2007 Abstracts
Abstracts on PFOS and PFOA for the following years:

Note: PFOS and PFOA are a class of perfluorinated chemicals that are best known for their use in the production of Teflon and other stain resistent materials. The interest of the FAN Pesticide Project in this issue is due to the use of several of the PFOS and PFOA chemicals as "inerts" in pesticides. However, most, but not all, have been deleted from use since 2001. The so-called "inerts" used in pesticides can account for as much as 99%, or more, of a pesticidal formulation. US EPA's policy is to allow the public information only on the "active substance" and to deny the public the names of the chemicals used as "inerts" in specific pesticide products -- even though the majority of inerts are toxic and biologically active.

The following is a selected list of abstracts. For more see PubMed or Toxnet.

Environ Int. 2007 Apr 16; [Epub ahead of print]

Identification and pattern of perfluorooctane sulfonate (PFOS) isomers in human serum and plasma.

Karrman A, Langlois I, Bavel BV, Lindstrom G, Oehme M.

Man-Technology-Environment Research Centre (MTM), Orebro University, SE-701 82 Orebro, Sweden.

Human serum and plasma from Sweden (n=17), the United Kingdom (the UK) (n=13) and Australia (n=40) were analyzed by high performance liquid chromatography coupled to mass spectrometry. The objective was to identify different perfluorooctane sulfonate (PFOS) isomers. Similar isomer patterns typical for the electrochemical fluorination (ECF) process were found for all samples. The linear PFOS (L-PFOS) was the major isomer found (58-70%) followed by the monosubstituted PFOS isomers 1/6-CF(3)-PFOS (18-22%) and 3/4/5-CF(3)-PFOS (13-18%). Disubstituted isomers were also detected. The percentage of L-PFOS found in the serum and plasma samples was lower compared to a standard PFOS product (76-79%). The pattern of PFOS isomers in human serum and plasma may be suggestive concerning potential isomeric discrimination since PFOS is only produced by ECF. Possibilities for such isomer discrimination are discussed. Significant higher content of L-PFOS (68%) in Swedish samples compared to Australia and the UK (59%) was also found, which may suggest differences in exposure sources for humans.

PMID: 17442394 [PubMed - as supplied by publisher]

Ann Epidemiol. 2007 Apr 18;

Bladder Cancer in Perfluorooctanesulfonyl Fluoride Manufacturing Workers.

Alexander BH, Olsen GW.

From the Division of Environmental Health Sciences, School of Public Health, University of Minnesota (B.H.A.), and 3M Company, Medical Department, Saint Paul (G.W.O.).

PURPOSE: To determine whether bladder cancer is associated with exposure to perfluorooctane sulfonate (PFOS) in an occupational cohort.
METHODS: Incidence of bladder cancer was ascertained by postal questionnaire to all living current and former employees of the facility (N = 1895) and death certificates for deceased workers (N = 188). Exposure to PFOS was estimated with work history records and weighted with biological monitoring data. Standardized incidence ratios (SIRs) were estimated using U.S. population-based rates as a reference. Bladder cancer risk within the cohort was evaluated using Poisson regression by cumulative PFOS exposure.
RESULTS: Questionnaires were returned by 1,400 of the 1895 cohort members presumed alive. Eleven cases of primary bladder cancer were identified from the surveys (n = 6) and death certificates (n = 5). The SIRs were 1.28 (95% confidence interval [CI] = 0.64-2.29) for the entire cohort and 1.74 (95% CI = 0.64-3.79) for those ever working in a high exposed job. Compared with employees in the lowest cumulative exposure category, the relative risk of bladder cancer was 0.83 (95% CI = 0.15-4.65), 1.92 (95% CI = 0.30-12.06), and 1.52 (95% CI = 0.21-10.99).
CONCLUSIONS: The results offer little support for an association between bladder cancer and PFOS exposure, but the limited size of the population prohibits a conclusive exposure response analysis.

PMID: 17448680 [PubMed - as supplied by publisher]

Int Arch Occup Environ Health. 2007 Jan 12; [Epub ahead of print]

Transplacental exposure of neonates to perfluorooctanesulfonate and perfluorooctanoate: a pilot study.

Midasch O, Drexler H, Hart N, Beckmann MW, Angerer J.

Institute and Outpatient Clinic of Occupational, Social and Environmental Medicine, University of Erlangen-Nuremberg, Schillerstrasse 25, 91054, Erlangen, Germany,

OBJECTIVES: Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) can be released of perfluorinated compounds by biotic and/or metabolic decomposition. Due to their ubiquitous occurrence, persistence and bioaccumulative properties they can be found in blood of the general population all over the world. In animal studies PFOS and PFOA provoked cancer and showed developmental toxic potential besides other adverse health effects. On the basis of the comparison of maternal and umbilical cord plasma sample pairs we wanted to examine whether infants are exposed to PFOS and PFOA via their mothers' blood.
METHODS: We determined PFOS and PFOA in 11 plasma samples of mothers and the 11 corresponding cord plasma samples of neonates. An analytical method based on plasma protein precipitation followed by HPLC with MS/MS-detection was employed. As internal standards we used 1,2,3,4-(13)C(4)-PFOS and 1,2-(13)C(2)-PFOA.
RESULTS: We found PFOS and PFOA in every plasma sample analysed. In maternal plasma samples PFOS concentrations were consistently higher compared to those of the related cord plasma samples (median: 13.0 mug/l vs. 7.3 mug/l). In the case of PFOA we observed only minor differences between PFOA concentrations within the analysed sample pairs (median: 2.6 mug/l vs. 3.4 mug/l for maternal and cord plasma samples, respectively).
DISCUSSION: For both substances a crossing of the placental barrier could be shown. For PFOS we observed a decrease from maternal to cord plasma concentrations by a factor of 0.41-0.80. To the contrary, PFOA crosses the placental barrier obviously unhindered. These findings show that neonates are exposed to PFOS and PFOA via their mothers' blood. Given the current situation that only little is known about the consequences of PFOS and PFOA exposure in the early state of development of humans and the fact that in animal studies both substances showed developmental toxic effects further research regarding human health effects is indispensable.

PMID: 17219182 [PubMed - as supplied by publisher]

Toxicol Sci. 2007 Mar;96(1):133-44. Epub 2006 Nov 28.

Gestational PFOA exposure of mice is associated with altered mammary gland development in dams and female offspring.

White SS, Calafat AM, Kuklenyik Z, Villanueva L, Zehr RD, Helfant L, Strynar MJ, Lindstrom AB, Thibodeaux JR, Wood C, Fenton SE.

Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.

