Global quantification of emerging and legacy per- and polyfluoroalkyl substances in indoor dust: Levels, profiles and human exposure.

This study investigated the occurrence and distribution of per- and polyfluoroalkyl substances (PFASs) in house dust samples from six regions across four continents. PFASs were detected in all indoor dust samples, with total median concentrations ranging from 17.3 to 197 ng/g. Among the thirty-one PFAS analytes, eight compounds, including emerging PFASs, exhibited high detection frequencies in house dust from all six locations. The levels of PFASs varied by region, with higher concentrations found in Adelaide (Australia), Tianjin (China), and Carbondale (United States, U.S.). Moreover, PFAS composition profiles also differed among regions. Dust from Australia and the U.S. contained high levels of 6:2 fluorotelomer phosphate ester (6:2 diPAP), while perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were predominant in other regions. Furthermore, our results indicate that socioeconomic factors impact PFAS levels. The assessment of human exposure through dust ingestion and dermal contact indicates that toddlers may experience higher exposure levels than adults. However, the hazard quotients of PFASs for both toddlers and adults were below one, indicating significant health risks are unlikely. Our study highlights the widespread occurrence of PFASs in global indoor dust and the need for continued monitoring and regulation of these chemicals.

[Contamination levels of perfluorinated and polyfluoroalkyl compounds in breast milk and assessment of their exposure risk to infants].

The purposes of this study are to explore the contamination levels of perfluorinated and polyfluoroalkyl substances (PFASs) in breast milk and assess their exposure risk to infants. Based on data from a birth cohort study conducted in Yingcheng, Hubei Province, from 2018 to 2021, the contents of 23 types of PFASs in the breast milk of 324 pregnant women were determined using isotope dilution-high performance liquid chromatography-tandem mass spectrometry. Multiple linear regression was then performed to analyze the effects of various demographic characteristics and eating habits on the concentration of PFASs in breast milk. The daily PFASs intake of infants through breast milk was estimated, and the exposure risk of infants was also assessed. The results revealed that 23 types of PFASs in breast milk had good linear relationships in the range of 0.2-100 ng/mL, with correlation coefficients greater than 0.992. The limits of detection were 5-42 pg/mL, the limits of quantification were 15-126 pg/mL, the recoveries were 65.6%-108.1%, and the relative standard deviations were 1.6%-12.8%. Perfluorooctane sulfonic acid (PFOS), perfluorooctanoate acid (PFOA), and perfluorohexanesulfonic acid (PFHxS), with median concentrations of 200.7, 63.5, and 25.2 pg/mL, respectively, were the main PFASs found in breast milk. The detection rates of these three contaminants were higher than 80%, whereas the detection rates of other compounds were lower than 45%. The results of multiple linear regression showed that older pregnant women and a higher frequency of pickled food intake may be related to increased PFAS levels in breast milk whereas a higher frequency of legume intake may be related to decreased PFAS levels in breast milk. The median estimated daily intakes (EDIs) of PFOS, PFOA, and PFHxS for infants were 25.1, 7.9, and 3.2 ng/(kg·d), respectively. In summary, this study found notable PFAS levels in breast milk in Yingcheng, Hubei Province. Among these PFASs, PFOS, PFOA, and PFHxS were the main contaminants. Maternal age as well as pickled food and legume intake may affect the PFAS level in breast milk. The health risk of PFAS intake through breast milk to some infants is worthy of attention and further study.

Human health risk-based soil generic assessment criteria of representative perfluoroalkyl acids (PFAAs) under the agricultural land use in typical Chinese regions.

