Dominant Perfluorinated Compounds Research Articles

Bioaccumulation and Ecological Risk of Perfluorinated Compounds in Aquatic Plants of Nansi Lake, China

ABSTRACT The work investigated the concentration of perfluorinated compounds (PFCs) in surface water, sediments and aquatic plants of Nansi Lake, China. The total concentration of 12 PFCs was in the range of 34.07–153.39 ng/L in surface water. The short-chain PFCs were dominant PFC homologs, and the concentration of PFOA was higher than that of PFOS in water samples. The total concentration of 12 PFCs was in the range of 0.63–1.62 ng/g (dry weight, DW) in the sediments. There were more long-chain PFCs (PFOA and PFOS) than short-chain PFCs in sediments, with no apparent connection according to the concentration of PFCs in water and sediments. Moreover, the bioaccumulation factors (BAF) indicated the aquatic plants had significant absorption for long-chain PFCs (PFOA and PFOS), especially PFOS. The log BAF value of Ceratophyllum demersum Linn for PFOS was the highest in all aquatic plants. Risk assessment indicated that the water environment of Nansi Lake was at a safe level.

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 (0-20cm) 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 98.5μgkg-1 (dry weight, dw), with an average of 5.97μgkg-1dw. 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.

Occurrence of perfluorinated compounds in agricultural environment, vegetables, and fruits in regions influenced by a fluorine-chemical industrial park in China

The occurrence of perfluorinated compounds (PFCs) in vegetables and fruits, as well as agricultural environment, was investigated in the downstream regions of Changshu fluorine-chemical industrial park (CFCIP) in China. Twenty-one PFCs were analyzed in irrigation water, agricultural soil, typical vegetables, and fruits, with the maximum total PFC concentrations of 369.9 ng/L, 64.7 ng/g dw, 11.5 ng/g ww, and 10.5 ng/g ww, respectively. Short-chained perfluoroalkyl carboxylic acids (PFCAs) such as perfluorooctanoic acid (PFOA), perfluorobutanoic acid (PFBA), and perfluorohexanoic acid were the dominant PFCs in terms of their concentrations and detection frequency. PFCs in irrigation water and agricultural soils showed a decreasing trend with increasing distance from CFCIP, while this pattern was not observed in agricultural products. The predominant compounds varied in different vegetables and fruits. Simultaneous bioaccumulation of PFBA and PFOA was found in melons and solanaceous species and pears. Leafy vegetables and grapes exhibited high bioaccumulation of PFOA and PFBA, respectively. Health risk assessment by calculating estimated daily intake showed that no direct risk was caused by the consumption of vegetables and fruits for the residents in the investigated regions. However, the tolerable weekly intake of PFOA exceeded the established thresholds for the adult residents. A comprehensive health assessment of the dietary exposure of PFCs, including all exposure pathways, in fluorine-chemical industrial park-impacted regions is needed.

Distribution of perfluorinated compounds (PFASs) in the aquatic environment of the industrially polluted Vaal River, South Africa

Perfluorinated alkyl substances (PFASs) are highly persistent chemicals, which have a bioaccumulative potential and can be found in wildlife around the world. Although multiple studies have been performed on PFASs pollution of the aquatic environment, little is known on PFASs pollution on the African continent and their possible risks for human health. In the present study, we examined the distribution of 15 PFASs in fish, invertebrates, sediment and water, collected at three sites, representing a gradient of industrial and mining pollution, along the Vaal River, South Africa. Furthermore, possible risks for human health through consumption of contaminated fish were examined.Perfluorooctane sulfonate (PFOS) was the most dominant PFAS measured in biota, whereas perfluoropentanoic acid (PFPeA) was measured in higher concentrations in water. Mean PFAS concentrations in water ranged from <LOQ to 38.5ng/L. PFAS concentrations in water decreased along the gradient and were similar or lower compared to other studies in Europe, Asia and America. PFAS measurements in sediment were <LOQ, with the exception of PFOS at Thabela Thabeng (2.36ng/g dry weight (dw)). Average ∑PFAS concentrations in biota increased along the gradient and ranged from <LOQ to 34.5ng/g wet weight (ww) in invertebrates, <LOQ to 289ng/g ww in liver and <LOQ to 34.0ng/g ww in muscle tissue. Although PFOS concentrations were relatively high compared to literature, concentrations of other PFASs were rather low.A potential risk for humans through consumption of PFAS-contaminated fish was assessed. Tolerable daily intake values (grams of fish that can be eaten daily without risking health effects) were much lower than the average South African fish consumption per day, implying a potential risk for human health through consumption of PFAS contaminated fish. CapsuleConcentrations of perfluorinated compounds in water, sediment, fish and invertebrates from the Vaal River were low or intermediate and posed a potential risk for human health through consumption of contaminated fish.

