein content. Methods: Plasma samples were collected from the subset of 75-year old Swedes in the Prospective Investigation of the Vasculature of Uppsala Seniors (PIVUS) cohort who were not prescribed lipid lowering medication (n = 571). p,p'-DDE concentrations in plasma were measured using high-throughput solid phase extraction and gas chromatography-high resolution mass spectrometry. Analysis of plasma lipoprotein content was performed with nuclear magnetic resonance spectroscopy. Results: Detectable levels of p,p'-DDE were found in the plasma samples of all subjects. Elevated p,p'-DDE levels were associated with increased concentrations of lipoproteins of all diameters, with the exception of high density lipoprotein (HDL) of diameters between 14.3 nm–10.9 nm. Of the lipoprotein constituents, triglycerides were most uniformly associated with elevated p,p'-DDE across lipoproteins. p,p'-DDE was furthermore associated with apolipoprotein B, but not apolipoprotein A1. Conclusions: The positive associations observed between each lipoprotein class and elevated p,p'-DDE support previous data suggesting that p,p'-DDE interacts with lipoproteins within plasma. It is speculated that both physio-chemical and biological mechanisms may explain why p,p'-DDE does not uniformly associate with lipids across lipoproteins. [ABSTRACT FROM AUTHOR]

Background Prospective cohort studies evaluating the temporal trends of background-level persistent organic pollutants (POPs) and their potential negative health effects in humans are needed. Objective The objectives of this study are to examine the five year longitudinal trend in chlorinated and brominated (Cl/Br) POP concentrations in a sample of elderly individuals and to investigate the relationship between gender, changes in body weight, plasma lipid levels and POP concentrations. Methods In the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, plasma samples were collected from the same individuals over a 5 year period. Originally 992 subjects (all aged 70) were sampled between 2001 and 2004 and 814 returning subjects (all aged 75) were sampled again from 2006 to 2009. Plasma concentrations of 16 polychlorinated biphenyls (PCBs), 5 organochlorine pesticides (OCPs), octachlorinated dibenzo- p -dioxin (OCDD), and one polybrominated diphenylether (BDE 47) were determined using high-throughput 96-well plate solid phase extraction and gas chromatography-high resolution mass spectrometry (GC-HRMS). Results During the 5-year follow-up, plasma concentrations of all POPs significantly decreased (p < 0.00001). Median reductions ranged from 4% (PCB105) to 45% (PCB 99), with most reductions being in the 30–40% range. For most POPs, a larger decline was seen in men than in women. The relationship between the weight change and change in POP concentrations was generally negative, but a positive relationship between lipid levels and POP concentrations when expressed as wet-weight was observed. In general, similar changes in POP concentrations and their relationships to body weight were observed regardless of using either wet-weight (pg/mL) or lipid-normalized (ng/g lipid) concentrations. Conclusion In this longitudinal cohort study, gender and minor, but varying changes in body weight and lipid levels greatly influenced the individual-based changes in POP concentrations. In general, our findings suggest that men and women with larger decreases in body weight and greater increases in lipid levels have the slowest decline in body burden of POPs. Based on the results from this study, either wet-weight or lipid normalized concentrations can be used to determine the percent change in POP concentrations and their relationships to physiological changes and differences. [ABSTRACT FROM AUTHOR]

