Perfluoroalkyl substances (PFAS) occurrence, concentrations and spatial distribution along the French Mediterranean coast and lagoons, based on active biomonitoring

Tracking PFAS in ecosystems is challenging. In this context, monitoring programs are crucial to fill data gaps, especially in marine environments, which are the ultimate outlets for these forever chemicals. The 2021 chemical contamination monitoring campaign along the French Mediterranean coast established a baseline for PFAS concentrations in mussels, with 90 % of measurements below quantification limits. When detected, long-chain PFCA's were predominant. Spatial distribution patterns suggested continuous PFAS inputs and complex dynamics, shaped by the influence of large watersheds and rivers (Rhône, Aude, Huveaune). Lapeyrade shallow lagoon stood out as the most contaminated site. Similar PFAS profiles in connected sites implied shared sources but raised questions about accumulation processes in mussels. While certain sites had evident sources (e.g., military airbase for Palo lagoon), others remained uncertain (e.g., Toulon bay). Coastal stations (Banyuls, Cap Agde, Brégançon, Pampelonne) showed PFAS contamination without clear onshore sources, possibly due to insufficient transportation process understanding.

Trophic behaviors of PFOA and its alternatives perfluoroalkyl ether carboxylic acids (PFECAs) in a coastal food web

With the increasing restrictions and concerns about legacy poly- and perfluoroalkyl substances (PFAS), the production and usage of alternatives, i.e., perfluoroalkyl ether carboxylic acids (PFECAs), have risen recently. However, there is a knowledge gap regarding the bioaccumulation and trophic behaviors of emerging PFECAs in coastal ecosystems. The bioaccumulation and trophodynamics of perfluorooctanoic acid (PFOA) and its substitutes (PFECAs) were investigated in Laizhou Bay, which is located downstream of a fluorochemical industrial park in China. Hexafluoropropylene oxide trimer acid (HFPO-TrA), perfluoro-2-methoxyacetic acid (PFMOAA) and PFOA constituted the dominant compounds in the ecosystem of Laizhou Bay. PFMOAA was dominant in invertebrates, whereas the long-chain PFECAs preferred to accumulate in fishes. The PFAS concentrations in carnivorous invertebrates were higher than those in filter-feeding species. Considering migration behaviors, the ∑PFAS concentrations followed the order oceanodromous fish < diadromous fish < non-migratory fish. The trophic magnification factors (TMFs) of long-chain PFECAs (HFPO-TrA, HFPO-TeA and PFO5DoA) were >1, suggesting trophic magnification potential, while biodilution for short-chain PFECAs (PFMOAA) was observed. The intake of PFOA in seafood may constitute a great threat to human health. More attention should be given to the impact of emerging hazardous PFAS on organisms for the health of ecosystems and human beings.

Large-scale assessment of exposure to legacy and emerging per- and polyfluoroalkyl substances in China's shorebirds

Emerging per- and polyfluoroalkyl substances (PFAS) have become more widely applied, whereas legacy PFAS such as PFOS continue to distribute ubiquitously in the environment. Large-scale assessment of wildlife exposure to both emerging and legacy PFAS plays a key role in effective biomonitoring to better discriminate regional contamination patterns and provide early warnings. Using eggs of two closely-related shorebird species collected across China during the breeding season in 2021, we constructed contrasting PFAS levels and profiles in coastal versus inland populations. The highest ∑PFAS concentrations were found in two Kentish plover (Charadrius alexandrinus) populations from the Bohai Sea, a semi-enclosed shallow bay located in northeast China. These two populations showed exceptionally high PFOA concentrations (mean: 94 and 121 ng/g wet weight; West and North Bohai Sea, respectively) dominating the overall PFAS profile (66% for both). This pattern is characteristic, compared to that of other seabird eggs worldwide. By comparison, PFAS profile in the white-faced plover (Charadrius dealbatus) population at the South China Sea coast was dominated by PFOS (46%), which showed similar levels to those at the North Bohai Sea coast (mean: 29 and 20 ng/g, respectively). PFAS concentrations of Kentish plovers from the remote Qinghai Lake were lower compared to the three coastal populations, and were dominated by PFNA (mean: 2.6 ng/g, 29%) and PFOS (mean: 2.5 ng/g, 27%). None of the eggs analyzed in the present study exceeded estimated toxicity reference values for PFOS or PFOA. Additionally, the emerging 6:2 Cl-PFESA was detected in eggs from all regions, while its concentrations were highest in the Bohai Sea populations, and short-chain PFBS was only detected in the North Bohai Sea population. Our results indicate intensive local emissions of PFOA and emerging PFAS at the Bohai Sea region, and warrant further investigation and monitoring.

New insights into the oxidative damage and antioxidant defense mechanism in Manila clams (Ruditapes philippinarum) exposed to 8:2 polyfluoroalkyl phosphate diester stress

8:2 perfluoroalkyl phosphate diester (8:2 diPAP) is the main precursor of perfluoroalkyl carboxylic acids, and it has been detected in a wide range of environments. In this study, conventional biochemical and histopathological analyses and transcriptome methods were used to investigate the accumulation and oxidative stress of 8:2 diPAP in Manila clams (Ruditapes philippinarum) as well as the clam's defense mechanisms for the first time. The hepatopancreas was the main target organ for 8:2 diPAP accumulation; the concentration reached 484.0 ± 15.5 ng/g after 7 days of exposure to 10 μg/L of 8:2 diPAP, which was 2-100 times higher than that found in other organs. 8:2 diPAP accumulation resulted in significant lipid peroxidation, and the change in malondialdehyde content was highly correlated with 8:2 diPAP accumulation (r > 0.8). The antioxidant enzymes catalase and peroxidase were significantly activated at 7 days of exposure. Although the levels subsequently returned to normal, this restoration was unable to prevent damage. Histopathological analysis showed that 8:2 diPAP exposure resulted in inflammatory damage to the hepatopancreas, which failed to resolve during the recovery period. Transcriptomic analyses showed that the expression of differentially expressed genes had different degrees of positive/negative correlation with antioxidant indicators, and they were significantly enriched in cell death regulatory pathways such as autophagy, apoptosis, and necrosis. The core factor expression results indicated that 8:2 diPAP exposure induced activation of the organismal autophagy factor followed by a shift towards apoptosis. In addition, pathways related to amino acid metabolism and energy metabolism were involved in determining the cell fate of Manila clams. Overall, these results indicated that 8:2 diPAP induced peroxidation of membrane lipids, disturbed physiological processes, and ultimately initiated programmed cell death in Manila clams. The findings of this study provide new insights into the mechanism of toxicity of 8:2 diPAP exposure in marine bivalves.

Occurrence and Risks of Per- and Polyfluoroalkyl Substances in Shellfish

PURPOSE OF REVIEW

Per- and polyfluoroalkyl substances (PFAS) are a diverse class of persistent, fluorinated surfactants used widely in industrial and commercial applications with known adverse health effects. Seafood consumption is thought to be an underappreciated source of PFAS exposure in the general population. This review synthesizes the current understanding of PFAS occurrence in shellfish, a term used to describe animals such as mollusk bivalves, certain gastropods (snails), cephalopods (e.g., octopuses and squid), and crustaceans, and highlights scientific gaps relative to bioaccumulation and the protection of shellfish consumers.

RECENT FINDINGS

A range of sampling methodologies are used across studies, and the suite of PFAS surveyed across studies is highly variable. Concentrations of PFAS observed in shellfish vary by geographic location, shellfish species, habitat, and across PFAS compounds, and studies informing estimates of bioaccumulation of PFAS in shellfish are extremely limited at this time. This review identifies several important opportunities for researchers to standardize PFAS sampling techniques, sample preparation, and analytical methodologies to allow for better comparison of PFAS analytes both within and across future studies. Increasing the range of geographic locations where samples are collected is also a critical priority to support a greater knowledge of worldwide PFAS contamination. When put into the context of risk to consumer, concentrations of PFAS, especially PFOS, found in shellfish collected from sites containing aqueous film-forming foam (AFFF) and industrial contamination may present risks to frequent consumers. Further research is needed to protect shellfish consumers and to inform shellfish advisories and health protective policies.

