Perfluorooctanesulfonate and periluorooctanoate in red panda and giant panda from China

Hepatotoxicity assessment investigations on PFASs targeting L-FABP using binding affinity data and machine learning-based QSAR model

Per- and polyfluoroalkyl substances (PFASs) are persistent organic pollutants that have been detected in various environmental media and human serum, but their safety assessment remains challenging. PFASs may accumulate in liver tissues and cause hepatotoxicity by binding to liver fatty acid binding protein (L-FABP). Therefore, evaluating the binding affinity of PFASs to L-FABP is crucial in assessing the potential hepatotoxic effects. In this study, two binding sites of L-FABP were evaluated, results suggested that the outer site possessed high affinity to polyfluoroalkyl sulfates and the inner site preferred perfluoroalkyl sulfonamides, overall, the inner site of L-FABP was more sensitive to PFASs. The binding affinity data of PFASs to L-FABP were used as training set to develop a machine learning model-based quantitative structure-activity relationship (QSAR) for efficient prediction of potentially hazardous PFASs. Further Bayesian Kernel Machine Regression (BKMR) model disclosed flexibility as the determinant molecular property on PFASs-induced hepatotoxicity. It can influence affinity of PFASs to target protein through affecting binding conformations directly (individual effect) as well as integrating with other molecular properties (joint effect). Our present work provided more understanding on hepatotoxicity of PFASs, which could be significative in hepatotoxicity gradation, administration guidance, and safer alternatives development of PFASs.

Per- and polyfluoroalkyl substances (PFASs) in the blood of police and Beagle dogs from Harbin, China: Concentrations and associations with hematological parameters

Per-and polyfluoroalkyl substances (PFASs) have been omnipresent in the environment and marine organisms. However, little is known about these compounds and their associations with hematological parameters in dogs. In this research, we investigated the concentrations and distributions of PFASs in the blood of dogs and explored the associations between PFASs concentrations in blood and hematological parameters. Perfluorooctanoate (PFOA) was found to be the dominant PFAS in the blood (54.23%), followed by perfluorobutyric acid (PFBA) (16.05%) and perfluorooctanesulfonate (PFOS) (12.05%). On average, PFASs concentration in dogs was 3.553 ng/mL (SD: 2.146). Moreover, age is a key factor influencing the levels of PFBA, PFOA, and PFBS in males, as well as seven PFASs (6:2 Cl-PFESA, PFBA, PFOA, PFOS, PFHxS, PFDA, and PFNA) in female dogs' blood. The results revealed that PFHxS in dietary food accounted for most of the total daily PFASs consumption. We also discovered that greater PFASs exposure (including PFOA and PFOS) could significantly increase amylase (AMY) and decrease cholesterol (CHOL) levels. Furthermore, there are linear relationships between PFDA, PFNA and many biochemical parameters (AMY, CHOL, albumin/globulin (A/G), blood urea nitrogen (BUN), alkaline phosphatase (ALP), creatinine (CREA)). Thus, PFAS accumulation has a certain influence on dogs' health, and we must pay attention to the potential threat posed by these elements to dogs.

Evaluation of single and joint toxicity of perfluorooctanoic acid and arsenite to earthworm (Eisenia fetida): A multi-biomarker approach

Perfluorooctanoic acid (PFOA) and arsenic are ubiquitous environmental contaminants and could co-exist in soil. However, data on their possible combined toxic effects on terrestrial organisms are still lacking. In this study, we exposed earthworm Eisenia fetida to artificial soil spiked with different sub-lethal levels of PFOA, arsenite (As(III)) or their mixture for 28 days. The bioaccumulation and multi-biomarker responses in the earthworms were measured. Results showed that the co-existence of PFOA and As(III) in soil enhanced the bioaccumulation of arsenic while reduced the bioaccumulation of PFOA. Most selected biomarkers exhibited significant responses at higher exposure levels and indicated oxidative damages. Biomarker Response Index (BRI) was used to integrate the multi-biomarker responses and the results showed significant dose-effect relationships between biological health status and exposure levels. Moreover, variation analysis of multi-biomarkers and BRI proved that As(III) exhibited more toxicity than PFOA to the earthworms. Based on BRI results, Effect Addition Index (EAI) was calculated to evaluate the joint effects of the two toxicants. According to EAI, the joint toxicity of PFOA and As(III) was related to exposure concentration, changing from synergism to slight antagonism with the increase of exposure level. These results provide valuable toxicological information for the risk assessment of co-exposure to PFOA and arsenic in the soil environment. Moreover, this study proved that BRI is an effective tool to integrate multi-biomarker responses, and its combination with EAI provides a useful combined approach to evaluate the joint effects of mixed contamination systems.

Transfer of Per- and Polyfluoroalkyl Substances (PFAS) from Feed into the Eggs of Laying Hens. Part 2: Toxicokinetic Results Including the Role of Precursors

A feeding study was performed to examine the bioaccumulation of per- and polyfluoroalkyl substances (PFAS) in laying hens' tissues and plasma and feed-to-egg transfer rates and half-lives. A 25 day exposure was followed by a 42 day depuration period. A target analysis revealed substantial amounts of the precursors N-methyl and N-ethyl perfluorooctane sulfonamidoacetic acid (Me- and EtFOSAA), perfluorooctane sulfonamidoacetic acid (FOSAA), and perfluorooctane sulfonamide (FOSA). In tissues and eggs, the highest bioaccumulation was found for PFHxS, PFHpS, PFOS, and PFOA. Low levels of PFHxS (all samples), PFOS, and FOSAA (in yolk) were measurable even after the depuration period. The egg elimination half-lives of PFOS and aforementioned precursors were estimated to be 4.3 days, while the transfer rates of PFOS and all precursors taken together were 0.99. The transfer rate of PFOA was around 0.49. PFHxS and PFHpS showed apparent transfer rates of >100%, which is hypothesized to indicate the presence of precursors.

Per- and polyfluoroalkyl substances (PFASs) in blood of captive Siberian tigers in China: Occurrence and associations with biochemical parameters

Per- and polyfluoroalkyl substances (PFASs) have been ubiquitously detected in the environment and marine animals. However, little is known about these substances and their associations with health parameters in wild terrestrial mammals. In this study, we determined PFAS levels and distribution in the blood of captive Siberian tigers in Harbin, China, and evaluated potential exposure pathways by daily intake. In addition, for the first time, we explored the associations between serum PFAS concentrations and clinical parameters. Results showed that perfluorooctanoate (PFOA) was the dominant PFAS compound in blood (accounting for 64%), followed by perfluorooctanesulfonate (PFOS). In addition, 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) concentrations were also detected in blood and dietary food. Furthermore, significant positive age relationships were observed for levels of perfluoroheptanoate (PFHpA), PFOA, PFOS, and 6:2 Cl-PFESA in the blood of female tigers. Results showed that PFOA and PFOS in dietary food accounted for over 70% of total daily intake of PFASs, indicating that meat consumption is a predominant exposure pathway in tigers. We also found positive associations between higher exposure to PFASs (including PFOA, PFOS, and 6:2 Cl-PFESA) and elevated serum levels of alanine transaminase (ALT), a marker of liver damage. Thus, comprehensive health assessments of PFAS burdens in wildlife are needed.