The objective of this study was to develop and validate a 96-well plate solid phase extraction method for analysis of 23 lipophilic persistent organic pollutants (POPs) in low-volume plasma and serum samples which is applicable for biomonitoring and epidemiological studies. The analysis of selected markers for internal exposure: 16 polychlorinated biphenyls (PCBs), 5 organochlorine pesticides (OCPs), octachlorinated dibenzo- p -dioxin (OCDD), and polybrominated diphenylether 47 (BDE 47) was evaluated by comparing two SPE sorbents and GC-HRMS or GC–MS/MS detection. The final method extracted 23 POPs from 150 μL of serum and plasma using a 96-well extraction plate containing 60 mg Oasis HLB sorbent per well prior to GC-HRMS magnetic sector analysis. The extraction method was applied to 40 plasma samples collected for an epidemiological study. The recovery of selected POPs ranged from 31% to 63% (n = 48), and detection limits ranged from 2.2 to 45 pg/mL for PCBs, 4.2 to 167 pg/mL for OCPs, 7.8 pg/mL for OCDD and 6.1 pg/mL for BDE 47. This method showed good precision with relative standard deviations of selected POP concentrations in quality control samples (n = 48) ranging from 11% to 25%. The trueness was determined with standard reference material serum (n = 48) and the deviation from certified values ranged from 1 to 27%. Of the 23 POPs analyzed, 18 were detected in 43% to 100% of plasma samples collected for the epidemiological study. The method showed good robustness with low inter-well plate variation (11–31%) determined by twelve 96-well plate extractions, and can extract 96 samples, including quality controls and procedural blanks in 2–3 days. Comparison with GC–MS/MS analysis showed that similar concentrations (within 0.5% to 30%) of most POPs could be obtained with GC-APCI-MS/MS. Larger deviations were observed for PCB 194 (60%) and trans -nonachlor (43%). The developed method produces accurate concentrations of low-level marker POPs in plasma and serum, providing a suitable high-throughput sample preparation procedure for biomonitoring and epidemiological studies involving large sample size and limited sample volume. GC-HRMS was chosen over GC–MS/MS, however the latter showed promising results, and could be used as an alternative to GC-HRMS analysis for most POPs. [ABSTRACT FROM AUTHOR]

Background In 2012, drinking water contaminated with per- and polyfluoroalkyl substances (PFASs), foremost perfluorooctanesulfonic acid (PFOS) and perfluorohexanesulfonic acid (PFHxS) at levels over 20 ng/L and 40 ng/L, respectively, was confirmed in Uppsala, Sweden. Objectives We assessed how a longitudinally sampled cohort's temporal trend in PFAS plasma concentration was influenced by their residential location and determined the plausible association or disparity between the PFASs detected in the drinking water and the trend in the study cohort. Methods The Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort provided plasma samples three times from 2001 to 2014. Individuals maintaining the same zip code throughout the study (n = 399) were divided into a reference (no known PFAS exposure), low, intermediate and high exposure area depending on the proportion of contaminated drinking water received. Eight PFASs detected in the majority (75%) of the cohort's plasma samples were evaluated for significant changes in temporal PFAS concentrations using a random effects (mixed) model. Results PFHxS plasma concentrations continued to significantly increase in individuals living in areas receiving the largest percentage of contaminated drinking water (p < 0.0001), while PFOS showed an overall decrease. The temporal trend of other PFAS plasma concentrations did not show an association to the quality of drinking water received. Conclusions The distribution of contaminated drinking water had a direct effect on the trend in PFHxS plasma levels among the different exposure groups, resulting in increased concentrations over time, especially in the intermediate and high exposure areas. PFOS and the remaining PFASs did not show the same relationship, suggesting other sources of exposure influenced these PFAS plasma trends. [ABSTRACT FROM AUTHOR]

Poly- and perfluoroalkyl substances (PFASs) are a group of man-made fluorinated chemicals which have, at background levels, been associated with negative health effects in humans. Thus far, most human biomonitoring studies have evaluated the general change in PFAS concentration over time by continuously testing various individuals. This is one of the few studies to report the longitudinal trend of a range of PFAS concentrations in humans. In addition, this is the first known longitudinal study to include a large background level exposed cohort of both men and women with the same age and location who were repeatedly sampled from 2001 to 2014. The longitudinal change in concentration of eight PFASs detected in serum collected from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort were determined and compared to results from general population studies. The sex-dependent changes in PFAS concentrations over time were also assessed. Serum was sampled from the same individuals at ages 70 (collection period 2001–2004), 75 (2006–2009) and 80 (2011–2014,). Eight (C 6–11 ) of fourteen (C 4–13 ) analyzed PFASs were usually detected in over 75% of individuals and assessed using a random effects (mixed) model. In the 579 individuals attending all three examinations, PFOSA and PFOS concentrations significantly decreased, while the remaining six PFASs significantly increased between ages 70 and 75. However, between ages 75 and 80 all PFAS concentrations significantly decreased. Overall from age 70 to 80, concentrations of PFHxS, PFUnDA, PFNA, and PFDA showed a significant increase (7% to 34%), whereas concentrations of PFOSA, PFHpA, PFOS, and PFOA (− 75% to − 27%) significantly decreased. Over time PFHxS concentrations increased more among women, while PFHpA concentrations showed a greater decrease among men. From age 70 to age 80, spanning from 2001‐2004 to 2011–2014, the PIVUS cohort showed decreases in circulating levels of some PFASs phased out of production with the exception of PFHxS and C > 8 PFASs. Contrary to other studies, PFHxS concentrations showed the greatest overall increase, which is likely attributed to a local drinking water contamination incident. [ABSTRACT FROM AUTHOR]