Analysis of Per- and Poly(fluoroalkyl) Substances (PFASs) in Highly Consumed Seafood Products from U.S. Markets

Seafood consumption has been identified as one of the major contributors of per- and poly(fluoroalkyl) substances (PFASs) to the human diet. To assess dietary exposure, highly consumed seafood products in the United States were selected for analysis. The analytical method previously used for processed food was extended to include four additional long-chain perflurocarboxylic acids (PFCAs), which have been reported in seafood samples. This method was single-lab-validated, and method detection limits were reported at 345 ng kg^-1 for perfluorobutanoic acid (PFBA) and 207 ng kg^-1 for perfluoropentanoic acid (PFPeA) and below 100 ng kg^-1 for the rest of the PFAS analytes. The 81 seafood samples (clams, crab, tuna, shrimp, tilapia, cod, salmon, pollock) were analyzed for 20 PFASs using the updated analytical method. Most of the seafood packaging was also analyzed by Fourier transform infrared-attenuated total reflectance (FTIR-ATR) to identify packaging potentially coated with PFASs. None of the packaging samples in this study were identified as having PFASs. A wide range of concentrations was observed among the seafood samples, ranging from below the method detection limit to the highest concentration of 23 μg kg^-1 for the sum of PFASs in one of the canned clam samples. Such a wide range is consistent with those reported in previous studies. The highest concentrations were reported in clams and crabs, followed by cod, tuna, pollock, tilapia, salmon, and shrimp. Technical perfluorooctanoic acid (PFOA) dominated the profile of the clam samples, which has been consistently found in other clam samples, especially in Asia. Long-chain PFCAs, specifically perfluoroundecanoic (PFUdA) and perfluorododecanoic (PFDoA), were the most frequently detected analytes across all seafood samples. The trends observed are comparable with those in the literature where benthic organisms tend to have the highest PFAS concentrations, followed by lean fish, fatty fish, and aquaculture. The results from this study will be used to prioritize future studies and to inform steps to reduce consumer exposure to PFASs.

First Report on the Bioaccumulation and Trophic Transfer of Perfluoroalkyl Ether Carboxylic Acids in Estuarine Food Web

As novel alternatives to legacy poly- and perfluoroalkyl substances (PFAS), perfluoroalkyl ether carboxylic acids (PFECAs) have been widely detected in the environment; however, there is limited information and knowledge regarding their bioaccumulation and trophic transfer behavior along the food chain. This research presents the first known published data on the bioaccumulation and trophic transfer characteristics of PFECAs in a source-impacted estuary. Elevated PFECA concentrations were observed in organisms (for instance, conch, with perfluoro-2-methoxyacetic acid (PFMOAA) concentration reaches up to 16 700 ng/g dry weight (dw)), indicating exposure risks to the consumers. Conch can be acted as a potential environmental bioindicator of PFMOAA. PFMOAA, hexafluoropropylene oxide trimer acid (HFPO-TrA) and PFOA were predominant detected in biotas. On the basis of trophic magnification factors (TMFs), PFECAs with ≥6 perfluorinated carbons (HFPO-TrA, hexafluoropropylene oxide tetramer acid (HFPO-TeA) and perfluoro (3, 5, 7, 9, 11-pentaoxadodecanoic) acid (PFO5DoA)) could be biomagnified along the food chain (TMF > 1), while PFMOAA with the least perfluorinated carbons undergone biodilution (TMF < 1). As seafood is an important dietary source of protein to human, there is a potential health risk related to the consuming polluted aquatic products.

Estimating the dietary exposure and risk of persistent organic pollutants in China: A national analysis

Substantial heterogeneities have been found in previous estimations of the risk from dietary exposures to persistent organic pollutants (POPs) in China, mainly due to spatiotemporal variations. To comprehensively evaluate the dietary risks of POPs listed in the Stockholm Convention, more than 27,580 data records from 753 reports published over the last three decades were examined. Respectively, for various food categories, the results obtained for the range of mean concentrations of POPs are as follows: total dichlorodiphenyltrichloroethanes (DDTs: 1.4-27.1 μg/kg), hexachlorocyclohexanes (HCHs: 1.8-29.3 μg/kg), polybrominated diphenyl ethers (PBDEs: 0.046-2.82 μg/kg), polychorinated biphenyls (PCBs: 0.05-7.57 μg/kg), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD&Fs: 2.9-210 pg toxic equivalent (TEQ)/kg), perfluorooctanoic acid (PFOA: 0.02-0.97 μg/kg), perfluoroctane sulfonate (PFOS: 0.00082-2.76 μg/kg) and short-chain chlorinated paraffins (SCCPs: 64-348.92 μg/kg). Temporal decreasing trends were observed for DDTs, HCHs, PBDEs, PCDD&Fs, and PFOA, with no significant change for other POPs. Meanwhile, the estimated daily intake for adults were 75.2 ± 43.6 ng/kg/day for DDTs, 123 ± 87 ng/kg/day for HCHs, 0.37 ± 0.17 pg TEQ/kg/day for PCDD&Fs, 17.8 ± 9.5 ng/kg/day for PCBs, 3.3 ± 1.8 ng/kg/day for PBDEs, 3.6 ± 1.9 ng/kg/day for PFOA, 3.3 ± 2.0 ng/kg/day for PFOS, and 2.5 ± 1.6 μg/kg/day for SCCPs. Furthermore, non-carcinogenic risks were the highest for PCBs (0.89) and PCDD&Fs (0.53), followed by PFOA (0.18), PFOS (0.17), HCHs (0.062), SCCPs (0.025), DDTs (0.0075), and PBDEs (0.00047). These findings illustrated that exposure to POPs declined due to the control policies implemented in China, while the cumulative risk of POPs was still higher than 1, indicating continuous efforts are required to mitigate associated contamination.

Uptake, Tissue Distribution, and Elimination of 8:2 Polyfluoroalkyl Phosphate Diesters in Mytilus galloprovincialis

Although the distribution of 8:2 polyfluoroalkyl phosphate diester (8:2 diPAP) in aquatic environments has been reported, details on its uptake, tissue specificity, and elimination in bivalve mollusks remain to be clarified. The present study is the first report on the accumulation and elimination of 8:2 diPAP in mussels (Mytilus galloprovincialis). The tissue-specific accumulation and depuration of 8:2 diPAP and its metabolites were investigated via semistatic seawater exposure (8:2 diPAP at a nominal concentration of 10 μg/L), through water-borne exposure with static daily renewal over a 72-h exposure period and a 360-h depuration period. The digestive gland was found to be the target organ where accumulation and biotransformation primarily occur. The bioaccumulation factor values (mL/g dry wt) in different organs were in the following order: digestive gland (1249) > adductor muscle (315) > gills (289) > gonad (82.9) > mantle (33.0). Moreover, the distribution of 8:2 diPAP among tissues may be related to the total protein content. The 8:2 diPAP tended to be excreted in feces. The compounds 8:2 fluorotelomer carboxylic acid, 8:2 fluorotelomer unsaturated carboxylic acid, 7:3 fluorotelomer carboxylic acid, perfluorooctanoic acid, and perfluoroheptanoic acid were detected and quantified as phase I metabolites, and the concentration of all phase I metabolites relative to the 8:2 diPAP concentration (72 h) was 0.304 mol%. A phase II metabolite, 8:2 fluorotelomer alcohol conjugated with sulfate, was detected but not quantitated in the digestive gland. A biotransformation pathway of 8:2 diPAP in M. galloprovincialis was proposed on the basis of the results obtained in the present study and previous studies. These findings improve our understanding of the accumulation of perfluorocarboxylic acids in bivalve mollusks. Environ Toxicol Chem 2021;40:1992-2004. © 2021 SETAC.