Perfluoroalkyl acid substances (PFAAs), such as perfluorobutanoic acid (PFBA), perfluorobutanoic sulfonic acid (PFBS), perfluorooctane acid (PFOA) and perfluoroooctane sulfonic acid (PFOS) are frequently detected in the global environment and can cause potential health hazards even at low levels. In this study, quantitative human health risk assessment was undertaken to derive soil generic assessment criteria (GAC) for four PFAAs under the agricultural land scenario in the evaluated Chinese regions, which considered multiple exposure pathways including vegetables consumption, dermal absorption, ingestion of soil and dust, and exposure from non-soil sources. It is showed that the calculated GAC for four PFAAs in Guangdong and Shandong Provinces were less stringent than those in Zhejiang and Jiangsu Provinces, and Shanghai City, owing to the low exposure from non-soil sources in former two provinces. In addition, GAC of PFOS were the most stringent in the range of 0.28-0.50 µg kg-1 in the studied regions, followed by PFOA (1.36-2.20 µg kg-1), PFBA (42.59-68.03 µg kg-1) and PFBS (474.59-749.60 µg kg-1), mainly attributable to significantly more stringent toxicological values of PFOA and PFOS. Correspondingly, the potential health hazards exist for PFOA in the studied regions except Guangdong Province, and PFOS only in Zhejiang and Jiangsu Provinces as indicated by the hazard quotients ranging from 1.04 to 19.49, but no health hazards are identified for PFBA and PFBS. The dominant exposure pathway was found to be consumption of vegetables and attached soil for PFBA and PFBS, contributing to more than 93% of the total exposure, compared to 49.91-76.69% for PFOA and PFOS due to significant exposure from non-soil sources levels. Overall, this study provides a technical reference on how to derive scientifically justifiable soil GAC for representative PFAAs for maintaining and assessing soil quality and food safety internationally under the agricultural land use.

Perfluoroalkyl substances in Romanian wastewater treatment plants: Transfer to surface waters, environmental and human risk assessment.

The current study aimed to determine the concentration levels of nine perfluoroalkyl substances (PFAS) in the five most significant Romanian wastewater treatment plants (WWTPs) and their transfer to natural receivers. The analytes were concentrated using a solid-phase extraction/ultrasonic-assisted extraction procedures and then selectively quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) using electrospray ionization. In most of the wastewater samples investigated, the dominant compounds were perfluoropentanoic acid (PFPeA), perfluorooctanoic acid (PFOA), and perfluorooctansulfonate acid (PFOS), with the maximum concentration range between 105 and 316 ng/L in influents, 14.8-31.3 ng/L in effluents and removal efficiencies higher than 80 % for all selected PFAS compounds. In sewage sludge samples, PFOA and PFOS were the majority substances, with values up to 35.8 ng/g dw for PFOA and 27.8 ng/g dw for PFOS. PFOA and PFOS achieved the maximum levels by estimating mass loading and emission levels. As a result, 237 mg/day/1000 people of PFOA and 95.5 mg/day/1000 people of PFOS are entering daily in the WWTPs, while up to 31 mg/day/1000 people of PFOA and up to 13.6 mg/day/1000 people of PFOS are discharged daily into the natural emissaries. Human risk assessment shows that PFOA and PFOS are low to high risk for all age and gender categories. Children are the most exposed to PFOA and PFOS contamination in drinking water. Environmental risk assessment reveals that PFOA exhibits a low risk for some insect species, PFOS - a low risk for freshwater shrimps and a medium risk for midges, while perfluoroundecanoic acid (PFNuDA) could have a low to medium risk for midges. No assessment studies regarding the environmental and human risk of PFAS have been performed in Romania.

Occurrence, distribution, and risk assessment of perfluoroalkyl acids in drinking water sources from the lower Yangtze River.

