Biomedical subjects

Kurunthachalam Kannan

Publications and source records attributed to Kurunthachalam Kannan.

At least 19 recordsLinked to original sources

PubMed2025

Prenatal organophosphate ester exposure and epigenetic changes at birth: a characterization of the methylome in the ECHO cohort.

BACKGROUND: Prenatal exposure to organophosphate esters (OPEs) affects multiple child health domains. Alterations to the DNA methylome are a plausible mechanism through which these changes occur. This study characterized DNA methylation signatures at birth associated with prenatal OPE biomarkers. METHODS: We included 736 mother-infant pairs from 7 sites in the Environmental influences on Child Health Outcomes (ECHO) Cohort. Five OPE biomarkers were quantified in maternal urine samples collected during the second and third trimesters and modeled as log2-transformed continuous variables. Using covariate-adjusted linear regression, we tested associations between OPE biomarkers and locus-specific, regional, and global cord blood DNA methylation changes measured by Illumina 450 K and EPIC arrays, and gestational epigenetic age measured by the Knight gestational age epigenetic clock generated with measures from the 27 K, 450 K, and EPIC arrays. When feasible, we examined relationships by sex. FINDINGS: Global hypomethylation at multiple regions was associated with BDCPP concentrations (p = 0.003 to 0.02, coef = -0.002). Differentially methylated regions annotated to PCDHGB1 and SLC43A2 were associated with BDCPP and DPHP concentrations, respectively (FDR q < 0.05). In sex-specific analyses, global hypomethylation was associated with prenatal BDCPP (p = 0.006 to 0.03, coef = -0.0003 to -0.0002) and DBUP_DIBP (p = 0.01, coef = -0.0007 to -0.0006) concentrations in females; and global hypermethylation was associated with DBUP_DIBP concentrations in males (p < 0.05, coef = 0.0004). BCETP concentrations were significantly associated with decelerated epigenetic aging at birth in females (p < 0.05, coef = -0.05). INTERPRETATION: Prenatal exposure to OPEs impacts child methylation at birth, suggesting a potential mechanism for the association between prenatal OPE exposure and child health outcomes.

Humans↗

PubMed2007

A mouse model with liver-specific deletion and global suppression of the NADPH-cytochrome P450 reductase gene: characterization and utility for in vivo studies of cyclophosphamide disposition.

A mouse model combining liver-specific deletion with global suppression of the NADPH-cytochrome P450 reductase gene (Cpr) has been developed and characterized. These mice (designated "Cpr-low and liver-Cpr-null" or CL-LCN) retain the respective phenotypes of the previously reported Cpr-low (CL) and liver-Cpr-null (LCN) mouse strains, but hepatic deletion of the Cpr gene occurs at an earlier age in the CL-LCN mouse than in the LCN mouse. Residual hepatic microsomal CPR activities are very low in both CL-LCN and LCN mice (at 1.5 and 2.5% of wild-type levels, respectively). The utility of CL-LCN mice for in vivo drug metabolism studies was explored using the cytochrome P450 (P450) prodrug cyclophosphamide (CPA). After i.p. injection of CPA at 100 mg/kg, the t1/2 and the area under the concentration-time curve for plasma CPA were significantly increased in mice deficient in liver CPR compared with wild-type controls, indicating a lower rate of metabolism, with the effects greater in CL-LCN mice than in LCN mice. Correspondingly, substantial decreases in Cmax, and increases in Tmax, and t1/2, of 4-hydroxycyclophosphamide (4-OH-CPA) formation were observed in both LCN and CL-LCN mice relative to wild-type controls. In contrast, CPA and 4-OH-CPA pharmacokinetic parameters were essentially unchanged in CL mice, relative to wild-type controls. The slower elimination of CPA in CL-LCN mice compared with LCN mice suggests a role for extrahepatic P450 in the in vivo metabolism of CPA and demonstrates the utility of the CL-LCN model in determining the role of extrahepatic P450 enzymes in drug metabolism and chemical toxicity.

Animals↗

PubMed2006

Determination of trace levels of total fluorine in water using combustion ion chromatography for fluorine: a mass balance approach to determine individual perfluorinated chemicals in water.