Perfluorooctanoic acid (PFOA), with diverse and widespread commercial and industrial applications, has been detected in human and wildlife sera. Previous mouse studies linked prenatal PFOA exposure to decreased neonatal body weights (BWs) and survival in a dose-dependent manner. To determine whether effects were linked to gestational time of exposure or to subsequent lactational changes, timed-pregnant CD-1 mice were orally dosed with 5 mg PFOA/kg on gestation days (GD) 1-17, 8-17, 12-17, or vehicle on GD 1-17. PFOA exposure had no effect on maternal weight gain or number of live pups born. Mean pup BWs on postnatal day (PND) 1 in all PFOA-exposed groups were significantly reduced and decrements persisted until weaning. Mammary glands from lactating dams and female pups on PND 10 and 20 were scored based on differentiation or developmental stages. A significant reduction in mammary differentiation among dams exposed GD 1-17 or 8-17 was evident on PND 10. On PND 20, delays in normal epithelial involution and alterations in milk protein gene expression were observed. All exposed female pups displayed stunted mammary epithelial branching and growth at PND 10 and 20. While control litters at PND 10 and 20 had average scores of 3.1 and 3.3, respectively, all treated litters had scores of 1.7 or less, with no progression of duct epithelial growth evident over time. BW was an insignificant covariate for these effects. These findings suggest that in addition to gestational exposure, abnormal lactational development of dams may play a role in early growth retardation of developmentally exposed offspring.

PMID: 17132714 [PubMed - indexed for MEDLINE]

Toxicol Sci. 2007 Feb;95(2):462-73. Epub 2006 Nov 10.

Developmental toxicity of perfluorooctanoic acid in the CD-1 mouse after cross-foster and restricted gestational exposures.

Wolf CJ, Fenton SE, Schmid JE, Calafat AM, Kuklenyik Z, Bryant XA, Thibodeaux J, Das KP, White SS, Lau CS, Abbott BD.

Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.

Perfluorooctanoic acid (PFOA) is a persistent pollutant and is detectable in human serum (5 ng/ml in the general population of the Unites States). PFOA is used in the production of fluoropolymers which have applications in the manufacture of a variety of industrial and commercial products (e.g., textiles, house wares, electronics). PFOA is developmentally toxic and in mice affects growth, development, and viability of offspring. This study segregates the contributions of gestational and lactational exposures and considers the impact of restricting exposure to specific gestational periods. Pregnant CD-1 mice were dosed on gestation days (GD) 1-17 with 0, 3, or 5 mg PFOA/kg body weight, and pups were fostered at birth to give seven treatment groups: unexposed controls, pups exposed in utero (3U and 5U), lactationally (3L and 5L), or in utero + lactationally (3U + L and 5U + L). In the restricted exposure (RE) study, pregnant mice received 5 mg PFOA/kg from GD7-17, 10-17, 13-17, or 15-17 or 20 mg on GD15-17. In all PFOA-treated groups, dam weight gain, number of implantations, and live litter size were not adversely affected and relative liver weight increased. Treatment with 5 mg/kg on GD1-17 increased the incidence of whole litter loss and pups in surviving litters had reduced birth weights, but effects on pup survival from birth to weaning were only affected in 5U + L litters. In utero exposure (5U), in the absence of lactational exposure, was sufficient to produce postnatal body weight deficits and developmental delay in the pups. In the RE study, birth weight and survival were reduced by 20 mg/kg on GD15-17. Birth weight was also reduced by 5 mg/kg on GD7-17 and 10-17. Although all PFOA-exposed pups had deficits in postnatal weight gain, only those exposed on GD7-17 and 10-17 also showed developmental delay in eye opening and hair growth. In conclusion, the postnatal developmental effects of PFOA are due to gestational exposure. Exposure earlier in gestation produced stronger responses, but further study is needed to determine if this is a function of higher total dose or if there is a developmentally sensitive period.

PMID: 17098816 [PubMed - indexed for MEDLINE]

Toxicol Sci. 2007 Feb;95(2):452-61. Epub 2006 Nov 8.

Perfluorooctanoic acid and perfluorononanoic acid in fetal and neonatal mice following in utero exposure to 8-2 fluorotelomer alcohol.

Henderson WM, Smith MA.

Interdisciplinary Toxicology Program, College of Public Health, University of Georgia, Athens, Georgia 30602, USA.

8-2 Fluorotelomer alcohol (FTOH) and its metabolites, perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA), are developmental toxicants but metabolism and distribution during pregnancy are not known. To examine this, timed-pregnant mice received a single gavage dose (30 mg 8-2 FTOH/kg body weight) on gestational day (GD) 8. Maternal and neonatal serum and liver as well as fetal and neonatal homogenate extracts were analyzed using gas chromatography coupled with mass spectrometry. During gestation (GD9 to GD18), maternal serum and liver concentrations of PFOA decreased from 789 +/- 41 to 668 +/- 23 ng/ml and from 673 +/- 23 to 587 +/- 55 ng/g, respectively. PFOA was transferred to the developing fetuses as early as 24-h posttreatment with concentrations increasing from 45 +/- 9 ng/g (GD10) to 140 +/- 32 ng/g (GD18), while PFNA was quantifiable only at GD18 (31 +/- 4 ng/g). Post-partum, maternal serum PFOA concentrations decreased from 451 +/- 21 ng/ml postnatal day (PND) 1 to 52 +/- 19 ng/ml (PND15) and PFNA concentrations, although fivefold less, exhibited a similar trend. Immediately after birth, pups were cross-fostered with dams that had been treated during gestation with 8-2 FTOH (T) or vehicle (C) resulting in four treatment groups in which the first letter represents in utero (fetal) exposure and the second represents lactational (neonatal) exposure: C/C, T/C, C/T, T/T. On PND1, neonatal whole-body homogenate concentrations of PFOA from T/T and T/C groups averaged 200 +/- 26 ng/g, decreased to 149 +/- 19 ng/g at PND3 and this decreasing trend was seen in both neonatal liver and serum from PND3 to PND15. Based on detectible amounts of PFOA in neonatal serum in the C/T group on PND3 (57 +/- 11 ng/ml) and on PND15 (58 +/- 3 ng/ml), we suggest that the neonates were exposed through lactation. In conclusion, exposure of neonates to PFOA and PFNA occurs both pre- and postnatally following maternal 8-2 FTOH exposure on GD8.

PMID: 17093205 [PubMed - indexed for MEDLINE]

Toxicol Sci. 2007 Mar 22; [Epub ahead of print]

Toxicogenomic Study of Triazole Fungicides and Perfluoroalkyl Acids in Rat Livers Predicts Toxicity and Categorizes Chemicals Based on Mechanisms of Toxicity.

Martin MT, Brennan R, Hu W, Ayanoglu E, Lau C, Ren H, Wood CR, Corton JC, Kavlock RJ, Dix DJ.

Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.

