Background levels of Persistent Organic Pollutants in humans from Taiwan: Perfluorooctane sulfonate and perfluorooctanoic acid

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have recently received attention due to their widespread contamination of the environment. PFOS and PFOA are stable in the environment and resistant to metabolism, hydrolysis, photolysis and biodegradation. PFOS and PFOA have been found in human blood and tissue samples from both occupationally exposed workers and the general worldwide population. This study aimed to determine the background levels of PFOS and PFOA in the Taiwanese population, investigate related factors, and compare exposure in Taiwan to that in other countries. The concentration of PFOS in the 59 serum samples collected from the general population in Taiwan ranged from 3.45 to 25.65 ng mL⁻¹ (median: 8.52), and the concentration of PFOA ranged from 1.55 to 7.69 ng mL⁻¹ (median: 3.22). There was a significant positive correlation (r = 0.51; p < 0.0001) between PFOS and PFOA concentrations. Males had higher concentrations of PFOA and PFOS than females. PFOS levels in serum increased with age. This study is the first investigation to reveal the PFOS and PFOA levels of serum samples in the general population of Taiwan. The levels of PFOS and PFOA in Taiwanese serum samples were comparable with those from other countries (PFOS: 5.0–35 ng mL⁻¹, PFOA: 1.5–10 ng mL⁻¹).     

Sorption of perfluoroalkyl substances in sewage sludge

The sorption behaviour of three perfluoroalkyl substances (PFASs) (perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutanesulfonic acid (PFBS)) was studied in sewage sludge samples. Sorption isotherms were obtained by varying initial concentrations of PFOS, PFOA and PFBS. The maximum values of the sorption solid–liquid distribution coefficients (K_d,max) varied by almost two orders of magnitude among the target PFASs: 140–281 mL g^?1 for PFOS, 30–54 mL g^?1 for PFOA and 9–18 mL g^?1 for PFBS. Freundlich and linear fittings were appropriate for describing the sorption behaviour of PFASs in the sludge samples, and the derived K_F and K_d,linear parameters correlated well. The hydrophobicity of the PFASs was the key parameter that influenced their sorption in sewage sludge. Sorption parameters and log(K_OW) were correlated, and for PFOS (the most hydrophobic compound), pH and Ca?+?Mg status of the sludge controlled the variation in the sorption parameter values. Sorption reversibility was also tested from desorption isotherms, which were also linear. Desorption parameters were systematically higher than the corresponding sorption parameters (up to sixfold higher), thus indicating a significant degree of irreversible sorption, which decreased in the sequence PFOS?>?PFOA?>?PFBS.     

Spatial distribution of perfluoroalkyl acids in the Pearl River of Southern China

An intensive campaign was conducted in September 2012 to collect surface water samples along the tributaries of the Pearl River in southern China. Thirteen perfluoroalkyl acids (PFAAs), including perfluorocarboxylates (PFCAs, C4–C11) and perfluorosulfonates (PFSAs, C4, C6–C8, and C10), were determined using high-performance liquid chromatography/negative electrospray ionization–tandem mass spectrometry (HPLC/(-)ESI–MS/MS). The concentrations of total PFAAs (ΣPFAAs) ranged from 3.0 to 52 ng L⁻¹, with an average of 19 ± 12 ng L⁻¹. The highest concentrations of ΣPFAAs were detected in the surface water of the Dong Jiang tributary (17–52 ng L⁻¹), followed by the main stream (13–26 ng L⁻¹) and the Sha Wan stream (3.0–4.5 ng L⁻¹). Perfluorooctanoate (PFOA), perfluorobutane sulfonate (PFBS), and perfluorooctane sulfonate (PFOS) were the three most abundant PFAAs and on average accounted for 20%, 24%, and 19% of ΣPFAAs, respectively. PFBS was the most abundant PFAA in the Dong Jiang tributary, and PFOA was the highest PFAA in the samples from the main stream of the Pearl River. A correlation was found between PFBS and PFOA, which suggests that both of these PFAAs originate from common source(s) in the region. Nevertheless, the slope of PFBS/PFOA was different in the different tributaries sampled, which indicates a spatial difference in the source profiles of the PFAAs.     