Perfluorinated compounds (PFCs) such as perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) have received worldwide attention because of their environmental persistence and widespread distribution. Because of the lack of robust analytical methods and standards to detect all of the PFCs, and their precursors and metabolic intermediates, a mass balance approach involving the determination of total fluorine (TF), followed by fractionation of samples to separately determine inorganic and organic fluorine, is needed. In this study, we have developed a method to determine low microg/L levels of total fluorine (TF) in seawater samples. Further, seawater samples were fractionated into organic and inorganic fractions by extraction with organic solvents, which were then analyzed for TF, extractable organic fluorine (EOF) and inorganic fluorine (IF; i.e., fluoride). Concentrations of known perfluorinated compounds (PFCs) including PFOS and PFOA were also determined in water samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to enable calculation of the fraction of fluorine that is contributed by PFCs to TF. A major proportion of fluorine in seawater was in the form of fluoride (>90% in locations not affected by direct discharges). Nevertheless, within the organofluorine fraction, a major percentage (60-90%) of fluorine still remains unknown in water samples, suggesting the occurrence of other fluorinated acids in addition to known perfluorinated acids. Further studies are needed to identify and quantify the unidentified organofluorines in seawater. Mass balance analysis of total organic fluorine (TOF) and EOF is important, if we are to understand transport and fate of fluorinated compounds in the environment, and if we are to identify the sources of unidentified fluorinated compounds.

Chromatography, Liquid↗

PubMed2006

Atmospheric deposition of polybrominated diphenyl ethers (PBDEs) in coastal areas in Korea.

Atmospheric bulk samples were collected monthly, for one year, from urban, suburban, and rural sites located in the coastal areas of Korea, for the assessment of depositional fluxes and seasonal variations in atmospheric concentrations of PBDEs. Twenty individual PBDE congeners were found in atmospheric samples, and their depositional fluxes varied from 10.1 to 89.0 microg/m2/year. The highest depositional fluxes were found in two urbanized areas, with a strong urban-rural gradient. The relationship between PBDE and particulate depositional fluxes showed significant correlation for all locations, which suggested the association of PBDEs to particulate phase. Deca-BDE (BDE 209) was the predominant congener (>93%) in all deposition samples, which is consistent with a high consumption of deca-BDE for the flame-retardant market in Korea. Seasonal variability was observed in PBDE concentrations for the two urban sites, whereas no seasonal trend was found for either the suburban or the rural location.

Air Pollutants↗

PubMed2006

PCBs, PCDD/Fs, and organochlorine pesticides in farmed Atlantic salmon from Maine, eastern Canada, and Norway, and wild salmon from Alaska.

Farmed Atlantic salmon (Salmo salar) from Maine and eastern Canada, wild Alaskan Chinook salmon (Oncorhynchus tshawytscha), and organically farmed Norwegian salmon samples were analyzed for the presence of polychlorinated biphenyls (PCBs), dioxin-like PCBs, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzo-p-furans (PCDFs), and chlorinated pesticides. PCDD and PCDF congeners were not detected in > 80% of the samples analyzed. Total PCB concentrations (7.2-29.5 ng/g, wet weight, ww) in the farmed salmon were significantly higher than those in the wild Alaskan Chinook samples (3.9-8.1 ng/g, ww). Concentrations of PCBs, WHO PCB TEQs, and chlorinated pesticides varied significantly by region. PCB and WHO PCB TEQ concentrations in farmed salmon from eastern Canada were lower than those reported in samples collected two years earlier, possibly reflecting recent industry efforts to lower contaminant concentrations in feed. Organically farmed Norwegian salmon had the highest concentrations of PCBs (mean: 27 ng/g, ww) and WHO PCB TEQs (2.85 pg/g,ww); their TEQ values are in the higher range of those reported in farmed salmon from around the world. Removal of skin from salmon fillets resulted in highly variable reductions of lipids and contaminants, and in some skin-off samples, contaminant levels were higher, suggesting that skin removal does not protect the consumer from health risks associated with consumption of farmed salmon.

Alaska↗

PubMed2006

Developmental programming: differential effects of prenatal exposure to bisphenol-A or methoxychlor on reproductive function.

