Nationwide distribution of per- and polyfluoroalkyl substances (PFAS) in road dust from India.

In India, information on the occurrence and distribution of legacy and emerging per- and polyfluoroalkyl substances (PFAS) is deficient. In the present study, nationwide 79 road dust samples were collected from 12 states and 1 union territory for the analysis of 34 PFAS. Overall, total concentrations of 21 quantified PFAS (∑21PFAS) ranged 23-861 pg/g (median: 116 pg/g), with perfluorooctane sulfonic acid (PFOS) being predominant (median: 19.9 pg/g). Short to long chain perfluoroalkyl carboxylic acids (PFCAs; C4 - C18) were detected, where the concentrations of PFAS decreased with the increase in PFAS carbon chain length. ∑21PFAS was highest in road dust from urban area (n = 27; median: 230 pg/g), followed by suburban (n = 21; median: 126 pg/g) and rural areas (n = 31; median: 76 pg/g), suggesting environmental impacts of industriallization and urbanization on PFAS distribution. PFAS composition in rural road dust was significantly different from those in suburban and urban samples (p < 0.01). Regarding 4 geographical regions of India, PFAS in road dust showed spatial difference where higher concentrations were found in South India compared to other regions. ∑21PFAS were positively associated with city-wise population of India (rs = 0.40, p < 0.01). Strong to moderate positive correlation was observed between ∑21PFAS, fluorotelomer sulfonic acids, and PFCAs (rs = 0.23, 0.30, and 0.28, respectively; p < 0.05) and the total state-wise vehicles in India, suggesting that vehicles exhaust or non-exhaust (e.g., vehicle tire debris and polishing material) might contribute to the PFAS occurrence in Indian road dust. Toddlers (2-5 years) had the highest estimated daily intake of ∑PFAS via road dust ingestion under average-case and worst-case scenarios (0.55 and 1.16 pg/kg bw/day, respectively). This is the first time to evaluate PFAS in Indian road dust nationwide, aiding to provide first-hand data for human exposure to PFAS in India.

Residue Distribution and Daily Exposure of Per- and Polyfluoroalkyl Substances in Indica and Japonica Rice.

Per- and polyfluoroalkyl substances (PFAS) have excellent chemical stability but have adverse environmental impacts of concern. Furthermore, bioaccumulation of PFAS in rice varieties─which is the essential staple food crop in Asia─has not been verified. Therefore, we cultivated Indica (Kasalath) and Japonica rice (Koshihikari) in the same Andosol (volcanic ash soil) paddy field and analyzed the air, rainwater, irrigated water, soil, and rice plants for 32 PFAS residues, throughout the cultivation to human consumption. During the rice cultivation period, the cultivation environment in atmospheric particulate matter (PM) constituted perfluoroalkyl carboxylic acids (PFCAs), with minimal perfluorinated sulfonic acids (PFSAs). Furthermore, perfluorooctanesulfonic acid (PFOS) migrates at a PM > 10 to drop in a cultivation field and was conducive to leakage and accumulation of PFCAs in air particles in the field environment. Moreover, precipitation was a sources of irrigation water contamination, and cultivated soil with a high carbon content could capture PFSAs and PFCAs (over C10). There were no major differences in residual PFAS trends in the rice varieties, but the distribution of PFAS in the growing soil, air, and rainwater differed. The edible white rice part was mainly affected by irrigation water in both varieties. Monte Carlo simulations of daily exposure assessments of PFOS, PFOA, and perfluorononanic acid showed similar results for Indians consuming Indica rice and Japanese consuming Japonica rice. The results indicate that the ultratrace PFAS residue concentrations and their daily exposure were not cultivar-specific.

Evaluating the Distribution of Perfluoroalkyl Substances in Rice Paddy Lysimeter with an Andosol.

