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Sample records for perfluorooctanesulphonic acid pfos

  1. Early life perfluorooctanesulphonic acid (PFOS) exposure impairs zebrafish organogenesis

    PubMed Central

    Chen, Jiangfei; Tanguay, Robert L.; Tal, Tamara L.; Bai, Chenglian; Tilton, Susan C.; Jin, Daqing; Yang, Dongren; Huang, Changjiang; Dong, Qiaoxiang

    2014-01-01

    As a persistent organic contaminant, perfluorooctanesulphonic acid (PFOS) has been widely detected in the environment, wildlife, and humans. The present study revealed that zebrafish embryos exposed to 16 µM PFOS during a sensitive window of 48–96 hour post-fertilization (hpf) disrupted larval morphology at 120 hpf. Malformed zebrafish larvae were characterized by uninflated swim bladder, less developed gut, and curved spine. Histological and ultrastructural examination of PFOS-exposed larvae showed structural alterations in swim bladder and gut. Whole genome microarray was used to identify the early transcripts dysregulated following exposure to 16 µM PFOS at 96 hpf. In total, 1,278 transcripts were significantly misexpressed (p < 0.05) and 211 genes were changed at least two-fold upon PFOS exposure in comparison to the vehicle exposed control group. A PFOS-induced network of perturbed transcripts relating to swim bladder and gut development revealed that misexpression of genes were involved in organogenesis. Taken together, early life stage exposure to PFOS perturbs various molecular pathways potentially resulting in observed defects in swim bladder and gut development. PMID:24667235

  2. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) contamination from textiles.

    PubMed

    Supreeyasunthorn, Phenpimuk; Boontanon, Suwanna K; Boontanon, Narin

    2016-05-11

    The goals of this study were to determine the concentrations of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in textiles and to determine PFOS and PFOA contamination in textile washing water. Quantification analysis was performed by high performance liquid chromatography coupled with tandem mass spectrometry. Analysis of 32 textile samples by methanol extraction revealed that the average concentrations of PFOS and PFOA were 0.18 µg m(-2) (0.02 to 0.61 µg m(-2)) and 2.74 µg m(-2) (0.31 to 14.14 µg m(-2)), respectively. Although the average concentration of PFOS found in textile samples was below European Union (EU) Commission regulations (<1 µg m(-2)), the average concentration of PFOA was 2.74 µg m(-2), and 68.75% of textile samples had PFOA concentrations exceeding 1 µg m(-2). Thus, based on these results, the concentration of PFOA in products should also be regulated. Experiments on PFOS and PFOA leaching into washing water were conducted. The maximum concentrations of PFOS and PFOA were measured after the first washing; the concentrations gradually decreased with each subsequent washing. PFOS and PFOA migrated from textiles and were released into the environment, with disappearance percentages of 29.8% for PFOS and 99% for PFOA. The data presented in this study showed that textiles could be a significant direct and indirect source of PFOS and PFOA exposure for both humans and the environment. PMID:26864911

  3. Extent of Sorption and Biodegradability of Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic Acid (PFOS) in Aquifer Sediment

    EPA Science Inventory

    Fluoropolymers such as Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic acid (PFOS) were used provide non-stick surfaces on cookware and waterproof, breathable clothing. PFOA is very persistent in the environment and is found at low concentrations in the environment and...

  4. Extent of Sorption and Biodegradation of Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic Acid (PFOS) in Aquifer Sediment

    EPA Science Inventory

    Fluoropolymers such as Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic acid (PFOS) were used provide non-stick surfaces on cookware and waterproof, breathable clothing. PFOA is very persistent in the environment and is found at low concentrations in the environment and...

  5. Absorption and excretion of 14C-perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perfluoroalkyl compounds such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are industrial chemicals that are environmentally persistent. Both PFOS and PFOA are found in biosolids, and the application of these contaminated biosolids to pastures has raised concerns about possi...

  6. Absorption and excretion of 14C-perfluorooctanoic acid (PFOA) and perfluorooctane aulfonate (PFOS) in beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perfluoroalkyl compounds such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are industrial chemicals that are environmentally persistent. Both PFOS and PFOA are found in biosolids, and the application of these contaminated biosolids to pastures has raised concerns about possi...

  7. Extent of Sorption and Biodegradability of Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic acid (PFOS) in Aquifer Sediment (Maryland)

    EPA Science Inventory

    Fluoropolymers such as Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic acid (PFOS) were used provide non-stick surfaces on cookware and waterproof, breathable clothing. PFOA is very persistent in the environment and is found at low concentrations in the environment and...