The occurrence, spatial distribution, potential sources, and risk assessment of 14 perfluoroalkyl acids (PFAAs), including 11 perfluoroalkyl carboxylic acids and 3 perfluoroalkyl sulfonates acids, were investigated in 21 drinking water sources from the lower Yangtze River in November 2019. The total PFAAs (∑PFAAs) concentrations ranged from 39.3 to 220.3 ng/L, and perfluorooctanoic acid and perfluorooctanesulfonate were predominant with average concentrations of 19.4 and 15.4 ng/L, respectively. The higher ∑PFAAs concentrations in the southern shore and downstream could be attributed to industrial development and surface runoff/tide currents, respectively. Principal component analysis-multiple linear regression revealed that the primary sources of PFAAs were fluororesin coatings/metal plating, surface runoff/textile, effluent discharge/food packaging, and leather/fabrics. Human intake risks of PFAAs were assessed by target hazard quotient (THQ), which showed that human health risks of PFAAs decreased with increasing age, excluding 13-17 years age group. Moreover, the total exposure risks of PFOA/PFOS in all sampling sites to people aged over 18 years calculated based on contribution from drinking water were noted to be at safe level. The results obtained were helpful for improving our understanding of human health risks of PFAAs, and expanding our knowledge on PFAAs in drinking water.

Determination and risk assessment of perfluorinated alkylated substances (PFASs) in pork liver from mainland, China.

Animal-origin food has been suggested as the main dietary source of perfluorinated alkylated substances (PFASs) for humans, and pork liver is a major contributor. The nationwide survey data of PFASs from pork liver in China was limited. This study determined 17 PFASs in pork liver samples from 30 regions including different provinces, autonomous regions and municipalities, using traditional high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The average detection rate of PFASs (≥the limit of detection, LOD) in pork liver samples throughout China reached 97.4%, with ΣPFASs of 1.80 µg/kg. Both in areas with well-developed manufacturing industries and in non-production areas of perfluorinated compounds, PFASs were widely detectable in pork liver samples, especially for perfluorooctanoic acid (PFOA) and perfluorooctane sulphonate (PFOS). The detection rates of PFOA and PFOS (≥LOD) were 77.0% and 86.1%, with contents of 0.160 µg/kg and 0.397 µg/kg. The risk assessments of PFOA and PFOS from pork liver for different populations demonstrated the necessity for continuous exposure monitoring and risk investigation of PFASs. This work accomplished systematic and nationwide determination data of PFASs in pork liver, and provides a valuable reference for contamination monitoring and risk assessment of PFASs from animal origin food.

Sociodemographic and behavioral determinants of serum concentrations of per- and polyfluoroalkyl substances in a community highly exposed to aqueous film-forming foam contaminants in drinking water.

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) are a chemical class widely used in industrial and commercial applications because of their unique physical and chemical properties. Between 2013 and 2016 PFAS were detected in public water systems and private wells in El Paso County, Colorado. The contamination was likely due to aqueous film forming foams used at a nearby Air Force base. OBJECTIVE: To cross-sectionally describe the serum concentrations of PFAS in a highly exposed community, estimate associations with drinking water source, and explore potential demographic and behavioral predictors. METHODS: In June 2018, serum PFAS concentrations were quantified and questionnaires administered in 213 non-smoking adult (ages 19-93) participants residing in three affected water districts. Twenty PFAS were quantified and those detected in >50% of participants were analyzed: perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorononanoate (PFNA) and perfluoroheptane sulfonate (PFHpS). Unadjusted associations were estimated between serum PFAS concentrations and several predictors, including water consumption, demographics, personal behaviors and employment. A multiple linear regression model estimated adjusted associations with smoking history. RESULTS: Study participants' median PFHxS serum concentration (14.8 ng/mL) was approximately 12 times as high as the U.S. national average. Median serum concentrations for PFOS, PFOA, PFNA and PFHpS were 9.7 ng/mL, 3.0 ng/mL, 0.4 ng/mL and 0.2 ng/mL, respectively. Determinants of PFHxS serum concentrations were water district of residence, frequency of bottled water consumption, age, race/ethnicity, and smoking history. Determinants of serum concentrations for the other four PFAS evaluated included: water district of residence, bottled water consumption, age, sex, race/ethnicity, smoking history, and firefighter or military employment. CONCLUSIONS: Determinants of serum concentrations for multiple PFAS, including PFHxS, included water district of residence and frequency of bottled water consumption. Participants' dominant PFAS exposure route was likely consumption of PFAS-contaminated water, but certain demographic and behavioral characteristics also predicted serum concentrations.

