Concentrations Of Polyfluoroalkyl Compounds Research Articles

Association between serum levels of TSH and free T4 and per- and polyfluoroalkyl compounds concentrations in pregnant women

Many per- and polyfluoralkyl substances (PFASs) may disrupt maternal thyroid hormone homeostasis in pregnancy. Concerns should be raised regarding the PFASs exposure in pregnant women because thyroid hormones are involved in the early development of the fetus. In this study, we measured the concentrations of 13 PFASs, including five novel short-chain PFASs, in serum from 123 pregnant women in Beijing, China. Linear regression models were used to investigate the association between thyroid-stimulating hormone (TSH) or free thyroxine (FT4) levels and PFASs concentrations under consideration of the impacts of pregnancy-induced physiological factors. We found that perfluorobutanoic acid (PFBA) (β=0.189, 95%CI=-0.039, 0.417, p=0.10) and perfluorodecanoic acid (PFDA) (β=-0.554, 95%CI=-1.16, 0.049, p=0.071) were suggestive of significant association with TSH in thyroid peroxidase antibody (TPOAb) negative women. No association was observed between all PFASs and FT4 levels after controlling for these confounding factors, such as BMI, gestational weight gain and maternal age. These findings suggest that it should pay more attention to the association between thyroid hormone levels and short-chain PFASs concentrations. Future studies could consider a greater sample and the inclusion of other clinical indicators of thyroid function, such as free T3 and total T3.

Occurrence and incidence of 18 per- and polyfluoroalkyl compounds in edible oils commonly consumed in Guiyang, China

ABSTRACTA systematic examination was conducted for the first time of a wide carbon-chain range of per- and polyfluoroalkyl compounds (PFASs) in 83 samples of edible vegetable and animal oils from Guiyang, China. The occurrence and levels of 18 PFASs in seven types of edible oil were analysed. Analytes were determined based on a simplified, sensitive and reliable solvent extraction and liquid chromatography-tandem mass spectrometry method. Ten target PFASs were found and the most frequently detected compounds with maximum concentration were PFOS (88%, 1.93 ng g–1), PFNA (55.4%; 6.76 ng g–1), PFHxS (39.8%; 0.36 ng g–1), and PFOA (16.9%; 0.15 ng g–1), respectively. The total PFASs concentrations ranged from 0.02 to 6.76 ng g–1, with a mean of 0.94 ng g–1. Significant differences of occurrence between vegetable oils and animal oils were demonstrated based on comparative analysis of the existing data. The investigation results showed that the effect of production reductions of PFOS and PFOA by regulatory was also reflected in edible oils. The dietary intakes of PFOS and PFOA for adults were estimated, which were lower than the available tolerable daily intake (TDI). Because of the global lack of food regulatory thresholds for most per- or polyfluoroalkyl compounds, it was difficult to draw any conclusion at this stage as to how human health is affected through exposure to these compounds. The baseline information of this study will assist in guiding the direction for future investigations and monitoring studies on occurrence, fate and human health-effect research of PFASs.

Serum Concentrations of Polyfluoroalkyl Compounds in Young Girls and Duration of Being Breast Fed

BACKGROUND: Polyfluoroalkyl compounds (PFCs) have been detected in human breast milk which is a major exposure source for lactating infants. The objective of this study was to determine if being br...

Maternal concentrations of polyfluoroalkyl compounds during pregnancy and fetal and postnatal growth in British girls.

Background: Prenatal exposures to polyfluoroalkyl compounds (PFCs) may be associated with adverse changes in fetal and postnatal growth.Objective: We explored associations of prenatal serum concentrations of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorohexane sulfonate (PFHxS) with fetal and postnatal growth in girls.Methods: We studied a sample of 447 singleton girls and their mothers participating in the Avon Longitudinal Study of Parents and Children (ALSPAC). Data on weight and length were obtained at birth and at 2, 9, and 20 months. Serum samples were obtained in 1991–1992, from mothers during pregnancy. We explored associations between prenatal PFC concentrations and weight at birth as well as longitudinal changes in weight-for-age SD scores between birth and 20 months.Results: PFOS (median, 19.6 ng/mL), PFOA (median, 3.7 ng/mL), and PFHxS (median, 1.6 ng/mL) were detected in 100% of samples. On average, girls born to mothers with prenatal concentrations of PFOS in the upper tertile weighed 140 g less [95% confidence interval (CI): –238, –42] at birth than girls born to mothers with concentrations in the lower tertile in adjusted models. Similar patterns were seen for PFOA (–133 g; 95% CI: –237, –30) and PFHxS (–108 g; 95% CI: –206, –10). At 20 months, however, girls born to mothers with prenatal concentrations of PFOS in the upper tertile weighed 580 g more (95% CI: 301, 858) when compared with those in the lower tertile. No differences in weight were found for PFOA and PFHxS.Conclusions: Girls with higher prenatal exposure to each of the PFCs examined were smaller at birth than those with lower exposure. In addition, those with higher exposure to PFOS were larger at 20 months.