The level of PFAS (per- and polyfluorinated alkyl substances) contamination in freshwater and terrestrial Swedish environments in 2013/2014 was assessed by analyzing a range of perfluorinated alkyl acids, fluorotelomer acids, sulfonamides, sulfonamidoethanols and polyfluoralkyl phosphate diesters (diPAPs) in predator bird eggs. Stable isotopes ( 13 C and 15 N) were analyzed to elucidate the dietary source. The tawny owl ( Strix aluco , n=10) and common kestrel ( Falco tinnunculus , n=40), two terrestrial species, and the osprey ( Pandion haliaetus , n=30), a freshwater specie were included. In addition, a temporal trend (1997–2001, 2008–2009, 2013) in osprey was studied as well. The PFAS profile was dominated by perfluorooctane sulfonic acid (PFOS) in eggs from osprey and tawny owl, while for common kestrel perfluorinated carboxylic acids (∑PFCA) exceeded the level of PFOS. PFOS concentration in osprey eggs remained at the same level between 1997 and 2001 and 2013. For the long-chained PFCAs, there were a significant increase in concentrations in osprey eggs between 1997 and 2001 and 2008–2009. The levels of PFOS and PFCAs were about 10 and five times higher, respectively, in osprey compared to tawny owl and common kestrel. Evidence of direct exposure from PFCA precursor compounds to birds in both freshwater and terrestrial environment was observed. Low levels of diPAPs were detected in a few samples of osprey (<0.02–2.4 ng/g) and common kestrel (<0.02–0.16 ng/g) eggs, and 6:2 FTSA was detected in a majority of the osprey eggs (<6.3–52 ng/g). One saturated telomer acid (7:3 FTCA), which is a transformation marker from precursor exposure, was detected in all species (<0.24–2.7 ng/g). The 15 N data showed higher levels in osprey eggs compared to tawny owl and common kestrel, indicating that they feed on a 2–3 times higher trophic level. We conclude that ospreys are continuously exposed to PFAS at levels where adverse toxic effects have been observed in birds. [ABSTRACT FROM AUTHOR]

Associations between per- and polyfluoroalkyl substances (PFAS), mainly PFOS and PFOA, and increased blood lipids have been reported primarily from cross-sectional studies. The aim of the present study was to investigate associations between multiple PFAS and blood lipids in a longitudinal fashion. A total of 864 men and women aged 70 years and free from lipid medication were included from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study from Uppsala Sweden, 614 and 404 of those were reinvestigated at age 75 and 80. At all three occasions, eight PFAS were measured in plasma using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were also measured in plasma at all three occasions. Mixed-effects linear regression models were used to examine the relationship between the changes in PFAS levels and changes in lipid levels. Changes in plasma levels of six out of the eight investigated PFAS were positively associated with changes in plasma lipids after adjustment for sex, change in body mass index (BMI), smoking, physical activity, statin use (age was the same in all subjects), and correction for multiple testing. For example, changes in perfluorodecanoic acid (PFDA) were positively associated with the changes in total cholesterol (β: 0.23, 95% confidence interval (CI): 0.14 to 0.32), triglycerides (β: 0.08, 95% CI: 0.04–0.12) and HDL-cholesterol (β: 0.08, 95% CI: 0.04–0.11). In this longitudinal study with three measurements over 10 years of both plasma PFAS and lipids, changes in six out of the eight investigated PFAS were positively associated with changes in plasma lipids, giving further support for a role of PFAS exposure in human lipid metabolism. [Display omitted] • Plasma levels of PFAS and lipids were measured three times over 10 years. • Six out of the eight analyzed PFAS were positively associated with plasma lipids. • This study gives further evidence of PFAS exposure in human lipid metabolism. [ABSTRACT FROM AUTHOR]