The properties of potential emerging persistent contaminants, perfluoroalkyl substances (PFAS), in an andosol rice paddy lysimeter were analyzed to determine their mobility and leaching behavior regarding carbon chain length and functional groups. For this purpose, simulated contaminated water (ΣPFAS = 1,185,719 ng/L) was used in the lysimeter. The results showed that PFAS distribution in the paddy soil lysimeter was influenced by the migration of these substances into irrigation water and their adsorption into the soil. PFHxS (C6) and PFOS (C8), which are the main components of the simulated contaminated water, were mostly captured in the soil layers of the low-humic andosol layer (0-35 cm). PFAS distribution may depend on soil properties, such as total carbon (TC) content. Compared with perfluoroalkane sulfonic acids (PFSAs), the distribution of perfluoroalkyl carboxylic acids (PFCAs) in soil showed significant variation. The remaining PFCAs were distributed across all layers of the lysimeter, except for the longer-chain PFCAs. Moreover, the PFSA distribution was directly correlated with the carbon chain number, whereby longer- and shorter-chain PFSAs accumulated in the top and bottom soil layers, respectively. This study provides detailed information on the distribution, leaching, uptake, and accumulation of individual PFAS in andosol paddy fields in Japan.

Fluorine mass balance analysis and per- and polyfluoroalkyl substances in the atmosphere.

Given that only a small number of per- and polyfluoroalkyl substances (PFAS) are routinely monitored, levels of PFAS in the atmosphere may be underestimated. A protocol including analyses of target PFAS (n = 50), water-soluble fluoride, and total fluorine has been proposed and applied to atmospheric samples. The whole method recovery (including extraction recovery and sampling efficiency) of 90-110% were obtained for the majority of compounds (48/50) with low deviations between replicates (< 20%). Fluorotelomer alcohols were the most prevalent PFAS in the indoor air, while the outdoor air was dominated by the ultrashort-chain ionic PFAS (e.g., trifluoroacetic acid and perfluoropropanoic acid). Concentrations of organofluorine (OF) compounds calculated from the fluorine mass balance ranged from 1.74 ng F/m3 to 14.3 ng F/m3 and from 52.0 ng F/m3 to 1100 ng F/m3 in the particulate and gaseous phases, respectively, whereas only a minor proportion (around 1%) could be explained by target PFAS. In indoor air, OF compounds were observed in relatively high levels and with a shift to the fine particles (PM<1) . Our results reveal a large proportion of unidentified OF signatures in the atmosphere and suggest the need to use multiple approaches to improve our understanding of airborne fluorinated substances.

Particle size distribution, wet deposition and scavenging effect of per- and polyfluoroalkyl substances (PFASs) in the atmosphere from a subtropical city of China.

Per- and polyfluoroalkyl substances (PFASs) as emerging organic pollutants have received great attention, but the scavenging efficiency of particulate PFASs by wet deposition was rarely studied. For the first time, we reported the scavenging efficiency of PFASs on different particle sizes. In this study, both rainwater and particle samples were collected for a whole year from Xiamen, a subtropical city of China. Particulate PFASs ranged from 4.11 to 67.41 pg m-3, with an average value of 26.56 pg m-3, and perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA) were the main compounds. Perfluorocarboxylic acids (PFCAs) were predominantly observed on fine particles (<1 µm), while PFOS and 6:2 chlorinated polyfluoroalkyl ether sulfonic acid (6:2 Cl-PFESA) had large proportions on coarse particles (1-2.5 µm and 2.5-10 µm). In the rainwater, PFASs ranged from 0.20 to 180.65 ng L-1, with an average value of 10.71 ng L-1, and perfluorobutanoic acid (PFBA), PFOA were the main compounds. The wet deposition flux of ∑PFASs was 5200 mg km-2 yr-1, exhibiting high fluxes during the wet season (March to September). The scavenging efficiency of particulate PFOS and PFOA ranged from 68%-98% during the rainfall, and wash-out of the raindrops was found to be one of the main scavenging mechanisms. In addition, the precipitation duration and intensity influenced the scavenging efficiency. The scavenging capacity of PFCAs was large on fine particles, while for per-and polyfluoroalkyl sulfonic acids, the scavenging capacity was high on coarse particles. Our results showed that wet deposition effectively removed medium to long carbon chain (≥C6) PFASs in the atmosphere.

Occurrence, partitioning behavior and risk assessments of per- and polyfluoroalkyl substances in water, sediment and biota from the Dongshan Bay, China.