Chemical food contaminants during food processing: sources and control

With the development in international food trade, there has been emerging risks in the food chain. Food contamination can be caused by several factors in a complex food chain. This articles provides a comprehensive review of known chemical contaminants from the production of raw materials to the consumption of food products as well as prevention and control measures. Specifically, this review discusses the following topics, raw material contamination caused by environmental pollution, endogenous food contamination caused by processing methods, and cold chain system challenges in food e-commerce.

Transcriptome analysis of acute exposure of the Manila clam, Ruditapes philippinarum to perfluorooctane sulfonate (PFOS)

Perfluorooctane sulfonate (PFOS) is an increasingly important environmental pollutant, which has been detected almost everywhere in the environment. Despite the widespread presence of PFOS, much less notice is taken of its toxicology effects on marine bivalves. Thus, the transcriptome response to PFOS treatment (nominal concentration of 20 mg/L) in hepatopancreas of a sentinel organism, Ruditapes philippinarum was examined. Compared with the control group, 32,149 unigenes were up-regulated and 26,958 unigenes down-regulated. Notably, significant gene expression changes were found in carbohydrate metabolism, energy metabolism, amino acid metabolism, lipid metabolism and protein biosynthesis, indicating the metabolic disruptions caused by PFOS in R. philippinarum. Additionally, numerous other differentially expressed genes were involved in immune system, antioxidant defense system and detoxification metabolism. In summary, transcriptome profiling of R. philippinarum after exposure to PFOS provided molecular support for our current understanding of the detrimental toxicity of PFOS on marine bivalves.

Per- and polyfluoroalkyl substances (PFASs) in the blood of two colobine monkey species from China: Occurrence and exposure pathways

Per-/polyfluoroalkyl substances (PFASs), which are widely used in industrial and commercial products, have been identified as global and ubiquitous pollutants. Despite this, limited data are available regarding the impacts of PFAS exposure and intake in non-human primates. Here, we report for the first time on the occurrence of PFASs in the blood and dietary sources of two rare and endangered primate species, namely, the golden snub-nosed monkey (Rhinopithecus roxellana) and Francois' leaf monkey (Trachypithecus francoisi). Results showed that perfluorooctanoate (PFOA) and perfluorononanoate (PFNA) were dominant and found at the highest proportions in the blood of both species at the four study sites. The ∑PFAS levels in blood samples from captive golden snub-nosed monkeys in Tongling Zoo (mean: 2.51 ng/mL) and Shanghai Wild Zoo (3.52 ng/mL) near urbanized areas were one order of magnitude higher than the levels in wild monkeys from Shennongjia Nature Reserve (0.27 ng/mL). Furthermore, significant age positive relationships for perfluorodecanoic acid (PFDA), perfluorooctane sulfonate (PFOS), and 6:2 chlorinated polyfluorinated ether sulfonates (6:2 Cl-PFESA) were observed in both golden snub-nosed monkeys at Shanghai Wild Zoo and Francois' leaf monkeys at Wuzhou Breeding Center. In addition, PFAS levels in frequently consumed food and drinking water were analyzed for Francois' leaf monkeys. Results showed that tree leaves accounted for the highest percentage of total daily intake of PFASs, especially PFOA, thus highlighting tree leaf consumption as a primary PFAS exposure route for this species. Overall, however, dietary exposure to PFASs was of relatively low risk to Francois' leaf monkey health.

Establish an environmentally sustainable Giant Panda National Park in the Qinling Mountains

The giant panda (Ailuropoda melanoleuca) is one of the most endangered animals in the world and is recognized worldwide as a symbol for conservation. The Qinling subspecies of giant panda (Ailuropoda melanoleuca qinlingensis) is highly endangered; fewer than 350 individuals still inhabit the Qinling Mountains. Last year, China announced the establishment of the first Giant Panda National Park (GPNP) with a goal of restoring and connecting fragmented habitats; the proposal ignored the environmental pollution caused by economic development in panda habitats. The spatial distribution of heavy metals (Cd, Pb, Hg, Cu, Zn, Mn, Cr, Ni and As) was analyzed in giant panda feces, soil, bamboo, and water in four of GPNP's functional areas at different altitudes and latitudes. Heavy metal pollution decreased with anthropogenic influences, from outside the park through the buffer and into the core area. Cu, Mn, Ni and Zn accumulated from natural sources; As, Hg and Cr were associated with fuel combustion; and Pb and Cd were associated with traffic and agriculture sources. The presence of heavy metals at high altitudes and latitudes in the proposed GPNP is due to emissions from Xi'an and other upwind industrial cities. We conclude that reducing emissions and heavy metal input should be included in the design of the GPNP. Policy interventions should consider functional zones planning, wind direction, reducing mining, and the abandonment of existing roads and farmland within the GPNP to reduce other direct human impacts on the Qinling panda.

Exposure to PFDoA causes disruption of the hypothalamus-pituitary-thyroid axis in zebrafish larvae

Perfluorododecanoic acid (PFDoA), a kind of perfluorinated carboxylic acid (PFCA) with 12 carbon atoms, has an extensive industrial utilization and is widespread in both wildlife and the water environment, and was reported to have the potential to cause a disruption in the thyroid hormone system homeostasis. In this study, zebrafish embryos/larvae were exposed to different concentrations of PFDoA (0, 0.24, 1.2, 6 mg/L) for 96 h post-fertilization (hpf). PFDoA exposure caused obvious growth restriction connected with the reduced thyroid hormones (THs) contents in zebrafish larvae, strengthening the interference effect on the growth of fish larvae. The transcriptional level of genes within the hypothalamic-pituitary-thyroid (HPT) axis was analyzed. The gene expression levels of thyrotropin-releasing hormone (trh) and corticotrophin-releasing hormone (crh) were upregulated upon exposure to 6 mg/L of PFDoA, and iodothyronine deiodinases (dio2) was upregulated in the 1.2 mg/L PFDoA group. The transcription of thyroglobulin (tg) and thyroid receptor (trβ) were significantly downregulated upon exposure to 1.2 mg/L and 6 mg/L of PFDoA. PFDoA could also decrease the levels of sodium/iodide symporter (nis) and transthyretin (ttr) gene expression in a concentration-dependent manner after exposure. A significant decrease in thyroid-stimulating hormoneβ (tshβ), uridinediphosphate-glucuronosyltransferase (ugt1ab) and thyroid receptor (trα) gene expression were observed at 6 mg/L PFDoA exposure. Upregulation and downregulation of iodothyronine deiodinases (dio1) gene expression were observed upon the treatment of 1.2 mg/L and 6 mg/L PFDoA, respectively. All the data demonstrated that gene expression in the HPT axis altered after different PFDoA treatment and the potential mechanisms of the disruption of thyroid status could occur at several steps in the process of synthesis, regulation, and action of thyroid hormones.