  8. Distributions of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in Japan and their toxicities.

    PubMed

    Nakayama, Shoji; Harada, Kouji; Inoue, Kayoko; Sasaki, Kazuaki; Seery, Benjamin; Saito, Norimitsu; Koizumi, Akio

    2005-01-01

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are end products of many fluorochemical compounds in the natural environment. The aim of this review is to summarize several studies in Japan and characterize the toxicities of these compounds. We also compared the levels of contamination with those reported from various countries to illustrate the unique situation of the toxicological issues within Japan. PFOA and PFOS concentrations in surface water in Japan are in the ranges of 0.1-67,000 ng/L and 0.1-526 ng/L, respectively. While the origin of PFOS in surface water remains unknown, PFOA present in surface water is very likely to have been released from a few industries. The levels of PFOA and PFOS in the atmosphere are 71.8-919 pg/m3 and 2.3-21.8 pg/m3, respectively. The concentrations of PFOA and PFOS in Japanese serum range from an undetectable level to 52.2 ng/ml and from 0.2 to 57.7 ng/ml, respectively. The levels of PFOA and PFOS present in the serum of the inhabitants of Kyoto are higher than those of other cities. One epidemiological study conducted by 3M revealed an increase in prostate cancer mortality [3.3-fold increase (95% CI, 1.02-10.6)] among workers exposed to PFOA. Another study conducted by 3M revealed an increase in bladder cancer mortality (SMR 12.77, 95% CI 2.63-37.35) among workers exposed to PFOS. PFOA and PFOS had a low order of toxicity in an acute toxicity study in rodents; however, they exhibited versatile toxicities in primates. Both chemicals are carcinogenic in rodents, causing reproductive toxicity, neurotoxicity, and hepatotoxicity. Additionally, peroxisome proliferation and calcium channel modulation are demonstrated effects. There are large interspecies differences in toxicokinetics. PMID:16609670

  9. Worldwide surveys of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in water environment in recent years.

    PubMed

    Kunacheva, Chinagarn; Fujii, Shigeo; Tanaka, Shuhei; Seneviratne, S T M L D; Lien, Nguyen Pham Hong; Nozoe, Munehiro; Kimura, Koji; Shivakoti, Binaya Raj; Harada, Hidenori

    2012-01-01

    Recently, perfluorinated compounds (PFCs) have been noted as causes of some of the important environmental problems in recent years due to their occurrences and properties. The most commonly used PFCs are perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), which have been used in many kinds of products. They have been found in surface water and tap water in both developed and developing countries around the world including in North America, Europe and Asia. In most countries, rivers are the source of tap water, which is one of the important pathways in which PFCs reach humans. It is essential to evaluate PFOS and PFOA contamination in the river basin. The purpose of this field study was to determine the presence of PFOS and PFOA in rivers around the world. The surveys were conducted in 15 countries during 2004 to 2010. In total, 539 samples were collected from the rivers in 41 cities. A solid phase extraction (SPE) coupled with HPLC-ESI-MS/MS were used for the analysis of these chemicals. PFOS and PFOA were detected in all 41 cities not only in industrialized areas but also in non-industrialized areas, representing that these compounds undergo long-range transportation in the environment. The average concentration of PFOS in each city ranged from not detected to 70.1 ng/L. The average concentration of PFOA in each city was in the range 0.2-1,630.2 ng/L. The industrialized areas show higher contamination in both PFOS and PFOA concentrations than non-industrialized areas. Industrial activities are some of the major sources of PFCs contamination in rivers. PMID:23109596

  10. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA): emerging contaminants of increasing concern in fish from Lake Varese, Italy.

    PubMed

    Squadrone, S; Ciccotelli, V; Prearo, M; Favaro, L; Scanzio, T; Foglini, C; Abete, M C

    2015-07-01

    Perfluoroalkylated substances (PFASs) are highly fluorinated aliphatic compounds with high thermal and chemical stability, used in a range of industrial applications. Extensive screening analyses in biota samples from all over the world have shown the bioaccumulation of PFAS into higher trophic levels in the food chain. Perfluorooctane sulfonic acid (PFOS) and perfluoroctanoic acid (PFOA) are potential reproductive and developmental toxicants and are considered to be emerging endocrine disrupters. Ingestion of fish and other seafood is considered the main source of exposure of these contaminants. Here, we quantified PFOS and PFOA by LC-MS/MS in muscle samples of European perch from Lake Varese, Italy. PFOS was detected in all samples with concentrations of up to 17.2 ng g(-1). Although the reported values were lower than the recommended total daily intake (TDI) proposed by the European Food Safety Authority (EFSA), fish from Lake Varese may be a significant source of dietary PFOS exposure. PMID:26085281

  11. Transcriptional changes in steroidogenesis by perfluoroalkyl acids (PFOA and PFOS) regulate the synthesis of sex hormones in H295R cells.