Spatial distribution of per- and polyfluoroalkyl compounds in coastal waters from the East to South China Sea

The spatial distribution of per- and polyfluoroalkyl compounds (PFCs) were investigated in coastal waters collected onboard research vessel Snow Dragon from the East to South China Sea in 2010. All samples were prepared by solid-phase extraction and analyzed using high performance liquid chromatography/negative electrospray ionization-tandem mass spectrometry (HPLC/(−)ESI-MS/MS). Concentrations of 9 PFCs, including C 4 and C 8 (PFBS, PFOS) perfluoroalkyl sulfonate (PFSAs), C 5–C 9 and C 13 (PFPA, PFHxA, PFHpA, PFOA, PFNA, PFTriDA) perfluoroalkyl carboxylates (PFCAs), and N-ethyl perfluorooctane sulfonamide (EtFOSA) were quantified. The ΣPFC concentrations ranged from 133 pg/L to 3320 pg/L, with PFOA (37.5–1541 pg/L), PFBS (23.0–941 pg/L) and PFHpA (0–422 pg/L) as dominant compounds. Concentrations of PFCs were greater in coastal waters along Shanghai, Ningbo, Taizhou, Xiamen and along coastal cities of the Guangdong province compared to less populated areas along the east Chinese coast. Additionally, the comparison with other seawater PFC measurements showed lower levels in this study.

Wastewater Treatment Plant and Landfills as Sources of Polyfluoroalkyl Compounds to the Atmosphere

Polyfluoroalkyl compounds (PFCs) were determined in air around a wastewater treatment plant (WWTP) and two landfill sites using sorbent-impregnated polyurethane foam (SIP) disk passive air samplers in summer 2009. The samples were analyzed for five PFC classes (i.e., fluorotelomer alcohols (FTOHs), perfluorooctane sulfonamides (FOSAs), sulfonamidoethanols (FOSEs), perfluoroalkyl sulfonic acids (PFSAs), and perfluoroalkyl carboxylic acids (PFCAs)) to investigate their concentration in air, composition and emissions to the atmosphere. ∑PFC concentrations in air were 3-15 times higher within the WWTP (2280-24 040 pg/m(3)) and 5-30 times higher at the landfill sites (2780-26 430 pg/m(3)) compared to the reference sites (597-1600 pg/m3). Variations in the PFC pattern were observed between the WWTP and landfill sites and even within the WWTP site. For example, FTOHs were the predominant PFC class in air for all WWTP and landfill sites, with 6:2 FTOH as the dominant compound at the WWTP (895-12 290 pg/m(3)) and 8:2 FTOH dominating at the landfill sites (1290-17 380 pg/m(3)). Furthermore, perfluorooctane sulfonic acid (PFOS) was dominant within the WWTP (43-171 pg/m(3)), followed by perfluorobutanoic acid (PFBA) (55-116 pg/m(3)), while PFBA was dominant at the landfill sites (101-102 pg/m(3)). It is also noteworthy that the PFCA concentrations decreased with increasing chain length and that the emissions for the even chain length PFCAs outweighed emissions for the odd chain length compounds. Furthermore, highly elevated PFC concentrations were found near the aeration tanks compared to the other tanks (i.e., primary and secondary clarifier) and likely associated with increased volatilization during aeration that may be further enhanced through aqueous aerosol-mediated transport. ∑PFC yearly emissions estimated using a simplified dispersion model were 2560 g/year for the WWTP, 99 g/year for landfill site 1, and 1000 g/year for landfill site 2. These results highlight the important role of WWTPs and landfills as emission sources of PFCs to the atmosphere.