Removal of PFOS, PFOA and other perfluoroalkyl acids at water reclamation plants in South East Queensland Australia

This paper examines the fate of perfluorinated sulfonates (PFSAs) and carboxylic acids (PFCAs) in two water reclamation plants in Australia. Both facilities take treated water directly from WWTPs and treat it further to produce high quality recycled water. The first plant utilizes adsorption and filtration methods alongside ozonation, whilst the second uses membrane processes and advanced oxidation to produce purified recycled water. At both facilities perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorohexanoic acid (PFHxA) and perfluorooctanoic acid (PFOA) were the most frequently detected PFCs. Concentrations of PFOS and PFOA in influent (WWTP effluent) ranged up to 3.7 and 16 ng L⁻¹ respectively, and were reduced to 0.7 and 12 ng L⁻¹ in the finished water of the ozonation plant. Throughout this facility, concentrations of most of the detected perfluoroalkyl compounds (PFCs) remained relatively unchanged with each successive treatment step. PFOS was an exception to this, with some removal following coagulation and dissolved air flotation/sand filtration (DAFF). At the second plant, influent concentrations of PFOS and PFOA ranged up to 39 and 29 ng L⁻¹. All PFCs present were removed from the finished water by reverse osmosis (RO) to concentrations below detection and reporting limits (0.4-1.5 ng L⁻¹). At both plants the observed concentrations were in the low parts per trillion range, well below provisional health based drinking water guidelines suggested for PFOS and PFOA.     

First assessment of population exposure to perfluorinated compounds in Flanders, Belgium

With the objective to evaluate exposure of the population in Flanders (Belgium) to perfluorinated compounds (PFCs), we measured perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in settled dust in homes and offices, in a selection of food items from local origin, in drinking-water and in human serum. We complemented the data with results from a literature survey. Based on this dataset we calculated intake by children and adults from food, drinking-water, settled dust and soil, and air. Dietary exposure dominated overall intake. For adults, average dietary intake equalled 24.2 (P95 40.9) ng PFOS kg⁻¹ d⁻¹ and 6.1 (P95 9.6) ng PFOA kg⁻¹ d⁻¹, whereas for children the dietary intake was about 3 times higher. Predicted intake is high when compared to assessments in other countries, and to serum levels from Flanders, but comparable to the intakes published by The European Food Safety Authority (EFSA) in 2008. Intake of PFOS and PFOA remained below the Tolerable Daily Intake.     

Occurrence and source characterization of perfluorochemicals in an urban watershed

Perfluorochemicals (PFCs) are used in numerous applications, mainly as surfactants, and occur ubiquitously in the environment as complex mixtures. This study was undertaken to characterize the occurrence and sources of commonly detected PFC compounds in surface waters of the Marina catchment, a watershed that drains an urbanized section of Singapore. Of the 19 target PFCs, 13 were detected with perfluorooctanoic acid (PFOA) (5-31 ng L⁻¹) and perfluorooctane sulfonate (PFOS) (1-156 ng L⁻¹) being the dominant components. Other compounds detected included perfluoroalkyl carboxylates (C7-C12) and perfluoroalkyl sulfonates (C6 and C8). Sulfonamide compounds detected 2-(N-ethylperfluorooctanesulfonamido) acetic acid (N-EtFOSAA), 2-(N-methylperfluorooctanesulfonamido) acetic acid (N-MeFOSAA), perfluorooctanesulfonamido acetic acid (FOSAA) and perfluorooctanesulfonamide (FOSA) were putative transformation products of N-EtFOSE and N-MeFOSE, the N-ethylated and N-methylated ethyl alcohol derivatives, respectively. Surface water concentrations were generally higher during dry weather than during storm water flow: the median concentrations of total PFCs in dry and wet weather were 57 and 138 ng L⁻¹ compared to 42 and 79 ng L⁻¹, respectively, at Stamford and Alexandra canal, suggesting the presence of a continuous source(s) which is subject to dilution during storm events. In rain water, median concentrations were 6.4 ng L⁻¹, suggesting rain contributed from 12-25% to the total PFC load for non-point source sites. The longitudinal concentration profile along one of the canals revealed a point source of sulfonated PFCs (PFOS), believed to originate from aqueous film-forming foam (AFFF). Sources were characterized using principal component analysis (PCA) and by plotting PFHxS/PFOA against PFOS/PFOA. Typical surface waters exhibit PFOS/PFOA and PFHxS/PFOA ratios below 0.9 and 0.5, respectively. PCA plots reveal waters impacted by “non-typical” PFC sources in Alexandra canal.     