Spatial Distribution and Source of Perfluorinated Compounds in Urban Soil from Part of Cities in Anhui Province, China

In order to explore the spatial distribution and source of perfluorinated compounds (PFCs),eleven mixed urban soil samples were collected from 7 cities in Anhui Province in 2013.Fifteen individual PFCs were detected by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS),and principal components analysis was used to trace the different sources of PFCs in urban soil.The results showed that the total concentration of PFCs (ΣPFCs) ranged from 1.15 to 5.98 ng·g-1 dry weight (dw),with an average concentration of 2.69 ng·g-1.perfluorooctane sulfonate (PFOS) with a concentration range of n.d.-3.56 ng·g-1 and an average concentration of 0.96 ng·g-1 was the dominant PFC contaminant,followed by perfluorooctane acid (PFOA) with a concentration range of n.d.-2.89 ng·g-1 and an average concentration of 0.64 ng·g-1.The highest ΣPFCs concentration in all selected mixed urban soil samples was from Chuzhou City with the value of 5.89 ng·g-1,followed by Jingxian County of Xuancheng City (4.04 ng·g-1).Interestingly,the PFOS concentration was as high as 3.56 ng·g-1 in Jingxian County,accounting for 88.1% of the total PFCs concentration,which might be influenced by paper industry in this area.Comparing to other soil samples in China,ΣPFCs concentration of urban soil from Anhui Province was at middle level.Over 60% of ΣPFCs in urban soil of Anhui province could be attributed to the four principal components,represented by PFOA,perfluorobutane sulfonate,perfluorododecanoic acid,perfluorobutane acid and PFOS.

Identification, characterization, and human health risk assessment of perfluorinated compounds in groundwater from a suburb of Tianjin, China

This study investigated the occurrence of perfluorinated compounds (PFCs) in groundwater from 16 sampled wells for the public drinking water supply in a suburb of Tianjin, China. Thirteen PFC analytes were quantified by ultra-high performance liquid chromatography/electrospray tandem mass spectrometry. Concentrations of the total PFCs in groundwater ranged from 0.32 to 8.3 ng L−1 with an average of 2.4 ng L−1. The dominant PFCs were perfluorobutane sulfonic acid (PFBS) and perfluorooctanoic acid (PFOA) with averages of 1.1 and 0.81 ng L−1, respectively. Levels of perfluorocarboxylic acids containing 6–12 carbon atoms (except PFOA) in groundwater decreased with the increase of their carbon chain lengths. Strong positive correlations were observed between perfluoroheptanoic acid (PFHpA) and PFOA, PFHpA and perfluorononanoic acid (PFNA), PFHpA and PFBS, and PFOA and PFNA (Spearman Correlation test, p < 0.01), suggesting that these chemicals might originate from the same or similar pollution sources. The principal component analysis–multiple linear regression model analysis showed that PFCs mainly came from the fluorotelomer production and emission, followed by the introduction of the substitute compounds. PFC concentrations were positively correlated to the contents of dissolved organic carbon and Mn2+, and negatively correlated to the contents of total nitrogen and SO4 2− in groundwater. These indicated that PFC distributions and pollution levels in groundwater were related to organic carbon, nutrients and inorganic salts. The preliminary health risk assessment suggested that there was no significantly immediate harm of exposure to PFCs in drinking water for the villagers in the suburb of Tianjin, China.