Distribution of perfluorooctane sulfonate in mice and its effect on liver lipidomic

Perfluorooctane sulfonate (PFOS) is an emerging persistent organic pollutant (POP), and the harm caused by the enrichment of PFOS in living organism has attracted more and more attention. In this work, animal exposure model to PFOS was established. Mass spectrometry (MS), mass spectrometry imaging (MSI), hematoxylin and eosin (H&E) staining and lipidomics were combined for the study of the organ targeting of PFOS, the toxicity and possible mechanism caused by PFOS. PFOS most accumulated in the liver, followed by the lungs, kidneys, spleen, heart and brain. Combined with H&E staining and matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI MSI) results, it was found that the accumulation of PFOS indeed caused damage in particular areas of specific organ, like in the liver and in the marginal area of the heart. This work found that PFOS could cross the blood-brain barrier, entered the brain and caused the neurotoxicity, which was surprising and might be the reason that high dose of PFOS could cause convulsions. From the liver lipidomic analysis, we found that PFOS exposure mainly affected glycerophospholipid metabolism and sphingolipid metabolism. The up-regulated ceramide and lysophosphatidylcholine (LPC) might lead to liver cell apoptosis, and the decrease in liver triglyceride (TG) content might result in insufficient energy in mice and cause liver morphological damage. Phosphatidylcholine (PC) synthesis via phosphatidylethanolamine N-methyltransferase (PEMT) pathway might be a mechanism of self-protection in animals against PFOS induced inflammation. This study might provide new insight into underlying toxicity mechanism after exposure to PFOS.

Occurrence of and human exposure to benzothiazoles and benzotriazoles in mollusks in the Bohai Sea, China

The Bohai Sea is a semi-enclosed sea in northern China with highly industrialized and urbanized coastal areas and concomitant environmental degradation. Benzothiazoles (BTHs) and benzotriazoles (BTRs) are produced in high volume and widely applied in industrial and consumer products, and little is known about their occurrence and bioaccumulation in coastal marine invertebrates. We determined the concentrations of six BTH and five BTR analogues in mollusks (n = 166) collected from the Bohai Sea between 2006-2014. The total concentrations of BTHs were 229-13800 ng/g dry weight (dw) with a geometric mean of 778 ng/g dw and 7.19-322 ng/g dw for BTRs with a geometric mean of 54.6 ng/g dw. Benzothiazole (BTH) was the dominant compound among the BTHs, accounting for 83.0 % of the total concentration. Among the BTRs, 5,6-dimethyl-1-H-benzotriazole (XTR), 5-methyl-1-H-benzotriazole (5-Me-1-H-BTR), and benzotriazole (1-H-BTR) were major contributors, cumulatively accounting for 78.5 % of the total concentration. Mollusks accumulated elevated levels of BTHs/BTRs regardless of species, suggesting a considerable bioaccumulation potential of BTHs/BTRs in marine ecosystems. Human daily dietary intake of BTHs/BTRs through the consumption of mollusks was estimated based on the concentrations measured. This is the first report on the occurrence and distribution patterns of BTHs/BTRs in a variety of marine invertebrate species from a coastal ecosystem.

Current Status, Challenges, and Policy Recommendations of China's Marine Monitoring Systems for Coastal Persistent Organic Pollution Based on Experts' Questionnaire Analysis

Persistent organic pollutants (POPs) monitoring and management in typical semi-enclosed bays is a major global environmental issue. This study concentrated on a questionnaire survey and analysis of marine environmental management and monitoring departments at all levels in China, and proposed suggestions on the construction and improvement of POPs monitoring and management system. Results show that POPs are initially involved in China's current marine environmental monitoring system, and the monitoring strength and capability still need to be continuously improved, mainly in the recognition, funding input, relevant standards, monitoring, and evaluation technical regulations of marine environmental POPs monitoring. Therefore, in order to gradually improve the monitoring and management system of China's offshore marine environment POPs, this study suggests starting from four directions: (1) Building POPs monitoring system of a marine ecological environment, and strengthening POPs monitoring in different environmental media; (2) strengthening land-based POPs emission and the related human activities' intensity survey, and establishing a POPs information sharing database; (3) optimizing POPs monitoring technology in the marine environment, and improving POPs supervision and management technical support system; and (4) participating in regional and international marine environment POPs monitoring and evaluation projects, and strengthening the construction of talent teams.

Perfluoroalkyl substances (PFASs) in the marine environment: Spatial distribution and temporal profile shifts in shellfish from French coasts

Perfluoroalkyl substances (PFASs) were investigated in filter-feeding shellfish collected from 2013 to 2017 along the English Channel, Atlantic and Mediterranean coasts of France. PFOS (perfluorooctane sulfonate), PFTrDA (perfluorotridecanoic acid), PFTeDA (perfluorotetradecanoic acid), PFDoDA (perfluorododecanoic acid) and PFUnDA (perfluoroundecanoic acid) were detected in more than 80% of samples, thus indicating widespread contamination of the French coastal environment by these chemicals. The distribution of PFAS concentrations showed differences according to sampling locations and years. PFOS was the predominant PFAS in most samples collected from English Channel and Atlantic coasts until 2014, but the opposite was observed in 2015, 2016 and 2017, while perfluoroalkyl carboxylic acids (PFCAs) prevailed in Mediterranean samples in all study years. Among PFCAs, PFTrDA showed the highest maximum (1.36 ng g^-1 ww) and median (0.077 ng g^-1 ww) concentrations in 2016-2017. Other PFAS median concentrations were within the 0.014 (PFNA) - 0.055 (PFTeDA) ng g^-1 ww range. The profiles determined each year in most Mediterranean samples suggest distinctive sources. PFOS median concentrations showed a significant decrease over the study years, from 0.118 to 0.126 ng g^-1 ww in 2013-2015 to 0.066 ng g^-1 ww in 2016 and 2017. ∑PFCAs showed no trends in concentration ranges over the same years. The shift in PFAS profiles from PFOS to long-chain PFCAs over the study period reflects PFOS production phase-out, combined with continuous inputs of PFCAs into the marine environment. These results provide reference data for future studies of the occurrence of contaminants of emerging concern on European coasts.

Legacy and emerging pollutants in marine bivalves from the Galician coast (NW Spain)

The presence of pollutants in estuary and oceanic systems is a global problem and a serious concern to human and environmental health. Usually, environmental monitoring studies consider classical persistent organic pollutants (POPs). However, the lists of POPs keep continuously growing and new POPs and other emerging pollutants should be considered in new monitoring programs. So, this study aimed to investigate the distribution and profile of classical POPs (polychlorinated biphenyl (PCBs), organochlorine pesticides (OCPs), and polycyclic aromatic hydrocarbons (PAHs)), new POPs and emerging pollutants (polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs), novel halogenated flame retardants (NFRs) and UV filters) in bivalve mollusc samples (both raft-cultivated and wild mussel, Mytilus galloprovincialis; cockle, Cerestoderma edule; and clam, Ruditapes descussatus) collected in nine Galician Rias during the period February 2012 to February 2013. A predominance of PAHs (6.8-317 ng/g dry weight (dw)) followed by PCBs (0.47-261 ng/g dw), UV filters (1.4-157 ng/g dw), PFCs (0.53-62 ng/g dw), OCPs (0.07-29 ng/g dw), PBDEs (0.31-6.6 ng/g dw) and NFRs (0.07-3.2 ng/g dw) was found in the studied bivalves, being the UV filter octocrylene the compound found at the highest concentration (141 ng/g dw in a cockle sample), while the PAHs chrysene and benzo(b)fluoranthene were the compounds with the highest average concentration (20 and 14 ng/g dw, respectively). Inter-species, temporal and geographical variations on pollutants concentration were assessed by multifactorial analysis of variance. Statistically significant differences among the type of mollusc were observed for levels of organochlorinated and organobrominated pollutants considered (PCBs, OCPs and PBDEs), which were detected at higher concentrations in wild mussel. On the other hand, the main PFCs and UV filters showed a higher detection frequency in cockle samples. Location played significant role for PAHs, PCBs and the main PBDEs, being the most polluted rias those more industrialized and populated, i.e. A Coruña, Ferrol and/or Vigo. Finally, sampling timepoint was also a significant factor for most of the families considered but with different profiles. Thus, PAHs and PCBs showed higher concentrations in both February 2012 and 2013 and lower in August 2012, while the main PBDEs were measured at higher concentrations in November 2012 and lower in February 2012; and the main NFRs, PFCs and UV filters were present at lower levels in February 2013.

