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Sökning: WFRF:(Kannan Kurunthachalam)

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1.
  • Taniyasu, Sachi, et al. (författare)
  • Perfluoroalkyl Substances in the Blood of Wild Rats and Mice from 47 Prefectures in Japan : Use of Samples from Nationwide Specimen Bank
  • 2013
  • Ingår i: Archives of Environmental Contamination and Toxicology. - : Springer. - 0090-4341 .- 1432-0703. ; 65:1, s. 149-170
  • Tidskriftsartikel (refereegranskat)abstract
    • 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.
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2.
  • Bolan, Nanthi, et al. (författare)
  • Remediation of poly- and perfluoroalkyl substances (PFAS) contaminated soils : To mobilize or to immobilize or to degrade?
  • 2021
  • Ingår i: Journal of Hazardous Materials. - : Elsevier. - 0304-3894 .- 1873-3336. ; 401
  • Tidskriftsartikel (refereegranskat)abstract
    • Poly- and perfluoroalkyl substances (PFASs) are synthetic chemicals, which are introduced to the environment through anthropogenic activities. Aqueous film forming foam used in firefighting, wastewater effluent, landfill leachate, and biosolids are major sources of PFAS input to soil and groundwater. Remediation of PFAS contaminated solid and aqueous media is challenging, which is attributed to the chemical and thermal stability of PFAS and the complexity of PFAS mixtures. In this review, remediation of PFAS contaminated soils through manipulation of their bioavailability and destruction is presented. While the mobilizing amendments (e.g., surfactants) enhance the mobility and bioavailability of PFAS, the immobilizing amendments (e.g., activated carbon) decrease their bioavailability and mobility. Mobilizing amendments can be applied to facilitate the removal of PFAS though soil washing, phytoremediation, and complete destruction through thermal and chemical redox reactions. Immobilizing amendments are likely to reduce the transfer of PFAS to food chain through plant and biota (e.g., earthworm) uptake, and leaching to potable water sources. Future studies should focus on quantifying the potential leaching of the mobilized PFAS in the absence of removal by plant and biota uptake or soil washing, and regular monitoring of the long-term stability of the immobilized PFAS.
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3.
  • Gilbert, Mary E., et al. (författare)
  • An animal model of marginal iodine deficiency during development : the thyroid axis and neurodevelopmental outcome
  • 2013
  • Ingår i: Toxicological Sciences. - : Oxford University Press. - 1096-6080 .- 1096-0929. ; 132:1, s. 177-195
  • Tidskriftsartikel (refereegranskat)abstract
    • Thyroid hormones (THs) are essential for brain development, and iodine is required for TH synthesis. Environmental chemicals that perturb the thyroid axis result in modest reductions in TH, yet there is a paucity of data on the extent of neurological impairments associated with low-level TH disruption. This study examined the dose-response characteristics of marginal iodine deficiency (ID) on parameters of thyroid function and neurodevelopment. Diets deficient in iodine were prepared by adding 975, 200, 125, 25, or 0 µg/kg potassium iodate to the base casein diet to produce five nominal iodine levels ranging from ample (Diet 1: 1000 μg iodine/kg chow, D1) to deficient (Diet 5: 25 µg iodine/kg chow, D5). Female Long Evans rats were maintained on these diets beginning 7 weeks prior to breeding until the end of lactation. Dams were sacrificed on gestational days 16 and 20, or when pups were weaned on postnatal day (PN) 21. Fetal tissue was harvested from the dams, and pups were sacrificed on PN14 and PN21. Blood, thyroid gland, and brain were collected for analysis of iodine, TH, and TH precursors and metabolites. Serum and thyroid gland iodine and TH were reduced in animals receiving two diets that were most deficient in iodine. T4 was reduced in the fetal brain but was not altered in the neonatal brain. Neurobehavior, assessed by acoustic startle, water maze learning, and fear conditioning, was unchanged in adult offspring, but excitatory synaptic transmission was impaired in the dentate gyrus in animals receiving two diets that were most deficient in iodine. A 15% reduction in cortical T4 in the fetal brain was sufficient to induce permanent reductions in synaptic function in adults. These findings have implications for regulation of TH-disrupting chemicals and suggest that standard behavioral assays do not readily detect neurotoxicity induced by modest developmental TH disruption.
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4.