Occurrence and assessment of perfluorinated compounds in fish from the Danjiangkou reservoir and Hanjiang river in China

Residues of eight perfluorinated compounds (PFCs) were investigated in 15 fish samples from the Danjiangkou reservoir and Hanjiang river (Xiangyang and Zhongxiang sections). The total concentrations of PFCs in fish muscles ranged from 2.01 to 43.8ngg−1dry weight. The mean concentration of total PFCs from related muscles showed the following trend in various regions: Zhongxiang section<Xiangyang section<Danjiangkou reservoir. Perfluorooctane sulphonate (PFOS) was the dominant PFC in the fish liver samples from the Danjiangkou reservoir. The calculated hazard ratio (HR) of PFCs, for all fish muscle samples, was less than 1.0, and could be classified at safe levels for the general population. However, yellow croaker fish from the Danjiangkou reservoir and Hanjiang river–Xiangyang section had HRs of 0.2, indicating that frequent consumption of this contaminated fish may pose an unacceptable risk to human health.

Levels and spatial distribution of perfluorinated compounds (PFCs) in superficial sediments from the marine reserves of the Tuscan Archipelago National Park (Italy)

Surface sediments from marine reserves of the Tuscan Archipelago National Park (Italy), including remote islands not directly affected by anthropogenic influences, were analyzed for two dominant perfluorinated compounds (PFCs), namely perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), using LC–ESI-MS/MS. The concentrations of PFOS were low, with medians ranging from 0.25 to 1.50ng/g dry wt, whereas PFOA was always below the detection limit of 0.1ng/g dry wt. The present paper can be considered a baseline study useful in future environmental monitoring programs.

The relationships between sixteen perfluorinated compound concentrations in blood serum and food, and other parameters, in the general population of South Korea with proportionate stratified sampling method

Serum samples were collected from volunteers of various ages and both genders using a proportionate stratified sampling method, to assess the exposure of the general population in Busan, South Korea to perfluorinated compounds (PFCs). 16 PFCs were investigated in serum samples from 306 adults (124 males and 182 females) and one day composite diet samples (breakfast, lunch, and dinner) from 20 of the serum donors, to investigate the relationship between food and serum PFC concentrations. Perfluorooctanoic acid and perfluorooctanesulfonic acid were the dominant PFCs in the serum samples, with mean concentrations of 8.4 and 13ng/mL, respectively. Perfluorotridecanoic acid was the dominant PFC in the composite food samples, ranging from <DL to 1.48ng/g. PFC concentrations in the serum samples increased with the age of the volunteer, and were higher in males than in females, similar to the results of other studies. We confirmed from the relationships between questionnaire results and the PFC concentrations in the serum samples, that food is one of the important contribution factors of human exposure to PFCs. However, there were no correlations between the PFC concentrations in the one day composite diet samples and the serum samples, because a one day composite diet sample is not necessarily representative of a person's long-term diet and because of the small number of samples taken.

Blood plasma concentrations of endocrine disrupting chemicals in Hong Kong populations

In this study we report the human plasma concentrations of some common endocrine disrupting chemicals (EDCs) in the Hong Kong population. We have analyzed 153 plasma samples for the contaminants by methods involving labeled standards spiked into the samples. Quantification was performed using high performance liquid chromatography tandem mass spectrometry for bisphenol-A (BPA) and perfluorinated compounds (PFCs), and gas chromatography mass spectrometry methods for phthalates. We found BPA, several types of PFCs and phthalates in over 90% of the plasma samples. Perfluorooctane sulfonate (PFOS) was the dominant PFC, followed by perfluroroctanoic acid (PFOA) and perfluorohexane sulfonate (PFHxS). Eight out of ten phthalates were detected, with bis(2-ethylhexyl) phthalate (DEHP) as the most abundant, followed by bis(2-methoxyethyl) phthalate (DMEP) and dioctyl phthalate (DnOP). The levels of PFOS, PFOA, PFHxS and perfluorohexanoic acid (PFHxA) were significantly higher in the male plasma samples (p<0.05), while the mean plasma levels of DEHP and n-butyl benzyl phthalate (BBP) were significantly higher in the young age group (p<0.02). The presence of the selected EDCs in human blood plasma indicates common exposure routes among different population cohorts. Although the plasma levels of the EDCs were comparable to other countries, regular monitoring of human blood EDC contamination levels is necessary to provide a time-trend database for the estimation of exposure risk and to formulate appropriate public health policy.