Adsorption behavior of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) on boehmite

Understanding the interaction of perfluorochemicals, persistent pollutants with known human health effects, with mineral compounds in surface water and groundwater environments is essential to determining their fate and transport. Kinetic experiments showed that adsorption equilibrium can be achieved within 48 h and the boehmite (AlOOH) surface is receptive to perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) adsorption. The adsorption isotherms estimated the maximum adsorption capacities of PFOS and PFOA on boehmite as 0.877 μg m⁻² and 0.633 μg m⁻², respectively. Compared to the adsorption capacity on γ-alumina, the abundant hydroxyl groups on boehmite surfaces resulted in the 2-3 times higher adsorption of PFOS and PFOA. Increasing solution pH led to a moderate decrease in PFOS and PFOA adsorption, owing to an increase in ligand exchange reactions and the decrease of electrostatic interactions. The presence of NaCl and CaCl₂ in solution demonstrated negative effects for PFOS and PFOA adsorption on boehmite surfaces, with potential mechanisms being electrical double layer compression, competitive adsorption of chloride, and the Ca²⁺ bridging effect between perfluorochemicals.     

Perfluorinated compounds in the Pearl River and Yangtze River of China

A total of 14 perfluorinated compounds (PFCs) were quantified in river water samples collected from tributaries of the Pearl River (Guangzhou Province, south China) and the Yangtze River (central China). Among the PFCs analyzed, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the two compounds with the highest concentrations. PFOS concentrations ranged from 0.90 to 99 ng/l and <0.01–14 ng/l in samples from the Pearl River and Yangtze River, respectively; whereas those for PFOA ranged from 0.85 to 13 ng/l and 2.0–260 ng/l. Lower concentrations were measured for perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctanesulfoamide (PFOSA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorononaoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA). Concentrations of several perfluorocarboxylic acids, including perfluorododecanoic acid (PFDoDA), perfluorotetradecanoic acid (PFTeDA), perfluorohexadecanoic acid (PFHxDA) and perfluorooctadecanoic acid (PFOcDA) were lower than the limits of quantification in all the samples analyzed. The highest concentrations of most PFCs were observed in water samples from the Yangtze River near Shanghai, the major industrial and financial centre in China. In addition, sampling locations in the lower reaches of the Yangtze River with a reduced flow rate might serve as a final sink for contaminants from the upstream river runoffs. Generally, PFOS was the dominant PFC found in samples from the Pearl River, while PFOA was the predominant PFC in water from the Yangtze River. Specifically, a considerable amount of PFBS (22.9–26.1% of total PFC analyzed) was measured in water collected near Nanjing, which indicates the presence of potential sources of PFBS in this part of China. Completely different PFC composition profiles were observed for samples from the Pearl River and the Yangtze River. This indicates the presence of dissimilar sources in these two regions.     