Twenty-five per- and polyfluoroalkyl substances (PFASs) were analyzed in water, sediment and biota from the Dongshan Bay (DSB) to study their seasonal variations, composition profiles, potential pollution sources, partitioning behavior and risk assessments. The total concentrations of PFASs (∑PFASs) in water ranged from 3.2 to 6.5 ng L-1 (mean 4.0 ng L-1) during the dry season, and 0.11-4.5 ng L-1 (mean 1.3 ng L-1) during the wet season. Perfluoro-butane sulfonic acid (PFBS), perfluoro-butanoic acid (PFBA) and perfluoro-octanoic acid (PFOA) were dominated and frequently detected in water. ∑PFASs in sediment were 0.15-0.37 ng g-1 dw (mean 0.24 ng g-1 dw) with the long-chain PFASs perfluoro-octane sulfonic acid (PFOS) dominating. High concentrations of PFASs in land-based drainage outlets (2.0-384.6 ng L-1 in water) and Zhangjiang estuary indicated that land-based discharges and the river discharge were the main sources. High concentration (366.1 ng L-1) and proportion (94%) of PFBA on one drainage outlet agreed with the trend that PFBA was as an alternative to long-chain PFASs. ∑PFASs in biota ranged from 0.11 to 0.40 ng g-1 ww, and only long-chain PFASs were detected. The partition coefficients (log Kd) of PFASs between water and sediment ranged from 1.13 to 2.90, increased with carbon chain length, implied long-chain PFASs are more likely to adsorb to sediment. Results of ecological and health risk assessments indicated that PFASs had no significant risk for the aquatic organisms and local residents.

Quality assurance and quality control of solid phase extraction for PFAS in water and novel analytical techniques for PFAS analysis.

An inter-laboratory trial (ILT) has been performed to validate ISO 21675 method for the measurement of per-and polyfluoroalkyl substances (PFAS) in water samples using solid phase extraction method and high-performance liquid chromatography-tandem mass spectrometry. A total of twenty-seven laboratories from eleven countries (Belgium: 1, Canada: 2, China: 2, France: 1, Germany: 3, Italy: 2, Japan: 6, Netherlands: 2, South Korea: 1, Sweden: 4, and USA: 3) participated in the ILT. Results of the homogeneity of ILT water samples showed that the repeatability tended to increase from short-chain to long-chain of PFAS. Results of stability of PFAS in Milli-Q water stored at 5 ± 3 °C ranged from 75% to 121% including those ultra-short-chain compounds, except for N-MeFOSA (44%), N-EtFOSA (44%), and 8:2 FTOH (30%) at 168 days. As for stability of PFAS in environmental waters, they were in acceptable range (between 70 and 125%) for most of PFAS, except for 8:2 FTUCA in the river water, seawater, and wastewater, and 8:2 FTSA and 8:2 FTOH in wastewater. Based on the performance data (reproducibility (CVR): <40%, recoveries (η): 70-125%) of the ILT, current ISO 21675 is validated for up to 30 PFAS depending on water type. Novel analytical techniques namely "In-situ Solid Phase Extraction" and the "Purge and Trap Extraction" were developed and explored to measure volatile PFAS. Preliminary results showed acceptable recoveries for volatile PFAS such as fluorotelomer alcohols and iodides in spiked Milli-Q water.

Simultaneous analysis of neutral and ionizable per- and polyfluoroalkyl substances in air.

A new method is preliminarily validated for the simultaneous analysis of ionic and neutral per- and polyfluoroalkyl substances (PFASs) in both particulate and gaseous phases in air using a nanosampler-20 air sampler (NS20) composed of quartz fiber filters (QFFs), polyurethane foam (PUF) and artificial activated charcoal (GAIAC™). Perfluoroalkane sulfonamido ethanols (FOSEs) mainly remained in PUF, whereas the other neutral analytes were mainly found in GAIAC. Satisfactory recoveries were obtained for FOSEs, fluorotelomer alcohols (FTOHs), fluorotelomer iodides (FTIs), ranging fron 70%-120%, moderate recoveries were achieved for perfluorinated iodine alkanes (FIAs) and diiodofluoroalkanes (FDIAs), ranging from 50%-70%, while poor recoveries were found for perfluoroalkane sulfonamides (FOSAs). Breakthrough experiments revealed that almost all the target analytes were well trapped in GAIAC™, including the very volatile 4:2 FTOH. Applying to real sampling, our results showed that 6:2 and 8:2 FTOH were the most abundant species, with levels detected at 190 pg/m3 and 160 pg/m3. To the best of our knowledge, FDIAs were detected in ambient air for the first time at an average level of 8.3 pg/m3. Overall, the profiles observed from the real air samples reflected current industrial transition from longer chain to shorter chain in PFAS production. Our results revealed that the current method is promising for a more comprehensive understanding on the fates of PFASs in air.