Polyfluorinated and Perfluorinated Chemicals in Precipitation and Runoff from Cities Across Eastern and Central China

Twenty-three polychlorinated and perfluorinated compounds (PFCs) were investigated in water phase and particulate matters of 19 precipitation samples (18 snow samples and 1 rain sample) from different cities across eastern and central China collected in February 2010. The PFCs in samples of 9e precipitation events during more than half a year at 1 site in Tianjin and 6 successive samples during 1 precipitation event were measured to elucidate the change of PFC in precipitation. In addition, PFCs in 3 runoffs at different kinds of sites in Tianjin were compared with those in the corresponding precipitation. The results showed that the particulate matters separated from the precipitation contained undetectable PFCs. The total PFC concentration ranged between 4.7 and 152ngL(-1) in water phase of the precipitation samples, with perfluorooctanoic acid (PFOA) being detected at all of the sampling sites and the dominant PFC at most of the sampling sites. Some potential precursors of environmentally concerned PFCs and their degradation intermediates were measured simultaneously, among which 6:2 fluorotelomer unsaturated carboxylic acid (6:2 FTUCA), 8:2 FTUCA, and ×(3, 4, 5, 7):3 acid [F(CF(2))xCH(2)CH(2)COOH] were measured for the first time in Chinese precipitations; however, their concentrations were all lower than the limits of detection except that 6:2 FTUCA and 8:2 FTUCA could be detected in 3 and 8 precipitation samples, respectively. No clear seasonal variation in PFC concentrations in precipitation was observed during half a year; however, a relatively greater average concentration of total PFCs was observed during winter and summer compared with spring. The concentration of individual PFCs showed an obvious descending trend in the successive samples of the precipitation event. PFOA and perfluorononanoic acid in runoffs collected from different sites showed the following similar pattern-gas station>highway>university campus-whereas the other detected PFCs had no concurrent trend.

Perfluorinated compounds in surficial sediments of the Ganges River and adjacent Sundarban mangrove wetland, India

This study reports the first evidence of the quantification of two dominant perfluorinated compounds (PFCs), namely perfluorooctanesulfate (PFOS) and perfluorooctannoate (PFOA), in surface sediment samples (0–5cm; n=13) from the Ganges (Hugli) River including Sundarban wetland, India using HPLC–MS/MS. The concentrations of PFOA exhibited a wide range of concentrations from <0.5 to 14.09ng/gdry wt, whereas the concentration of PFOS was always below the detection limit of <0.5ng/g drywt. A consistent enrichment of PFOA was recorded in all the five sites of Sundarban (mean value 11.61±1.86) whereas it was of moderate concentration or below the detection level in the seven sites along with the lower stretch of the Ganges (Hugli) River estuary (mean value 5.96ng/gdry wt±5.36). Wastewater and untreated effluents are likely the major causes of accumulation of PFCs in sediments. The present paper could be used as baseline study to assess future monitoring programs of the ecosystem.