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.

Inhibition effects of perfluoroalkyl acids on progesterone production in mLTC-1

Perfluoroalkyl substances (PFASs) are a class of fluorine substituted carboxylic acid, sulfonic acid and alcohol, structurally similar to their corresponding parent compounds. Previous study demonstrated the potential endocrine disruption and reproductive toxicity of perfluorooctane sulfonic acid and perfluorooctanoic acid, two dominant PFASs in animals and humans. We explored the relationship between eleven perfluoroalkyl acids (PFAAs) with different carbon chain length and their ability to inhibit progesterone production in mouse Leydig tumor cells (mLTC-1). We found an obvious dose-response relationship between progesterone inhibition rate and PFAA exposure concentration in mLTC-1. The relative inhibition rate of progesterone by PFAAs was linearly related to the carbon chain length and molar refractivity of PFAAs. Mitochondrial membrane potential (MMP) decreased after PFAA exposure at the half-maximal inhibitory effect concentration (IC₅₀) of progesterone production in mLTC-1, while the reactive oxygen species (ROS) content increased significantly. These results imply that the inhibition effect of PFAAs on progesterone production might be due, in part, to ROS damage and the decrease in MMP in mLTC-1.

Photochemical defluorination of aqueous perfluorooctanoic acid (PFOA) by Fe(0)/GAC micro-electrolysis and VUV-Fenton photolysis

Perfluorooctanoic acid (PFOA) is extremely persistent and bioaccumulative in the environment; thus, it is very urgent to investigate an effective and moderate technology to treat the pollution of PFOA. In this study, a process combined iron and granular activated carbon (Fe(0)/GAC) micro-electrolysis with VUV-Fenton system is employed for the remediation of PFOA. Approximately 50 % PFOA (10 mg L(-1)) could be efficiently defluorinated under the following conditions: pH 3.0, dosage of Fe 7.5 g L(-1), dosage of GAC 12.5 g L(-1), and concentration of H2O2 22.8 mmol L(-1). Meanwhile, during the process, evident defluorination was observed and the concentration of fluoride ion was eventually 3.23 mg L(-1). The intermediates including five shorter-chain perfluorinated carboxylic acids (PFCAs), i.e., C7, C6, C5, C4, and C3, were also analyzed by high-performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS) and defluorination mechanisms of PFOA was proposed, which involved photochemical of OH·, direct photolysis (185-nm VUV), and photocatalytic degradation of PFOA in the presence of Fe(3+) (254-nm UV).

Bacterial community compositions in sediment polluted by perfluoroalkyl acids (PFAAs) using Illumina high-throughput sequencing

The characterization of bacterial community compositions and the change in perfluoroalkyl acids (PFAAs) along a natural river distribution system were explored in the present study. Illumina high-throughput sequencing was used to explore bacterial community diversity and structure in sediment polluted by PFAAs from the Xiaoqing River, the area with concentrated fluorochemical facilities in China. The concentration of PFAAs was in the range of 8.44-465.60 ng/g dry weight (dw) in sediment. Perfluorooctanoic acid (PFOA) was the dominant PFAA in all samples, which accounted for 94.2 % of total PFAAs. High-level PFOA could lead to an obvious increase in relative abundance of Proteobacteria, ε-Proteobacteria, Thiobacillus, and Sulfurimonas and the decrease in relative abundance of other bacteria. Redundancy analysis revealed that PFOA played an important role in the formation of bacterial community, and PFOA at higher concentration could reduce the diversity of bacterial community. When the concentration of PFOA was below 100 ng/g dw in sediment, no significant effect on microbial community structure was observed. Thiobacillus and Sulfurimonas were positively correlated with the concentration of PFOA, suggesting that both genera were resistant to PFOA contamination.

Enhanced photochemical decomposition of environmentally persistent perfluorooctanoate by coexisting ferric ion and oxalate

Perfluorooctanoic acid (PFOA), an environmentally persistent pollutant, was found to be quickly decomposed under 254 nm UV irradiation in the presence of ferric ion and oxalic acid. To understand the PFOA decomposition mechanism by this process, the effects of reaction atmosphere and concentrations of ferric ions and oxalic acids on PFOA decomposition were investigated, as well as decomposition intermediates. PFOA mainly decomposes via two pathways: (i) photochemical oxidation via Fe(III)-PFOA complexes and (ii) one-electron reduction caused by carboxylate anion radical (CO2 (•-)), which was generated by photolysis of ferrioxalate complexes. Under excess oxalic acid, PFOA decomposition was accelerated, and its corresponding half-life was shortened from 114 to 34 min as ferric concentration increased from 7 to 80 μM. Besides fluoride ions, six shorter chain perfluorinated carboxylic acids (PFCAs) bearing C2-C7 were identified as main intermediates. The presence of O2 promoted the redox recycling of Fe(3+)/Fe(2+) and thus avoided the exhaustion of the Fe(III).

Evaluation of single and joint toxicity of perfluorooctane sulfonate, perfluorooctanoic acid, and copper to Carassius auratus using oxidative stress biomarkers

Perfluorooctane sulfonate, perfluorooctanoic acid, and copper have been recently regarded as ubiquitous environmental contaminants in aquatic ecosystems worldwide. However, data on their possible combined toxic effects on aquatic organisms are still lacking. In this study, a systematic experimental approach was used to assess the impacts of these chemicals and their mixtures on hepatic antioxidant status of Carassius auratus after 4 days. Oxidative stress was apparently observed for joint exposure by determining biochemical parameters (superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, and malondialdehyde). The integrated biomarker response index was calculated to rank the toxicity order, from which the synergistic effect was tentatively proposed for joint-toxicity action. In addition, these treatments significantly altered trace element homeostasis in different fish tissues, and the concentration distribution of these test chemicals was also measured. Taken together, these results provided some valuable toxicological data on the joint effects of perfluorinated compounds and heavy metals on aquatic species, which can facilitate further understanding on the potential risks of other coexisting pollutants in the natural aquatic environment.