    PubMed

    Kang, Jae Soon; Choi, Jin-Soo; Park, June-Woo

    2016-07-01

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are two of the most widely used perfluoroalkyl acids (PFAAs). Because of their strong persistence, they have become widely distributed throughout the environment and human bodies. PFOA and PFOS are suspected to disrupt the endocrine system based upon many in vivo studies, but the underlying mechanisms are currently unclear. In this study, we investigated the endocrine-related effects of PFOA and PFOS using in vitro estrogen receptor (ER) and androgen receptor (AR) transactivation assays and steroidogenesis assay. The results showed that PFOA and PFOS exhibited weak antagonistic ER transactivation but did not exhibit agonistic ER or AR transactivation. In the steroidogenesis assay, PFOA and PFOS induced 17β-estradiol (E2) level and reduced testosterone level, which would be caused by the induction of aromatase activity. The qPCR analysis of genes involved in steroidogenesis indicates that PFOA and PFOS associate with sex hormone synthesis by the transcriptional induction of two genes, cyp19 and 3β-hsd2. Moreover, the transcriptional induction of cyp11b2 by PFOS suggests that this chemical may underlie the disruption of several physiological functions related to aldosterone. The results of the current study suggest that PFOA and PFOS are potential endocrine disrupting chemicals (EDCs) and provide information for further studies on the molecular events that initiate the adverse endocrine effects. PMID:27139122

  12. Association of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) with age of puberty among children living near a chemical plant.

    PubMed

    Lopez-Espinosa, Maria-Jose; Fletcher, Tony; Armstrong, Ben; Genser, Bernd; Dhatariya, Ketan; Mondal, Debapriya; Ducatman, Alan; Leonardi, Giovanni

    2011-10-01

    Animal studies suggest that perfluorocarbons (PFCs) may alter sexual maturation. Relationships of human PFC exposure with puberty are not clear. We conducted a cross-sectional study to investigate whether perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were associated with indicators of sexual maturation in a 2005-2006 survey of residents with PFOA water contamination from the Mid-Ohio Valley. Participants were 3076 boys and 2931 girls aged 8-18 years. They were classified as having reached puberty based on either hormone levels (total >50 ng/dL and free >5 pg/mL testosterone in boys and estradiol >20 pg/mL in girls) or onset of menarche. We estimated the odds of having reached puberty classified by these criteria and the fitted median age of reaching puberty in relation to serum PFOA and PFOS concentrations measured when puberty status was assigned. For boys, there was a relationship of reduced odds of reached puberty (raised testosterone) with increasing PFOS (delay of 190 days between the highest and lowest quartile). For girls, higher concentrations of PFOA or PFOS were associated with reduced odds of postmenarche (130 and 138 days of delay, respectively). In conclusion, our study showed a later age of puberty in this population correlated with PFC concentrations. PMID:21534542

  13. Investigation of the Effects of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) on Apoptosis and Cell Cycle in a Zebrafish (Danio rerio) Liver Cell Line.

    PubMed

    Cui, Yuan; Liu, Wei; Xie, Wenping; Yu, Wenlian; Wang, Cheng; Chen, Huiming

    2015-01-01

    This study aimed to explore the effects of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) on apoptosis and cell cycle in a zebrafish (Danio rerio) liver cell line (ZFL). Treatment groups included a control group, PFOA-IC50, PFOA-IC80, PFOS-IC50 and PFOS-IC80 groups. IC50 and IC80 concentrations were identified by cellular modeling and MTT assays. mRNA levels of p53, Bcl-2, Bax, Caspase-3 and NF-κB p65 were detected by qPCR. Cell apoptosis and cell cycle were detected by flow cytometry and the protein levels of p53, Bcl-2, Bax, Caspase-3 and NF-κB p65 were determined by western blotting. Both PFOA and PFOS inhibited the growth of zebrafish liver cells, and the inhibition rate of PFOS was higher than that of PFOA. Bcl-2 expression levels in the four groups were significantly higher than the control group and Bcl-2 increased significantly in the PFOA-IC80 group. However, the expression levels of Bax in the four treatment groups were higher than the control group. The percentage of cell apoptosis increased significantly with the treatment of PFOA and PFOS (p < 0.05). Cell cycle and cell proliferation were blocked in both the PFOA-IC80 and PFOS-IC80 groups, indicating that PFOA-IC80 and PFOS-IC50 enhanced apoptosis in ZFL cells. PMID:26690195