Increased occurrence of reproductive disorders has raised concerns regarding the impact of endocrine-disrupting chemicals on reproductive health, especially when such exposure occurs during fetal life. Prenatal testosterone (T) treatment leads to growth retardation, postnatal hypergonadotropism, compromised estradiol-positive feedback, polycystic ovaries, and infertility in the adult. Prenatal dihydrotestosterone treatment failed to affect ovarian morphology or estradiol-positive feedback, suggesting that effects of prenatal T may be facilitated via conversion of T to estradiol, thus raising concerns regarding fetal exposure to estrogenic endocrine-disrupting chemicals. This study tested whether fetal exposure to methoxychlor (MXC) or bisphenol A (BPA) would disrupt cyclicity in the ewe. Suffolk ewes were administered MXC (n=10), BPA (n=10) (5 mg/kg.d sc in cotton seed oil) or the vehicle (C; n=16) from d 30 to 90 of gestation. On d 60 of treatment, maternal MXC concentrations in fat tissue and BPA in blood averaged approximately 200 microg/g fat and 37.4+/-3.3 ng/ml, respectively. Birth weights of BPA offspring were lower (P<0.05) relative to C. There was no difference in the time of puberty between groups. BPA females were hypergonadotropic during early postnatal life and ended their breeding season later, compared with C. Characterization of cyclic changes after synchronization with prostaglandin F2alpha in five C, six MXC, and six BPA females found that the onset of the LH surge was delayed in MXC (P<0.05) and the LH surge magnitude severely dampened (P<0.05) in BPA sheep. These findings suggest that prenatal BPA and MXC exposure have long-term differential effects on a variety of reproductive endocrine parameters that could impact fertility.

Animals↗

PubMed2006

Perfluorinated contaminants in sediments and aquatic organisms collected from shallow water and tidal flat areas of the Ariake Sea, Japan: environmental fate of perfluorooctane sulfonate in aquatic ecosystems.

Perfluorinated compounds (PFCs), such as perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorononanoate (PFNA), perfluorohexane sulfonate (PFHS), and perfluorooctane sulfonamide (PFOSA) are widely distributed in aquatic ecosystems. Despite studies reporting the occurrence of PFCs in aquatic organisms, the fate of PFCs in tidal flat and marine coastal ecosystems is not known. In this study, we determined concentrations of PFOS, PFOA, PFNA, PFHS, and PFOSA in sediments; benthic organisms, including lugworm, mussel, crab, clam, oyster, and mudskipper fish from tidal flat; and shallow water species, such as filefish, bream, flounder, shark, finless porpoise, gull, and mallard collected from the Ariake Sea, Japan. PFOS and PFOA were detected in most of the samples analyzed, followed by PFNA, PFOSA, and PFHS. In shallow water species, PFOS was the dominant contaminant, and elevated concentrations were found in higher trophic level species, such as marine mammals and omnivorous birds. These results suggest biomagnification of PFOS through the coastal food chain. In contrast, PFOA was the most abundant compound in tidal flat organisms and sediments. PFOA concentrations in sediments, lugworms, and omnivorous mudskippers in tidal flat were approximately 1 order of magnitude greater than the levels of PFOS. This indicates differences in exposure pattern and bioavailability of PFOS and PFOA between shallow water and tidal flat organisms. The accumulation profiles of PFCs were compared with those of organochlorines (polychlorinated biphenyls, PCB), organotin (tributyltin,TBT), and polycyclic aromatic hydrocarbons (PAHs) in tidal flat and shallow water samples collected from the Ariake Sea. Concentrations of PFCs in sediments and in tidal flat organisms were significantly lower than that found for PCBs, TBT, and PAHs. Nevertheless, PFOS concentrations in shallow water species were comparable to and/or significantly greater than those of other classes of contaminants. This implies that the aqueous phase is a major sink for PFCs, which is different from what was observed for nonpolar organic pollutants.

Alkanesulfonic Acids↗

PubMed2006

Association between perfluorinated compounds and pathological conditions in southern sea otters.