Perfluorinated Compounds (PFCs) in Soil of the Pearl River Delta, China: Spatial Distribution, Sources, and Ecological Risk Assessment.

This study investigated the levels, spatial distribution, sources, and ecological risks of 16 perfluorinated compounds (PFCs) in 68 surface soil samples (0-20 cm) from 7 cities in the Pearl River Delta (PRD), China. Sixteen target PFCs, including perfluoroalkyl carboxylic acids (PFCAs, C5-C14, C16, and C18) and perfluoroalkyl sulfonic acids (PFSAs, C4, C6, C8, and C10), were analyzed by high-performance liquid chromatography-negative electrospray ionization-tandem mass spectrometry (HPLC/ESI-MS/MS). Concentrations of total PFCs (∑PFCs) ranged from 2.19 to 98.5 µg kg-1 (dry weight, dw), with an average of 5.97 µg kg-1 dw. Perfluorooctane sulfonate (PFOS) was the dominant PFC, accounting for 23.9% of ∑PFCs. The highest ∑PFCs was found in the soil sample collected from Dongguan with a large number of manufacturing industries. There were no significant differences of ∑PFCs among unban, industrial, and agricultural soils, indicating similar pollution sources in soil of the PRD. More than 70% of ∑PFCs in soil of the PRD could be attributed to the four principal components, represented by PFOS and perfluorooctanoic acid (PFOA), perfluoropentanoic acid (PFPeA) and perfluorohexanoic acid (PFHxA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUdA). Ecological risk assessment indicated that PFOA had low risk to soil plants and animals. However, the risk of PFOS to soil plants was relatively high in some studied regions.

Perfluoroalkyl acids (PFAAs): Distribution, trends and aquatic ecological risk assessment in surface water from Tagus River basin (Spain).

Rivers can receive the input of treated or untreated sewage effluents from wastewater treatment plants, urban and industrial discharges and agricultural run-off, becoming an important pathway for the transport and mobilization of pollutants to the oceans. In the present study, the occurrence of 20 PFAAs was determined in the water of Tagus River basin (Spain). PFAAs were detected in 76 out of 92 water samples collected during 5 years (2013-2018), being perfluorooctanesulfonic acid (PFOS) the predominant compound (<0.01-34 ng/L). The annual average PFOS concentrations (2.9-11 ng/L) detected in Tagus River were above the annual average environmental quality standards (AA-EQS) established in the Directive, 2013/39/EU (0.65 ng/L for inland surface waters) but below the maximum allowable concentration (MAC-EQS; 36000 ng/L). The levels of PFAAs detected in urban and industrial areas were statistically higher (p < 0.01) than those at background or remote areas. The mass flow rates amounted to <0.01-46 kg/y for PFOS and <0.01-22 kg/y for perfluorooctanoic acid (PFOA). A quantitative ecotoxicological risk assessment was conducted to evaluate the environmental potential risk related to PFAAs in the aquatic ecosystem. Risk characterization ratios (RCRwater, RCRsed and RCRoral, fish) were below 1 in all cases.

Exposure assessment to parabens, bisphenol A and perfluoroalkyl compounds in children, women and men by hair analysis.