Per- and polyfluoroalkyl substances in surface water, gas and particle in open ocean and coastal environment.

A simultaneous sampling of atmospheric and seawater samples was performed in the Taiwan Western Strait, western Arctic Ocean, and the Antarctic Ocean. Analysis of both particle and gas phase PFAS in oceanic air was conducted using cascade impactor particle fractionator, cryogenic air sampler and activated charcoal fiber sorbent for the first time with application in the Taiwan Western Strait. Mean concentration of Σ12PFAS in surface seawater and atmospheric samples were 1178 pg/L and 24 pg/m3 in the Taiwan Western Strait, 430 pg/L and 6 pg/m3 in the western Arctic Ocean, and 456 pg/L and 3 pg/m3 in the Antarctic Ocean. In oceanic air from the Taiwan Western Strait, fluorotelomer alcohol (FTOH) and the ionic PFAS [perfluoroalkyl sulfonic acid (PFSA) and perfluoroalkyl carboxylic acid (PFCA)] were found in 76% and 7% respectively. Regional comparison of air/water exchange (KAW) and gas-particle (Kp) partition coefficients of PFAS in the oceanic environment indicated potential partitioning of ionic PFAS between surface seawater and oceanic air. These findings highlight the advancement in atmospheric PFAS measurements through combined novel technologies, namely size-fractionated particle sampling with cryogenic air trapping and/or activated charcoal sorption. Correlation between Kp and carbon chain length of PFAS was observed using both hyphenated techniques.

Per- and Polyfluoroalkyl Substances in the Air Particles of Asia: Levels, Seasonality, and Size-Dependent Distribution.

Information regarding the size-dependent distribution of per- and polyfluoroalkyl substances (PFAS) in atmospheric particulate matter (PM) is very limited. In this study, 248 size-specific PM samples were collected from 9 Asian cities using a portable 4-stage cascade impactor for the analysis of PFAS. Of the 34 investigated PFAS, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) were the major compounds. In particular, the emerging PFAS, hexafluoropropylene oxide dimer acid, was quantified in the PM for the first time, with concentrations ranging from <0.086 to 21.5 pg/m3. Spatially, PFOA and PFOS were the predominant compounds in China, while precursors, emerging PFAS, and short-chain PFAS dominated in India, Japan, and South Korea, respectively. Seasonal variations of PFAS may be controlled by regional climate, local or seasonal emission sources, and long-range transport of air masses. Size-dependent distribution was investigated, showing that the majority of PFAS predominantly affiliated in fine particles, while PFOS and its alternatives tended to attach on coarser particles. Moreover, PFOS distributed on specific sizes exhibited seasonal and regional dependency, while no such patterns were observed for PFOA. These findings will provide useful information on the geographical and size-dependent distribution of PFAS in the atmospheric PM.

Nationwide distribution and potential risk of bisphenol analogues in Indian waters.

Bisphenol A (BPA) has been frequently found in surface waters worldwide, and its estrogenic effects in humans are well documented. Nevertheless, less is known about other bisphenol analogues (BPs), such as bisphenol S (BPS) and bisphenol F (BPF) which are alternative to BPA. There have been few environmental investigations on BPs in developing countries, especially India. In the present study, eight BPs were analyzed, among which BPA, BPS, and BPF were found prevalent in surface water and wastewater from drains collected from 12 states and Delhi-National Capital Territory in India. The detection frequencies of BPA, BPS, and BPF were 67.6%, 41.9%, and 29.7%, respectively in all samples (n = 74). BPA was the predominant species among the three analogues. The highest BPA concentration was observed in the Yamuna River (14,800 ng/L), followed by the Cooum River (1,420 ng/L). The highest concentrations of BPS and BPF were 438 ng/L and 333 ng/L, respectively, both found in wastewater samples. The occurrence of BPS and BPF in nationwide surface water and wastewater samples from India for the first time suggests that new BPs as BPA replacements are being used and released in India. Ecological risk assessment of BPA, BPS and BPF exposure was performed using hazard quotient (HQ) for three aquatic taxonomic groups: algae, crustaceans, and fish, with the last group exhibiting the highest HQs (0.89-148) for BPA exposure. The human exposure risk of BPA through drinking river water was observed negligible in the present study. Our findings indicate the urgent need for, (1) regulations on the use and release of BPs in India, (2) effective processes to remove BPs in wastewater treatment plants, (3) more investigations on the distribution and toxicity of BPs in India, in particular BPA, BPS and BPF, as these analogues were detected at substantial concentration in Indian waters.