Determination and partitioning behavior of perfluoroalkyl carboxylic acids and perfluorooctanesulfonate in water and sediment from Dianchi Lake, China

Perfluorinated compounds (PFCs) have received much attention on their distribution in various matrices including water bodies, precipitations, sediment and biota in different areas globally, however, little attention has been paid to their occurrence and distribution in urban lakes. In this study, water and sediment samples collected from 26 sites in Dianchi Lake, a plateau urban lake in the southwestern part of China were analyzed via high performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) for ten analytes involving nine perfluoroalkyl carboxylic acids (PFOAs) and perfluorooctanesulfonate (PFOS). Total levels of PFCs were 30.98±32.19ngL−1 in water and 0.95±0.63ngg−1 in sediment. In water samples PFOA was the dominant PFC contaminant, with concentrations ranging from 3.41 to 35.44ngL−1, while in sediments PFOS was the main PFC contaminant at levels from 0.07–0.83ngg−1 dry weight. Field-based sediment water distribution coefficients (KD) were calculated and corrected for organic carbon content (Koc), which reduced variability among samples. The logKoc ranged from 2.54 to 3.57 for C8–C12 perfluorinated carboxylic acids, increasing by 0.1–0.4 log units with each additional CF2 moiety. The logKoc of PFOS was 3.35±0.32. Magnitudes and trends in logKD or logKoc appeared to agree well with previously published laboratory data. Results showed that different PFC composition profiles were observed for samples from the lake water and sediments, indicating the presence of dissimilar characteristics of the PFCs compounds, which is important for PFC fate modeling and risk assessment.

Tissue distribution of perfluorinated compounds in farmed freshwater fish and human exposure by consumption

In the present study, the levels of 14 perfluorinated compounds (PFCs) were analyzed in the blood, liver, muscle, brain, and eggs of popular farmed freshwater fish from Beijing. Perfluorooctane sulfonate (PFOS) was the predominant compound in all samples, with the highest concentration at 70.7 ng/g wet weight. The highest mean levels of PFOS in all tissues were observed in bighead (1.48-22.5 ng/g wet wt) and the lowest in tilapia (0.260-1.63 ng/g wet wt). In addition, perfluoroundecanoic acid was the second dominant PFC in blood, liver, muscle, and eggs, with the highest concentration at 19.2 ng/g wet weight. However, perfluorodecanoic acid levels (less than the limit of detection [LOD] to 0.963 ng/g wet wt) were similar to or slightly higher than perfluoroundecanoic acid levels (<LOD to 0.918 ng/g wet wt) in the brain. Generally, the highest mean concentrations of PFOS and total PFCs were found in fish blood, followed by liver, brain, and muscle, further supporting the premise that PFOS can bind more easily to serum proteins than to fatty tissues. The egg to liver ratios as maternal transfer ratios were calculated for PFOS, ranging from 0.93 to 2.0. Furthermore, based on consumption information for fish in Beijing, the human dietary intake of PFCs through fish consumption were estimated at 0.24 ng/kg/d for PFOS and 0.44 ng/kg/d for total PFC. These results indicate a low health risk posed from PFCs to the residents of Beijing through the consumption of fish.

Distribution of perfluorinated compounds in water, sediment, biota and floating plants in Baiyangdian Lake, China

The distribution of perfluorinated compounds (PFCs) in Baiyangdian Lake, China, was determined in this study. Perfluorooctanoic acid (PFOA) was the dominant PFC in lake water (1.70-73.5 ng L(-1), median 9.72 ng L(-1)), while perfluorooctane sulfonate (PFOS) was the dominant PFC in sediments (0.06-0.64 ng g(-1) dry wt, median 0.19 ng g(-1) dry wt) and in aquatic animals (0.57-13.7 ng g(-1) wet wt, median 2.56 ng g(-1) wet wt). Significant differences in PFC levels were observed among various aquatic animals. We also determined, for the first time, the PFC levels in floating plants, including Ceratophyllum demersum L., Hydrocharis dubia (Bl.) Backer and Salvinia natans (L.), and we found that PFOA and PFNA were the dominant PFCs in these plants. Furthermore, floating plants were observed to have different composition profiles compared to aquatic animals. Geographical differences in PFC levels were also observed, with higher PFC levels in samples from the north part of Baiyangdian Lake than those in the south. The differences in human and industrial activities in different parts of the lake and the discharged wastewater from the Fuhe River may be the major contributors for these geographical differences.