Abstract: In this study, the role that some food processing and packaging might play as a source of perfluorinated compounds (PFCs) through the diet was assessed. The levels of PFCs were determined in composite samples of veal steak (raw, grilled, and fried), pork loin (raw, grilled, and fried), chicken breast (raw, grilled, and fried), black pudding (uncooked), liver lamb (raw), marinated salmon (home-made and packaged), lettuce (fresh and packaged), pate of pork liver, foie gras of duck, frankfurt, sausages, chicken nuggets (fried), and common salt. Among the 11 PFCs analyzed, only PFHxS, PFOS, PFHxA, and PFOA were detected in at least one composite sample, while the levels of the remaining PFCs (PFBuS, PFHpA, PFNA, PFDA, PFUnDA, and PFDoDA) were under their respective detection limits. PFOS was the compound most frequently detected, being found in 8 of the 20 food items analyzed, while PFHxA was detected in samples of raw veal, chicken nuggets, frankfurt, sausages, and packaged lettuce. According to the results of the present study, it is not sufficiently clear if cooking with non-stick cookware, or packaging some foods, could contribute to a higher human exposure to PFCs. [Copyright &y& Elsevier]

Monitoring the vast number of micropollutants in the environment by using comprehensive chemical screening is a major analytical challenge. The aim of this study was to evaluate a comprehensive analysis method for screening purposes of fish muscle samples by comparing sample preparation methods for a broad range of mid-to non-polar contaminants. Five extraction and three clean-up methods were evaluated for the analysis of 60 compounds with a log Kow range between 0.8 and 8.3 in fish. Both fresh and freeze-dried muscle tissue and extraction sodium sulphate blanks were included to assess recoveries and matrix effects. The performance of the different methods was evaluated using both comprehensive target and nontarget analysis using high resolution mass spectrometry (HRMS). The results showed that open-column and ultrasonication extractions (recoveries mostly between 20 and 160 %) resulted in higher recoveries than accelerated solvent extraction (ASE) (recoveries mostly between 20 and 80 %) and bead mixer homogenization extractions (recoveries between 0 and 50 % for the whole Kow range). Multilayer silica was the clean-up method resulting in the lowest matrix effects and highest recoveries, however some compounds (mostly pesticides) were denatured under the acidic conditions used. The convenient and time efficient ultrasonication extraction followed by deactivated silica clean-up proved to be promising for both target and nontarget approaches. The large difference in recoveries and number of detected peaks using target and nontarget approaches between fresh and freeze-dried fish seen for all methods calls for careful consideration, and further studies are needed to improve performance for screening of mid-to non-polar compounds in freeze-dried fish. [Display omitted] • Comparison of extraction and clean-up methods for wet weight and freeze-dried fish. • Determination of recoveries and matrix effects for 60 relevant pollutants. • Sonication extraction followed by deactivated silica is the most suitable method. • Open-column and ASE extraction and multilayer silica can also be suitable. • Comparison of total and halogenated detected features applying nontarget approach. [ABSTRACT FROM AUTHOR]

The presence of unidentified organofluorine compounds (UOF) has been investigated in recent publication, but their environmental occurrence is still poorly understood. Fluorine mass balance analysis was performed on environmental samples from lake Mjøsa and river Alna (surface water (n = 9), sediment (n = 5) and fish liver (n = 4)) and sewage samples from Oslo (n = 5), to reveal to the fraction of UOF. In samples that had extractable organofluorine (EOF) concentrations above the limit of detection (LoD), more than 70% of their EOF could not be accounted for by the 37 PFAS monitored in this study. The surface water samples from lake Mjøsa had EOF concentrations several times higher than what has been reported elsewhere in Nordic nations. The flux of EOF in river Alna and selected sewage pipes revealed that it was 1-2 orders of magnitude higher than the flux of the measured PFAS. The elevated concentrations of EOF in all samples pose a potential health and environmental hazard, as their composition remains mostly unknown. [Display omitted] • 84–99% of EOF in surface water samples, sediment and fish was of unidentified origin. • Adding diPAPs, neutral PFAS, and chlorinated PFAS ethers did not have a large impact on the fluorine mass balance. • Trace levels of PFECHS were found in environmental and sewage samples. [ABSTRACT FROM AUTHOR]