  • Horii, Yuichi, et al. (författare)
  • Novel evidence for natural formation of dioxins in ball clay
  • 2008
  • Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 70:7, s. 1280-1289
  • Tidskriftsartikel (refereegranskat)abstract
    • Elevated concentrations of dioxins in ancient ball clay from the Mississippi Embayment suggest natural formation of dioxins in the environment. Evidence for such natural formation in ball clay derives from unique congener profiles in undisturbed ancient clay deposits and from the lack of other anthropogenic contaminants. Here we present novel evidence of natural formation of dioxins based on congener-specific carbon isotopic analysis of octachlorodibenzo-p-dioxin (OCDD) in ball clays from the USA and Japan. The analyses were performed using a combination of double-column high performance liquid chromatography clean-up and two-dimensional gas chromatography-isotope ratio mass spectrometry. Elevated concentrations of OCDD found in ball clays from the USA and Japan were isotopically distinguished from the anthropogenic source materials (fly ash and pentachlorophenol) and environmental samples (sediment and soil). The isotopic signatures and the occurrence of OCDD in ancient ball clays deposited in the Tertiary Era provide evidence for the in situ formation of dioxins.
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5.
  • Kwok, Karen Y., et al. (författare)
  • Flux of Perfluorinated Chemicals through Wet Deposition in Japan, the United States, And Several Other Countries
  • 2010
  • Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 44:18, s. 7043-7049
  • Tidskriftsartikel (refereegranskat)abstract
    • The widespread distribution of perfluorinated chemicals (PFCs) in different environmental matrices has prompted concern about the sources, fate, and transport of these classes of chemicals. PFCs are present in the atmosphere, but only a few studies have investigated their occurrence in precipitation. In this study, concentrations of 20 PFCs, including C3-C5 short-chain PFCs, were quantified using HPLC-MS/MS in precipitation samples from Japan (n = 31), the United States (n = 12), China (n = 5), India (n = 2), and France (n = 2). Among the PFCs measured, perfluoropropanoic acid (PFPrA) was detected in all of the precipitation samples. Average total PFC concentrations ranged from 1.40 to 18.1 ng/L for the seven cities studied. The greatest total PFC concentrations were detected in Tsukuba, Japan, whereas the lowest concentrations were detected in Patna, India. PFPrA, perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were found to be the dominant PFCs in Japanese and U.S. precipitation samples. No observable seasonal trend was found in precipitation samples from two locations in Japan. Annual fluxes of PFCs were estimated for Japan and the U.S. and the evidence for precipitation as an effective scavenger of PFCs in the atmosphere is reported.
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6.
  • Li, Zhong-Min, et al. (författare)
  • Concentrations of 45 Per- and Polyfluoroalkyl Substances in North American River Otters (Lontra canadensis) from West Virginia, USA
  • 2024
  • Ingår i: Environmental Science and Technology. - 0013-936X .- 1520-5851. ; 58:4, s. 2089-2101
  • Tidskriftsartikel (refereegranskat)abstract
    • North American river otters (Lontra canadensis) aretop predators in riverine ecosystems and are vulnerable to per- andpolyfluoroalkyl substance (PFAS) exposure. Little is known aboutthe magnitude of exposure and tissue distribution of PFAS in riverotters. We measured 45 PFAS in various tissues of 42 river otterscollected from several watersheds in the state of West Virginia,USA. The median concentrations of ΣAll (sum concentration of45 PFAS) varied among tissues in the following decreasing order:liver (931 ng/g wet weight) > bile > pancreas > lung > kidney >blood > brain > muscle. Perfluoroalkylsulfonates (PFSAs) were thepredominant compounds accounting for 58−75% of the totalconcentrations, followed by perfluoroalkyl carboxylates (PFCAs;21−35%). 8:2 fluorotelomer sulfonate (8:2 FTS), 10:2 FTS, and 6:2 chlorinated polyfluoroalkyl ether sulfonate were frequentlyfound in the liver (50−90%) and bile (96−100%), whereas hexafluoropropylene oxide dimer acid (HFPO-DA) was rarely found.The hepatic concentrations of ΣAll in river otters collected downstream of a fluoropolymer production facility located along theOhio River were 2-fold higher than those in other watersheds. The median whole body burden of ΣAll was calculated to be 1580μg. PFOS and perfluorooctanoic acid (PFOA) concentrations in whole blood of some river otters exceeded the human toxicityreference values, which warrant further studies.
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7.