Toxicogenomic analysis of five environmental chemicals was performed to investigate the ability of genomics to predict toxicity, categorize chemicals and elucidate mechanisms of toxicity. Three triazole antifungals (myclobutanil, propiconazole and triadimefon) and two perfluorinated chemicals (perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS)) were administered daily via oral gavage for 1, 3, or 5 consecutive days to male Sprague-Dawley rats at single doses of 300, 300, 175, 20, or 10 mg/kg/d, respectively. Clinical chemistry, hematology and histopathology were measured at all time points. Gene expression profiling of livers from 3 rats per treatment group at all time points was performed on the CodeLink RU1 rat array. Data were analyzed in the context of a large reference toxicogenomic database containing gene expression profiles for over 630 chemicals. Genomic signatures predicting hepatomegaly and hepatic injury preceded those results for all five chemicals and further analysis segregated chemicals into two distinct classes. The triazoles caused similar gene expression changes as other azole antifungals, particularly the induction of PXR (pregnane X receptor)-regulated xenobiotic metabolism and oxidative stress genes. In contrast, PFOA and PFOS exhibited PPARalpha (peroxisome proliferator-activated receptor alpha) agonist-like effects on genes associated with fatty-acid homeostasis. PFOA and PFOS also resulted in downregulation of cholesterol biosynthesis genes, matching an in vivo decrease in serum cholesterol, and perturbation of thyroid hormone metabolism genes matched by serum thyroid hormone depletion in vivo. The concordance of in vivo observations and gene expression findings demonstrated the ability of genomics to accurately categorize chemicals, identify toxic mechanisms of action, and predict subsequent pathological responses.

PMID: 17383973 [PubMed - as supplied by publisher]

Int J Mol Med. 2007 May;19(5):733-9.

Perfluorooctane sulfonate influences feeding behavior and gut motility via the hypothalamus.

Asakawa A, Toyoshima M, Fujimiya M, Harada K, Ataka K, Inoue K, Koizumi A.

Department of Health and Environmental Sciences, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan.

Perfluorinated compounds (PFCs) have been employed as surface treatment agents in a variety of products. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the two most commonly found PFCs in the environment and human blood. We investigated the effects of PFOS and PFOA on feeding behavior. PFOS or PFOA was administered intracerebroventricularly in mice or rats. Following administration, food intake, gastroduodenal motility, gastric emptying, gene expression of hypothalamic neuropeptides, and c-Fos expression along with immunoreaction for urocortin 2 in the paraventricular nucleus (PVN) were determined. Centrally administered PFOS and PFOA decreased food intake. Administration of PFOS decreased gastric emptying and disrupted the fasted motor activity in the antrum and duodenum. The gene expression of urocortin 2 in the hypothalamus and c-Fos expression and immunoreaction for urocortin 2 in the PVN were increased by the action of PFOS. A centrally administered corticotropin-releasing factor type 2 receptor (CRFR2) antagonist blocked PFOS-induced anorexia. These findings indicate that PFOS and PFOA influence feeding behavior. This effect is mediated via the activation of hypothalamic urocortin 2 and CRFR2, and the suppression of gastroduodenal motor activity. These observations indicate that PFCs may act centrally to influence behavior and physiological functions in humans.

PMID: 17390077 [PubMed - in process]

Environ Res. 2007 Feb;103(2):176-84. Epub 2006 Aug 8.

Comparison of human whole blood, plasma, and serum matrices for the determination of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and other fluorochemicals.

Ehresman DJ, Froehlich JW, Olsen GW, Chang SC, Butenhoff JL.

Medical Department, 3M Company, Mail Stop 220-6W-08, St. Paul, MN 55144-1000, USA.

Interest in human exposure to perfluorinated acids, including perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHS), perfluorooctanesulfonate (PFOS), and perfluorooctanoate (PFOA) has led to their measurement in whole blood, plasma and serum. Comparison of measurements in these different blood-based matrices, however, has not been rigorously investigated to allow for across-matrix comparisons. This research evaluated concentrations of PFBS, PFHS, PFOS, and PFOA in whole blood collected in heparin (lithium) and ethylenediamine tetraacetic acid (EDTA), plasma samples collected in heparin and EDTA, and serum (from whole blood allowed to clot). Blood samples were collected from 18 voluntary participants employed at 3M Company. Solid phase extraction methods were used for all analytical sample preparations, and analyses were completed using high-pressure liquid chromatography/tandem mass spectrometry methods. Serum concentrations ranged from: limit of quantitation (LOQ, 5 ng/mL) to 25 ng/mL for PFBS; LOQ (5 ng/mL) to 75 ng/mL for PFHS; LOQ (5 ng/mL) to 880 ng/mL for PFOS; and LOQ (5 or 10 ng/mL) to 7320 ng/mL for PFOA. Values less than the LOQ were not included in the statistical analyses of the mean of the ratios of individual values for the matrices. PFBS was not quantifiable in most samples. Serum to plasma ratios for PFHS, PFOS, and PFOA were 1:1 and this ratio was independent of the level of concentrations measured. Serum or plasma to whole blood ratios, regardless of the anticoagulant used, approximated 2:1. The difference between plasma and serum and whole blood corresponded to volume displacement by red blood cells, suggesting that the fluorochemicals are not found intracellularly or attached to the red blood cells.

PMID: 16893538 [PubMed - indexed for MEDLINE]

J Agric Food Chem. 2007 Apr 18;55(8):3203-10. Epub 2007 Mar 24.

Dietary Exposure of Canadians to Perfluorinated Carboxylates and Perfluorooctane Sulfonate via Consumption of Meat, Fish, Fast Foods, and Food Items Prepared in Their Packaging.

Tittlemier SA, Pepper K, Seymour C, Moisey J, Bronson R, Cao XL, Dabeka RW.

Food Research Division, Banting Research Centre 2203D, and Chemical Health Hazard Assessment Division, Banting Research Centre 2204D, Health Canada, Ottawa, Ontario K1A 0L2, Canada.

Human exposure to perfluorinated compounds is a worldwide phenomenon; however, routes of human exposure to these compounds have not been well-characterized. Fifty-four solid food composite samples collected as part of the Canadian Total Diet Study (TDS) were analyzed for perfluorocarboxylates and perfluorooctanesulfonate (PFOS) using a methanol extraction liquid chromatography tandem mass spectrometry method. Foods analyzed included fish and seafood, meat, poultry, frozen entrees, fast food, and microwave popcorn collected from 1992 to 2004 and prepared as for consumption. Nine composites contained detectable levels of perfluorinated compounds-four meat-containing, three fish and shellfish, one fast food, and one microwave popcorn. PFOS and perfluorooctanoate (PFOA) were detected the most frequently; concentrations ranged from 0.5 to 4.5 ng/g. The average dietary intake of total perfluorocarboxylates and PFOS for Canadians was estimated to be 250 ng/day, using results from the 2004 TDS composites. A comparison with intakes of perfluorocarboxylates and PFOS via other routes (air, water, dust, treated carpeting, and apparel) suggested that diet is an important source of these compounds. There was a substantial margin of exposure between the toxicological points of reference and the magnitude of dietary intake of perfluorinated compounds for Canadians >/= 12 years old. Keywords: PFOS; PFOA; diet; food; exposure estimate.