Electrochemical degradation of perfluorooctanoic acid (PFOA) by Yb-doped Ti/SnO2–Sb/PbO2anodes and determination of the optimal conditions

Model aqueous solutions of perfluorooctanoic acid (PFOA, 100 mg L⁻¹) were electro-oxidized in a homemade container.

Effects of pH on photochemical decomposition of perfluorooctanoic acid in different atmospheres by 185nm vacuum ultraviolet

Perfluorooctanoic acid (PFOA), a persistent organic pollutant, receives increasing concerns due to its worldwide occurrence and resistance to most conventional treatment processes. The photochemical decomposition by 185nm vacuum ultraviolet (VUV) is one of the efficient methods for PFOA decomposition. The effects of pH on PFOA decomposition in nitrogen atmosphere or oxygen atmosphere were investigated. At its original pH (4.5) of PFOA aqueous solution, PFOA decomposed efficiently both in nitrogen and in oxygen atmosphere. However, when the pH increased to 12.0, PFOA decomposition was greatly inhibited in oxygen atmosphere, while it was greatly accelerated in nitrogen atmosphere with a very short half-life time (9min). Furthermore, fluorine atoms originally contained in PFOA molecules were almost completely transformed into fluoride ions. Two decomposition pathways have been proposed to explain the PFOA decomposition under different conditions. In acidic and neutral solutions, PFOA predominantly decomposes via the direct photolysis in both atmospheres; while in the alkaline solution and in the absence of oxygen, the decomposition of PFOA is mainly induced by hydrated electrons.

Giant pandas are not an evolutionary cul-de-sac: evidence from multidisciplinary research

The giant panda (Ailuropoda melanoleuca) is one of the world's most endangered mammals and remains threatened by environmental and anthropogenic pressure. It is commonly argued that giant pandas are an evolutionary cul-de-sac because of their specialized bamboo diet, phylogenetic changes in body size, small population, low genetic diversity, and low reproductive rate. This notion is incorrect, arose from a poor understanding or appreciation of giant panda biology, and is in need of correction. In this review, we summarize research across morphology, ecology, and genetics to dispel the idea, once and for all, that giant pandas are evolutionary dead-end. The latest and most advanced research shows that giant pandas are successful animals highly adapted to a specialized bamboo diet via morphological, ecological, and genetic adaptations and coadaptation of gut microbiota. We also debunk misconceptions around population size, population growth rate, and genetic variation. During their evolutionary history spanning 8 My, giant pandas have survived diet specialization, massive bamboo flowering and die off, and rapid climate oscillations. Now, they are suffering from enormous human interference. Fortunately, continued conservation effort is greatly reducing impacts from anthropogenic interference and allowing giant panda populations and habitat to recover. Previous ideas of a giant panda evolutionary cul-de-sac resulted from an unsystematic and unsophisticated understanding of their biology and it is time to shed this baggage and focus on the survival and maintenance of this high-profile species.

Serum biomarkers of polyfluoroalkyl compound exposure in young girls in Greater Cincinnati and the San Francisco Bay Area, USA

PFC serum concentrations were measured in 6-8 year-old girls in Greater Cincinnati (GC) (N = 353) and the San Francisco Bay Area (SFBA) (N = 351). PFOA median concentration was lower in the SFBA than GC (5.8 vs. 7.3 ng/mL). In GC, 48/51 girls living in one area had PFOA concentrations above the NHANES 95th percentile for children 12-19 years (8.4 ng/mL), median 22.0 ng/mL. The duration of being breast fed was associated with higher serum PFOA at both sites and with higher PFOS, PFHxS and Me-PFOSA-AcOH concentrations in GC. Correlations of the PFC analytes with each other suggest that a source upriver from GC may have contributed to exposures through drinking water, and water treatment with granular activated carbon filtration resulted in less exposure for SWO girls compared to those in NKY. PFOA has been characterized as a drinking water contaminant, and water treatment systems effective in removing PFCs will reduce body burdens.

Perfluorinated compounds in blood of Caretta caretta from the Mediterranean Sea

Perfluorinated compounds (PFCs), widely used for their hydro-oil repellent properties, are almost non-degradable in the environment; there is scientific evidence that indicate bioaccumulation. They represent a threat to many organisms, because they are toxic and are endocrine disruptors. Scientific studies have demonstrated the presence of PFCs in blood and liver samples of fish, turtles, birds and mammals of marine ecosystems in different geographical areas. The aim of this study was to determine the distribution of PFOS and PFOA in blood samples of the marine turtle Caretta caretta, using a minimally invasive sampling procedure. 49 blood samples of marine turtle, taken from several Italian marine turtle rescue centers, were analyzed. While PFOA was never detected, measurable concentrations of PFOS were found in 15 blood samples; the values show a range from 1.14 ng/g to 28.51 ng/g (wet wt.). No differences between groups of samples taken from different areas were found.

Age- and gender-related accumulation of perfluoroalkyl substances in captive Chinese alligators (Alligator sinensis)

Fourteen perfluoroalkyl substances (PFASs) were measured in serum of the highly endangered captive Chinese alligators, whole body homogenates of six kinds of fish (alligator prey species), and pond water (alligator habitat) in the Anhui Research Center for Chinese Alligator Reproduction. Six PFASs, including PFOS and five perfluorinated carboxylates, were detected in all alligator samples. The most dominant PFAS was PFUnDA, with a mean value of 31.4 ng/mL. Significant positive correlations were observed among the six PFASs, suggesting that they shared similar sources of contamination. Significantly higher PFOS and PFUnDA levels were observed in males, but the other four PFCAs did not differ between genders. An age related PFAS bioaccumulation analysis showed a significant negative correlation of the concentrations for five PFCAs to age, which means that higher concentrations were found in younger animals. Bioaccumulation factors (BAF) in fish for PFASs ranged from 21 to 28,000, with lower BAF for PFOA than that for longer carbon chain PFCAs, including PFUnDA, PFDA, and PFNA.