Species-specific accumulation and temporal trends of bisphenols and benzophenones in mollusks from the Chinese Bohai Sea during 2006-2015

Information on the occurrence and bioaccumulation of bisphenols and benzophenones in coastal marine invertebrates is limited. In this study, concentrations of eight bisphenol and five benzophenone analogues were determined in 186 mollusks collected from coastal areas of the Chinese Bohai Sea during the period 2006-2015. Total concentrations of bisphenols and benzophenones were in range of not detected (nd)-58 (geometric mean: 13.0 ng/g) and nd-59.1 (2.06 ng/g) on a dry-weight basis, respectively. BPA and BPF were the major bisphenols, collectively accounting for >90% of the total concentrations. BP-3 was the predominant benzophenone, representing 74% of the total concentrations. The mollusk species, Meretrix meretrix, accumulated high concentrations of both bisphenols and benzophenones. A steady increase in bisphenol concentrations in mollusks was observed in recent years, whereas no obvious temporal trend was found for benzophenones. The estimated daily intakes of bisphenols through consumption of mollusks were lower than the current reference dose. This study establishes a baseline concentration for bisphenols and benzophenones in mollusks in Chinese coastal waters.

Distribution of methylsiloxanes in benthic mollusks from the Chinese Bohai Sea

Methylsiloxanes are a class of silicone compounds that have been widely used in various industrial processes and personal care products for several decades. This study investigated the spatial distribution of three cyclic methylsiloxanes (D4-D6) and twelve linear methylsiloxanes (L5-L16) in mollusks collected from seven cities along the Bohai Sea. D4-D6 (df = 71%-81%) and L8-L16 (df = 32%-40%) were frequently detectable in the mollusk samples, while L5-L7 were not found in any mollusk samples. Cyclic methylsiloxanes (D4-D6) were found in mollusks with the mean concentrations of 15.7 ± 12.3 ng/g ww for D4, 24.6 ± 15.8 ng/g ww for D5 and 34.0 ± 23.0 ng/g ww for D6. Among the seven sampling cities, the cyclic methylsiloxanes were predominant in mollusks, with the total cyclic methylsiloxanes (sum of D4-D6, ∑CMS) accounting for 74.2%-80.7% of the total methylsiloxanes. ∑CMS along the coastline demonstrated a clear gradient, with the highest concentrations in mollusks at the sampling sites located in the western part of the Bohai Sea and the lowest concentrations in mollusks from cities located in the eastern part of the Bohai Sea. The biota-sediment accumulation factors for cyclic methylsiloxanes (D4-D6) and linear methylsiloxanes (L8-L16) were estimated as 0.42 ± 0.06-0.53 ± 0.06 and 0.13 ± 0.03-0.19 ± 0.05, respectively.

Distribution of perfluorinated alkyl substances in marine shellfish along the Chinese Bohai Sea coast

Perfluorinated alkyl substances (PFASs) are emerging persistent organic pollutants, which pose a threat to human health primarily by dietary exposure, especially through seafood. Bohai Sea (a semi-closed sea located north of China) is an important shellfish aquaculture area that is possibly highly-polluted with PFASs. In this study, we first evaluated contamination by PFASs in a total of 230 samples of marine shellfish from the Bohai Sea. Samples included five important shellfish species, collected from important aquaculture spots distributed around the Bohai Sea. Samples were analyzed by an ultra-fast liquid chromatography-tandem mass spectrometry method, which could simultaneously detect 23 PFASs in shellfish. Our research verified that PFASs have become a threat to the safety of shellfish products in this area. Furthermore, contamination by PFASs in shellfish changed depending on the components of PFASs, the species of shellfish, and the sampling sites. Many of the 23 target compounds contributed to the high detection ratio (>50%) as follows: perfluorooctanoic acid (PFOA) > perfluorononanoic acid > perfluorodecanesulfonic acid > perfluorooctanesulfonic acid (PFOS). Compared with other dominant components, PFOA not only had the highest detection percentage in shellfish samples (98.3%), but its detection level contributed to 87.2% of total PFASs concentrations, indicating that PFOA is the major threat to the safety of shellfish products. The highest level of PFAS was found in clams (62.5 ng g^-1 wet weight of PFOA). The concentration of total PFAS in different shellfish species showed the following trend: clams > mussels > scallops > whelks > oysters. The maximum concentration of total PFAS or PFOA was found in Shouguang. The total concentration of PFOS and its precursor were highest in Cangzhou, possibly due to local industrial activities. The results presented in this paper provide new data on the contamination of marine shellfish along the Bohai Sea coasts in China, and constitute a reference for future monitoring of contamination by emerging contaminants in Bohai coast.

Distribution, bioaccumulation and trophic transfer of chlorinated polyfluoroalkyl ether sulfonic acids in the marine food web of Bohai, China

Chlorinated polyfluoroalkyl ether sulfonic acids (Cl-PFESAs) caused great concerns recently as novel fluorinated alternatives. However, information on their bioconcentration, bioaccumulation and biomagnification in marine ecosystems is limited. In this study, 152 biological samples including invertebrates, fishes, seabirds and mammals collected from Bohai Sea of China were analyzed to investigate the residual level, spatial distribution, bioaccumulation and biomagnification of Cl-PFESAs. 6:2 Cl-PFESA was found in concentrations ranging from <MDL (method detection limit) to 3.84 ng/g ww and it is the dominant congener when compared with concentrations of 8:2 Cl-PFESA. Compared with other bays and regions, levels of 6:2 Cl-PFESA are relatively high in bivalves and fishes from Liaodong Bay. These levels were also found to tend to increase as compared with those in 2010-2014. Logarithm bioaccumulation factors (BAFs) for 6:2 Cl-PFESA ranged from 2.23 to 4.21, implying the bioaccumulation of this compound. The trophic magnification factor (BMF) for 6:2 Cl-PFESA was determined to be 3.37 in the marine food web, indicating biomagnification potential along the marine food chain.

A short review on human exposure to and tissue distribution of per- and polyfluoroalkyl substances (PFASs)

PFASs are widely distributed in natural and living environment and can enter human bodies via different routes. Many studies have reported that PFASs may be associated with human diseases, such as urine acid and thyroid diseases. In this study, we reviewed PFAS levels in human bodies reported in past seven years, including blood, urine, milk, and tissues (hair and nails). Most studies focused on human blood. Blood type, spatiality, human age, and gender were found to have a strong relationship with PFAS levels in blood samples. The PFAS distribution in urine samples was reported to be associated with the chain length of PFASs and human gender. Urinary excretion was found to be an important pathway of PFAS elimination. PFAS levels in human milk might be affected by various factors, such as mothers' age, dietary habit, parity of mothers and the interval of interpregnancy. Data in hair and nails remain very limited, but these matrices offer a non-invasive approach to evaluate human exposure to PFASs.