Nontarget Discovery of Per- and Polyfluoroalkyl Substances in Atmospheric Particulate Matter and Gaseous Phase Using Cryogenic Air Sampler.

Novel per- and polyfluoroalkyl substances (PFASs) have become a key issue in global environmental studies. Although several novel PFASs have been discovered in atmospheric particulate matter through nontarget analysis, information on the environmental occurrence of novel PFASs in atmospheric gaseous phases and conventional sampling techniques is somewhat deficient. Therefore, this Article describes a new type of air sampler, the cryogenic air sampler (CAS), which was used to collect all atmospheric components simultaneously. Nontarget analysis then was performed through PFASs homologue analysis. A total of 117 PFAS homologues (38 classes) were discovered, 48 of which (13 classes) were identified with confidence Level 4 or above. Eleven chlorinated perfluoropolyether alcohols (3 classes) and four chlorinated perfluoropolyether carboxylic acids (2 classes) have been reported for the first time in this Article. This Article is also the first report of 12 hydrosubstituted perfluoroalkyl carboxylates (H-PFCAs) in the atmosphere. H-PFCAs and chlorinated perfluoropolyether carboxylic acids were mainly distributed in the particular phase. These results are evidence that novel chlorinated polyether PFASs should be the focus of future study.

Occurrence and partitioning behavior of per- and polyfluoroalkyl substances (PFASs) in water and sediment from the Jiulong Estuary-Xiamen Bay, China.

Twenty-four per- and polyfluoroalkyl substances (PFASs) were analyzed in water and sediment from the Jiulong Estuary-Xiamen Bay to study their seasonal variations, transport, partitioning behavior and ecological risks. The total concentration of PFASs in water ranged from 11 to 98 ng L-1 (average 45 ng L-1) during the dry season, 0.19-5.7 ng L-1 (average 1.5 ng L-1) during the wet season, and 3.0-5.4 ng g-1 dw (average 3.9 ng g-1 dw) in sediment. In water samples, short-chain PFASs were dominated by perfluorooctanoic acid (PFBA) in the dry season and perfluorobutane sulfonate (PFBS) in the wet season, while long chain PFASs, such as perfluorooctane sulfonate (PFOS), dominated in the sediment. The highest concentration of PFASs in water were found in the estuary; in contrast, the highest level of PFASs in sediment were found in Xiamen Bay. These spatial distributions of PFASs indicate that river discharge is the main source of PFASs in estuarine water, while the harbor, airport and wastewater treatment plant near Xiamen Bay may be responsible for the high PFBS and PFOS concentrations in water and sediment. The partition coefficients (log Kd) of PFASs between sediment and water (range from 1.64 to 4.14) increased with carbon chain length (R2 = 0.99) and also showed a positive relationship with salinity. A preliminary environmental risk assessment indicated that PFOS and perfluorooctanoic acid (PFOA) in water and sediment pose no significant ecological risk to organisms.

Evaluation of perfluoroalkyl substances in field-cultivated vegetables.

Perfluoroalkyl substances (PFASs) were investigated in three types of vegetables (fruit, leafy, and root vegetables) that were cultivated and harvested from 2014 to 2017. The cultivated soil was mainly affected by perfluoroalkyl carboxylic acid (PFCAs; 91.8% detection rate) rather than perfluoroalkyl sulfonic acids (PFSAs; 8.2%). The cultivated soil (i.e., a volcanic cohesive soil) had a high total organic carbon (TOC = 3.4%) and therefore showed strong adsorption of long-chain PFASs. Short-chain PFCAs (i.e., under C9) were mainly detected in vegetables; specifically, PFBA showed high concentration in tomato shoots. Principal component analysis (PCA) plots clearly showed that PFASs in vegetables were different from those of cultivated soil, air, and rainwater. Interestingly, the whole potato (i.e., including peel) was in the same group as soil, indicating that the whole potato can easily be affected by the cultivated soil. Energy Dispersive X-ray Spectrometry-Scanning Electron Microscope (EDS-SEM) results showed that presence of unremovable micron-sized cultivated soil particles on the potato surface. Comparing the regional differences between the cultivated area of Tsukuba city (East Japan) and Osaka city (West Japan), PFASs patterns were similar in cucumber but differed in green perilla and potato.