Serum levels of perfluorinated compounds in the general population in Shenzhen, China

Perfluorinated compounds (PFCs) have been detected in many environmental matrices, biota, and nonoccupationally exposed populations in China recently. However, little is known about the distribution and levels of various PFCs in the general population living in areas where there is PFC exposure. In the present study, the levels and prevalence of ten target PFCs were determined in 227 serum samples from a population of nonoccupationally exposed individuals in Shenzhen, China. Results indicated that human exposure to PFCs was prevalent in Shenzhen. Perfluorooctanoate (PFOA) was the dominant PFC contaminant in the serum samples, with a median concentration of 6.72 ng/mL, followed by perfluorooctane sulfonate (PFOS) with a median concentration of 2.07 ng/mL. Other PFCs were detected at much lower concentrations, with median concentrations ranging from 0.02 to 0.87 ng/mL. Statistically, no significant (P>0.05) gender differences were observed for any of the PFCs. Significant (P<0.01) positive correlations were found between age and serum concentrations of the target PFCs, except for perfluorobutane sulfonate (R = −0.16, P = 0.01), perfluorohexanoic acid (R = 0.08, P = 0.22), and perfluoroheptanoic acid (R = −0.11, P = 0.10). Based on the one-compartment pharmacokinetic model, the total daily intakes of PFOA and PFOS for the general population in Shenzhen were calculated as 0.63 and 0.20 ng/kg body weight/day, respectively.

Determination of perfluorinated compounds (PFCs) in solid and liquid phase river water samples in Chao Phraya River, Thailand

Perfluorinated compounds (PFCs), especially perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are fully fluorinated organic compounds, which have been used in many industrial applications. These chemicals have contaminated surface water all over the world even in developing countries like Thailand. The previous study showed the contamination in Chao Phraya River in 2006 and 2007. The purposes of this field study were to determine the solid and liquid phase of PFCs contamination in Chao Phraya River and to compare the changes of PFC concentration in 2008. Surveys were conducted in the lower reach of Chao Phraya River in the industrialized area. A solid phase extraction (SPE) coupled with HPLC-ESI-MS/MS were used for the analysis for ten PFCs. Ten PFCs were analyzed to identify the contamination in both solid and liquid phases. PFCs were detected in both the solid and liquid phase in every sample. PFOA was the most dominant PFC while PFPA and PFOS were also highly detected in most samples. The average loadings of PFPA, PFOA and PFOS in Chao Phraya River were 94.3, 284.6 and 93.4 g/d, respectively. PFOS concentrations did not show differences between 2006 and 2008. However, PFOA concentrations were higher in 2008/5/26, while comparing other samplings. The ratio of solid:liquid PFPA (2.1:1.0) [(ng/g)/(ng/L)] was lower than PFOA (13.9:1.0) [(ng/g)/(ng/L)] and PFOS (17.6:1.0) [(ng/g)/(ng/L)]. The shorter chain (more hydrophilic) PFC was better to dissolve in water rather than adsorb onto suspended solids. PFOS also showed more potential to attach in the suspended solids than PFOA.

Perfluorinated compounds in surface waters from Northern China: Comparison to level of industrialization