Temporal Trends of Parabens and Their Metabolites in Mollusks from the Chinese Bohai Sea during 2006-2015: Species-Specific Accumulation and Implications for Human Exposure

Parabens are used as preservatives in many consumer products, and human exposure to these chemicals has been a public concern. In this study, mollusks ( n = 186), collected from the Chinese Bohai Sea during 2006-2015, were analyzed for six parabens and their five metabolites. The total concentration of parabens was in the range of 2.66-299 ng/g dw (geometric mean: 24.1). Methyl paraben and 4-hydroxybenzoic acid were the predominant parent and metabolic parabens, respectively found in mollusks. Mollusk species, Mactra veneriformis, Mytilus edulis, and Cyclina sinensis contained elevated concentrations of both parent and metabolic parabens. A gradual increase in paraben concentrations was found in mollusks collected between 2006 and 2012. Principal component analysis suggested the existence of a common source for these chemicals in mollusks. Consumption of mollusks can contribute to human exposures and we estimated daily intakes of parabens through the consumption of mollusks. This is the first study to report temporal trends and accumulation of parabens and their metabolites in a variety of invertebrate species from coastal marine environments.

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

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

Perfluorinated substance assessment in sediments of a large-scale reservoir in Danjiangkou, China

The occurrence of eight perfluorinated compounds (PFCs) in the surface sediments from 10 sampling sites spread across the Danjiangkou Reservoir was investigated by isotope dilution ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) after solid-phase extraction (SPE). All the sediments from the 10 sites contained detectable levels of PFCs. The total concentration of the target PFCs in each sediment sample (C_∑PFCs) ranged from 0.270 to 0.395 ng g^-1 of dry weight, and the mean value of C_∑PFCs was 0.324 ± 0.045 ng g^-1 of dry weight for the whole reservoir. For each perfluorinated compound in one sediment, perfluorooctane sulfonate (PFOS) or perfluoro-n-butanoic acid (PFBA) consistently had a higher concentration than the other six PFCs, while perfluoro-n-octanoic acid (PFOA) was always undetectable. In terms of spatial distribution, the total and individual concentrations of PFCs in sediment from downstream sites of the Danjiangkou Reservoir were higher than those from upstream sites. Factor analysis revealed that PFCs in the sediment samples originated from electroplating and anti-fog agents in industry, food/pharmaceutical packaging and the water/oil repellent paper coating, and the deposition process. The quotient method was utilized to assess the ecological risk of PFCs in the sediments of the Danjiangkou Reservoir, which showed that the concentrations of PFCs were not considered a risk. In this study, detailed information on the concentration level and distribution of PFCs in the sediments of the Danjiangkou Reservoir, which is the source of water for the Middle Route Project of the South-to-North Water Transfer Scheme in China, was reported and analyzed for the first time. These results can provide valuable information for water resource management and pollution control in the Danjiangkou Reservoir.

Species-specific profiles and risk assessment of perfluoroalkyl substances in coral reef fishes from the South China Sea

The contamination profiles of sixteen perfluoroalkyl substances (PFAS) were examined in coral reef fish samples collected from the South China Sea (SCS) where no information about this topic was available in the literature. The results revealed that six PFAS were found in coral reef fish samples from the SCS. Perfluorooctane sulfonate (PFOS) was the most predominant PFAS contaminant detected in most of the samples, with the highest concentration value of 27.05 ng/g wet weight (ww) observed in Cephalopholis urodelus. Perfluoroundecanoic acid (PFUnDA) and Perfluorotridecanoic acid (PFTrDA) were the second and third dominant PFAS, respectively. Mean PFOS concentrations in muscle of seven coral reef fish varied from 0.29 ng/g ww in Lethrinus olivaceus to 10.78 ng/g ww in Cephalopholis urodelus. No significant linear relationship was observed between PFOS levels and coral reef fish traits (length, weight) collected in this region. Average daily intake of PFOS for the seven coral reef fishes ranged from 0.79 ng/kg/d for Lethrinus olivaceus to 29.53 ng/kg/d for Cephalopholis urodelus. The hazard ratio (HR) values for human consumption of PFOS-contaminated coral reef fishes ranged from 0.04 to 1.48, with Cephalopholis urodelus having the highest HR value of 1.18 (higher than 1) among the species, indicating frequent consumption of Cephalopholis urodelus might pose potential health risk to local population. The present work have provided the first hand data of PFAS in coral reef fishes in the SCS and indirectly demonstrated the existence of low level PFAS pollution in the SCS in China.

Global distribution of perfluorochemicals (PFCs) in potential human exposure source-A review

Human exposure to perfluorochemicals (PFCs) has attracted mounting attention due to their potential harmful effects. Breathing, dietary intake, and drinking are believed to be the main routes for PFC entering into human body. Thus, we profiled PFC compositions and concentrations in indoor air and dust, food, and drinking water with detailed analysis of literature data published after 2010. Concentrations of PFCs in air and dust samples collected from home, office, and vehicle were outlined. The results showed that neutral PFCs (e.g., fluorotelomer alcohols (FTOHs) and perfluorooctane sulfonamide ethanols (FOSEs)) should be given attention in addition to PFOS and PFOA. We summarized PFC concentrations in various food items, including vegetables, dairy products, beverages, eggs, meat products, fish, and shellfish. We showed that humans are subject to the dietary PFC exposure mostly through fish and shellfish consumption. Concentrations of PFCs in different drinking water samples collected from various countries were analyzed. Well water and tap water contained relatively higher PFC concentrations than other types of drinking water. Furthermore, PFC contamination in drinking water was influenced by the techniques for drinking water treatment and bottle-originating pollution.

Atmospheric chlorinated polyfluorinated ether sulfonate and ionic perfluoroalkyl acids in 2006 to 2014 in Dalian, China

Chlorinated polyfluorinated ether sulfonate (Cl-PFESA; trade name F-53B) is an alternative product for perfluorooctane sulfonate (PFOS) used in metal plating; little is known about its levels in the environment and its risks. To our knowledge, the present study constitutes the first report of Cl-PFESA in the atmosphere. In 2006 to 2014, C8 Cl-PFESA, along with ionic perfluoroalkyl acids (PFAAs), was detected in atmospheric particulate matter in Dalian, China. Concentrations of C8 Cl-PFESA increased from 140 pg/m³ in 2007 to 722 pg/m³ in 2014. Levels of 11 (total) ionic PFAAs increased in 2006 to 2008 and decreased afterward, with a range of 35.7 to 860 pg/m³ . The PFAAs in the particulate matter were dominated by perfluorocarboxylates, with perfluorooctanoate detected at the highest concentration at a mean level of 71.7 pg/m³ , followed by perfluoroheptanoate and perfluorohexanoate. Perfluorosulfonates were detected at lower levels, with mean concentrations of PFOS, perfluorobutanesulfonate, and perfluorohexane sulfonate of 5.73, 1.64, and 1.24 pg/m³ , respectively. Back-trajectory analysis suggested that the air mass approaching Dalian during the sampling originated from the northwest, where fluorochemical industry parks and metal plating industries are densely located. No significant correlation was observed between Cl-PFESA and the ionic PFAAs. The relatively high Cl-PFESA concentrations suggested that it possibly contributed largely to the previously reported exposure to undefined organic fluorine compounds, for which further research on emission and environmental risks is needed. Environ Toxicol Chem 2017;36:2581-2586. © 2017 SETAC.

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

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

Chlorinated Polyfluoroalkyl Ether Sulfonic Acids in Marine Organisms from Bohai Sea, China: Occurrence, Temporal Variations, and Trophic Transfer Behavior

F-53B, the commercial product of chlorinated polyfluoroalkyl ether sulfonic acids (Cl-PFESAs), has been used in Chinese chrome plating industry for 30 years, and was recently identified in the environment, which caused great concerns. So far, limited investigations have been performed on their environmental occurrence, fate and impact. In this study, we demonstrated the wide occurrence of Cl-PFESAs and their trophic transfer behavior in marine organisms from Chinese Bohai Sea. 6:2 Cl-PFESA (<0.016-0.575 ng/g wet weight) was the dominant congener, and 8:2 Cl-PFESA (<0.022-0.040 ng/g) was occasionally detected. Compared to other perfluoroalkyl and polyfluoroalkyl substances (PFASs) of concern, the levels of Cl-PFESAs were relatively lower in marine organisms. Based on the comparative analysis of Cl-PFESA contamination in mollusk samples collected in 2010-2014, both the concentrations and detection frequencies of Cl-PFESAs tended to increase in this region. And this kind of chemicals were more vulnerable to be accumulated in marine organisms at relatively higher trophic levels. Similar to perfluorooctanesulfonate (PFOS) and the long chain perfluorinated carboxylates (PFCAs), 6:2 Cl-PFESA could be magnified along the food chain. Accordingly, the potential threat might be posed to the wildlife and human beings due to unintended exposure to Cl-PFESAs.