Occurrence of perfluoroalkyl substances in selected Victorian rivers and estuaries: An historical snapshot.

This reconnaissance study was undertaken in 2012 to examine the occurrence of common perfluoroalkyl substances (PFAS), including perfluoroalkyl sulphonic acids and perfluoroalkyl carboxylic acids in rivers and estuaries in Port Philip Bay, Victoria, Australia. In total, 19 PFAS were screened in grab samples of water using a combination of solid phase extraction and liquid chromatography - mass spectrometry measurement techniques. Eighteen of the PFAS screened were observed in samples. The highest level of PFOS observed at a freshwater site was 0.045 µg/L; this concentration is approximately half the draft Australian 95% species protection level for total PFOS. The highest level of PFOA in the study (0.014 µg/L) was some four orders of magnitude lower than the draft Australian trigger value for PFOA (220 µg/L). However, none of the PFAS observed at the freshwater sites had research quotient (RQ) or toxicity unit (TU) values above 1 or -3, respectively. The highest concentration of PFOS observed at an estuarine site was 0.075 µg/L; the highest level of PFOA, 0.09 µg/L). There are no Australian marine water quality trigger values for PFAS, so potential risk was assessed using the European environment quality standards (EQS) adopted in EU Directive 2013/39/EU, RQ and TU methods. In that context, none of the PFAS observed at estuary sites had concentrations higher than the EU standards, or RQ above 1 or Log 10 TU above -3. Together these assessments suggest none of the PFAS screened would have posed an acute risk to organisms in the fresh or estuary waters studied at the time of sampling on an individual or collective basis. However, the detection of these PFAS in Victorian estuaries highlights that the issue is not just an issue for more densely populated countries in the northern hemisphere, but also potentially of concern in Australia. And, in that context, more sampling campaigns in Port Philip Bay are of paramount importance to assess the potential risk pose by these compounds to aquatic ecosystems.

Vertical distribution of perfluoroalkyl substances in water columns around the Japan sea and the Mediterranean Sea.

Perfluoroalkyl substances (PFASs) have become an important class of global environmental contaminants, yet their vertical profile in the marine water column is still less understood, especially for the semi-closed seas. In this study, the contamination level and spatial distribution of 8 PFASs were investigated in both surface and vertical water samples from two semi-closed seas, the Japan Sea and the Mediterranean Sea. Similar levels and compositions of PFASs were found between these two seas. The vertical profile of PFASs in the Mediterranean Sea was variable while that was relatively steady in the Japan Sea, probably due to their different pollution sources. The accumulation rate of PFASs from the East China Sea to the Japan Sea was calculated, for which perfluorooctanesulfonic acid and perfluorooctanoic acid were found to have high accumulation potency in both surface and deep water; most of the investigated PFASs were accumulated in the deep water due to the long residence time while they were more likely to escape to the Pacific Ocean in the surface water. This work aimed (i) to study the distribution of PFASs in both surface and vertical water samples in two semi-closed seas, namely the Japan Sea and for the first time the Mediterranean Sea, (ii) to assess the temporal trend in the Japan Sea, and (iii) to firstly investigate the potential transport of PFASs from the East China Sea and Taiwan Strait in order to estimate the inventory of PFASs in whole water mass in the Japan Sea.

Accumulation of perfluoroalkyl substances in lysimeter-grown rice in Japan using tap water and simulated contaminated water.