PMID: 17381114 [PubMed - in process]

Environ Health Perspect. 2007 Feb;115(2):226-30. Epub 2006 Nov 28.

Exposure of perfluorinated chemicals through lactation: levels of matched human milk and serum and a temporal trend, 1996-2004, in Sweden.

Karrman A, Ericson I, van Bavel B, Darnerud PO, Aune M, Glynn A, Lignell S, Lindstrom G.

Man-Technology-Environment (MTM) Research Centre, Orebro University, Orebro, Sweden.

BACKGROUND: Only limited data exist on lactation as an exposure source of persistent perfluorinated chemicals (PFCs) for children.
OBJECTIVES: We studied occurrence and levels of PFCs in human milk in relation to maternal serum together with the temporal trend in milk levels between 1996 and 2004 in Sweden. Matched, individual human milk and serum samples from 12 primiparous women in Sweden were analyzed together with composite milk samples (25-90 women/year) from 1996 to 2004.
RESULTS: Eight PFCs were detected in the serum samples, and five of them were also above the detection limits in the milk samples. Perfluorooctanesulfonate (PFOS) and perfluorohexanesulfonate (PFHxS) were detected in all milk samples at mean concentrations of 0.201 ng/mL and 0.085 ng/mL, respectively. Perfluorooctanesulfonamide (PFOSA), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were detected less frequently.
DISCUSSION: The total PFC concentration in maternal serum was 32 ng/mL, and the corresponding milk concentration was 0.34 ng/mL. The PFOS milk level was on average 1% of the corresponding serum level. There was a strong association between increasing serum concentration and increasing milk concentration for PFOS (r(2) = 0.7) and PFHxS (r(2) = 0.8). PFOS and PFHxS levels in composite milk samples were relatively unchanged between 1996 and 2004, with a total variation of 20 and 32% coefficient of variation, respectively.
CONCLUSION: The calculated total amount of PFCs transferred by lactation to a breast-fed infant in this study was approximately 200 ng/day. Lactation is a considerable source of exposure for infants, and reference concentrations for hazard assessments are needed.

PMID: 17384769 [PubMed - in process]

Environ Sci Technol. 2007 Apr 1;41(7):2237-42.

Serum concentrations of 11 polyfluoroalkyl compounds in the U.S. population: data from the national health and nutrition examination survey (NHANES).

Calafat AM, Kuklenyik Z, Reidy JA, Caudill SP, Tully JS, Needham LL.

Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA.

We measured the concentrations of 11 polyfluoroalkyl compounds (PFCs), including perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonic acid (PFHxS) in 1562 serum samples collected from a representative U.S. population 12 years of age and older in the 1999-2000 National Health and Nutrition Examination Survey. Participants represented both sexes, three race/ethnicities (non-Hispanic blacks, non-Hispanic whites, and Mexican-Americans), and four age categories (12-19 years, 20-39 years, 40-59 years, and 60 years and older). PFCs were extracted from 100 microL of serum using on-line solid-phase extraction coupled to isotope dilution-high performance liquid chromatography-tandem mass spectrometry; limits of detection ranged from 0.05 to 0.2 ng/ mL. PFOS, PFOA, PFHxS, and perfluorooctane sulfonamide were detected in all samples analyzed; 2-(N-ethyl-perfluorooctane sulfonamido) acetic acid, 2-(N-methyl-perfluorooctane sulfonamido) acetic acid, and perfluorononanoic acid were detected in more than 90% of samples, which suggests prevalent exposures to several PFCs in the U.S. population. The concentrations of most PFCs were similar regardless of the participants' ages but were higher in males than in females. Mexican Americans had lower concentrations than non-Hispanic blacks and non-Hispanic whites, whose concentrations were similar. Higher education was associated with higher concentrations of PFOS and PFOA. These data will serve as a nationally representative baseline of the U.S. population's exposure to PFCs to which other populations can be compared, and will play an important role in public health by helping set research priorities, ranging from health effects studies to defining sources and pathways of exposure.

PMID: 17438769 [PubMed - in process]

Environ Int. 2007 Feb 5; [Epub ahead of print]

Perfluorinated chemicals in blood of residents in Catalonia (Spain) in relation to age and gender: A pilot study.

Ericson I, Gomez M, Nadal M, van Bavel B, Lindstrom G, Domingo JL.

Man-Technology-Environment (MTM) Research Center, Department of Natural Sciences, Orebro University, SE-701 82 Orebro, Sweden.

Fluorinated organic compounds (FOCs) are a group of chemicals widely used as surfactants, lubricants, polymers, and fire-fighting foams. Recent studies have shown the ubiquitous distribution of FOCs in the environment, wildlife, and humans. We here report the results of a pilot study conducted to provide preliminary data on the levels of 13 FOCs in the blood of 48 residents in Catalonia, Spain, in relation to gender and age (25+/-5 and 55+/-5 years). The highest mean concentration was obtained for perfluorooctane sulfonate (PFOS, 7.64 ng/ml), followed by perfluorohexane sulfonate (PFHxS, 3.56 ng/ml) and perfluorooctanoic acid (PFOA, 1.80 ng/ml). Four other FOCs showed mean levels between 0.30 and 0.44 ng/ml, whereas those of the remaining 6 compounds were below the detection limit. Regarding gender, the blood levels of PFHxS and PFOA were significantly higher (p<0.05) in men than in women, while differences according to age were only noted for PFHxS (p<0.05) and perfluorooctane sulfonamide (PFOSA) (p<0.001), for which the levels were higher in the younger (25+/-5 years) group of subjects. A significant correlation between PFOS levels and those of the remaining detected FOCs (except PFDA) was found. In general terms, the current FOC concentrations were lower than those found in recent studies concerning levels of these chemicals in human blood and serum of subjects from different countries.

PMID: 17289145 [PubMed - as supplied by publisher]

Chemosphere. 2007 May;68(1):105-11. Epub 2007 Jan 30.

Preliminary evidence of a decline in perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) concentrations in American Red Cross blood donors.

Olsen GW, Mair DC, Reagen WK, Ellefson ME, Ehresman DJ, Butenhoff JL, Zobel LR.

3M Company, Medical Department, St. Paul, MN 55144, United States.