Perfluoroalkyl substances in the blood of wild rats and mice from 47 prefectures in Japan: use of samples from nationwide specimen bank

Numerous studies have reported on the global distribution, persistence, fate, and toxicity of perfluoroalkyl and polyfluoroalkyl substances (PFASs). However, studies on PFASs in terrestrial mammals are scarce. Rats can be good sentinels of human exposure to toxicants because of their habitat, which is in close proximity to humans. Furthermore, exposure data measured for rats can be directly applied for risk assessment because many toxicological studies use rodent models. In this study, a nationwide survey of PFASs in the blood of wild rats as well as surface water samples collected from rats' habitats from 47 prefectures in Japan was conducted. In addition to known PFASs, combustion ion chromatography technique was used for analysis of total fluorine concentrations in the blood of rats. In total, 216 blood samples representing three species of wild rats (house rat, Norway rats, and field mice) were analyzed for 23 PFASs. Perfluorooctanesulfonate (PFOS; concentration range <0.05-148 ng/mL), perfluorooctane sulfonamide (PFOSA; <0.1-157), perfluorododecanoate (<0.05-5.8), perfluoroundecanoate (PFUnDA; <0.05-51), perfluorodecanoate (PFDA; <0.05-9.7), perfluorononanoate (PFNA; <0.05-249), and perfluorooctanoate (PFOA) (<0.05-60) were detected >80 % of the blood samples. Concentrations of several PFASs in rat blood were similar to those reported for humans. PFSAs (mainly PFOS) accounted for 45 % of total PFASs, whereas perfluoroalkyl carboxylates (PFCAs), especially PFUnDA and PFNA, accounted for 20 and 10 % of total PFASs, respectively. In water samples, PFCAs were the predominant compounds with PFOA and PFNA found in >90 % of the samples. There were strong correlations (p < 0.001 to p < 0.05) between human population density and levels of PFOS, PFNA, PFOA, and PFOSA in wild rat blood.

Absorption, distribution, and milk secretion of the perfluoroalkyl acids PFBS, PFHxS, PFOS, and PFOA by dairy cows fed naturally contaminated feed

The transfer of the perfluoroalkyl acids (PFAAs) perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHxS), perfluorooctanesulfonate (PFOS), and perfluorooctanoate (PFOA) from feed into tissue and milk of dairy cows was investigated. Holstein cows (n = 6) were fed a PFAA-contaminated feed for 28 days. After the PFAA-feeding period, three cows were slaughtered while the others were fed PFAA-free feed for another 21 days (depuration period). For PFAA analysis plasma, liver, kidney, and muscle tissue, urine, and milk were sampled and analyzed using high-performance liquid chromatography (HPLC) with tandem mass spectrometry (MS/MS). The average daily intake of dairy cows was 3.4 ± 0.7, 4.6 ± 1.0, 7.6 ± 3.7 and 2.0 ± 1.2 μg/kg body weight (bw) for PFBS, PFHxS, PFOS, and PFOA, respectively. Overall, PFBS, PFHxS, PFOS, and PFOA showed different kinetics in dairy cows. In plasma, concentrations of PFBS (mean = 1.2 ± 0.8 μg/L) and PFOA (mean = 8.5 ± 5.7 μg/L) were low, whereas PFHxS and PFOS continuously increased during the PFAA-feeding period up to maximal concentrations of 419 ± 172 and 1903 ± 525 μg/L, respectively. PFOS in plasma remained constantly high during the depuration period. PFOS levels were highest in liver, followed by kidney, without significant differences between feeding periods. The highest PFHxS levels were detected in liver and kidney of cows slaughtered on day 29 (61 ± 24 and 98 ± 31 μg/kg wet weight (ww)). The lowest PFAA levels were detected in muscle tissue. At the end of the feeding study, cumulative secretion in milk was determined for PFOS (14 ± 3.6%) and PFHxS (2.5 ± 0.2%). The other two chemicals were barely secreted into milk: PFBS (0.01 ± 0.02%) and PFOA (0.1 ± 0.06%). Overall, the kinetics of PFOA were similar to those of PFBS and substantially differed from those of PFHxS and PFOS. The very low concentration of PFBS in plasma and milk, the relatively high urinary excretion, and only traces of PFBS in liver (0.3 ± 0.3 μg/kg ww) and kidney (1.0 ± 0.3 μg/kg ww) support the conclusion that PFBS does not accumulate in the body of dairy cows.

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.

Transfer of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from contaminated feed into milk and meat of sheep: pilot study

A pilot study was performed with dairy sheep to generate the first data on the transfer of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from feed into food of animal origin. Corn silage was cultivated on cropland in Lower Saxony in Germany where, as a result of illegal waste disposal in 2006, farmland was contaminated with perfluorinated alkylacids (PFAAs). Two sheep were exposed by way of PFAA-contaminated corn silage to PFOS (1.16 and 1.45 μg/kg body weight [bw]/d, respectively) and PFOA (0.43 and 0.53 μg/kg bw/d) during a period of 21 days. During the PFAA-feeding period, PFOS levels in plasma increased continuously to maximum concentration of 103 and 240 μg/L for sheep 1 and sheep 2, respectively. The PFOA plasma concentration remained low (sheep 1 = 3.3 ± 2.2 μg/L; sheep 2 = 15.6 ± 8.3 μg/L). Data indicate that urinary excretion is the primary clearance route for PFOA (sheep 1 = 51 %; sheep 2 = 55 %), whereas PFOS excretion by way of urine could not be quantified. The highest PFOS excretion (4 to 5 %) was detected in faeces. PFOS was also excreted at higher levels than PFOA by way of milk. During a period of 21 days, a total PFOS transfer into milk ≤ 2 % was calculated. Overall, total excretion of PFOS was significantly lower compared with that of PFOA (PFOS 6 %; PFOA 53 to 56 %). PFOS levels in sheep 1 and sheep 2 were highest in liver (885 and 1,172 μg/kg weight wet [ww], respectively) and lowest in muscle tissue (24.4 and 35.1 μg/kg ww, respectively). PFOA levels in muscle tissue were low for sheep 2 (0.23 μg/kg ww) and not detectable after the PFAA-free feeding period in sheep 1. A slight background load of PFOS in liver (1.5 μg/kg ww) and kidney (0.3 μg/kg ww) was detected in sheep 3 (control).

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.