Perfluoroalkyl substances (PFASs) are a group of contaminants of concern in agricultural crops, but little is known of their accumulation or behavior in grains. We grew Japanese rice (Oryza sativa subsp. indica) in lysimeters irrigated with tap water or tap water plus simulated contaminated water for 2 years, then analyzed the roots, straw, unhulled rice, white rice, bran, soil, and water for PFASs residues. Total fluorine was measured by combustion ion chromatography. Estimated per-plant residue levels were 3.0 pg perfluorooctanesulfonic acid (PFOS) (bran: 0.5%, hull: 99.5%), 0.54 pg N-ethylperfluorooctanesulfonamide (N-EtFOSA) (white rice: 67%, hull: 33%), 1.2 pg perfluorobutanoic acid (PFBA) (white rice: 13%, bran: 7%, hull: 79%), 0.68 pg perfluoropentanoic acid (hull: 100%), 0.50 pg perfluorohexanoic acid (PFHxA) (white rice: 65%, bran: 16%, hull: 19%), 0.21 pg perfluoroheptanoic acid (hull: 100%), 0.25 pg perfluorooctanoic acid (PFOA) (hull: 100%), and 0.12 pg perfluorodecanoic acid (PFNA) (white rice: 81%, bran: 19%). Estimated daily PFASs intakes were <1-3 ng perfluorooctanesulfonamide, <1-7 ng N-EtFOSA, 1-2 ng PFBA, <3-4 ng PFHxA, and 1-2 ng PFNA. Estimated PFOS, PFOA, and total PFASs in straw feed were 0.4, 0.1, and 2 kg yr-1 and 0.7, 0.4, and 8 kg yr-1 in 2015 and 2016, respectively. Estimated PFOS, PFOA, and total PFASs in straw fertilizer were 4, 1, and 23 kg yr-1 and 7, 4, and 86 kg yr-1 in 2015 and 2016, respectively. PFASs accumulation may cause longer residence time in agricultural systems owing to straw being used as animal feed and organic fertilizer.

Assessing exposure to legacy and emerging per- and polyfluoroalkyl substances via hair - The first nationwide survey in India.

In recent years, environmental issues emerging from per- and polyfluoroalkyl substances (PFAS) have raised high concern worldwide. Levels of human exposure to PFAS remain unknown in India. Biomonitoring data obtained from hair analysis have been evidenced to provide insight into retrospective human exposure to PFAS. In this study, 25 PFAS, including perfluoroalkyl acids and their precursors, were measured in 39 human hair samples collected from 14 cities in India. The inuflence of gender on the PFAS levels was also examined. To our knowledge, this is the first attempt to provide preliminary indicative data (due to the limited sample size and variability in hair-length sampling) on the levels of PFAS in Indian hair. The concentrations of total PFAS in hair varied from below matrix-specific limit of quantification (<0.02 ng/g) to 3.78 ng/g. Among 9 PFAS quantified, perfluorohexanesulfonic acid (PFHxS), perfluorooctanesulfonic acid (PFOS), and perfluorooctanoic acid (PFOA) were the predominant compounds. Categorized into 4 regions, PFAS contamination exhibited certain regional difference where South India may show higher levels than the other regions. Highly significant positive correlation was observed between PFHxS and PFOS (p ≪ 0.001; r = 0.644), suggesting similar pathways of exposure to the two compounds. Higher PFAS occurrence was generally observed in the hair of females. Our results highlighted the urgent need to investigate the deposition mechanism of PFAS in hair.

Accumulation of quaternary ammonium compounds as emerging contaminants in sediments collected from the Pearl River Estuary, China and Tokyo Bay, Japan.

In this work, the distribution of quaternary ammonium compounds (QACs) in two dated sediment cores, collected from the Pearl River Estuary (PRE) and Tokyo Bay (TB), were investigated to understand the historical input of QACs and their diagenetic behavior in urban estuarine environments. The vertical variation profiles of QAC concentrations showed that benzylalkyldimethyl ammonium compounds (BACs) and dialkyldimethyl ammonium compounds (DADMACs) were widely used during 1970s and 1980s both in China and Japan. The declining environmental concentrations of QACs suggested a compositional change of commodities and the effectiveness of emission control strategies. For the individual QAC homologues, BAC homologues decreased significantly over time, while DADMAC compositions remained relatively stable. The differences in concentration and composition profiles of BACs and DADMACs in the sediment cores provided useful information on the patterns of use of QACs in China and Japan, as well as their diagenetic behaviors in the sediments.

Current Contamination Status of Perfluoroalkyl Substances in Tapwater from 17 Cities in the Eastern China and Their Correlations with Surface Waters.

The contamination status of perfluoroalkyl substances (PFASs) were investigated in 64 tapwater samples collected from 17 cities and 45 surface water samples from adjacent areas in the eastern China. The total PFAS concentrations in tapwater ranged from 1.4 to 175 ng/L; relatively higher PFAS levels were observed in samples collected from the Yangtze River Delta region, which was similar to the geographical distribution pattern of PFAS levels observed in rivers and lakes. The highest total PFASs in tapwater was found in Changshu, where several fluorine-related industries are located, whereas the lowest was observed in Beijing. Significant positive correlations between PFAS compositions in tap water sample and their source waters were noted. Several industries such as paper, textile, and leather industries may contribute to the contamination of PFASs in tapwater.