Concentrations of four perfluorinated contaminants, including perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA), were measured in liver tissue from 80 adult female sea otters collected from the California coast during 1992-2002. Concentrations of PFOS and PFOA were in the ranges of <1-884 and <5-147 ng/g, wet wt, respectively. Concentrations of PFOA in the livers of these sea otters were among the highest values reported for marine mammals to date. Liver tissue from 6 male sea otters also was analyzed and contained significantly higher concentrations of PFOS than did tissues from female otters. To examine the association between exposures and potential effects, concentrations of PFOS and PFOA were compared among the adult female otters that died from infectious diseases, noninfectious causes, and from apparent emaciation. Concentrations of both PFOA and PFOS were significantly higher in sea otters in the infectious disease category than in the noninfectious category. Concentrations of PFOS and PFOA were not significantly different between noninfectious and emaciated otters, suggesting that the poor nutritive (body) status of emaciated otters did not affectthe concentrations of perfluorochemicals in livers. Concentrations of PFOA increased significantly from 1992 to 2002, whereas PFOS concentrations increased from 1992to 1998 and then decreased after 2000. Significant association between infectious diseases and elevated concentrations of PFOS/PFOA in the livers of sea otters is a cause for concern and suggests the need for further studies.

Alkanesulfonic Acids↗

PubMed2006

Comparison of trace element concentrations in livers of diseased, emaciated and non-diseased southern sea otters from the California coast.

Infectious diseases have been implicated as a cause of high rates of adult mortality in southern sea otters. Exposure to environmental contaminants can compromise the immuno-competence of animals, predisposing them to infectious diseases. In addition to organic pollutants, certain trace elements can modulate the immune system in marine mammals. Nevertheless, reports of occurrence of trace elements, including toxic heavy metals, in sea otters are not available. In this study, concentrations of 20 trace elements (V, Cr, Mn, Co, Cu, Zn, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, Pb, and Bi) were measured in livers of southern sea otters found dead along the central California coast (n=80) from 1992 to 2002. Hepatic concentrations of trace elements were compared among sea otters that died from infectious diseases (n=27), those that died from non-infectious causes (n=26), and otters that died in emaciated condition with no evidence of another cause of death (n=27). Concentrations of essential elements in sea otters varied within an order of magnitude, whereas concentrations of non-essential elements varied by two to five orders of magnitude. Hepatic concentrations of Cu and Cd were 10- to 100-fold higher in the sea otters in this study than concentrations reported for any other marine mammal species. Concentrations of Mn, Co, Zn, and Cd were elevated in the diseased and emaciated sea otters relative to the non-diseased sea otters. Elevated concentrations of essential elements such as Mn, Zn, and Co in the diseased/emaciated sea otters suggest that induction of synthesis of metallothionein and superoxide dismutase (SOD) enzyme is occurring in these animals, as a means of protecting the cells from oxidative stress-related injuries. Trace element profiles in diseased and emaciated sea otters suggest that oxidative stress mediates the perturbation of essential-element concentrations. Elevated concentrations of toxic metals such as Cd, in addition to several other organic pollutants, may contribute to oxidative stress-meditated effects in sea otters.

Animals↗

PubMed2006

Occurrence of polybrominated biphenyls, polybrominated dibenzo-p-dioxins, and polybrominated dibenzofurans as impurities in commercial polybrominated diphenyl ether mixtures.

The objective of this study was to determine the concentrations and compositions of polybrominated biphenyls (PBBs), polybrominated dibenzo-p-dioxins (PBDDs), and polybrominated dibenzofurans (PBDFs) as contaminants in the commercial polybrominated diphenyl ether (PBDE) mixtures DE-71, DE-79, and DE-83 and to ascertain the lot-to-lot variations in the proportions of these contaminants. Commercial PBDE mixtures tested in the present study contained both PBBs and PBDFs, as impurities, at concentrations in the range of several tens to several thousands of nanograms per gram. Concentrations of total PBDFs were greater than those of total PBBs in DE-79 and DE-83 mixtures. PBDDs were not detected at levels above the limit of detection. Profiles of PBB and PBDF congeners varied with the degree of bromination of the commercial PBDE mixtures (i.e., more highly brominated mixtures of PBDEs contained heavily brominated homologues of PBBs and PBDFs). On the basis of the production/ usage of commercial PBDE mixtures in 2001, potential global annual emissions of PBBs and PBDFs were calculated to be 40 and 2300 kg, respectively. Results of our study suggestthat PBDFs can also be formed during the production of commercial PBDE mixtures, in addition to their formation during pyrolysis of brominated flame retardants.

Benzofurans↗

PubMed2006

Polybrominated diphenyl ethers (PBDEs) in sediment and bivalves from Korean coastal waters.