Concentrations of PFOS, PFOA and other perfluorinated alkyl acids in Australian drinking water

Perfluorinated alkyl acids (PFAAs) are persistent environmental pollutants, found in the serum of human populations internationally. Due to concerns regarding their bioaccumulation, and possible health effects, an understanding of routes of human exposure is necessary. PFAAs are recalcitrant in many water treatment processes, making drinking water a potential source of human exposure. This study was conducted with the aim of assessing the exposure to PFAAs via potable water in Australia. Sixty-two samples of potable water, collected from 34 locations across Australia, including capital cities and regional centers. The samples were extracted by solid phase extraction and analyzed via liquid chromatography/tandem mass spectrometry for a range of perfluoroalkyl carboxylates and sulfonates. PFOS and PFOA were the most commonly detected PFAAs, quantifiable in 49% and 44% of all samples respectively. The maximum concentration in any sample was seen for PFOS with a concentration of 16 ng L⁻¹, second highest maximums were for PFHxS and PFOA at 13 and 9.7 ng L⁻¹. The contribution of drinking water to daily PFOS and PFOA intakes in Australia was estimated. Assuming a daily intake of 1.4 and 0.8 ng kg⁻¹ bw for PFOS and PFOA the average contribution from drinking water was 2-3% with a maximum of 22% and 24% respectively.     

Extraction procedure optimization for perfluorooctane sulfonate and perfluorooctanoic acid in food packaging determination by LC-MS/MS

This research aimed to optimize the extraction method parameters for sample pretreatment and determine the levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) contamination in food packaging made of paper. Techniques used were pressurized liquid extraction (PLE) followed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Influence parameters of PLE were carefully evaluated for extracted concentration of samples in low level (ng g^?1). The study found that the optimal conditions for PLE were 30 min static extraction time with a flush volume of 100% cell volume and one extraction cycle at 80°C and 1,000 psi. The extraction technique validated the absolute recovery from PFOS and PFOA fortified control samples at three different levels (5, 50, and 200 ng g^?1), with seven repeats at each fortification level. The average recoveries were 79% or higher, with relative standard deviation (RSD) less than 11%. Optimization of the PLE method was established based on recovery data, accuracy, precision, and repeatability of the method. Using optimal PLE technique, PFOS and PFOA were extracted from 34 food-packaging samples collected in Thailand. PFOS and PFOA were detected in all kinds of collected samples, with average concentrations of 4.89 and 2.87 ng g^?1, respectively. The concentrations of PFOS and PFOA were highest in fast-food container samples: 36.99 and 9.99 ng g^?1, respectively.     

Perfluorinated compounds in Haihe River and Dagu Drainage Canal in Tianjin, China

In this study, nine perfluorinated compounds (PFCs) were investigated in water and sediment of Haihe River (HR) and Dagu Drainage Canal (DDC), Tianjin, China. The total PFCs in water samples from DDC (40-174 ng L⁻¹) was much greater than those from HR (12-74 ng L⁻¹). PFC contamination was severe at lower reaches of HR due to industry activities, while high PFCs were found in the middle of DDC due to the effluents from wastewater treatment plants. Perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were the predominant PFCs in aqueous phase. The total PFCs in sediments from DDC (1.6-7.7 ng g⁻¹ dry weight) were lower as compared to HR (7.1-16 ng g⁻¹), maybe due to the dredging of sediment in DDC conducted recently. PFOS was the major PFC in HR sediments followed by PFOA; while PFHxA was the major PFC in DDC sediments. Organic carbon calibrated sediment-water distribution coefficients (K_OC) were calculated for HR. The Log K_OC ranged from 3.3 to 4.4 for C7-C11 perfluorinated carboxylic acids, increasing by 0.1-0.6 log units with each additional CF₂ moiety. The log K_OC for 8:2 fluorotelomer unsaturated acid was reported for the first time with a mean value of 4.0. The log Koc of PFOS was higher than perfluoronanoic acid by 0.8 log units.     