The purpose of this pilot study was to determine whether perfluorooctanesulfonate (PFOS,C(8)F(17)SO(3)(-)) and perfluorooctanoate (PFOA,C(7)F(15)CO(2)(-)) concentrations in American Red Cross blood donors from Minneapolis-St. Paul, Minnesota have declined after the 2000-2002 phase-out of perfluorooctanesulfonyl-fluoride (POSF, C(8)F(17)SO(2)F)-based materials by the primary global manufacturer, 3M Company. Forty donor plasma samples, categorized by age and sex, were collected in 2005, and PFOS and PFOA concentrations were compared to 100 (non-paired) donor serum samples collected in 2000 from the same general population that were analyzed at the time using ion-pair extraction methods with tetrahydroperfluorooctanesulfonate as an internal standard. Eleven of the 100 samples originally collected were reanalyzed with present study methods that involved (13)C- labeled PFOA spiked into the donor samples, original samples, control human plasma, and the calibration curve prior to extraction, and was used as a surrogate to monitor extraction efficiency. Quantification was performed by high performance liquid chromatography tandem mass spectrometry methods. Among the 100 serum samples analyzed for PFOS, the geometric mean was 33.1ngml(-1) (95% CI 29.8-36.7) in 2000 compared to 15.1ngml(-1) (95% CI 13.3-17.1) in 2005 (p<0.0001) for the 40 donor plasma samples. The geometric mean concentration for PFOA was 4.5ngml(-1) (95% CI 4.1-5.0) in 2000 compared to 2.2ngml(-1) (95% CI 1.9-2.6) in 2005 (p<0.0001). The decrease was consistent across donors' age and sex. To confirm these preliminary findings, additional sub-sets of year 2000 samples will be analyzed, and a much larger biomonitoring study of other locations is planned.

PMID: 17267015 [PubMed - in process]

J Chromatogr A. 2007 Mar 28; [Epub ahead of print]

Trace analysis of total fluorine in human blood using combustion ion chromatography for fluorine: A mass balance approach for the determination of known and unknown organofluorine compounds.

Miyake Y, Yamashita N, So MK, Rostkowski P, Taniyasu S, Lam PK, Kannan K.

National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan.

The number of perfluorochemicals (PFCs) that have been found in biological and environmental matrices is increasing as analytical standards and methods evolve. Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) constitute only a fraction of the total suite of PFCs found in environmental and biological matrices. A robust method and approach is needed to evaluate the mass of fluorinated compounds in biological matrices. In this study, we developed a method to measure total fluorine (TF) and organic fluorine (TOF) in human blood matrices using combustion ion chromatography (CIC). Blood matrices (whole blood, serum, and plasma) were analyzed in bulk to determine TF. An aliquot of the blood was also extracted with organic solvents such as methyl-tert-butyl ether (MTBE) and hexane, and organic and aqueous extracts were separated, to fractionate organofluorines from inorganic fluorine. The organic layer was analyzed for TF by CIC, and for known PFCs by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). PFCs measured by HPLC-MS/MS accounted for >80% of the TF in the organic fraction. The aqueous fraction contained inorganic fluorine and other non-extractable organofluorines. However, in the bulk sample, fluoride and non-extractable organofluorines accounted for >70% of the TF in blood samples from the general population. In occupationally exposed individuals, known organofluorines accounted for a major proportion of the TF. These results suggest the existence of yet uncharacterized fluorine fraction in human blood. Further studies are needed to characterize the aqueous fraction that contains inorganic fluorine and non-extractable forms of fluorine.

PMID: 17416376 [PubMed - as supplied by publisher]

Toxicol Sci. 2007 Mar 15; [Epub ahead of print]

Exposure to the Immunosuppresant, Perfluorooctanoic Acid, Enhances the Murine Ige and Airway Hyperreactivity Response to Ovalbumin: PFOA Enhances OVA Induced Allergic Response.

Fairley K, Purdy R, Kearns S, Anderson S, Meade B.

National Institute for Occupational Safety and Health, Morgantown, WV 26505, B.J. Meade's email:

These studies were conducted to investigate the role of dermal exposure to Perfluorooctanoic acid (PFOA), a known immunosuppressant, on the hypersensitivity response to ovalbumin in a murine model of asthma. PFOA has had widespread use as a carpet and fabric protectant. BALB/c mice were exposed dermally, on the dorsal surface of each ear, to concentrations of PFOA ranging from 0.01-1.5% (applied dose 0.25-50 mg/kg) for 4 days. In hypersensitivity studies, mice were also intraperitoneally injected with 7.5 mug ovalbumin and 2 mg alum on days 1 and 10 and in some studies, challenged with 250 mug ovalbumin by pharyngeal aspiration on days 17 and 26. Following exposure to PFOA, an increase in liver weights and a decrease in thymus and spleen weights and cellularities were observed. Similar immunomodulatory trends were demonstrated in mice co-administered PFOA and ovalbumin (OVA). Compared to the OVA alone exposed animals, an increase in total IgE was demonstrated when mice were co-exposed to OVA and concentrations of PFOA ranging from 0.75-1.5%, while the OVA-specific IgE response peaked with 0.75% PFOA co-exposure (p </= 0.05). OVA-specific airway hyperreactivity was increased in the 1.0% PFOA co-exposed group (p </= 0.05), with an increased pleiotropic cell response characterized by eosinophilia and mucin production, in animals co-exposed to concentrations of PFOA up to 1.0%, as compared to the ovalbumin alone exposed animals. In a murine model, PFOA was demonstrated to be immunotoxic following dermal exposure, with an enhancement of the hypersensitivity response to ovalbumin, suggesting that PFOA exposure may augment the IgE response to environmental allergens.

PMID: 17369199 [PubMed - as supplied by publisher]

Toxicol Sci. 2007 Jan;95(1):108-17. Epub 2006 Oct 17.

Activation of mouse and human peroxisome proliferator-activated receptors (alpha, beta/delta, gamma) by perfluorooctanoic acid and perfluorooctane sulfonate.

Takacs ML, Abbott BD.

Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.

This study evaluates the potential for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) to activate peroxisome proliferator-activated receptors (PPARs), using a transient transfection cell assay. Cos-1 cells were cultured in Dulbecco's Minimal Essential Medium (DMEM) with fetal bovine serum in 96-well plates and transfected with mouse or human PPARalpha, beta/delta, or gamma reporter plasmids. Transfected cells were exposed to PFOA (0.5-100 microM), PFOS (1-250 microM), positive controls (i.e., known agonists and antagonists), and negative controls (i.e., DMEM, 0.1% water, and 0.1% dimethyl sulfoxide). Following treatment for 24 h, activity was measured using the Luciferase reporter assay. In this assay, PFOA had more transactivity than PFOS with both the mouse and human PPAR isoforms. PFOA significantly increased mouse and human PPARalpha and mouse PPARbeta/delta activity relative to vehicle. PFOS significantly increased activation of mouse PPARalpha and PPARbeta/delta isoforms. No significant activation of mouse or human PPARgamma was observed with PFOA or PFOS. The PPARalpha antagonist, MK-886, significantly suppressed PFOA and PFOS activity of mouse and human PPARalpha. The PPARgamma antagonist, GW9662, significantly suppressed PFOA activity on the human isoform. In conclusion, this study characterized the dose response and differential activation of mouse and human PPARalpha, beta/delta, gamma by PFOA and PFOS. While this model allows opportunities to compare potential activation by perfluoroalkyl acids, it only evaluates the interaction and activation of the PPAR reporter constructs and is not necessarily predictive of a toxicological response in vivo.