  14. Investigation of the Effects of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) on Apoptosis and Cell Cycle in a Zebrafish (Danio rerio) Liver Cell Line

    PubMed Central

    Cui, Yuan; Liu, Wei; Xie, Wenping; Yu, Wenlian; Wang, Cheng; Chen, Huiming

    2015-01-01

    This study aimed to explore the effects of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) on apoptosis and cell cycle in a zebrafish (Danio rerio) liver cell line (ZFL). Treatment groups included a control group, PFOA-IC50, PFOA-IC80, PFOS-IC50 and PFOS-IC80 groups. IC50 and IC80 concentrations were identified by cellular modeling and MTT assays. mRNA levels of p53, Bcl-2, Bax, Caspase-3 and NF-κB p65 were detected by qPCR. Cell apoptosis and cell cycle were detected by flow cytometry and the protein levels of p53, Bcl-2, Bax, Caspase-3 and NF-κB p65 were determined by western blotting. Both PFOA and PFOS inhibited the growth of zebrafish liver cells, and the inhibition rate of PFOS was higher than that of PFOA. Bcl-2 expression levels in the four groups were significantly higher than the control group and Bcl-2 increased significantly in the PFOA-IC80 group. However, the expression levels of Bax in the four treatment groups were higher than the control group. The percentage of cell apoptosis increased significantly with the treatment of PFOA and PFOS (p < 0.05). Cell cycle and cell proliferation were blocked in both the PFOA-IC80 and PFOS-IC80 groups, indicating that PFOA-IC80 and PFOS-IC50 enhanced apoptosis in ZFL cells. PMID:26690195

  15. ACTIVATION OF MOUSE AND HUMAN PEROXISOME PROLIFERATOR-ACTIVATED RECEPTORS (PPAR ALPHA, GAMMA, BETA DELTA) BY PERFLUOROOCTANOIC ACID (PFOA) AND PERFLUOROOCTANE SULFONATE (PFOS)

    EPA Science Inventory

    This study evaluates the potential for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) to activate peroxisome proliferator-activated receptors (PPARs), using a transient transfection cell assay. Cos-1 cells were cultured in DMEM with fetal bovine serum (FBS) in ...

  16. Exposure to perfluorooctane sulfonic acid (PFOS) adversely affects the life-cycle of the damselfly Enallagma cyathigerum.

    TOXLINE Toxicology Bibliographic Information

    Bots J; De Bruyn L; Snijkers T; Van den Branden B; Van Gossum H

    2010-03-01

    We evaluated whether life-time exposure to PFOS affects egg development, hatching, larval development, survival, metamorphosis and body mass of Enallagma cyathigerum (Insecta: Odonata). Eggs and larvae were exposed to five concentrations ranging from 0 to 10000 microg/L. Our results show reduced egg hatching success, slower larval development, greater larval mortality, and decreased metamorphosis success with increasing PFOS concentration. PFOS had no effect on egg developmental time and hatching or on mass of adults. Eggs were the least sensitive stage (NOEC=10000 microg/L). Larval NOEC values were 1000 times smaller (10 microg/L). Successful metamorphosis was the most sensitive response trait studied (NOEC<10 microg/L). The NOEC value suggests that E. cyathigerum is amongst the most sensitive freshwater organisms tested. NOEC for metamorphosis is less than 10-times greater than the ordinary reported environmental concentrations in freshwater, but is more than 200-times smaller than the greatest concentrations measured after accidental releases.

  17. Exposure to perfluorooctane sulfonic acid (PFOS) adversely affects the life-cycle of the damselfly Enallagma cyathigerum.