Population is continuously exposed to endocrine disrupting compounds present in everyday products such as parabens, bisphenol A (BPA), and perfluoroalkyl compounds (PFCs). The aims of this study were, first, to evaluate human exposure to three parabens (methylparaben (MeP), ethylparaben (EtP) and propylparaben (PrP)), BPA and six PFCs (perfluorobutanoic acid, perfluoropentanoic acid, perfluorohexanoic acid, perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS)) through the analysis of hair samples from children, women and men and, then, to evaluate possible relationships between pollutant concentration in hair and age, gender, smoking and dyeing habits or hair colour. Hair samples were collected from 42 volunteers from Seville (Spain) (10 children, 16 women and 16 men). Six of the monitored pollutants (MeP, EtP, PrP, BPA, PFHpA and PFOS) were detected in at least 76% of the samples analysed. The highest concentrations and frequency of detection (100% of the samples) corresponded to MeP and PrP (up to 14,187 and 9009 ng/g, respectively). BPA was found in 83% of the samples at concentrations in the range from 24 to 1427 ng/g whereas PFCs were detected at concentrations in the range from 0.6 to 15.5 ng/g, being PFHpA and PFOS the ones most frequently detected (86% and 76%, respectively). Concentrations of BPA and parabens in adults were statistically higher than those in children. The results of this study reveal the suitability of hair for biomonitoring endocrine disrupting compounds of high concern (PFCs, parabens and BPA) to which population is internally or/and externally but continuously exposed.

High contamination, bioaccumulation and risk assessment of perfluoroalkyl substances in multiple environmental media at the Baiyangdian Lake.

The contamination of perfluoroalkyl substances (PFASs) in the Baiyangdian Lake has exacerbated readily since 2008. This study analyzed the perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs) in the surface water, sediment, and fish of the Baiyangdian Lake. In the surface water, the total concentration of PFASs ranged in 1193-3462 ng L-1 (mean 1734 ng L-1) in the rainy season and 469-1724 ng L-1 (mean 876 ng L-1) in the dry season. The total concentration of PFASs in the sediment ranged in 1.97-13.3 ng g-1 (mean 6.53 ng g-1). It was found that PFCAs and PFSAs with longer chains were more easily adsorbed in the sediment. Among the collected fish samples, the enrichment of PFASs in the tissues fell in the order of liver > cheek > muscle. For the muscle, stomach, and liver tissues of the fish samples, significant correlations existed between the δ15N values and the concentration of perfluorooctane sulfonic acid (PFOS). The contents of PFOS and perfluorooctanoic acid (PFOA) in the fish were not at a level high enough to significantly risk human health.

The occurrence of perfluoroalkyl acids in an important feed material (fishmeal) and its potential risk through the farm-to-fork pathway to humans.

Few studies have attempted to elucidate the occurrence of perfluoroalkyl acids (PFAAs) in animal feeds and how they play a role in human ingestion. Fishmeal was the most important animal-derived feed in global husbandry and may have been subjected to PFAA contamination considering the PFAAs' ubiquitous distribution in aquatic ecosystems. We collected ninety-two commercial fishmeal from the most important fishmeal-producing countries and found that Σ16PFAAs ranged from 0.65 to 85.5 ng/g (average: 18.2 ng/g, 12% moisture). PFOS still predominated, with unexpected high detection of PFUnDA. The wide occurrence of short-chain PFAAs (e.g., PFBA, PFBS) in fishmeal were found for the first time. From a geographical view, PFAA levels in fishmeal that originated from the Northern Hemisphere were significantly higher than those from the Southern Hemisphere (p < 0.01). Higher levels of under-studied long-chain PFAAs (PFNA, PFDA, PFUnDA, PFDoDA and PFTrDA) weighted more in industrialized areas than less industrialized areas, whereas the legacy PFAAs (PFOS, PFOA and PFHxS) were comparable among all regions. The estimated daily intake was calculated from animal feed to humans (via cultured fish) from 20 Chinese provinces by the Monte Carlo Simulation. A proportion of 29.8% of residents from the Fujian Province exceeded the EFSA's suggestion for PFOS ingestion.

Perfluoroalkyl acids in drinking water of China in 2017: Distribution characteristics, influencing factors and potential risks.