PMID: 17047030 [PubMed - indexed for MEDLINE]

Environ Sci Technol. 2007 Mar 1;41(5):1554-9.

Spatial distribution of perfluoroalkyl contaminants in lake trout from the Great Lakes.

Furdui VI, Stock NL, Ellis DA, Butt CM, Whittle DM, Crozier PW, Reiner EJ, Muir DC, Mabury SA

Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6.

Individual whole body homogenates of 4 year old lake trout (Salvelinus namaycush) samples collected in 2001 from each of the Great Lakes were extracted using a novel fluorophilicity cleanup step and analyzed for perfluoroalkyl compounds (PFCs). Standard addition and internal standardization were used for quantification. Results were reported (+/- SE) for perfluorinated carboxylates (PFCAs), perfluorinated sulfonates (PFSAs), and unsaturated fluorotelomer carboxylates (8:2 and 10:2 FTUCA). The lowest average concentration of sigmaPFC was found in samples from Lake Superior (13+/-1 ng g(-1)), while the highest average concentration was found in samples from Lake Erie (152+/-14 ng g(-1)). Samples from Lake Ontario (60+/-5 ng g(-1)) and Lake Huron (58 +/-10 ng g(-1)) showed similar average sigmaPFC concentrations, although the perfluorinated sulfonate/carboxylate ratios were different. The major perfluoroalkyl contaminant observed was perfluorooctane sulfonate (PFOS) with the highest concentration found in samples from Lake Erie (121+/-14 ng g(-1)), followed by samples from Lake Ontario (46+/-5 ng g(-1)), Lake Huron (39 +/-10 ng g(-1)), Lake Michigan (16+/-3 ng g(-1)), and Lake Superior (5+/-1 ng g(-1)). Perfluorodecane sulfonate (PFDS) was detected in 89% of the samples, with the highest concentration in Lake Erie samples (9.8+/-1.6 ng g(-1)), and lowest concentration in samples from Lake Superior (0.7 +/- 0.1 ng g(-1)). Statistically significant correlations were observed between PFOS and PFDS concentrations, and PFOS concentration and body weight, respectively. The PFCAs were detected in all samples, with the highest total average concentration in samples from Lake Erie (19 ng g(-1)), followed by samples from Lake Huron (16 ng g(-1)), Lake Ontario (10 ng g(-1)), Lake Michigan (9 ng g(-1)) and Lake Superior (7 ng g(-1)). The compounds with significant contributions to the sigmaPFCA concentrations were PFOA and C9-C13-PFCAs. The 8:2 FTUCA was detected at concentrations ranging between 0.1 and 0.2 ng g-1, with the highest level in samples showing also elevated concentrations of PFOA (4.4 ng g(-1) for Lake Michigan vs 1.5 ng g(-1) for all other samples). The 10:2 FTUCA was detected only in 9% of all samples (nd, 45 pg g(-1)). For those PFCs where we determined lake water concentrations, the highest log BAFs were calculated for PFOS (4.1), PFDA (3.9), and PFOSA (3.8).

PMID: 17396640 [PubMed - in process]

Anal Bioanal Chem. 2007 Feb;387(4):1469-78. Epub 2007 Jan 3.

Polar herbicides, pharmaceutical products, perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and nonylphenol and its carboxylates and ethoxylates in surface and tap waters around Lake Maggiore in Northern Italy.

Loos R, Wollgast J, Huber T, Hanke G.

European Commission - DG Joint Research Centre, Institute for Environment and Sustainability, Via Enrico Fermi, TP 290, 21020 Ispra, Italy.

A survey of contamination of surface and drinking waters around Lake Maggiore in Northern Italy with polar anthropogenic environmental pollutants has been conducted. The target analytes were polar herbicides, pharmaceuticals (including antibiotics), steroid estrogens, perfluorooctanesulfonate (PFOS), perfluoroalkyl carboxylates (including perfluorooctanoate PFOA), nonylphenol and its carboxylates and ethoxylates (NPEO surfactants), and triclosan, a bactericide used in personal-care products. Analysis of water samples was performed by solid-phase extraction (SPE) then liquid chromatography-triple-quadrupole (tandem) mass spectrometry (LC-MS-MS). By extraction of 1-L water samples and concentration of the extract to 100 microL, method detection limits (MDLs) as low as 0.05-0.1 ng L(-1) were achieved for most compounds. Lake-water samples from seven different locations in the Southern part of Lake Maggiore and eleven samples from different tributary rivers and creeks were investigated. Rain water was also analyzed to investigate atmospheric input of the contaminants. Compounds regularly detected at very low concentrations in the lake water included: caffeine (max. concentration 124 ng L(-1)), the herbicides terbutylazine (7 ng L(-1)), atrazine (5 ng L(-1)), simazine (16 ng L(-1)), diuron (11 ng L(-1)), and atrazine-desethyl (11 ng L(-1)), the pharmaceuticals carbamazepine (9 ng L(-1)), sulfamethoxazole (10 ng L(-1)), gemfibrozil (1.7 ng L(-1)), and benzafibrate (1.2 ng L(-1)), the surfactant metabolite nonylphenol (15 ng L(-1)), its carboxylates (NPE(1)C 120 ng L(-1), NPE(2)C 7 ng L(-1), NPE(3)C 15 ng L(-1)) and ethoxylates (NPE( n )Os, n = 3-17; 300 ng L(-1)), perfluorinated surfactants (PFOS 9 ng L(-1), PFOA 3 ng L(-1)), and estrone (0.4 ng L(-1)). Levels of these compounds in drinking water produced from Lake Maggiore were almost identical with those found in the lake itself, revealing the poor performance of sand filtration and chlorination applied by the local waterworks.

PMID: 17200857 [PubMed - in process]

J Toxicol Environ Health A. 2007 Jan;70(1):28-57.

A methodology for estimating human exposure to perfluorooctanoic acid (PFOA): a retrospective exposure assessment of a community (1951-2003)

Paustenbach DJ, Panko JM, Scott PK, Unice KM.

ChemRisk, Inc., San Francisco, California 94105, USA.