Concentrations of polybrominated diphenyl ethers (PBDEs) were determined in sediment and bivalves collected from 25 coastal locations in Korea. Twenty major PBDE congeners were found in all sediment and bivalve samples. SigmaPBDE20 concentrations ranged from 0.45 to 494 ng/g, dry weight (average 27.8 ng/g dry weight) in sediments, and from 0.38 to 9.19 ng/g, wet weight (average 2.94 ng/g wet weight) in bivalves. The highest concentrations were found at locations near industrial complexes and large harbors, suggesting that human activities contribute to PBDEs contamination in Korean coastal environment. PBDE concentrations measured in our study, excluding BDE congener 209 (deca-BDE), in sediment and bivalves were lower than those reported from other countries; whereas BDE 209 concentrations were comparable to or higher than those reported from other countries. The predominant PBDE congener in sediments and bivalves was deca-BDE, which accounted for >90% and >60% of the total PBDE concentrations in sediment and bivalves, respectively. This is consistent with high consumption of deca-BDE for the flame-retardant market in Korea. Significant correlations existed among BDEs 28, 47, 99, 100, 153 and 154 in sediments and bivalves; however, BDEs 183 and 209 showed little correlation compared with less highly brominated congeners.

Animals↗

PubMed2006

Mass loading and fate of perfluoroalkyl surfactants in wastewater treatment plants.

Wastewater treatment plants have recently been identified as a significant pathway for the introduction of perfluoroalkyl surfactants (PASs) to natural waters. In this study, we measured concentrations and fate of several PASs in six wastewater treatment plants (WWTPs) in New York State. We also monitored and measured matrix effects (ionization suppression and enhancement) by postcolumn infusion and standard additions. Concentrations of perfluorooctanoate (PFOA) in effluents of the six WWTPs ranged from 58 to 1050 ng/L. Perfluorooctanesulfonate (PFOS) was also ubiquitous in effluents of these WWTPs, albeit at much lower concentrations (3-68 ng/L). Two of these WWTPs employed identical treatment processes, with similar hydraulic retentions, but differed only in that Plant B treated domestic and commercial waste, whereas Plant A had an additional industrial influence. We found that this industrial influence resulted in significantly greater mass flows of all of the PASs analyzed. Primary treatment was found to have no effect on the mass flows of PASs. Secondary treatment by activated sludge in Plant A significantly increased (p < 0.05) the mass flows of PFOS, PFOA, perfluorononanoate (PFNA), perfluorodecanoate (PFDA), and perfluoroundecanoate (PFUnDA). However, in Plant B, only the mass flow of PFOA was significantly increased. The observed increase in mass flow of several PASs may have resulted from biodegradation of precursor compounds such as fluorotelomer alcohols, which is supported by significant correlations in the mass flow of PFOA/PFNA and PFDA/PFUnDA. Furthermore, the masses of PFDA and PFUnDA were significantly correlated only after the secondary treatment. In Plant A, concentrations of odd-number PFCAs were greater than those of even-number PFCAs, and concentration decreased with increasing chain length (from C8 to C12). A different pattern was observed in sludge samples, in which the dominance of PFOA decreased, and PFDA and PFUnDA increased, suggesting preferential partitioning of longer-chain PFCAs to sludge.

Chromatography, High Pressure Liquid↗

PubMed2006

Changes in thyroid and vitamin A status in mink fed polyhalogenated-aromatic-hydrocarbon-contaminated carp from the Saginaw River, Michigan, USA.

A study was conducted to determine whether changes in thyroid and vitamin A dynamics were induced in ranch mink exposed to environmentally relevant concentrations of polyhalogenated aromatic hydrocarbons. Adult female mink were fed diets that contained 0% (control), 10%, 20%, or 30% wild carp (Cyprinus carpio) collected from the Saginaw River, Michigan, USA. Total polychlorinated biphenyls concentrations were 0.03, 0.83, 1.05, and 1.69 mg/kg feed, respectively; the 2,3,7,8-tetrachlorodibenzo-p-diozin toxic equivalents were 3.4, 27.9, 47.6, and 73.2 ng/kg, respectively. Diets were fed 3 weeks prior to breeding and throughout gestation and lactation. When the kits were weaned at 6 weeks of age, they were continued on their respective diets until 27 weeks of age. Plasma thyroid hormone concentrations, thyroid gland activity and structure, and vitamin A dynamics were assessed in young mink at 6 and 27 weeks of age. Plasma total T4 and free T4 in 6-week-old female and male kits fed the 10% carp diet were significantly higher than those of controls, while kits fed the 20% and 30% carp diet had nonsignificant decreases relative to the control mink. Plasma total T3 concentrations in 27-week-old juvenile males fed the 30% carp diet were significantly lower than those in individuals fed the 10% carp diet. No overt thyroid toxicity was apparent as thyroid weight, activity, and structure in kits and juveniles of both sexes were similar among diet groups. Plasma retinol and total ester concentrations in both kits and juveniles were reduced in mink fed the 30% carp diet relative to controls. The ratio of retinol to retinyl palmitate in livers of juveniles fed the 30% carp diet was two times higher than that in control mink. Significant reductions in kidney retinol and fatty acyl retinyl esters were observed in kits and juveniles fed the 30% carp diet relative to control values.