Air concentrations and particle–gas partitioning of polyfluoroalkyl compounds at a wastewater treatment plant

Environmental contextPolyfluoroalkyl compounds, widely used chemicals in consumer and industrial products, are global pollutants in the environment. Transport mechanisms and environmental pathways of these compounds, however, are not yet fully understood. We show that a wastewater treatment plant can be an important source for polyfluoroalkyl compounds to the atmosphere where they have the potential to be transported long distances. AbstractAn air sampling campaign was conducted at a wastewater treatment plant (WWTP) to investigate air concentrations and particle–gas partitioning of polyfluoroalkyl compounds (PFCs). Samples were collected at an aeration tank and a secondary clarifier using both active high volume samplers and passive samplers comprising sorbent-impregnated polyurethane foam (SIP) disks. Water to air transport of PFCs was believed to be enhanced at the aeration tank owing to aerosol-mediated transport caused by surface turbulence induced by aeration. Mean air concentrations of target PFCs at the aeration tank were enriched relative to the secondary clarifier by factors of ~19, ~4 and ~3 for ∑fluorotelomer alcohols (FTOHs) (11 000 v. 590 pg m–3), ∑perfluorooctane sulfonamides & perfluorooctane sulfonamidoethanols (FOSAs & FOSEs) (120 v. 30 pg m–3) and ∑perfluoroalkyl carboxylates & perfluoroalkyl sulfonates (PFCAs & PFSAs) (4000 v. 1300 pg m–3) respectively. The particle associated fraction in the atmosphere increased with increasing chain length for PFCAs (from 60 to 100%) and PFSAs were predominantly bound to particles (~98%). Lower fractions on particles were found for FTOHs (~3%), FOSAs (~30%) and FOSEs (~40%). The comparison of the active and passive air sampling showed good agreement.

Global Pilot Study of Legacy and Emerging Persistent Organic Pollutants using Sorbent-Impregnated Polyurethane Foam Disk Passive Air Samplers

Sorbent-impregnated polyurethane foam (SIP) disk passive air samplers were deployed alongside polyurethane foam (PUF) disk samplers at 20 sites during the 2009 spring sampling period of the Global Atmospheric Passive Sampling (GAPS) Network. The SIP disk samplers consisted of PUF disks impregnated with finely ground XAD-4 resin. The addition of XAD-4 greatly improves the sorptive capacity of the PUF disk samplers for more volatile and polar chemicals, and allows for linear-phase sampling over several weeks for these compounds. The SIP and PUF disks were analyzed for polychlorinated biphenyls (PCBs), neutral polyfluoroalkyl compounds (PFCs), and ionic PFCs. Correlations between sampler-derived air concentrations for PCBs in the PUF and SIP disks samplers were significant (p < 0.05). The SIP disks effectively captured 4-50% more of the low molecular weight PCBs than the PUF disks samplers, and the PUF disks also had limitations for time-weighted passive sampling of neutral PFCs in air. Theoretical uptake curves for PUF disks showed rapid equilibration occurring in just hours for 8:2 FTOH and in a few days for MeFOSE, while theoretical curves for SIP disks showed superior sampling profiles for the neutral PFCs. PFCs were measured on SIP disks at all sites with 8:2 FTOH being the dominant compound detected and urban centers (n = 3) having the highest total neutral PFC concentrations ranging from 51.7 to 248 pg/m(3). A positive correlation was found between the FTOHs and FOSAs/FOSEs (p < 0.001, Pearson correlation) indicating similar contamination sources. The SIP disk appears to be a promising passive air sampler for measuring both emerging and legacy POPs on a global scale. They can also be used as a complement to the PUF disk sampler for capturing broader classes of compounds, or as a replacement for PUF disks entirely, especially when longer than quarterly deployment periods are desired.

Distribution of polyfluoroalkyl compounds in water, suspended particulate matter and sediment from Tokyo Bay, Japan

This study examined the environmental behaviour and fate of polyfluoroalkyl compounds (PFCs) found in water, suspended particulate matter (SPM) and sediment. The sampling of the sediment was performed at two stations from Tokyo Bay, Japan, in 2008. In addition, a depth profile of seawater was collected at three water layers from both sampling stations. The ∑PFC concentrations ranged from 16.7 to 42.3 ng L −1 in the water column, from 6.4 to 15.1 ng g −1 dry weight (dw) in the SPM fraction and from 0.29 to 0.36 dw in surface sediment. The distribution of PFCs was found to depend on their physicochemical characteristics. While short-chain perfluoroalkyl carboxylic acids (PFCAs) (C < 7) were exclusively detected in the dissolved phase, longer-chain PFCAs (C ⩾ 7), perfluoroalkyl sulfonates (PFSAs), ethylperfluorooctane sulfonamidoacetic acid (EtFOSAA), and perfluorooctane sulfonamide (PFOSA) appeared to bind more strongly to particles. Results showed that the sorption of PFCs on SPM increases by 0.52–0.75 log units for each additional CF 2 moiety and that the sorption of PFSAs was 0.71–0.76 log units higher compared to the PFCA analogs. In addition, the sorption of PFCs was influenced by the organic carbon content. These data are essential for modelling the transport and environmental fate of PFCs.