Perfluoroalkyl acids (PFAAs) are a group of emerging persistent organic pollutants (POPs), which have been ubiquitously detected in the environmental media. However, national scale investigations on their occurrence and distribution in drinking water are still insufficient. In this study, we detected the 17 priority PFAAs in drinking water from 79 cities of 31 provincial-level administrative regions throughout China, and investigated their occurrence and distribution. Additionally, we also analyzed the influencing factors on their profiles, such as the existence of industrial sources, socioeconomic factors (population density and GDP), and assessed levels of risk associated with contaminated drinking water. On the national scale, the sum concentrations of the 17 PFAAs (∑17PFAAs) in drinking water was in a range of 4.49-174.93 ng/L with a mean value of 35.13 ng/L. Among the 17 individual PFAAs, perfluorobutanoic acids (PFBA) was the most abundant individual PFAAs with the median concentration of 17.87 ng/L, followed by perfluorooctanoic acid (PFOA, 0.74 ng/L), perfluorononanoic acid (PFNA, 0.40 ng/L) and perfluorooctane sulfonic acid (PFOS, 0.25 ng/L). The geographic distribution characteristic of ∑17PFAAs in drinking water was in a descending order of Southwestern China (57.67 ng/L) > Eastern coastal China (32.85 ng/L) > Middle China (29.89 ng/L) > Northwestern China (28.49 ng/L) > Northeastern China (22.03 ng/L), and in general, the existence of the industrial sources could positively affect the contamination levels of PFAAs in drinking water. The pollution level of PFAAs in drinking water also varied among the three different city levels (medium-sized city > big city > town). In towns, the positive correlations were observed between the population density and the ∑17PFAAs (R2 = 0.45, p < 0.01), and the individual concentration of PFHxA, PFBS, and PFOA (p < 0.01). Moreover, besides PFAAs in Yunnan, Jiangsu, and Jiangxi, concentrations of related PFAAs in drinking water from 28 provinces were less than the suggested drinking water advisories. The relatively higher concentrations of PFAAs in Yunnan, Jiangsu, and Jiangxi suggest that further studies focusing on their sources and potential health risk to humans are needed.

Assessment of individual-based perfluoroalkly substances exposure by multiple human exposure sources.

Individual exposure of perfluoroalkyl substances (PFASs) was assessed by analyzing serum, food, dust, drinking water, and hand wipes from 50 individuals. The PFASs concentrations in serum were correlated most strongly with exposure to PFASs through the (direct and indirect) ingestion of dust (p < 0.01). Daily PFOA intakes were estimated to be 2.07 ng/kg/day from food, 0.003 ng/kg/day from dust, 0.053 ng/kg/day from hand-to-mouth activity, and 0.020 ng/kg/day from drinking water. Daily perfluorooctanesulfonic acid (PFOS) intakes were estimated to be 0.689 ng/kg/day from food, 0.001 ng/kg/day from dust, 0.018 ng/kg/day from hand-to-mouth activity, and 0.005 ng/kg/day from drinking water. The daily PFOA and PFOS intakes calculated for individuals in this study and in group/scenario based exposure assessment of previous studies were compared. The estimated PFOS intake on individual basis (0.695 ng/kg/day) was a little bit higher than the intake on group/scenario basis (0.652 ng/kg/day). However, the estimated daily PFOA intake on individual basis (1.41 ng/kg/day) was about four times higher than the intake on group/scenario basis (0.339 ng/kg/day). Among the exposure pathways, food ingestion was major contributor to the total daily PFOA and PFOS intakes on individuals (99% of total intake) and group/scenario basis (64% of total intake).

Elevated concentrations of perfluorohexanesulfonate and other per- and polyfluoroalkyl substances in Baiyangdian Lake (China): Source characterization and exposure assessment.