Occurrence of perfluoroalkyl substances in cord serum and association with growth indicators in newborns from Beijing

Perfluoroalkyl substances (PFASs), a group of environmental pollutants, persistently exist in the environment. To investigate the associations between PFASs levels in cord serum and birth weight, birth length and ponderal index, we measured PFASs in cord serum samples from 170 infants from Feb. 2012 to Jun. 2012 in Beijing, China. The mean concentrations in cord serum samples for perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnA) were 1.285 ng/mL, 1.228 ng/mL, 0.230 ng/mL, 0.224 ng/mL, 0.100 ng/mL and 0.085 ng/mL, respectively. First-born children had slightly higher exposure levels of PFHxS (p < 0.001) and PFOA (p = 0.03) than second-born or third-born children. The spearman correlation coefficients with gestation time were individually 0.160 (p = 0.038) for PFHxS and 0.202 (p = 0.008) for PFOA. Both univariate and multivariate linear regression analysis showed that the exposure levels of PFASs had no statistically significant associations with birth weight, birth length or ponderal index in the present population. For male infants, we observed that PFHxS positively correlated with birth length, but the levels of PFUnA were negatively associated with birth length.

Concentrations of select dissolved trace elements and anthropogenic organic compounds in the Mississippi River and major tributaries during the summer of 2012 and 2013

The Mississippi River drainage basin includes the Illinois, Missouri, Ohio, Tennessee, and Arkansas rivers. These rivers drain areas with different physiography, population centers, and land use, with each contributing a different suites of metals and wastewater contaminants that can affect water quality. In July 2012, we determined 18 elements (Be, Rb, Sr, Cd, Cs, Ba, Tl, Pb, Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn) and chlorophyll-a (Chl-a) in the five major tributaries and in the Upper Mississippi River. The following summer, we determined both trace elements and 25 trace organic compounds at 10 sites in a longitudinal study of the main stem of the Mississippi River from Grafton, Illinois to Natchez, Mississippi. We detected wastewater contaminants, including pharmaceuticals and endocrine disrupting compounds, throughout the river system, with the highest concentrations occurring near urban centers (St. Louis and Memphis). Concentrations were highest for atrazine (673 ng L^-1), DEET (540 ng L^-1), TCPP (231 ng L^-1), and caffeine (202 ng L^-1). The Illinois, Missouri, and Yazoo rivers, which drain areas with intense agriculture, had relatively high concentrations of Chl-a and atrazine. However, the Ohio River delivered higher loads of contaminants to the Mississippi River, including an estimated 177 kg day^-1 of atrazine, due to higher flow volumes. Concentrations of heavy metals (Ni, V, Co, Cu, Cd, and Zn) were relatively high in the Illinois River and low in the Ohio River, although dissolved metal concentrations were below US EPA maximum contaminant levels for surface water. Multivariate analysis demonstrated that the rivers can be distinguished based on elemental and contaminant profiles.

Shifts in production of perfluoroalkyl acids affect emissions and concentrations in the environment of the Xiaoqing River Basin, China

Perfluoroalkyl acids (PFAAs) have been widely used in surfactant applications, especially as processing acids for fluoropolymer production. This study provides an analysis of sources of certain PFAAs emitted from the intensive fluoropolymer facilities in the Xiaoqing River Basin of China. Concentrations of perfluorooctanoic acid (PFOA) as great as 0.97mg/L in surface water and 10.5μg/g dry weight in surface sediment have been detected near the effluent of one facility (F1) that produces polytetrafluoroethylene (PTFE) and other fluoropolymers with massive capacity. With the great emission of PFAAs to water in natural conditions, the log KOC values decreased for short-chain PFCAs. Mass loads of PFAAs indicated that emissions of PFAAs from other facilities or sources were much less than those from F1, which emitted 174kg/d of PFAAs including 159kg/d of PFOA to the rivers. Even though production and emissions of PFOA have been strictly controlled in other countries since 2006, production of PFOA as well as several other fluoropolymers that use PFOA as processing aids has been increasing at F1 in recent years. We recommended that production shift should be taken into consideration in PFOA elimination actions.

Uptake of perfluoroalkyl acids in the leaves of coniferous and deciduous broad-leaved trees

Analytical methods for determining perfluoroalkyl acids (PFAAs) in leaves were developed to quantify a suite of analytes in both coniferous and deciduous broad-leaved trees. Sodium hydroxide-methanol and solid-phase extraction was selected as the extracting and cleanup strategy for PFAA analysis. Ten perfluorocarboxylic acids (PFCAs) and 4 perfluorosulfonic acids (PFSAs) were monitored in 7 kinds of leaves grown in the urban areas of Dalian, China. The results show that coniferous tree leaves take up more PFAAs than broad-leaved tree leaves, with the highest amount of 150 ng/g in pine needles. Leaf PFCA levels were much higher than PFSAs level. Short carbon-chain PFCAs with 3 to 6 perfluorinated carbons account for approximately 40% to 80% of the total leaf PFAAs, where uptake decreased with increasing carbon chain length. Temporal observation of leaf PFAAs revealed no significant variation of concentrations in the leaves over a weekly interval and the absence of significant seasonal change in pine needles and sophora. The present study provides some evidence for the accumulation of PFAAs in leaves, which is valuable for understanding their environmental behavior and the development of alternative bioindicator.

Removal of perfluorinated compounds in wastewater treatment plant effluents by electrochemical oxidation

The presence of perfluorinated compounds (PFCs) in the effluents of a wastewater treatment plant (WWTP) in Beijing was investigated in the current study. Perfluorooctanoate acid and perfluorooctane sulfonate were the predominant PFCs in wastewater, accounting for 19-27% and 18-31%, respectively. The concentrations of PFCs with long chains were much lower than those PFCs with short chains (≤C8). An electrochemical oxidation reactor was employed for advanced treatment of PFCs in WWTP effluents using stainless steel plates as anode and cathode electrodes. It was concluded that the removal efficiency of PFCs was improved accordingly with the increasing applied current density. The removal efficiencies of target PFCs ranged from 23.53 to 51.79% with a reaction time of 30 minutes, current density of 20 mA/cm(2), electrode plate distance of 1.0 cm and electrode plate amounts of five pairs.

Occurrence and fate of perfluoroalkyl substances in marine sediments from the Chinese Bohai Sea, Yellow Sea, and East China Sea

In this study, 166 surface sediments and 3 sediment cores from the Bohai Sea (BS), Yellow Sea (YS) and East China Sea (ECS) in China were collected to investigate the spatial and temporal distributions and the transport of PFASs. PFASs concentrations in the surface sediments ranged from below detection limit (<LOD) to 2.78 ng g(-1) with an average value of 0.55 ng g(-1) on a dry weight basis (dw). A general decreasing trend of PFASs from the coast areas to the open sea was found. Multivariate regression analysis indicated pH and longitude were the major factors influencing surficial distributions of PFASs in the sampling areas (R(2) = 0.29, p < 0.01). Total PFASs concentrations in the sediment cores ranged from <LOD to 1.65 ng g(-1) dw, with an increasing trend from the lower to the upper layers, corresponding well to the increasing production and usage in China in recent years.