Polyfluoroalkyl compounds in landfill leachates

Polyfluoroalkyl compounds (PFCs) are widely used in industry and consumer products. These products could end up finally in landfills where their leachates are a potential source for PFCs into the aqueous environment. In this study, samples of untreated and treated leachate from 22 landfill sites in Germany were analysed for 43 PFCs. SigmaPFC concentrations ranged from 31 to 12,819 ng/L in untreated leachate and 4-8060 ng/L in treated leachate. The dominating compounds in untreated leachate were perfluorobutanoic acid (PFBA) (mean contribution 27%) and perfluorobutane sulfonate (PFBS) (24%). The discharge of PFCs into the aqueous environment depended on the cleaning treatment systems. Membrane treatments (reverse osmosis and nanofiltrations) and activated carbon released lower concentrations of PFCs into the environment than cleaning systems using wet air oxidation or only biological treatment. The mass flows of summation operatorPFCs into the aqueous environment ranged between 0.08 and 956 mg/day.

Trends of polyfluoroalkyl compounds in marine biota and in humans

Environmental context Polyfluoroalkyl compounds are used in a variety of industrial and consumer applications, including polymer production and for surface treatment of textiles and paper. Research over the last 10 years has shown that these compounds are ubiquitous environmental contaminants – they are extremely persistent, show toxic effects and accumulate in the food chain. We evaluate global, temporal and spatial trends of these important emerging contaminants. Abstract This review gives an overview of existing knowledge of polyfluoroalkyl compounds (PFCs) in humans and in marine biota. Temporal trends and spatial distribution of PFCs were globally compared in humans, marine mammals, seabirds and fish. In general, PFC concentrations in the environment have increased significantly from the beginning of the production up to the 1990s. After the phase-out of perfluorooctane sulfonyl fluoride (POSF) production starting in 2000, PFC concentrations in humans generally decreased. In marine biota no clear temporal trends were observed. The temporal trends depended on the species, their trophic levels and the geographical locations. PFC patterns in humans and in marine wildlife species were compared regarding perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), their shorter and longer chain homologues (C4–C15) and precursor compounds. Finally knowledge gaps were identified and recommendations for future work were presented.

Spatial distribution of polyfluoroalkyl compounds in dab (Limanda limanda) bile fluids from Iceland and the North Sea

The spatial distribution of polyfluoroalkyl compounds (PFCs) was investigated in dab (Limanda limanda) bile fluids collected from Iceland and the North Sea. Concentrations of various PFCs, including perfluorinated sulfonates (C4–C6, C8 PFSAs), perfluorinated carboxylic acids (C9–C14 PFCAs) and n-methyl perfluorooctane sulfonamidoethanol (MeFOSE), were quantified. Perfluorooctane sulfonate (PFOS) was the predominant compound with highest concentrations along the Danish and German coast (mean 9.36ng/g wet weight (ww)). Significantly lower PFOS concentrations were found at the other sampling stations in the North Sea and Iceland (p<0.01, t-test). Conversely, the spatial distribution of the PFCAs in Iceland and the North Sea was more uniform. The most abundant PFCA was perfluorononanoic acid (PFNA), while the mean concentration decreased with increasing chain length from 4.7ng/g ww for PFNA to 0.04ng/gww for perfluorotetradecanoic acid (PFTeDA). Overall, the different spatial distribution of PFCs indicates different origin of sources and different transportation mechanism.

Spatial distribution of polyfluoroalkyl compounds in seawater of the German Bight

The spatial distribution of polyfluoroalkyl compounds (PFCs) and their composition profile was investigated in 48 water samples collected from the German Bight. All samples were prepared by solid-phase extraction with Strata XAW cartridges and analysed using high performance liquid chromatography/negative electrospray ionisation–tandem mass spectrometry (HPLC/(−)ESI–MS/MS). Concentrations of various PFCs, including perfluorinated sulfonates (PFSAs), perfluorinated carboxylic acids (PFCAs), unsaturated fluorotelomercarboxylic acids, perfluoralkyl sulfonamide and sulfonamidoethanol, were quantified. The ∑PFC concentration ranges from 9.36 ng L −1 to 31.2 ng L −1, while perfluorobutane sulfonate (PFBS, 3.38–17.7 ng L −1) and perfluorooctanoic acid (PFOA, 2.67–7.83 ng L −1) dominated. The rivers Elbe, Weser and Ems had a high influence on the distribution of most PFCs in the German Bight, with maximum PFC concentrations found in their estuaries, and concentrations decreasing with increasing distance from the coast. Conversely, PFBS had its maximum concentration not in the estuaries but in the western German Bight, which suggest an additional source, where PFBS was transported into the German Bight with the westerly current.