Novel 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) and legacy PFASs, such as perfluorohexane sulfonate (PFHxS), have been used to replace perfluorooctane sulfonate (PFOS), a known persistent organic pollutant. Thus, it is critical to understand these PFOS alternatives regarding their sources and concentrations in the natural environment. In this study, 41 surface water samples as well as edible aquatic organisms were collected from Baiyangdian Lake, the largest freshwater lake in Hebei Province, China. Perfluorooctanoate acid (PFOA) and PFHxS were the predominant PFASs detected in the surface water, reaching concentrations of 8 397.23 ng/L and 1 478.03 ng/L, respectively, with PFHxS accounting for the greatest proportion (∼80.00%) in most water samples. PFHxS (mean: 87.53 ng/g) and PFOS (mean: 35.94 ng/g) were also the most prevalent compounds detected in aquatic organisms. Estimated daily intake (EDI) values of PFOS (16.56 ng/kg bw/d) and PFHxS (16.11 ng/kg bw/d) via aquatic food and drinking water were the highest among PFASs, indicating potential exposure risks to residents. In addition, fish product consumption was the important exposure pathway for residents to PFOA, PFHxS, PFOS, and 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA). This study reports on the highest PFHxS levels ever recorded in surface water, suggesting that further quantification of PFHxS in human serum and assessment of its health risks to local residents are warranted and critical.

Pollution levels and risk assessment of perfluoroalkyl acids (PFAAs) in beef muscle and liver from southern Xinjiang.

The presence of perfluoroalkyl acids (PFAAs) in animal foods is worldwide, and their fate and spatial distribution in Xinjiang are not well understood. In this study, beef muscle and liver collected from five major cities in southern Xinjiang were analyzed (n = 70) for 13 PFAAs using an ion-pairing method combined with HPLC-MS/MS. Overall, PFAA contamination was widespread, exceeding 50% of samples with concentrations ranged from below the limits of detection to 6.118 ng/g. Perfluorooctane sulfonate, perfluorooctanoic acid, and perfluoroundecanoic acid were the predominant PFAAs of ten detected compounds, with maximum concentrations in Korla liver samples of 2.543, 0.856, and 1.386 ng/g, respectively. When comparing the five cities, the highest levels and detection frequencies were observed in samples from Korla (muscle, 0.013 ng/g; liver, 3.336 ng/g), followed by Yanqi, Akesu, Kashgar, and Hotan. The different pollution patterns and distribution profiles of PFAAs among cities were significantly related to local economy and geographical conditions. In addition, the dietary intake assessments for PFAAs showed that samples originating from Korla had the greatest impact on human health, but the total hazard ratio was 0.814 × 10-3, which is far less than 1, indicating that consumption of beef muscle and liver poses no immediate harm to local residents.

Distribution, source identification and health risk assessment of PFASs and two PFOS alternatives in groundwater from non-industrial areas.

Little research has been carried out for the per- and polyfluoroalkyl substances (PFASs) in groundwater from non-industrial areas, even though it has been proved that PFASs can transport for long distance. In this study, the concentration profiles and geographical distribution of 14 PFASs, including two alternatives of perfluorooctane sulfonate (PFOS), 6:2 fluorotelomer sulfonate (6:2 FTS) and potassium 9-chlorohexadecafluoro-3-oxanonane-1-sulfonate (F-53B), were analyzed in groundwater samples (n = 102) collected from water wells in non-industrial areas. The total concentrations of PFASs (Σ14PFASs) in groundwater samples ranged from 2.69 to 556 ng/L (mean 43.1 ng/L). The detection rates of shorter chain (C4-C9) PFASs were 62.75-100%, higher than those of long chain (> C10) PFASs with detection rates of less than 40%. The source identification using hierarchical cluster analysis and Spearman rank correlation analysis suggested that domestic sewage and atmospheric deposition may contribute significantly to the PFAS occurrence in groundwater in non-industrial areas, while the nearby industrial parks may contribute some, but not at a significant level. Furthermore, the human health risk assessment analysis shows that the health hazards associated with perfluorooctanoic acid (PFOA) and PFOS, two of the main PFAS constituents in groundwater from non-industrial areas, were one or two orders of magnitude higher than those in a previous study, but were unlikely to cause long-term harm to the residents via the drinking water exposure pathway alone.