    PubMed

    Bots, Jessica; De Bruyn, Luc; Snijkers, Tom; Van den Branden, Bert; Van Gossum, Hans

    2010-03-01

    We evaluated whether life-time exposure to PFOS affects egg development, hatching, larval development, survival, metamorphosis and body mass of Enallagma cyathigerum (Insecta: Odonata). Eggs and larvae were exposed to five concentrations ranging from 0 to 10000 microg/L. Our results show reduced egg hatching success, slower larval development, greater larval mortality, and decreased metamorphosis success with increasing PFOS concentration. PFOS had no effect on egg developmental time and hatching or on mass of adults. Eggs were the least sensitive stage (NOEC=10000 microg/L). Larval NOEC values were 1000 times smaller (10 microg/L). Successful metamorphosis was the most sensitive response trait studied (NOEC<10 microg/L). The NOEC value suggests that E. cyathigerum is amongst the most sensitive freshwater organisms tested. NOEC for metamorphosis is less than 10-times greater than the ordinary reported environmental concentrations in freshwater, but is more than 200-times smaller than the greatest concentrations measured after accidental releases. PMID:19811863

  18. MEASUREMENT OF THYROID HORMONES IN THE RAT SERA CONTAINING PERFLUOROOCTANESULFONATE (PFOS)

    EPA Science Inventory

    Perfluorooctanesulfonate (PFOS), a persistent and bioaccumulative acid, is widely distributed in humans and wildlife. Prior studies with PFOS (rats and monkeys) have observed decreased total and free thyroid hormones (TH) in serum without a rise in thyrotropin (TSH). Measuremen...

  19. Chronic perfluorooctane sulfonate (PFOS) exposure induces hepatic steatosis in zebrafish.

    PubMed

    Cheng, Jiangfei; Lv, Suping; Nie, Shangfei; Liu, Jing; Tong, Shoufang; Kang, Ning; Xiao, Yanyan; Dong, Qiaoxiang; Huang, Changjiang; Yang, Dongren

    2016-07-01

    Perfluorooctane sulfonate (PFOS), one persistent organic pollutant, has been widely detected in the environment, wildlife and human. Currently few studies have documented the effects of chronic PFOS exposure on lipid metabolism, especially in aquatic organisms. The underlying mechanisms of hepatotoxicity induced by chronic PFOS exposure are still largely unknown. The present study defined the effects of chronic exposure to low level of PFOS on lipid metabolism using zebrafish as a model system. Our findings revealed a severe hepatic steatosis in the liver of males treated with 0.5μM PFOS as evidenced by hepatosomatic index, histological assessment and liver lipid profiles. Quantitative PCR assay further indicated that PFOS significantly increase the transcriptional expression of nuclear receptors (nr1h3, rara, rxrgb, nr1l2) and the genes associated with fatty acid oxidation (acox1, acadm, cpt1a). In addition, chronic PFOS exposure significantly decreased liver ATP content and serum level of VLDL/LDL lipoprotein in males. Taken together, these findings suggest that chronic PFOS exposure induces hepatic steatosis in zebrafish via disturbing lipid biosynthesis, fatty acid β-oxidation and excretion of VLDL/LDL lipoprotein, and also demonstrate the validity of using zebrafish as an alternative model for PFOS chronic toxicity screening. PMID:27108203

  20. DEVELOPMENTAL TOXICOGENOMIC STUDIES OF PFOA AND PFOS IN MICE.

    EPA Science Inventory

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are developmentally toxic in rodents. To better understand the mechanism(s) associated with this toxicity, we have conducted transcript profiling in mice. In an initial study, pregnant animals were dosed througho...

  1. Challenges of non-PFOS top antireflective coating material

    NASA Astrophysics Data System (ADS)

    Hsu, Shu-Hao; Vermeir, Inge; Scholze, Matthias; Voigt, Matthias; Gierth, Janine; Mittermeier, Armelle; Mäge, Iris; Voelkel, Lars

    2008-03-01

    Top anti-reflective coating (TARC) material is very useful in decreasing standing waves and minimizing swing amplitude of critical dimensions (CD) because it can reduce the reflectivity of structures by interference. TARC can also help to control resist defects, improve CD uniformity, and solve CD variation issues caused by post exposure bake (PEB) delay. The perfluorooctyl sulfonate (PFOS) or perfluorooctanoic acid (PFOA) are used as a surfactant in actual TARC materials. They can reduce surface tension to improve the coating performance of TARC. However, PFOS and PFOA are restricted for future applications due to environmental concerns and should be omitted from TARC materials. Therefore, material vendors start working hard on Non-PFOS TARC material development. In this paper, the PEB delay behavior with and without TARC was discussed. The effect of PEB delay is not only related to the pattern density, but also strongly related to resist material. According to the testing results, there are still some issues in Non-PFOS TARC materials such as coating performance, material removing, defect control, and film loss etc. Taking these Non-PFOS TARC materials as examples, Non-PFOS TARC-3 could not be dissolved completely in alkaline developer. There are serious embedded defects of Non-PFOS TARC-2 on patterned wafer. Additionally, Non-PFOS TARC-1 shows an acceptable defect level without TARC baking, but it has poor edge coating and more film loss issues. The issue of poor film coating could be solved by coating recipe modification and also by improvements on the material itself made by the material vendor. Therefore, Non-PFOS TARC-1 without TARC baking can be a candidate for a Non-PFOS TARC process because of its acceptable Litho performances and defect density.