Temporal trends of polyfluoroalkyl compounds in harbor seals ( Phoca vitulina) from the German Bight, 1999–2008

Temporal trends of polyfluoroalkyl compounds (PFCs) were examined in liver samples from harbor seals ( Phoca vitulina) collected from the German Bight (1999–2008). Concentrations of various PFCs, including C 4–C 10 perfluoroalkyl sulfonates (PFSAs), perfluorooctane sulfinate (PFOSi), perfluorooctane sulfonamide (FOSA) and C 8–C 15 perfluoroalkyl carboxylic acids (PFCAs) were quantified. Perfluorooctane sulfonate (PFOS) was the predominant compound with a maximum concentration of 3676 ng g −1 ww (1996), making up on average 94% of the measured PFCs. Significantly higher concentrations were found in <7 month old in comparison to ⩾7 month old harbor seals for C 6–C 8 PFSAs, perfluorododecanoic acid (PFDoDA) and FOSA, whereas perfluorodecanoic acid (PFDA) showed significantly lower concentrations in the younger harbor seals ( p < 0.05). These results suggest a transplacental transfer of PFCs to the foetus and/or consumption of different contaminated food. Regression analysis of logarithmic transformed PFC mean concentrations indicated a significant temporal trend with decreasing concentrations for C 5–C 7 PFSAs ( p < 0.001), PFOSi ( p = 0.028), FOSA ( p < 0.001) and perfluorooctanoic acid (PFOA) ( p = 0.031) between 1999 and 2008. Furthermore, PFOS decreased by 49% between 1999 and 2008, which correspond with decreasing concentration levels of its metabolic precursors PFOSi and FOSA of 83% and 95% in the same time period. However, the decreasing trend of PFOS is not significant ( p = 0.067). The reason for the decline during the past 10 years could be an effect of the replacement of these PFCs by shorter chained and less bioaccumulative compounds. But the observations of increasing perfluorodecane sulfonate (PFDS) levels ( p = 0.070), the high concentrations of PFOS and constant levels of C 9–C 13 PFCAs indicates that further work on the reduction of environmental emissions of PFCs are necessary.

PFOS and PFOA in Humans: New Study Links Prenatal Exposure to Lower Birth Weight

Scientists have accumulated a wealth of evidence that perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA, also known as perfluorooctanoic acid) accumulate in the environment and humans. Animal studies have shown these compounds to cause a variety of health effects, including reduced birth size and infant mortality. Now researchers are presenting the first evidence to suggest that human exposure to the chemicals is linked to reduced birth weight [EHP 115:1670–1676; Apelberg et al.].

Serum Concentrations of 11 Polyfluoroalkyl Compounds in the U.S. Population: Data from the National Health and Nutrition Examination Survey (NHANES) 1999−2000

We measured the concentrations of 11 polyfluoroalkyl compounds (PFCs), including perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonic acid (PFHxS) in 1562 serum samples collected from a representative U.S. population 12 years of age and older in the 1999-2000 National Health and Nutrition Examination Survey. Participants represented both sexes, three race/ethnicities (non-Hispanic blacks, non-Hispanic whites, and Mexican-Americans), and four age categories (12-19 years, 20-39 years, 40-59 years, and 60 years and older). PFCs were extracted from 100 microL of serum using on-line solid-phase extraction coupled to isotope dilution-high performance liquid chromatography-tandem mass spectrometry; limits of detection ranged from 0.05 to 0.2 ng/ mL. PFOS, PFOA, PFHxS, and perfluorooctane sulfonamide were detected in all samples analyzed; 2-(N-ethyl-perfluorooctane sulfonamido) acetic acid, 2-(N-methyl-perfluorooctane sulfonamido) acetic acid, and perfluorononanoic acid were detected in more than 90% of samples, which suggests prevalent exposures to several PFCs in the U.S. population. The concentrations of most PFCs were similar regardless of the participants' ages but were higher in males than in females. Mexican Americans had lower concentrations than non-Hispanic blacks and non-Hispanic whites, whose concentrations were similar. Higher education was associated with higher concentrations of PFOS and PFOA. These data will serve as a nationally representative baseline of the U.S. population's exposure to PFCs to which other populations can be compared, and will play an important role in public health by helping set research priorities, ranging from health effects studies to defining sources and pathways of exposure.