Perfluorinated compounds in surface waters of Shanghai, China: Source analysis and risk assessment.

17 perfluorinated compounds (PFCs) were systematically investigated in the surface water from principal watersheds of Shanghai, China. 10 PFCs were above the detection limit (0.08-0.28ng/L) in 39 surface water samples. The perfluorooctanoic acid (PFOA) and perfluorobutanesulfonate (PFBS) were the two dominant compounds with a median concentration 50.67ng/L and 29.84ng/L, respectively. Concentrations of perfluorooctanesulfonate (PFOS) were generally less than PFBS, which might result from the global phase-out of PFOS production and the use of PFBS as a substitute for PFOS-based products. There were three major polluted areas of PFOA along the Huangpu River. The PFOA concentration in groundwater samples collected from one of the three areas indicated that chemical industry might be the possible source. The perfluoroalkane sulfonates (PFSAs) level had a spatial trend that indicated northwest had higher concentrations than the southeast. The distribution of PFCs was not much affected by atmospheric deposition. Mass loading analysis in the surface water revealed that the Huangpu River exhibited relatively large mass loading of total PFCs of 1742.43kg/year to Yangtze River Estuary. The predominant of the PFC species was PFOA with 652.65kg/year. The current concentrations of PFOA and PFOS were at middle level comparing to other studies in China and worldwide. Risk assessment of 6 PFCs showed that there is no risk to the aquatic organisms in Shanghai. PFOS and PFBS had low risk to the avian. Furthermore, the adults living in Shanghai were at low risk to exposure to PFCs through water consumption.

Perfluoroalkyl acids in surface sediments of the East China Sea.

The occurrence of 17 target PFAA analytes was determined in surface sediments (n = 37) of the East China Sea and potential influencing factors were examined. ΣPFAAs ranged from 0.41 ng/g dw to 3.06 ng/g dw, with perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) as the most abundant perfluorocarboxylic acid and perfluoroalkyl sulfonate, respectively. PFAAs in the sediments were strongly influenced by terrigenous input. Analysis of the relationship between dynamic influence factors and PFAA concentrations showed that the characteristics of PFAA distribution were rather complex. ΣPFAA concentrations and TOC were positively correlated (p < 0.0001). Circumfluence also influenced the whole PFAA distribution and seasonal variation. In addition, correlation analysis suggested that log Koc values increased with increasing perfluoroalkyl chain length. Given the rapid economic development of eastern coastal cities of China, the environmental hazards of land source pollution cannot be ignored.

Occurrence and dietary exposure assessment of PFOS and PFOA in cultured Trachinotus ovatus in China.

In this study, investigation was conducted into concentrations of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in Chinese farmed Trachinotus ovatus between 2014 and 2015 using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and ultra fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) method. The tissue distribution (muscle, skin, liver, kidney and gill) in Trachinotus ovatus was also assessed. The detection frequencies of PFOS and PFOA in fish were 92% and 3%, respectively, and the mean concentrations were 0.392 and 0.015 µg/kg wet weight. The analysis of PFOS distribution in different tissues in Trachinotus ovatus showed the following trend: skin> gill> kidney> liver> flesh. Results revealeded farmed Trachinotus ovatus in China to generally be contaminated with PFOS. Moreover, the average daily intake for Chinese urban residents calculated on the basis of pollution content was 0.268 ng/kg body weight/d (PFOS) and 0.014 ng/kg body weight /d (PFOA), respectively. Both hazard ratio values were less than 1, indicating that exposure levels of PFOS and PFOA through Trachinotus ovatus consumption may not lead to adverse health effects in the Chinese population.