Structure-activity relationship assessment of four perfluorinated chemicals using a prolonged zebrafish early life stage test

Perfluorinated compounds (PFCs) are a group of anthropogenic chemicals containing diverse functional groups and chain lengths. They are known to be persistent and bioaccumulative explaining their worldwide environmental presence. The toxicological information on these chemicals is still incomplete and insufficient to assess their environmental impact and structure-activity relationship. In the present study, the developmental effects of PFOS (perfluorooctane sulfonate, C8), PFOA (perfluorooctanoic acid, C8), PFBS (perfluorobutane sulfonate, C4) and PFBA (perfluorobutanoic acid, C4) were evaluated in zebrafish embryos (Danio rerio). The different chain lengths and functional groups of the selected chemicals made it possible to determine the structure-activity relationship of these compounds. PFCs with longer chain lengths (C8) tend to be more toxic than PFCs with shorter chain lengths (C4). Comparison based on the functional groups of compounds with the same chain length indicates that PFCs with a sulfonate group have a larger toxic potential than the ones with a carboxyl group. Furthermore, exposure to the different PFCs resulted in some general effects, such as deformations of the tail and an uninflated swim bladder, as well as in more specific effects which might be related to the structure of the tested chemicals. Oedemas and effects on length could only be detected in 8-carbon PFCs while malformations of the head were a more specific action of the sulfonated PFCs. Effects on hatching rate and success were found in PFOA exposed embryos and heart rates were affected after exposure to PFOS, PFOA and PFBS.     

Partitioning of perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS) and perfluorooctane sulfonamide (PFOSA) between water and sediment

Laboratory partitioning experiments were conducted to elucidate the sorption behaviour and partitioning of perfluoroalkyl compounds (PFCs). Three different sediment types were used and separately spiked with perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS) and perfluorooctane sulfonamide (PFOSA) at low environmentally realistic concentrations. PFOA, PFOS and PFOSA were mainly distributed in the dissolved phase at low suspended solid concentrations, indicating their long-range transport potential in the marine environment. In all cases, the equilibrium isotherms were linear and the organic carbon normalised partition coefficients (K_OC) decreased in the following order: PFOSA (log K_OC = 4.1 ± 0.35 cm³ g⁻¹) > PFOS (3.7 ± 0.56 cm³ g⁻¹) > PFOA (2.4 ± 0.12 cm³ g⁻¹). The level of organic content had a significant influence on the partitioning. For the sediment with negligible organic content the density of the sediment became the most important factor influencing the partitioning. Ultimately, data on the partitioning of PFCs between aqueous media and suspended solids are essential for modelling their transport and environmental fate.     

Tissue bioaccumulation patterns, xenobiotic biotransformation and steroid hormone levels in Atlantic salmon (Salmo salar) fed a diet containing perfluoroactane sulfonic or perfluorooctane carboxylic acids

In the present study, groups of juvenile Atlantic salmon (Salmo salar) were fed gelatine capsules containing fish-food spiked with PFOA or PFOS (0.2 mg kg⁻¹ fish) and solvent (methanol). The capsules were given at days 0, 3 and 6. Blood, liver and whole kidney samples were collected prior to exposure (no solvent control), and at days 2, 5, 8 and 14 after exposure (Note: that day 14 after exposure is equal to 7 d recovery period). We report on the differences in the tissue bioaccumulation patterns of PFOS and PFOA, in addition to tissue and compound differences in modulation pattern of biotransformation enzyme genes. We observed that the level of PFOS and PFOA increased in the blood, liver and kidney during the exposure period. Different PFOS and PFOA bioaccumulation patterns were observed in the kidney and liver during exposure- and after the recovery periods. Particularly, after the recovery period, PFOA levels in the kidney and liver tissues were almost at the control level. On the contrary, PFOS maintained an increase with tissue-specific differences, showing a higher bioaccumulation potential (also in the blood), compared with PFOA. While PFOS and PFOA produced an apparent time-dependent increase in kidney CYP3A, CYP1A1 and GST expression, similar effects were only temporary in the liver, significantly increasing at sampling day 2. PFOA and PFOS exposure resulted in significant decreases in plasma estrone, testosterone and cortisol levels at sampling day 2, and their effects differed with 17α-methyltestostrerone showing significant decrease by PFOA (also for cholesterol) and increase by PFOS. PFOA significantly increased estrone and testosterone, and no effects were observed for cortisol, 17α-methyltestosterone and cholesterol at sampling day 5. Overall, the changes in plasma steroid hormone levels parallel changes in CYP3A mRNA levels. Given that there are no known studies that have demonstrated such tissue differences in bioaccumulation patterns with associated differences in toxicological responses in any fish species or lower vertebrate, the present findings provide some potential insights and basis for a better understanding of the possible mechanisms of PFCs toxicity that need to be studied in more detail.     