The vast number of per- and polyfluoroalkyl substances (PFASs) that are in global commerce (n > 4700) pose immense challenges for environmental monitoring. The large discrepancy between this large number and the few PFASs usually monitored suggest that environmental exposure might be substantially underestimated. This study applied a workflow, which included analysis of total fluorine (TF), extractable organofluorine (EOF), 24 target PFASs and suspect screening. The workflow aimed to close the organofluorine mass balance and to tentatively identify overlooked PFASs in various matrices from an aqueous film forming foam (AFFF) contaminated pond and its adjacent riparian zone. PFAS target analysis revealed that water, aquatic invertebrates as well as emergent aquatic insects had high concentrations with up to 2870 ng L−1, 9230 ng g−1 dry weight (dw) and 1470 ng g−1 dw ∑ 24 PFASs, respectively. The EOF mass balance could be explained by target PFAS analysis for most biota samples such as aquatic invertebrates, emergent aquatic insects and terrestrial spiders and earthworms (i.e. EOF ≈ ∑ 24 PFASs). In the pond surface water, 42–58% of the EOF was not explained by target PFASs. However most new tentatively identified PFASs (n = 25) were detected in water, which could contribute to the unknown EOF. Nine suspects could be further identified, which where perfluoroalkyl sulfonamide-based compounds and derivatives that all have been found in historical AFFFs produced by electrochemical fluorination. One suspect, F5S-PFOS, was also detected for the first time in aquatic and terrestrial invertebrates. • Organofluorine (EOF), PFAS target and suspect screening analysis were combined. • Aquatic and terrestrial invertebrates from an AFFF impacted pond were analyzed. • For most biota ∑PFAS ≈ EOF concentrations. • Most newly identified PFASs (n = 25) found in water samples. • F5S-PFOS was detected for the first time in invertebrates. [ABSTRACT FROM AUTHOR]

• PFASs suspect screening by NORMAN suspect list exchange was examined. • In total, 116 PFASs were observed in firefighting foam impacted waters. • Proposed PFASs were classified by the characterizations (e.g., functional groups). • Long-chain PFASs were specifically found around the firefighting training area. • Drinking water treatment processes can form perfluoroalkyl sulfonic acids from their precursors. Per- and polyfluoroalkyl substances (PFASs) are a group of persistent contaminants detected in firefighting foam impacted waters. Previous studies have performed suspect and non-target screening by high-resolution mass spectrometry (HRMS) to determine the composition of PFAS contamination and to discover unknown PFASs. Here, we performed a profile analysis with suspect screening against two lists in the NORMAN Suspect List Exchange in firefighting foam impacted environmental and drinking water (n = 18) collected in Okinawa, Japan, in April 2019. Samples were analyzed by liquid chromatography (LC) quadrupole time-of-flight (QTOF) MS in electron spray ionization mode. Suspect screening returned 116 candidate PFASs with their molecular weights, functional groups, and perfluoroalkyl chain lengths. Long-chain perfluoroalkyl acids (PFAAs) and some of their precursors were specifically found around the firefighting training area. Short-chain PFAAs were assumed to be formed from precursors by environmental processes. Perfluoroalkyl sulfonamide precursors were found to be transformed to perfluoroalkyl sulfonic acids (PFSAs) in the drinking water treatment process. In contrast, biological activated carbon filtration formed perfluoroalkyl carboxylic acids (PFCAs). The PFAS profile showed that a large number of different substances needs to be considered. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Background: It has previously been reported that the environmental contaminants perfluoroalkyl substances (PFASs) are linked to atherosclerosis in cross-sectional studies. Since cross-sectional studies could be subject to reverse causation, the purpose of this study was to analyze if the longitudinal changes in PFASs during a 10-year follow-up were related to the change in carotid artery intima-media thickness (IMT, ultrasound) during the same period.Methods: In the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, 1016 individuals were investigated at age 70; 826 of them were reinvestigated at age 75 and 602 at age 80 years. Eight different PFASs were measured in plasma by ultra-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and IMT was measured at all three time points. Random-effects mixed regression models were used to examine the associations over time.Results: IMT increased 0.058 mm during the 10-year period (p < 0.0001). Following adjustment for baseline values of PFASs (age 70) and sex, the changes in plasma levels of 6 of the 8 measured PFASs were significantly related to the change in IMT over the 10-year follow-up period in a positive fashion (p < 0.0062 using Bonferroni correction for 8 tests). Further adjustment for traditional cardiovascular (CV) risk factors (HDL and LDL cholesterol, smoking, systolic blood pressure, statin use, fasting glucose and serum triglycerides) affected these relationships only marginally.Conclusion: The change in plasma levels of several PFASs during 10 years was positively related to increase in IMT seen during the same period, giving prospective evidence that PFASs might interfere with the atherosclerotic process. [ABSTRACT FROM AUTHOR]