Perfluorooctanoic acid and perfluorooctane sulfonate in liver and muscle tissue from wild boar in Hesse, Germany

Approximately 15,000 tons of wild boar meats (Sus scrofa) are consumed per year in Germany. Boar meat therefore plays a definite role in regard to human diet. Because they are omnivores and because of their high body fat quotient, wild boar may accumulate large concentrations of persistent organic compounds, such as halogenated hydrocarbons, and could thus possibly serve as bioindicators for persistent xenobiotics. In addition, consumption of wild boar meat and liver could lead to increased contaminant levels in humans. Between 2007 and 2009, we tested a total of 529 livers and 506 muscle tissue samples from wild boar for the presence of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). PFOA concentrations ≤45 μg/kg and PFOS concentrations ≤1,780 μg/kg were detected in the liver samples. PFOA concentrations ≤7.4 μg/kg and PFOS concentrations ≤28.6 μg/kg were detected in muscle tissue. Our results show that PFOS may be detected in considerably greater concentrations than PFOA in organs and tissues, which is in agreement with results from other published studies. The comparisons between both organs for the same substance, as well as the comparisons between the substances within an organ, showed clear and statistically significant differences at P < 0.0001. Assuming a tolerable daily intake value of PFOA (1.5 μg/kg bw/d) and PFOS (0.15 μg/kg bw/d) as recommended by the European Food Safety Authority, the results of model calculations based on the maximum concentrations of PFOA and PFOS found in wild boar indicate that there should be no PFC-related health danger resulting from moderate consumption of wild boar meat or liver.

China's water pollution by persistent organic pollutants

Available data were reviewed to assess the status of contamination by persistent organic pollutants (POPs), including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), in drinking water sources and coastal waters of China. The levels of POPs in China's waters were generally at the high end of the global range. A comparison of China's regulatory limits indicated that PCBs in rivers and coastal water may pose potential human health risk. Occurrence of DDTs in some rivers of China may also pose health risk to humans using the regulatory limits of DDTs recommended by the European Union. Future monitoring of POPs in China's waters should be directed towards analytes of concern (e.g. PCBs and PCDD/Fs) and to fill data gaps for analytes (e.g. PBDEs, PCDD/Fs, and chlordane) and in watersheds/regions (e.g. West China) where data are scarce.

Emission inventory for PFOS in China: review of past methodologies and suggestions

Perfluorooctane sulfonate (PFOS) is a persistent, bioaccumulative, and toxic chemical that has the potential for long-range transport in the environment. Its use in a wide variety of consumer products and industrial processes makes a detailed characterization of its emissions sources very challenging. These varied emissions sources all contribute to PFOS' existence within nearly all environmental media. Currently, China is the only country documented to still be producing PFOS, though there is no China PFOS emission inventory available. This study reviews the inventory methodologies for PFOS in other countries to suggest a China-specific methodology framework for a PFOS emission inventory. The suggested framework combines unknowns for PFOS-containing product penetration into the Chinese market with product lifecycle assumptions, centralizing these diverse sources into municipal sewage treatment plants. Releases from industrial sources can be quantified separately using another set of emission factors. Industrial sources likely to be relevant to the Chinese environment are identified.

Risk assessment for human consumption of perfluorinated compound-contaminated freshwater and marine fish from Hong Kong and Xiamen

Perfluorinated compounds (PFCs) are man-made fluoro-surfactants that are identified as global pollutants and can pose health risks to humans and wildlife. Two aspects of risk assessment were conducted in this study, including exposure and response. Exposure was estimated by using the concentrations of PFCs in fish and applying standard exposure factors. Among different PFCs, PFOS, PFOA, PFNA, PFDA, PFUdA and PFTrDA were detected. Total concentrations of PFC in fish ranged from 0.27-8.4 ng g(-1) to 0.37-8.7 ng g(-1) respectively in Hong Kong and Xiamen. The calculated hazard ratio (HR) of PFOS for all fish was less than 1.0. However, the HR for mandarin fish in Hong Kong and bighead carp, grass carp and tilapia in Xiamen, had HR values of approximately 0.5, indicating that frequent consumption of these 4 more contaminated fish species might pose an unacceptable risk to human health. Our data support the notion that the released/disposed chemical pollutants into water systems make fish a source of environmental toxicants to humans. The risks and potential effects of PFCs to health of coastal population in the Pearl River Delta are of concern.

Disturbance of perfluorooctanoic acid on development and behavior in Drosophila larvae

Perfluorooctanoic acid (PFOA) is a well-known perfluorinated compound (PFC), and its toxicological impact is currently of worldwide concern. In this study, we sought to evaluate the potential biological effects and modes of action of PFOA in a range of physiologically and developmentally related phenotypes in the fruit fly Drosophila melanogaster. The results clearly indicated that the toxic effects of PFOA at the organismal level were associated with the developmental status of the organism, with larvae being most sensitive to this chemical. Except for the decreased weight of both sexes and the reduced longevity of male adults, PFOA had a robust effect on larval development, as determined by reduced body volume, aberrant foraging behavior, molting arrest, and polyphasic lethality. Remarkably, nutrient supplementation of the diet efficiently rescued the lethal effect of high PFOA concentrations on larval development. This result indicated that PFOA probably competed with nutritional components, leading to a disruption of the metabolic pathways responsible for larval development.

Quantitative characterization of short- and long-chain perfluorinated acids in solid matrices in Shanghai, China

Perfluorinated acids (PFAs) have been recognized as emerging environmental pollutants because of their widespread occurrences, persistence, and bioaccumulative and toxicological effects. PFAs have been detected in aquatic environment and biota in China, but the occurrences of these chemicals have not been reported in solid matrices in China. In the present study, short- and long-chain PFAs (C2-C14) have been quantitatively determined in solid matrices including sediments, soils and sludge collected in Shanghai, China. The results indicate that sludge contains more PFAs than sediments and soils, and the total PFAs concentrations in sediments, soil and sludge are 62.5-276 ng g(-1), 141-237 ng g(-1) and 413-755 ng g(-1), respectively. In most cases, trifluoroacetic acid was the major PFA and accounted for 22-90% of the total PFAs. Although the levels of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) were not only lower than trifluoroacetic acid, but also lower than some short-chain PFCAs (<C8) in some individual cases, PFOA and PFOS were still the major pollution compounds in most cases and they constituted 2-34% and 1-9% of the total PFAs, respectively. Meanwhile, unlike previous studies, PFOS levels were not always higher than PFOA in solids collected in Shanghai, China. Given that some short-chain PFAs such as trifluoroacetic acid are mildly phytotoxic and their higher levels in solid matrices were collected in Shanghai, China, these chemicals should be included in future environmental monitoring efforts.