Distribution and sources of polyfluoroalkyl substances (PFAS) in the River Rhine watershed

The concentration profile of 40 polyfluoroalkyl substances (PFAS) in surface water along the River Rhine watershed from the Lake Constance to the North Sea was investigated. The aim of the study was to investigate the influence of point as well as diffuse sources, to estimate fluxes of PFAS into the North Sea and to identify replacement compounds of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). In addition, an interlaboratory comparison of the method performance was conducted. The PFAS pattern was dominated by perfluorobutane sulfonate (PFBS) and perfluorobutanoic acid (PFBA) with concentrations up to 181 ng/L and 335 ng/L, respectively, which originated from industrial point sources. Fluxes of ΣPFAS were estimated to be ∼6 tonnes/year which is much higher than previous estimations. Both, the River Rhine and the River Scheldt, seem to act as important sources of PFAS into the North Sea.     

Removing perfluorooctane sulfonate and perfluorooctanoic acid from solid matrices, paper, fabrics, and sand by mineral acid suppression and supercritical carbon dioxide extraction

The removal of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from solid matrices has received considerable attention because of the environmental persistence, bioaccumulation, and potential toxicity of these compounds. This study presents a simple method using concentrated HNO₃ as a suppression agent, and methanol-modified supercritical carbon dioxide (Sc-CO₂) extraction for removing PFOS and PFOA from solid matrices. The optimal conditions were 16 M HNO₃ and 20% (v/v) methanol containing Sc-CO₂, under a pressure of 20.3 MPa and a temperature of 50 °C. Extraction time was set at 70 min (40 min for static and 30 min for dynamic extraction). PFOA and PFOS were identified and quantitated by liquid chromatography/mass spectrometry. The extraction efficiencies (with double extractions) were close to 100% for PFOA and 80% for PFOS for both paper and fabric matrices. The extraction efficiencies for sand were approximately 77% for PFOA and 59% for PFOS. The results show that this method is accurate, and effective, and that it provides a promising and convenient approach to remediate the environment of hazardous PFOA and PFOS contamination.     

Occurrence of perfluorooctanoate and perfluorooctanesulfonate in the Korean water system: implication to water intake exposure

Perfluorinated compounds (PFCs) measured in surface running waters indicated the existence of different emission sources in eight main city basins. The tap water reflected the contamination pattern and levels in their corresponding source water basins. The daily intakes through tap water consumption ranged from <0.01 to 0.73 ng kg⁻¹ d⁻¹ for perfluorooctanoate (PFOA) and <0.01 to 0.08 ng kg⁻¹ d⁻¹ for perfluorooctanesulfonate (PFOS). Tap water intake-derived exposure accounted for 8.6%-101% (for PFOA) and while <10% (for PFOS) of total daily exposure, which was estimated from Korean serum concentrations using a pharmacokinetic model. Our findings indicate that tap water intake could be an important contributor to PFOA exposure in Korean populations; accordingly, additional efforts are necessary to improve the removal efficiency of perfluorinated compounds (PFCs) in the water purification process. However, more fundamentally the aim would be to reduce the discharge of PFCs from potential sources within the basin.     