Occurrence and transport of 17 perfluoroalkyl acids in 12 coastal rivers in south Bohai coastal region of China with concentrated fluoropolymer facilities

Perfluoroalkyl acids (PFAAs) are emerging contaminants that have raised great concern in recent years. While PFAAs manufacturing becomes regulated in developed countries, production has been partly shifted to China. Eight fluoropolymer manufacturing facilities located in the South Bohai coastal region, one of the most populated areas of China, have been used to manufacture PFAA-related substances since 2001. The environmental consequence of the intensive production of PFAAs in this region remains largely unknown. We analyzed 17 PFAAs in twelve coastal rivers of this region, and found staggeringly high concentrations of perfluorooctanoic acid (PFOA) ranging from 0.96 to 4534.41 ng/L. The highest concentration was observed in the Xiaoqing River which received effluents from certain fluoropolymer facilities. Principal component analysis indicated similar sources of several perfluoroalkyl carboxylic acids (PFCAs) in all rivers, which indicated that atmospheric transport, wastewater treatment and surface runoff also acted as important supplements to direct discharge to surface water.

Emerging persistent organic pollutants in Chinese Bohai Sea and its coastal regions

Emerging persistent organic pollutants (POPs) have widely aroused public concern in recent years. Polybrominated diphenyl ethers (PBDEs) and perfluorooctane sulfonyl fluoride/perfluorooctane sulfonic acid (POSF/PFOS) had been newly listed in Stockholm Convention in 2009, and short chain chlorinated paraffins (SCCPs) and hexabromocyclododecanes (HBCDs) were listed as candidate POPs. Bohai Sea is located in the arms of numbers of industrial cities, the semienclosed location of which makes it an ideal sink of emerging pollutants. In the present paper, latest contamination status of emerging POPs in Bohai Sea was reviewed. According to the literature data, Bohai Sea areas are not heavily contaminated by emerging POPs (PBDE: 0.01–720 ng/g; perfluorinated compounds: 0.1–304 ng/g; SCCPs: 64.9–5510 ng/g; HBCDs: nd-634 ng/g). Therefore, humans are not likely to be under serious risk of emerging POPs exposure through consuming seafood from Bohai Sea. However, the ubiquitous occurrence of emerging POPs in Bohai Sea region might indicate that more work should be done to expand the knowledge about potential risk of emerging POPs pollution.

Susceptibility of riparian wetland plants to perfluorooctanoic acid (PFOA) accumulation

As plants have been shown to accumulate organic compounds from contaminated sediments, there is a potential for long-lasting ecological impact as a result of contaminant accumulation in riparian areas of wetlands, particularly the accumulation of non-biodegradable contaminants such as perfluorooctanoic acid (PFOA). In this study, commonly found riparian wetland plants including reeds, i.e., Xanthium strumarium, Phragmites australis, Schoenoplectus corymbosus, Ruppia maritime; Populus canescens, Polygonum salicifolium, Cyperus congestus; Persicaria amphibian, Ficus carica, Artemisia schmidtiana, Eichhornia crassipes, were studied to determine their susceptibility to PFOA accumulation from PFOA contaminated riparian sediment with a known PFOA concentration, using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The bioconcentration factor (BCF) indicated that the plants affinity to PFOA accumulation was; E. crassipes, > P. sali-cifolium, > C. congestus, > P. x canescens, > P. amphibian, > F. carica, > A. schmidtiana, > X. strumarium,> P. australis, > R. maritime, > S. corymbosus. The concentration of PFOA in the plants and/or reeds was in the range 11.7 to 38 ng/g, with a BCF range of 0.05 to 0.37. The highest BCF was observed in sediment for which its core water had a high salinity, total organic carbon and a pH which was near neutral. As the studied plants had a higher affinity for PFOA, the resultant effect is that riparian plants such as E. crassipes, X. strumarium, and P. salicifolium, typified by a fibrous rooting system, which grow closer to the water edge, exacerbate the accumulation of PFOA in riparian wetlands.

Levels and trends of the emerging contaminants HBCDs (hexabromocyclododecanes) and PFCs (perfluorinated compounds) in marine shellfish along French coasts

The levels and congener patterns of HBCDs (hexabromocyclododecanes) and PFCs (perfluorinated compounds) were determined in filter-feeding molluscs collected in 2008 and 2010 along the coasts of mainland France. α-HBCD and PFOS (perfluorooctane sulfonate) were detected in all samples, revealing widespread contamination of the coastal environment by these emerging contaminants. The spatial distribution of Σ-HBCD concentrations showed higher median levels in samples from the Mediterranean Sea and English Channel respectively, i.e. 0.19 ng g(-1) wet weight (ww) and 0.08 ng g(-1) ww, related to high anthropogenic pressure from urban and industrial activities, while the median concentration was 0.05 ng g(-1) ww in samples from the Atlantic coast. Among PFCs, PFOS was the only compound detected in all samples and PFDA (perfluorodecanoic acid) was the second most frequently-detected compound. PFOS median concentrations were 0.18 ng g(-1) ww, 0.09 ng g(-1) ww and 0.04 ng g(-1) ww in samples from the English Channel, the Atlantic coast and the Mediterranean coast respectively. The highest PFOS concentration was found in the Loire estuary, possibly related to local industrial activities. The Mediterranean samples showed a different pattern, with predominant long-chain PFCAs (perfluorocarboxylic acids), suggesting the presence of alternative sources on the Mediterranean coast. The temporal trends studied in archived samples from the Seine estuary site showed a significant exponential increase in HBCD concentrations between 1981 and 2011, with a doubling time of 7 years, while PFOS levels underwent a significant linear decrease over time. These trends are coherent with current regulations on the use of these compounds. The results presented in this paper provide the first data on the contamination of the French coastal marine environment by the selected emerging compounds, and constitute a reference for the future monitoring of French coastal contamination by emerging contaminants.

Environmental contamination, human exposure and body loadings of perfluorooctane sulfonate (PFOS), focusing on Asian countries

Perfluorinated compounds (PFCs) are man-made fluorinated hydrocarbons, which are very persistent in the environment. Since the early 1980s, the usage of PFCs has sharply increased for a wide array of industrial and commercial applications. Being the most important PFC, perfluorooctane sulfonate (PFOS) has received much attention. In the past decades, increasing surveys have been focused on this compound, to study its sources, fates and effects in the environment. According to the large production volume and wide usage in industrial and commercial products in the past, PFOS can be detected in various environmental media and matrix, even in human tissues. This article attempted to review the current status of PFOS contaminations in Asia, focusing on water systems, sediments, wide animals and human tissues. A special section is devoted to examine the pathways of human exposure to this compound, as well as human body loadings of PFOS and their possible association with diseases.

Bioaccumulation and distribution of perfloroalkyl acids in seafood products from Bohai Bay, China

Ten perfluoroalkyl acids (PFAAs) were measured in seafood collected from Bohai Bay, China in 2010. The summed concentrations of the PFAAs were in the ranges of not detected to 194 ng/g dry weight and 4.0 to 304 ng/g dry weight for invertebrates and fish, respectively. The levels of perflurooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) in the seafood were lower than those from North America, the Mediterranean Sea, and South Korea. Living habitat, trophic level, and feeding habits had important impacts on the bioaccumulation and distribution of PFAAs in the seafood. The species at higher trophic levels had the potential to accumulate more PFAAs than benthic invertebrates. Tidal-flat organisms tended to accumulate more PFOA than PFOS, whereas the opposite was seen for shallow-water species. For all the species, PFOS and PFOA were partitioned preferentially in the liver or viscera. Risk assessment indicated that the current level of PFAAs in the seafood of Bohai Bay does not represent an immediate source of harm to public health.

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 (121 ng/l), PFOA (82 ng/l) and PFOS (31 ng/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.