Chronic effects of water-borne PFOS exposure on growth, survival and hepatotoxicity in zebrafish: a partial life-cycle test

Perfluorooctane sulfonate (PFOS) is widely distributed and persistent in the environment and wildlife. The main aim of this study was to investigate the impact of long-term exposure to low concentrations of PFOS in zebrafish. Zebrafish fry (F(0), 14 d post-fertilization, dpf) were exposed via the water for 70 d to 0 (control), 10, 50 and 250 microg L(-1) PFOS, followed by a further 30 d to assess recovery in clean water. The effects on survival and growth parameters and liver histopathology were assessed. Although growth suppression (weight and length) was observed in fish treated with high concentrations PFOS during the exposure period, no mortality was observed throughout the 70 d experiment. Embryos and larvae (F(1)) derived from maternal exposure suffered malformation and mortality. Exposure to 50 and 250 microg L(-1) PFOS could inhibit the growth of the gonads (GSI) in the female zebrafish. Histopathological alterations, primary with lipid droplets accumulation, were most prominently seen in the liver of males and the changes were not reversible, even after the fish were allowed to recover for 30 d in clean water. The triiodothyronine (T(3)) levels were not significantly changed in any of the exposure groups. Hepatic vitellogenin (VTG) gene expression was significantly up-regulated in both male and female zebrafish, but the sex ratio was not altered. The overall results suggested that lower concentrations of PFOS in maternal exposure could result in offspring deformation and mortality.

Ferric ion mediated photochemical decomposition of perfluorooctanoic acid (PFOA) by 254nm UV light

The great enhancement of ferric ion on the photochemical decomposition of environmentally persistent perfluorooctanoic acid (PFOA) under 254nm UV light was reported. In the presence of 10microM ferric ion, 47.3% of initial PFOA (48microM) was decomposed and the defluorination ratio reached 15.4% within 4h reaction time. While the degradation and defluorination ratio greatly increased to 80.2% and 47.8%, respectively, when ferric ion concentration increased to 80microM, and the corresponding half-life was shortened to 103min. Though the decomposition rate was significantly lowered under nitrogen atmosphere, PFOA was efficiently decomposed too. Other metal ions like Cu(2+) and Zn(2+) also slightly improved the photochemical decomposition of PFOA under irradiation of 254nm UV light. Besides fluoride ion, other intermediates during PFOA decomposition including formic acid and five shorter-chain perfluorinated carboxylic acids (PFCAs) with C7, C6, C5, C4 and C3, respectively, were identified and quantified by IC or LC/MS. The mixture of PFOA and ferric ion had strong absorption around 280nm. It is proposed that PFOA coordinates with ferric ion to form a complex, and its excitation by 254nm UV light leads to the decomposition of PFOA in a stepwise way.

Perfluorooctane sulfonate (PFOS) and other fluorochemicals in fish blood collected near the outfall of wastewater treatment plant (WWTP) in Beijing

Perfluorinated compounds (PFCs) were measured in zooplankton and five fish species collected from Gaobeidian Lake, which receives discharge from wastewater treatment plant (WWTP) in Beijing, China. The mean total PFCs in five fish were in the order: crucian carp>common carp>leather catfish>white semiknife carp>tilapia. Perfluorooctane sulfonate (PFOS) occurred at the greatest concentrations, with mean concentrations ranging from 5.74 to 64.2 ng/ml serum. Perfluorodecanoic acid (PFDA) was the second dominant PFC in fish samples except for common carp in which perfluorooctane sulfonamide (PFOSA) was dominant. A positive linear relationship (r(2)=0.85, p<0.05) was observed between lnPFOS concentrations (ln ng/ml) and trophic level (based on delta15N) if tilapia was excluded. The risk assessment showed that PFOS might not pose an immediate risk to fish in Gaobeidian Lake.

Modeling single and repeated dose pharmacokinetics of PFOA in mice

Perfluorooctanoic acid (PFOA) displays complicated pharmacokinetics in that serum concentrations indicate long half-lives despite which steady state appears to be achieved rapidly. In this study, serum and tissue concentration time-courses were obtained for male and female CD1 mice after single, oral doses of 1 and 10 mg/kg of PFOA. When using one- and two-compartment models, the pharmacokinetics for these two dosages are not consistent with serum time-course data from female CD1 mice administered 60 mg/kg, or with serum concentrations following repeated daily doses of 20 mg/kg PFOA. Some consistency between dose regimens could be achieved using the saturable resorption model of Andersen et al. In this model PFOA is cleared from the serum into a filtrate compartment from which it is either excreted or resorbed into the serum by a process presumed transporter mediated with a Michaelis-Menten form. Maximum likelihood estimation found a transport maximum of T(m) = 860.9 (1298.3) mg/l/h and half-maximum concentration of K(T) = 0.0015 (0.0022) mg/l where the estimated standard errors (in parentheses) indicated large uncertainty. The estimated rate of flow into and out of the filtrate compartment, 0.6830 (1.0131) l/h was too large to be consistent with a biological interpretation. For these model parameters a single dose greater than 40 mg/kg, or a daily dose in excess of 5 mg/kg were necessary to observe nonlinear pharmacokinetics for PFOA in female CD1 mice. These data and modeling analyses more fully characterize PFOA in mice for purposes of estimating internal exposure for use in risk assessment.

Cleft palate caused by perfluorooctane sulfonate is caused mainly by extrinsic factors

Perfluorooctane sulfonate (PFOS) is found ubiquitously in the environment, and is known to cause developmental toxicity, including cleft plate (CP). The aim of the present study was to elucidate the mechanism of CP associated with in utero exposure to PFOS in mice. We first examined whether the concentration of PFOS in fetal serum was related to susceptibility to CP. We compared palatogenesis following the administration of various concentrations of PFOS to dams. We conducted histological examination on gestational day (GD) 15 and 18, and alizarin red/alcian blue staining of fetal heads on GD18. Finally, we cultured palatal shelves (PSs) of GD14 fetuses, which had not yet made contact with each other, for 48h, to examine whether the shelves maintained the ability to fuse. The incidence of CP increased from 7.3% with a fetal serum concentration of PFOS of 110.7+/-13.4microg/ml (13mg/kg) to 78.3% with 138.6+/-0.9microg/ml (20mg/kg). PFOS at 50mg/kg on GD11-15 caused CP at a rate of 6.1%, meanwhile PFOS at 20mg/kg on GD1-17 caused a CP rate of 89.3%. Failure of palatal shelf elevation was observed with 20mg/kg PFOS. PFOS at 20mg/kg on GD1-17 and 50mg/kg on GD11-15 inhibited mandibular growth to the same extent, even though the rate of CP was different. Explants exposed to PFOS 20mg/kg and Tween 20 showed 94% (34/36) and 100% (31/31) fusion, respectively. We demonstrated that increasing the oral dose of PFOS from 13 to 20mg/kg resulted in a significant increase in CP even though there was only a small increase in serum concentration of PFOS. PFOS prevented elevation of the PSs above the tongue because their growth/fusion potential was maintained. Mandibular hypoplasia did not seem to play a critical role in the pathogenesis of CP.