Animals↗

PubMed2006

Occurrence of perfluoroalkyl surfactants in water, fish, and birds from New York State.

Concentrations of perfluorooctanesulfonate (PFOS) and several other perfluoroalkyl surfactants (PASs) were determined in nine major water bodies (n = 51) of New York State (NYS). These PASs were also measured in the livers of two species of sport fish (n = 66) from 20 inland lakes in NYS. Finally, perfluorinated compounds were measured in the livers of 10 species of waterfowl (n = 87) from the Niagara River region in NYS. PFOS, perfluorooctanoic acid (PFOA), and perfluorohexanesulfonate (PFHS) were ubiquitous in NYS waters. PFOA was typically found at higher concentrations than were PFOS and PFHS. Elevated concentrations of PFOS were found in surface waters of Lake Onondaga, and elevated concentrations of PFOA were found in the Hudson River. PFOS was the most abundant perfluorinated compound in all fish and bird samples. PFOS concentrations in the livers of fishes ranged from 9 to 315 ng/g wet weight. PFOS, PFOA, and PFOSA (perfluorooctanesulfonamide) concentrations in smallmouth and largemouth bass (taken together) caught in remote mountain lakes with no known point sources of PAS contamination were 14 to 207, < 1.5 to 6.1, and < 1.5 to 9.8 ng/g wet weight, respectively. PFOS concentrations in the livers of birds ranged from 11 to 882 ng/g wet weight. PFOS concentrations were 2.5-fold greater (p = 0.001) in piscivorous birds than in non-piscivorous birds. However, PFOA, PFOSA, and PFHS were not found in bird livers. Overall, average concentrations of PFOS in fish were 8850-fold greater than those in surface water. An average biomagnification factor of 8.9 was estimated for PFOS in common merganser relative to that in fish. This study highlights the significance of dietary fish in PFOS accumulation in the food chain. Furthermore, our results provide information on the distribution of PASs in natural waters, fish, and several bird species in NYS.

Alkanesulfonic Acids↗

PubMed2006

Effects of air cell injection of perfluorooctane sulfonate before incubation on development of the white leghorn chicken (Gallus domesticus) embryo.

Fifty white leghorn chicken (Gallus domesticus) eggs per group were injected with 0.1, 1.0, 10.0, or 20.0 microg perfluorooctane sulfonate (PFOS)/g egg before incubation to investigate the effects of PFOS on the developing embryo. Hatchlings were weighed, examined for gross developmental abnormalities, and transferred to a battery brooder, where they were raised for 7 d. Chicks were then weighed, and 20 birds per treatment were randomly chosen for necropsy. The brain, heart, kidneys, and liver were removed and weighed. Livers were processed further for determination of PFOS concentrations and histological assessment. Hatchability was reduced significantly in all treatment groups in a dose-dependent manner. The calculated median lethal dose was 4.9 microg PFOS/g egg. Perfluorooctane sulfonate did not affect posthatch body or organ weights. Exposure to PFOS caused pathological changes in the liver characterized by bile duct hyperplasia, periportal inflammation, and hepatic cell necrosis at doses as low as 1.0 microg PFOS/g egg. Perfluorooctane sulfonate concentrations in the liver increased in a dose-dependent manner. Based on reduced hatchability, the lowest-observed-adverse-effect level was 0.1 microg PFOS/g egg.

Alkanesulfonic Acids↗

PubMed2006

Perfluorinated compounds in streams of the Shihwa Industrial Zone and Lake Shihwa, South Korea.