Perfluorooctanoic acid (PFOA) is a persistent chemical that was recently shown to be widely distributed in the ambient environment. Because of concerns about the possible adverse health effects on persons exposed to PFOA, a retrospective exposure assessment was conducted for a population of about 50,000 persons who reside near one of the facilities where this chemical was used. No similar study of any chemical with the properties of PFOA had ever been performed; thus, several novel methods were developed and applied in this analysis. Historical records of the emissions from the facility were the basis for the estimates of the potential intake of (PFOA) by residents over the past 53 yr. Various well-accepted environmental models were dynamically combined in order to estimate the concentrations in all relevant environmental media including ambient air, surface soil, drinking water, and homegrown vegetables. Following considerable analyses, particulate deposition from facility air emissions to soil and the subsequent transfer of the chemical through the soil was determined to be the most likely source of PFOA that was detected in groundwater. The highest off-site environmental concentrations were predicted to occur about 1 mile away. For this approximately square mile area, during the time period 1951-2003, the model-estimated average air concentration was 0.2 microg/m3, the estimated surface soil concentration was 11 microg/kg, and the estimated drinking water concentration was 4 microg/L. Similar data were generated for 20 additional geographical areas around the facility. Comparison of measured PFOA concentrations in groundwater in the various water districts indicated that the models appeared to overpredict recent groundwater concentrations by a factor of 3 to 5. The predicted historical lifetime and average daily estimates of PFOA intake by persons who lived within 5 miles of the plant over the past 50 yr were about 10,000-fold less than the intake of the chemical not considered as a health risk by an independent panel of scientists who recently studied PFOA.

PMID: 17162497 [PubMed - indexed for MEDLINE]

Int Arch Occup Environ Health. 2007 Feb;80(4):313-9. Epub 2006 Aug 17.

Occurrence of perfluorinated substances in an adult German population in southern Bavaria.

Fromme H, Midasch O, Twardella D, Angerer J, Boehmer S, Liebl B.

Bavarian Health and Food Safety Authority, Department of Environmental Health, Veterinaerstrasse 2, 85764, Oberschleissheim, Germany,

OBJECTIVES: Perfluorinated compounds (PFCs) are a large group of chemicals produced for several decades and widely used for many industrial and consumer applications. Because of their global occurrence in different environmental media, their persistence, and their potential to bioaccumulate in organisms they are of toxicological and public concern.
METHODS: In the present study, the internal exposure to perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in 356 human plasma samples collected from an adult population in Germany in 2005 is quantified.
RESULTS: We were able to detect the target analytes in all plasma samples and observed a significant correlation between the PFOS and PFOA concentrations. In female participants, the levels of PFOS and PFOA ranged between 2.5-30.7 (median: 10.9 mug/l) and 1.5-16.2 mug/l (median: 4.8 mug/l), respectively. In males we observed concentrations from 2.1 to 55.0 mug/l (median: 13.7 mug/l) for PFOS and from 0.5 to 19.1 mug/l (median: 5.7 mug/l) for PFOA. A significant correlation between both PFOS and PFOA concentrations and gender was observed. We also found increased levels of the PFCs with increasing age of the participants, but this association reached statistical significance among females only.
CONCLUSIONS: Our data agree well with results of other recent studies in Europe and suggest that the current exposure of the adult German population is lower than the exposure of the US and Canadian population. The sources of human exposure are currently not well understood. Toxicological implications are restricted to animal studies and occupational investigations not adequate for quantitative risk assessment in humans. Overall, more scientific research is necessary to characterize the body burden of PFCs (especially for relevant subsets of the population) and the main sources and routes, which are responsible for human exposure and possible health implications of these compounds.

PMID: 16915390 [PubMed - in process]

Chemosphere. 2007 Mar 16; [Epub ahead of print]

Perfluorinated compounds in the Pearl River and Yangtze River of China.

So MK, Miyake Y, Yeung WY, Ho YM, Taniyasu S, Rostkowski P, Yamashita N, Zhou BS, Shi XJ, Wang JX, Giesy JP, Yu H, Lam PK.

Centre for Coastal Pollution and Conservation, Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, People's Republic of China; National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan.

A total of 14 perfluorinated compounds (PFCs) were quantified in river water samples collected from tributaries of the Pearl River (Guangzhou Province, south China) and the Yangtze River (central China). Among the PFCs analyzed, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the two compounds with the highest concentrations. PFOS concentrations ranged from 0.90 to 99ng/l and <0.01-14ng/l in samples from the Pearl River and Yangtze River, respectively; whereas those for PFOA ranged from 0.85 to 13ng/l and 2.0-260ng/l. Lower concentrations were measured for perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctanesulfoamide (PFOSA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorononaoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA). Concentrations of several perfluorocarboxylic acids, including perfluorododecanoic acid (PFDoDA), perfluorotetradecanoic acid (PFTeDA), perfluorohexadecanoic acid (PFHxDA) and perfluorooctadecanoic acid (PFOcDA) were lower than the limits of quantification in all the samples analyzed. The highest concentrations of most PFCs were observed in water samples from the Yangtze River near Shanghai, the major industrial and financial centre in China. In addition, sampling locations in the lower reaches of the Yangtze River with a reduced flow rate might serve as a final sink for contaminants from the upstream river runoffs. Generally, PFOS was the dominant PFC found in samples from the Pearl River, while PFOA was the predominant PFC in water from the Yangtze River. Specifically, a considerable amount of PFBS (22.9-26.1% of total PFC analyzed) was measured in water collected near Nanjing, which indicates the presence of potential sources of PFBS in this part of China. Completely different PFC composition profiles were observed for samples from the Pearl River and the Yangtze River. This indicates the presence of dissimilar sources in these two regions.

PMID: 17368725 [PubMed - as supplied by publisher]

Aquat Toxicol. 2007 May 1;82(2):135-43. Epub 2007 Feb 15.

Induction of oxidative stress and apoptosis by PFOS and PFOA in primary cultured hepatocytes of freshwater tilapia (Oreochromis niloticus).

Liu C, Yu K, Shi X, Wang J, Lam PK, Wu RS, Zhou B.

State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China; Graduate School of the Chinese Academy of Sciences, Beijing 100039, PR China.