Perfluorooctane sulfonate and other fluorochemicals in waterbird eggs from south China

To our knowledge, this is the first study reporting concentrations of perfluorinated compounds (PFCs) in waterbird eggs in south China. Concentrations of 11 PFCs (PFOS, PFHxS, PFBS, PFOSA, PFDoDA, PFUnDA, PFDA, PFNA, PFOA, PFHpA, PFHxA) were measured in night heron, great egret, and little egret eggs from south China (Hong Kong, Xiamen, Quanzhou). PFOS was found to be the dominant PFC in the waterbird eggs. Total concentrations of the 11 PFCs in waterbird eggs ranged from 27.0 ng/g ww (great egret from Hong Kong) to 160 ng/g ww (night heron from Quanzhou). Significant differences in PFOS concentrations were found among species, but not among locations. The composition profiles of the individual PFCs among egg samples were generally similar. Positive correlations were found between PFOS and some of the PFCAs in the egg samples from Hong Kong. Concentrations of some of the PFCs were significantly correlated with total PCB concentrations reported in a previous study in the night heron egg samples, but not in the great egret samples. Preliminary risk assessment suggests that there is no immediate risk of a reduction in offspring survival in waterbirds in south China due to PFOS, but more information is needed on the potential effects of PFCs in waterbirds.

Accumulation of perfluorinated compounds in captive Bengal tigers (Panthera tigris tigris) and African lions (Panthera leo Linnaeus) in China

The accumulation of perfluorinated compounds (PFCs) in the sera of captive wildlife species Bengal tigers (Panthera tigris tigris) and African lions (Panthera leo Linnaeus) from Harbin Wildlife Park, Heilongjiang Province, in China were analyzed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Perfluorooctanesulfonate (PFOS) was the predominant contaminant with a mean serum concentration of 1.18 ng mL(-1) in tigers and 2.69 ng mL(-1) in lions. Perfluorononanoic acid (PFNA) was the second most prevalent contaminant in both species. The composition profiles of the tested PFCs differed between tigers and lions, and the percentages of perfluorooctanoic acid (PFOA) were greater in lions than in tigers, indicating different exposures and/or metabolic capabilities between the two species. Assessments of the risk of PFC contamination to the two species were obtained by comparing measured concentrations to points of departure or toxicity reference values (TRVs). Results suggest no risk of PFOS exposure or toxicity for the two species.

Perfluorooctanesulfonate and related fluorochemicals in the Amur tiger (Panthera tigris altaica) from China

Perfluorinated compounds (PFCs) are used in a variety of industrial applications. We tested the hypothesis that, in Amur tigers (Panthera tigris altaica), captivity in industrialized areas increases PFC levels, potentially presenting a health risk to these animals. Serum samples were collected from 100 tigers from industrialized or nonindustrialized regions in China with nonpoint sources of PFCs. Mean concentrations of PFCs in these samples ranged from 1.57 +/- 0.83 ng/mL in nonindustrial Hailin to 4.31 +/- 2.90 ng/mL in industrial Beijing. PFC concentrations were significantly higher in tigers from the industrial city of Harbin than those from Hailin (p < 0.05). Perfluorooctanesulfonate (PFOS) was the most abundant PFC in all tigers and increased with age, regardless of industrial/ nonindustrial background (p < 0.01). However, PFOS concentrations were 2-4 orders of magnitude less than the current no-observed-effect level. In addition, overall PFC levels in Amur tigers were low compared with various species living in other countries, consistent with the relatively short history of PFC use in China. These results are consistent with the hypothesis that captivity in industrialized areas increases PFC levels in Amurtigers. They also suggestthat PFC accumulation will persist, and even increase, with continued use of PFCs in China.

Current levels of airborne polyfluorinated telomers in Japan

Fluorotelomer alcohols (FTOHs), a class of per- and poly-fluorochemicals (PFCs), are environmental contaminants characterized by high volatility and are therefore prone to long-range atmospheric transport. In this study, airborne FTOHs were identified in Japan using a newly developed passive air sampler containing activated carbon felts. Air sampling was conducted at 33 sites all over Japan from April to June 2007. 8:2 FTOH, the dominant analyte, ranged from <32 to 2466pgm(-3) (mean: 241pgm(-3)) followed by 6:2 FTOH from n.d. to 768pgm(-3) (mean: 51.6pgm(-3)), 10:2 FTOH from <17 to 113pgm(-3) (mean: 26.8pgm(-3)) and 8:2 FTOAcryl from n.d. to 480pgm(-3) (mean: 25.8pgm(-3)). 8:2 FTOMethacryl was not detected above detection limit (3pgm(-3)) in all samples. The highest concentration of total investigated PFCs was found in Chiba (35 degrees 43'20'' N 140 degrees 39'46'' E) (2152-3181pgm(-3)). On the other hand, in three locations of Higashi-Yodogawa (34 degrees 44' N 135 degrees 32' E), high levels of 8:2 FTOAcryl (239pgm(-3), 109-480pgm(-3)) were detected, the levels of which were comparable to those of 8:2 FTOH (mean: 175pgm(-3), range: 115-292pgm(-3)). This study is the first national wide-scale survey of FTOHs and 8:2 FTOAcryl across Japan, showing that 8:2 FTOH was ubiquitous in the environment in Japan.

Perfluorochemicals in water reuse

Faced with freshwater shortages, water authorities are increasingly utilizing wastewater reclamation to augment supplies. However, concerns over emerging trace contaminants that persist through wastewater treatment need to be addressed to evaluate potential risks. In the present study, perfluorinated surfactant residues were characterized in recycled water from four California wastewater treatment plants that employ tertiary treatment and one that treats primary sewage in a wetland constructed for both treatment and wildlife habitat. Effluent concentrations were compared with surface and groundwater from a creek where recycled water was evaluated as a potential means to augment flow (Upper Silver and Coyote Creeks, San Jose, CA). In the recycled water, 90-470 ng/l perfluorochemicals were detected, predominantly perfluorooctanoate (PFOA; 10-190 ng/l) and perfluorooctanesulfonate (PFOS; 20-190 ng/l). No significant removal of perfluorochemicals was observed in the wetland (total concentration ranged 100-170ng/l across various treatment stages); in this case, 2-(N-ethylperfluorooctanesulfonamido) acetic acid (N-EtFOSAA), perfluorodecanesulfonate (PFDS), and PFOS were dominant. Though there is currently no wastewater discharge into the creeks, perfluorochemicals were found in the surface water and underlying groundwater at a total of 20-150 ng/l with PFOS and PFOA again making the largest contribution. With respect to ecotoxicological effects, perfluorochemical release via recycled water into sensitive ecosystems requires evaluation.