Inclusion of Perfluorooctane Sulfonate (PFOS) in the Stockholm Convention because of its exemptions, has resulted in increased annual production of PFOS-containing chemicals in China to accommodate domestic and overseas demands. Accordingly, concern about environmental contamination with perfluorinated compounds (PFCs), such as PFOS, has arisen. However, little information is available on the status and trends in the distribution, sources or risk of PFCs in aquatic environments of China. In the present study, forty two surface water samples collected from five regions with different levels of industrialization were monitored for concentrations of PFCs by use of solid phase extraction and LC/MS/MS. Mean concentrations (maximum concentration) of PFOA and PFOS, which were the dominant PFCs, were 1.2 (2.3) and 0.16 (0.52)ng/l for Guanting, 1.2 (1.8) and 0.32 (1.1)ng/l for Hohhot, 2.7 (15) and 0.93 (5.7)ng/l for Shanxi, 6.8 (12) and 2.6 (11)ng/l for Tianjin, 27 (82) and 4.7 (31)ng/l for Liaoning, respectively. The greatest concentrations of PFCs (121ng/l), PFOA (82ng/l) and PFOS (31ng/l) were observed in Liaoning, which might originate from tributaries of the Liaohe River, the most polluted watershed in Northeast China. While, concentrations of PFCs in the Guanting and Hohhot regions were 3 to 20 fold less than those from Tianjin and Liaoning. This result is consistent with little contribution of PFCs being released from agricultural and non-industrial activities. The magnitudes of mass flow for PFOA and PFOS in decreasing order were: Guanting<Hohhot<Tianjin<Liaoning<Shanxi and Guanting<Hohhot<Shanxi<Tianjin<Liaoning. The larger mass flows of PFOS were accompanied by relatively larger magnitudes of PFOA. Concentrations of both PFOA and PFOS in waters from all regions were less than suggested allowable concentrations. However, the relatively greater concentrations of PFCs in Tianjin and Liaoning suggest that further studies characterizing their sources and potential risk to both humans and wildlife are needed.

Evaluation of perfluorinated compounds in seven wastewater treatment plants in Beijing urban areas

The presence of perfluorinated compounds (PFCs) in seven major wastewater treatment plants (WWTPs) in Beijing was investigated in the current study. We detected nine PFCs in all the wastewater and sludge samples. Perfluorooctane acid (PFOA) is the dominant PFCs in influents and effluents, while perfluorooctane sulfonate (PFOS) is the major contaminant in sludge. The highest PFC concentration was found in plants at Qinghe and Jiuxianqiao WWTP, while the lowest was found at Fangzhuang WWTP. The total values of PFC range from 2.88 to 176 ng/L in influents, from 5.48 to 498 ng/L in effluents, and from 1.21 to 32.0 ng/g (dry wt) in sludge. The fact that effluents usually contain higher levels of PFCs than influents suggests that additional PFCs are produced during the wastewater treatment processes. However, PFOS decreases in effluents than in influents in 62% of the water samples. This may be due to the adsorption and removal of the sludge during the active process. Perfluoroalkyl carboxylates (PFCAs) were found significantly correlated with each other in the effluents, which may indicate their similar sources or the existence of their potential precursors in the wastewater or treatment processes. The mass flows of PFC discharges into WWTPs are 0.4–51.4 mg/day, and the mass flows of PFCs in effluents exceed those in influents by 127%. Domestic and commercial wastewaters are suggested to be the major sources of PFC pollution in WWTPs in Beijing.

Perfluorinated compounds in urban river sediments from Guangzhou and Shanghai of China

Perfluorinated compounds (PFCs) have been determined in various matrices within China including water bodies, precipitations, biota and non-occupationally PFCs-exposed populations in recent years, yet little attention has been focused on the distributions of PFCs in urban river sediments from Chinese major metropolises such as Guangzhou and Shanghai so far. In this study, sediment samples of 0–2 cm were collected from 13 sites in the Zhujiang River across Guangzhou and nine sites in the Huangpu River across Shanghai. PFCs analysis on these sediments via high performance liquid chromatography-tandem mass spectrometry (HPLC–MS/MS) system was implemented targeting eight analytes involving perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorododecanoic acid (PFDoA) and perfluorotetradecanoic acid (PFTA). According to the analytical results, total concentrations of PFCs (∑PFCs) in sediments from the Zhujiang River were between 0.09 and 3.6 ng/g dry weight (dw), with PFOS being the dominant PFC contaminant in the river ranged from below LOD to 3.1 ng/g dw; while ∑PFCs in sediments from the Huangpu River were between 0.25 and 1.1 ng/g dw, with PFOA being the main PFC contaminant in the river determined in the levels of 0.20–0.64 ng/g dw. Additionally, an overall decreasing trend of PFCs contaminations with depth was observed in both of two 60 cm sediment cores from the Zhujiang River and the Huangpu River each.