Perfluorinated organic compounds (PFOCs) are emerging persistent organic pollutants (POPs) widely present in the environment, wildlife and human. We studied the cellular toxicology of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) on oxidative stress and induction of apoptosis in primary cultured hepatocytes of freshwater tilapia (Oreochromis niloticus). Cultured hepatocytes were exposed to PFOS or PFOA (0, 1, 5, 15 and 30mgL(-1)) for 24h, and a dose-dependent decrease in cell viability was determined using trypan blue exclusion method. Significant induction of reactive oxygen species (ROS) accompanied by increases in activities of superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) were found, while activities of glutathione peroxidase (GPx) and glutathione-S-transferase (GST) were decreased. Glutathione (GSH) content was reduced following treatment of PFOA and PFOS. A dose-dependent increase in the lipid peroxidation (LPO) level (measured as maleic dialdehyde, MDA) was observed only in the PFOA exposure groups, whereas LPO remained unchanged in the PFOS exposure groups. Furthermore, a significant activation of caspase-3, -8, -9 activities was evident in both PFOS and PFOA exposure groups. Typical DNA fragmentation (DNA laddering) was further characterized by agarose gel electrophoresis. The overall results demonstrated that PFOS and PFOA are able to produce oxidative stress and induce apoptosis with involvement of caspases in primary cultured tilapia hepatocytes.

PMID: 17374408 [PubMed - in process]

Biochim Biophys Acta. 2007 May;1768(5):1299-308. Epub 2007 Feb 9.

Effect of potassium perfluorooctanesulfonate, perfluorooctanoate and octanesulfonate on the phase transition of dipalmitoylphosphatidylcholine (DPPC) bilayers.

Xie W, Kania-Korwel I, Bummer PM, Lehmler HJ.

The University of Iowa, Department of Occupational and Environmental Health, 100 Oakdale Campus #221 IREH, Iowa City, IA 52242-5000, USA.

Perfluorooctanesulfonic acid (PFOS) is a persistent environmental pollutant that may cause adverse effects by inhibiting pulmonary surfactant. To gain further insights in this potential mechanism of toxicity, we investigated the interaction of PFOS potassium salt with dipalmitoylphosphatidylcholine (DPPC) - the major component of pulmonary surfactant - using steady-state fluorescence anisotropy spectroscopy and DSC (differential scanning calorimetry). In addition, we investigated the interactions of two structurally related compounds, perfluorooctanoic acid (PFOA) and octanesulfonic acid (OS) potassium salt, with DPPC. In the fluorescence experiments a linear depression of the main phase transition temperature of DPPC (T(m)) and an increased peak width was observed with increasing concentration of all three compounds, both using 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene p-toluenesulfonate (TMA-DPH) as fluorescent probes. PFOS caused an effect on T(m) and peak width at much lower concentrations because of its increased tendency to partition onto DPPC bilayers, i.e., the partition coefficients decrease in the K(PFOS)>K(PFOA)>>K(OS). Similar to the fluorescence anisotropy measurements, all three compounds caused a linear depression in the onset of the main phase transition temperature and a significant peak broadening in the DSC experiments, with PFOS having the most pronounced effect of the peak width. The effect of PFOS and other fluorinated surfactants on DPPC in both mono- and bilayers may be one mechanism by which these compounds cause adverse biological effects.

PMID: 17349969 [PubMed - in process]

Biochim Biophys Acta. 2007 Apr;1771(4):506-13. Epub 2007 Jan 9.

Defect in fatty acid esterification of dolichol in Niemann-Pick type C1 mouse livers in vivo.

Turunen M, Schedin-Weiss S.

Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.

Fatty acid esterification of dolichol and cholesterol in Niemann-Pick type C1 mouse (Balb/c NIH npc1(-/-)) livers was investigated in response to treatment with peroxisomal proliferators. These inducers have hypolipidemic properties and influence the mevalonate pathway and the intracellular transport of the final products of this biosynthetic route. Such inducers are consequently interesting to use in a disease model with defective intracellular transport of lipids. In wild-type mice, the levels of dolichol and cholesterol found as free alcohols were not changed to any great extent upon treatment with the peroxisomal inducers dehydroepiandrosterone, clofibrate and diethylhexylphtalate. In contrast, the amounts of dolichyl esters increased whereas cholesteryl esters decreased by the same treatments. The rate of enzymatic esterification of dolichol in isolated microsomes was accordingly elevated after 5- to 7-day treatments with the efficient peroxisomal proliferators DEHP and PFOA, while the corresponding esterification of cholesterol was decreased. Upon peroxisomal induction in npc1(-/-) mice, the enzymatic dolichol esterification in vitro increased whereas the low concentration of dolichyl esters remained unchanged. The results thus demonstrate that the induction of fatty acid esterification of dolichol in vivo is impaired in npc1(-/-) mouse liver. It is therefore proposed that the intracellular lipid transport defect in npc1(-/-) mouse liver disables either dolichol and/or the fatty acid from reaching the site of esterification in vivo. This proposal was strengthened by the finding that the amount of dolichol was decreased in an isolated Golgi fraction from npc1(-/-) mice.

PMID: 17292665 [PubMed - in process]

J Chromatogr A. 2007 Mar 2;1143(1-2):98-104. Epub 2006 Dec 23.

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.

Miyake Y, Yamashita N, Rostkowski P, So MK, Taniyasu S, Lam PK, Kannan K.

National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan.

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.

PMID: 17229428 [PubMed - in process]

Int J Hyg Environ Health. 2007 Mar 16; [Epub ahead of print]

The Environmental Specimen Bank for Human Tissues as part of the German Environmental Specimen Bank.

Wiesmuller GA, Eckard R, Dobler L, Gunsel A, Oganowski M, Schroter-Kermani C, Schluter C, Gies A, Kemper FH.

Environmental Specimen Bank for Human Tissues, University Hospital Munster, Domagkstrasse 11, 48149 Munster, Germany.

The German Environmental Specimen Bank for Human Tissues (ESBHum) as part of the German Environmental Specimen Bank (ESB) focuses on documenting and assessing trends of human exposure via real-time monitoring of body burden and long-term storage of samples under stable deep freezing conditions (-150 degrees C) for later retrospective analyses. Real-time monitoring is performed after completing sampling processes of one year and covers actually 20 inorganic and 5 organic substances. While concentrations of several substances, e.g., arsenic, cadmium and mercury, are remained unchanged over time, other substances, e.g., lead and pentachlorophenol (PCP), show a clearly perceptible decrease. Substances which are not routinely analyzed in real-time monitoring are retrospectively measured by indication in the stored human specimens. Indications of retrospective monitoring are availability of valid analytical methods, e.g., in case of PCDF and PCDD, or assessment of concentration trends of substances with actual interest of toxicology and/or environmental medicine, e.g., polybrominated diphenyl ethers (PBDE), perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). While over time the body burden of dioxins as well as PFOS and PFOA decreased, the PBDE concentrations in human blood increase. The observed decrease of blood lead and PCP levels over time is a consequence of legal prohibition and restriction. The time-dependent concentrations of the aforementioned substances agree with results of other national studies. So it can be concluded that the German ESBHum is an important instrument for health-related environmental observation and protection in Germany.

PMID: 17369091 [PubMed - as supplied by publisher]

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