Perfluorinated compounds in seafood from coastal areas in China

Diet is an important source of perfluorinated compound (PFC) exposure and seafood is an important diet component for coastal populations. Therefore, it is necessary to monitor the concentrations of PFCs in seafood. In this study, we measured thirteen PFCs in 47 fatty fish and 45 shellfish samples collected from six coastal provinces in China (Liaoning, Shandong, Jiangsu, Zhejiang, Fujian, and Guangdong), using an ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS). Perfluorooctanesulfonate (PFOS) was the dominant PFC in fatty fish which accounted for 38% of total PFCs, whereas perfluoroctanoic acid (PFOA) was the predominant PFC in shellfish. Concentrations of PFOS were ranged from less than 1.4 to 1627 pg/g wet weight in fatty fish, with the highest concentration in red drum from Jiangsu. Concentrations of PFOA in shellfish ranged from less than 5.4 to 7543 pg/g wet weight, with the maximum concentration found in briny clam also from Jiangsu. Compared with other studies, the PFC levels in seafood collected from our studied areas are relatively low. The estimated dietary intakes (EDI, pg/kg body weight /day) of PFOA, PFOS and total PFCs for the reference man (63 kg body weight) were calculated by multiplying the mean concentrations (pg/g wet weight) of PFOA, PFOS and total PFCs in six coastal provinces with the daily consumption data (g/day) from the fourth Chinese total diet study carried out in 2007. The highest EDI of PFOS and PFOA were found to be 694 pg/kg body weight/day and 914 pg/kg body weight/day in Guangdong and Jiangsu, respectively. However, the highest EDI of total PFCs was found in Fujian at 2513 pg/kg body weight/day. The EDI from seafood is much lower than the tolerable daily intake (TDI) recommended by the European Food Safety Authority in 2008 indicating low health risk of PFC exposure via eating seafood among the coastal populations in China.

Short chain chlorinated paraffins in mollusks from coastal waters in the Chinese Bohai Sea

As an extremely complex group of persistent organic pollutants (POPs) candidates in the Stockholm Convention, short chain chlorinated paraffins (SCCPs) have been of extensive concern in recent years. In this study, nine bivalve and two gastropod species were collected in 2009 to evaluate the spatial distributions and potential factors influencing the bioaccumulation of SCCPs in mollusks in the Chinese Bohai Sea. The concentrations of ∑ SCCPs in the mollusks were in the range 64.9-5510 ng/g (dry weight) with an average chlorine content of 61.1%. C(10) and C(11) were the predominant homologue groups of SCCPs, which accounted for about 29.7% and 34.9% of ∑ SCCPs, respectively. Six and seven chlorinated substituents were the main congener groups. Mya arenaria (Mya), Mactra veneriformis (Mac), and Crassostrea talienwhanensis (Oyster, Ost) had higher average concentrations of SCCPs than other species, implying that these bivalves could be used as sentinels to indicate SCCPs contamination in this coastal region. A significant positive linear relationship was found between SCCP concentrations and lipid content of the mollusks, whereas the lipid-normalized SCCP concentrations were negatively linear-related to the trophic levels (TL), which implied that SCCPs did not show biomagnification in mollusks in this region.

Perfluorinated compounds in a coastal industrial area of Tianjin, China

Perfluorinated compounds (PFC) in water, sediment, soil, and biota from the coastal industrial area of Tianjin, China, were measured to provide baseline information and to determine possible sources and potential risk to wildlife. Perfluorooctanesulfonate (PFOS) was the predominant PFC with maximum concentrations of 10 ng/L in water, and 4.3, 9.4, and 240 ng/g dw in sediment, soil, and fish, respectively. Perfluorooctanoate (PFOA) concentration in water ranged from 3.0 to 12 ng/L. Perfluoroundecanoate (PFUnA) and Perfluorododecanoate (PFDoA) were detected in solid matrices, respectively, at concentrations of <LOQ to 1.2 ng/g dw and 0.27-0.81 ng/g dw in sediments, and <LOQ to 1.0 ng/g dw and 0.26-0.61 ng/g dw in soils. Concentrations of PFOS, PFUnA, and PFDoA in sediment and soil from this industrialized and urbanized area were greater than those previously reported, while PFOS and PFOA in water and biota were both less than reported threshold concentrations for adverse effects in wildlife.

Investigation of antibiotics in mollusks from coastal waters in the Bohai Sea of China

This study focused on the presence and distribution of 22 antibiotics, including eight quinolones, nine sulfonamides and five macrolides in mollusks from the Bohai Sea of China. 190 samples of eleven species were collected in 2006, 2007 and 2009. Laboratory analyses revealed that antibiotics were widely distributed in the mollusks with quinolones as the major compounds with concentrations of 0.71~1575.10 μg/kg, which were up to two orders of magnitude higher than those of sulfonamides (0~76.75 μg/kg) and macrolides (0~36.21 μg/kg). The contents of quinolones and macrolides did not show significant changes from 2006, 2007 to 2009, while sulfonamides decreased significantly from 2006 to 2009. Compared with other sites, the city of Dalian was more polluted with quinolones, while Beidaihe was more contaminated with erythromycin and sulfapyridine. In addition, Mactra veneriformis and Meretrix merehjgntrix Linnaeus contained higher concentrations of quinolones and sulfamonomethoxine, while Mytilus edulis had higher levels of erythromycin and sulfapyridine.

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.

Perfluorinated compounds in human blood around Bohai Sea, China

Perfluorinated compounds (PFCs) including perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) have been used in a wide range of industrial and consumer applications since 1960s. The previous studies have reported the occurrences of PFOS and PFOA in human blood and serum from various countries. In this study, 141 human whole blood samples collected from four cities around Bohai Sea in China including Qinhuangdao, Tangshan, Weihai, and Zouping were analyzed for PFCs. The highest median concentration of total PFCs was found in whole blood samples from Tangshan (14.01 ng mL(-1)). The median concentration of total PFCs in samples from Zouping (7.28 ng mL(-1)) was the lowest, but the median concentration of PFOA (3.26 ng mL(-1)) was the highest among four cities and the percentage proportion of PFOA (45%) was higher than that of PFOS (30%). Based on the different profiles of PFCs between coastal cities, it was suggested that there might be different human exposure sources and pathways of PFCs around Bohai Sea.

Determination of perfluorinated compounds in mollusks by matrix solid-phase dispersion and liquid chromatography-tandem mass spectrometry

Perfluorinated compounds (PFCs) have been used for over 40 years in different commercial and industrial applications mainly as surfactants and surface protectors and have become an important class of marine emerging pollutants. This study presents the development and validation of a new analytical method to determine the simultaneous presence of eight PFCs in different kinds of mollusks using matrix solid-phase dispersion (MSPD) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Simplicity of the analytical procedure, low volume of solvent and quantity of sample required, low global price, and integration of extraction and clean-up into a single step, are the most important advantages of the developed methodology. Solvent, solid support (dispersing agent), clean-up sorbent, and their amounts were optimized by means of an experimental design. In the final method, 0.5 g of sample are dispersed with 0.2 g of diatomaceous earth and transferred into a polypropylene syringe containing 4 g of silica as clean-up sorbent. Then, analytes are eluted with 20 mL of acetonitrile. The extract is finally concentrated to a final volume of 0.5 mL in methanol, avoiding extract dryness in order to prevent evaporation losses and injected in the LC-MS/MS. The combination of this MSPD protocol with LC-MS/MS afforded detection limits from 0.05 to 0.3 ng g(-1). Also, a good linearity was established for the eight PFCs in the range from limit of quantification (LOQ) to 500 ng mL(-1) with R(2) > 0.9917. The recovery of the method was studied with three types of spiked mollusk and was in the 64-126% range. Moreover, a mussel sample was spiked and aged for more than 1 month and analyzed by the developed method and a reference method, ion-pair extraction, for comparison, producing both methods statistically equal concentration values. The method was finally applied to the determination of PFCs in different kinds of mollusks revealing concentrations up to 8.3 ng g(-1) for perfluoroundecanoic acid.