Perfluoroalkyl acids in blood serum samples from children in Taiwan

Severe perfluoroalkyl acid (PFAA) contamination resulting from the fast-growing semiconductor, electrochemical, and optoelectronic industries has been determined in the river water in the vicinity of the Taipei area, Taiwan, during recent years. However, little is known about body burdens of the PFAA contaminations in local residents, especially children living in the Taipei area recently. In this study, ten target PFAA analytes consisted of three perfluorosulfonates (PFSAs) and seven perfluorocarboxylates (PFCAs) in the blood serum samples, collected from 225 healthy children with an average age of 13.6 years in the Taipei area from 2009 to 2010, were analyzed via high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). As the dominant PFAA contaminant in the blood serum samples from Taiwanese children, perfluorooctane sulfonate (PFOS) contributed 86 % of all the target PFAA analytes, while the other nine analytes contributed less than 5 % individually. PFOS showed the highest median up to 29 ng/mL, ranging from 0.03 to 148 ng/mL, which was higher than that observed in the serum samples collected from Taiwanese children between 2006 and 2008. Statistically, serum concentrations of perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), and perfluorooctanoic acid (PFOA) had significantly positive correlations with ages of children (p?<?0.05). Furthermore, serum PFBS, PFHxS, and PFOA concentrations in the male children were considerably higher than those in the female children (p?=?0.049, p?=?0.000, p?=?0.000).     

Watershed-based riverine discharge loads and emission factor of perfluorinated surfactants in Korean peninsula

Long-range transport of and exposure to perfluorinated substances (PFSs) strongly depend on their emission mode. In the present study, watershed-based riverine discharge loads and emission factors are estimated for perfluorooctanoate (PFOA), perfluorononanoate (PFNA), perfluorohexylsulfonate (PFHxS), and perfluorooctylsulfonate (PFOS) by using spatially distributed data of chemical concentrations together with water flows and a geographic information system (GIS). Average per capita emissions (emission factor, μg capita⁻¹ d⁻¹) are 75 for PFOA, 36 for PFNA, 17 for PFHxS, and 43 for PFOS, which are several times lower than the estimates for Japan and the European continent. A relatively uniform distribution is observed for PFHxS and PFOS emission factors, while elevated values of PFOA and PFNA predominate in one of eight river basins. This may indicate the leading contribution of diffusive sources (e.g. nonpoint source) for PFHxS and PFOS versus the presence of localized point sources for PFOA and PFNA. The lower-upper bound of total riverine loads discharged annually from the Korean peninsula are in the range of 0.53-1.3 tons for PFOA, 0.09-0.60 tons for PFNA, 0.07-0.29 tons for PFHxS, and 0.19-0.73 tons for PFOS, accounting for <1% of global annual emissions. Furthermore, these riverine discharge loads are significantly greater than the discharge loads from a wastewater treatment plant, indicating the necessity of further study of nonpoint sources.     

The impact of semiconductor, electronics and optoelectronic industries on downstream perfluorinated chemical contamination in Taiwanese rivers

This study provides the first evidence on the influence of the semiconductor and electronics industries on perfluorinated chemicals (PFCs) contamination in receiving rivers. We have quantified ten PFCs, including perfluoroalkyl sulfonates (PFASs: PFBS, PFHxS, PFOS) and perfluoroalkyl carboxylates (PFCAs: PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFDoA) in semiconductor, electronic, and optoelectronic industrial wastewaters and their receiving water bodies (Taiwan's Keya, Touchien, and Xiaoli rivers). PFOS was found to be the major constituent in semiconductor wastewaters (up to 0.13 mg/L). However, different PFC distributions were found in electronics plant wastewaters; PFOA was the most significant PFC, contributing on average 72% to the effluent water samples, followed by PFOS (16%) and PFDA (9%). The distribution of PFCs in the receiving rivers was greatly impacted by industrial sources. PFOS, PFOA and PFDA were predominant and prevalent in all the river samples, with PFOS detected at the highest concentrations (up to 5.4 μg/L).