  • Loi, Eva I. H., et al. (författare)
  • Trophic Magnification of Poly- and Perfluorinated Compounds in a Subtropical Food Web
  • 2011
  • Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 45:13, s. 5506-5513
  • Tidskriftsartikel (refereegranskat)abstract
    • Perfluorinated compounds (PFCs) are known to biomagnify in temperate and Arctic food webs, but little is known about their behavior in subtropical systems. The environmental distribution and biomagnification of PFCs, extractable organic fluorine (EOF), and total fluorine were investigated in a subtropical food web. Surface water, sediment, phytoplankton, zooplankton, gastropods, worms, shrimps, fishes, and waterbirds collected in the Mai Po Marshes Nature Reserve in Hong Kong were analyzed. Trophic magnification was observed for perfluorooctanesulfonate (PFOS), perfluorodecanoate (PFDA), perfluoroundecanoate (PFUnDA), and perfluorododecanoate (PFDoDA) in this food web. Risk assessment results for PFOS, PFDA, and perfluorooctanoate (PFOA) suggest that current PFC concentrations in waterbird livers are unlikely to pose adverse biological effects to waterbirds. All hazard ratio (HR) values reported for PFOS and PFOA are less than one, which suggests that the detected levels will not cause any immediate health effects to the Hong Kong population through the consumption of shrimps and fishes. However, only 10-12% of the EOF in the shrimp samples was comprised of known PFCs, indicating the need for further investigation to identify unknown fluorinated compounds in wildlife.
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8.
  • Mak, Yim Ling, et al. (författare)
  • Perfluorinated Compounds in Tap Water from China and Several Other Countries
  • 2009
  • Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 43:13, s. 4824-4829
  • Tidskriftsartikel (refereegranskat)abstract
    • The recent development of a sensitive and accurate analytical method for the analysis of 20 perfluorinated compounds (PFCs), including several short-chain PFCs, has enabled their quantification in tap water collected in China, Japan, India, the United States, and Canada between 2006 and 2008. Of the PFCs measured, PFOS, PFHxS, PFBS, PFPrS, PFEtS, PFOSA, N-EtFOSAA, PFDoDA, PFUnDA, PFDA, PFNA, PFHpA, PFHxA, PFPeA, PFBA, and PFPrA were found at detectable concentrations in the tap water samples. The water samples from Shanghai (China) contained the greatest concentrations of total PFCs (arithmetic mean = 130 ng/L), whereas those from Toyama (Japan) contained only 0.62 ng/L. In addition to PFOS and PFOA, short-chain PFCs such as PFHxS, PFBS, PFHxA, and PFBA were found to be prevalent in drinking water. According to the health-based values (HBVs) and advisory guidelines derived for PFOS, PFOA, PFBA, PFHxS, PFBS, PFHxA, and PFPeA by the U.S.EPA and the Minnesota Department of Health, tap water may not pose an immediate health risk to consumers.
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9.
  • Martin, Jonathan, et al. (författare)
  • Analytical challenges hamper perfluoroalkyl research
  • 2004
  • Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 38:13, s. 248A-255A
  • Tidskriftsartikel (refereegranskat)
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10.
  • Taniyasu, Sachi, et al. (författare)
  • Analysis of trifluoroacetic acid and other short-chain perfluorinated acids (C2-C4) in precipitation by liquid chromatography-tandem mass spectrometry : Comparison to patterns of long-chain perfluorinated acids (C5-C18)
  • 2008
  • Ingår i: Analytica Chimica Acta. - : Elsevier. - 0003-2670 .- 1873-4324. ; 619:2, s. 221-230
  • Tidskriftsartikel (refereegranskat)abstract
    • A method has been developed to measure 29 perfluorinated acids (PFAs) including short-chain perfluorocarboxylates (PFCAs) such as trifluoroacetic acid (TFA; C2) and long-chain PFCAs, perfluoroalkylsulfonates, fluorotelomer acids, and two perfluorooctylsulfonamides in water matrices. The method involves solid phase extraction (SPE) using a weak anion-exchange (WAX) cartridge, an ion-exchange high-performance liquid chromatography (HPLC) column separation, and tandem mass spectrometry (MS/MS) detection. To our knowledge, this is the first HPLC-MS/MS method to determine TFA in water at sub-ng L-1 concentrations. The method is selective, simple, and robust, capable of measuring 29 PFAs in a single analysis, with overall recoveries of the target analytes ranging from 75% to 132%. The method was applied to the analysis of rainwater samples collected from two cities in Japan. TFA and several short-chain PFAs were the major compounds found in rainwater.
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