Concentrations of perfluorinated alkyl compounds (PFAs), including perfluorooctane sulfonate (PFOS), perfluorohexanesulfonate, perfluorobutanesulfonate, perfluorooctanesulfonamide, perfluorodecanoate, perfluorononanoic acid, perfluorooctanoate (PFOA), perfluoroheptanoate, and perfluorohexanoate, were measured in the streams of the Shihwa and Banweol industrial areas on the west coast of South Korea as well as the adjacent Lake Shihwa (an artificial lake) and Gyeonggi Bay. Perfluorinated alkyl compounds were concentrated from water using solid-phase extraction and were identified and quantified by liquid chromatography/ triple-quadrapole tandem mass spectrometry. Of the PFAs measured, PFOS and PFOA occurred at the greatest concentrations. Concentrations of PFOS ranged from 2.24 to 651 ng/L, and concentrations of PFOA ranged from 0.9 to 62 ng/L. The concentrations of PFOS observed in Lake Shihwa were among the greatest ever measured in the environment. These results suggest local industrial sources of PFOS and PFOA as well as other PFAs. Because of dilution, the greatest concentrations occur in a rather restricted area, near the points of discharge of the streams that empty into the lake. The greatest measured concentration of PFOS exceeded the threshold for effects predicted for predatory birds consuming aquatic organisms continuously exposed to this level.

Fluorocarbons↗

PubMed2005

Characterization of trace organic contaminants in marine sediment from Yeongil Bay, Korea: 2. Dioxin-like and estrogenic activities.

This study employed mechanism-specific in vitro bioassays to help characterize the occurrence and distribution of dioxin-like and estrogenic contaminants in sediment from Yeongil Bay, Korea. Approximately 85% of the sediments tested induced significant dioxin-like activity in the H4IIE-luc bioassay, while approximately 50% induced significant estrogenic activity in the MVLN bioassay. Instrumentally-derived estimates of 2,3,7,8-tetrachlorodibenzo-p-dioxin and 17beta-estradiol equivalents tended to underestimate the magnitude of response observed in the bioassays, suggesting that compounds detected by chemical analysis did not account for all the activity associated with Yeongil Bay sediments, or that non-additive interactions were occurring. The greatest dioxin-like and estrogenic activity was associated with the mid-polarity Florisil fractions (F2) expected to contain polycyclic aromatic hydrocarbons (PAHs) as well as chlorinated dioxins and furans. As in previous studies of Korean coastal sediment, more polar fractions (F3) generated more modest responses both in terms of magnitude and the number of samples responding.

Biological Assay↗

PubMed2005

Perfluorinated compounds in the plasma of loggerhead and Kemp's ridley sea turtles from the southeastern coast of the United States.

Perfluorinated compounds (PFCs) have been measured in blood of humans and wildlife and are considered globally distributed contaminants. We examined 12 PFCs in the plasma of 73 loggerhead sea turtles (Caretta caretta) and 6 Kemp's ridley sea turtles (Lepidochelys kempii) captured from inshore waters of Core Sound, North Carolina (NC), and offshore waters of South Carolina, Georgia, and Florida (SC-FL). Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the dominant compounds, with respective mean concentrations of 11.0 ng/mL and 3.20 ng/mL for loggerhead turtles and 39.4 ng/mL and 3.57 ng/mL for Kemp's ridley turtles. Mean PFOS concentrations were 2- to 12-fold higher than typical mean sigmaPCB concentrations (approximately 5 ng/g wet mass) measured previously in sea turtle blood. More than 79% of the samples had detectable levels of perfluorocarboxylates (PFCAs) with 8-12 carbons, whereas only 17% or less of samples had detectable levels of PFCAs with 6 or 7 carbons. No samples had detectable levels of PFCAs with 4 or 5 carbons. In loggerhead turtles, sigmaPFC concentrations were not influenced by sex (p > 0.05), but were higher in turtles captured from inshore waters of NC than in turtles from offshore waters of SC-FL (p = 0.009). A backward stepwise multiple regression model showed that sigmaPFC concentrations were (1) significantly higher in Kemp's ridley turtles than loggerhead turtles (p < 0.0001), (2) higher in larger turtles (p = 0.018; carapace length used as a proxy for age), and (3) higher in turtles captured toward the north (p = 0.006). These findings suggest that bioaccumulation of PFCs in sea turtles is influenced by species, age, and habitat.

Animals↗