  2. CHRONIC ZEBRAFISH PFOS EXPOSURE ALTERS SEX RATIO AND MATERNAL RELATED EFFECTS IN F1 OFFSPRING

    PubMed Central

    Wang, Mingyong; Chen, Jiangfei; Lin, Kuanfei; Chen, Yuanhong; Hu, Wei; Tanguay, Robert L.; Huang, Changjiang; Dong, Qiaoxiang

    2012-01-01

    Perfluorooctanesulfonic acid (PFOS) is an organic contaminant ubiquitous in the environment, wildlife, and humans. Few studies have assessed its chronic toxicity on aquatic organisms. The present study defined the effects of long-term exposure to PFOS on zebrafish development and reproduction. Specifically, zebrafish at 8 h postfertilization (hpf) were exposed to PFOS at 0, 5, 50, and 250 μg/L for five months. Growth suppression was observed in the 250 μg/L PFOS-treated group. The sex ratio was altered, with a significant female dominance in the high-dose PFOS group. Male gonad development was also impaired in a dose-dependent manner by PFOS exposure. Although female fecundity was not impacted, the F1 embryos derived from high-dose exposed females paired with males without PFOS exposure developed severe deformity at early development stages and resulted in 100% larval mortality at 7 d postfertilization (dpf). Perfluorooctanesulfonic acid quantification in embryos indicated that decreased larval survival in F1 offspring was directly correlated to the PFOS body burden, and larval lethality was attributable to maternal transfer of PFOS to the eggs. Lower-dose parental PFOS exposure did not result in decreased F1 survival; however, the offspring displayed hyperactivity of basal swimming speed in a light-to-dark behavior assessment test. These findings demonstrate that chronic exposure to PFOS adversely impacts embryonic growth, reproduction, and subsequent offspring development. Environ. PMID:21671259

  3. Devopmental toxicity of perfluorooctane Sulfonate (PFOS) is not dependent on expression on peroxisome proliferator activated receptor-alpha (PPAR-alpha)in the mouse

    EPA Science Inventory

    Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are members of a family of perfluorinated compounds. Both are environmentally persistent and found in the serum of wildlife and humans. PFOS and PFOA are developmentally toxic in laboratory rodents. Exposure to t...

  4. Study on the biodegradation of perfluorooctanesulfonate (PFOS) and PFOS alternatives

    PubMed Central

    2016-01-01

    Objectives In this study, we investigated the biodegradation features of 4 perfluorooctanesulfonate (PFOS) alternatives developed at Changwon National University compared to those of PFOS. Methods Biodegradation testing was performed with microorganisms cultured in the good laboratory practice laboratory of the Korea Environment Corporation for 28 days following the Organization for Economic Cooperation and Development guidelines for the testing of chemicals (Test No. 301 C). Results While C8F17SO3Na, PFOS sodium salt was not degraded after 28 days, the 4 alternatives were biodegraded at the rates of 20.9% for C15F9H21S2O8Na2, 8.4% for C17F9H 25S2O8Na2, 22.6% for C23F18H28S2O8Na2, and 23.6% for C25F17H32O13S3Na3. Conclusions C25F17H32S3O13Na3, C23F18H28S2O8Na2, and C15F9H21S2O8Na2 were superior to PFOS in terms of biodegradation rates and surface tension, and thus they were considered highly applicable as PFOS alternatives. Environmental toxicity, human toxicity, and economic feasibility of these compounds should be investigated prior to their commercialization. PMID:26987483

  5. Modeling Bioaccumulation as a Potential Route of Riverine Foodweb Exposures to PFOS

    EPA Science Inventory

    Perfluorinated acids are compounds of interest as bioaccumulators; these persistent chemicals have been found in humans and animals throughout the world. Perfluoroctane sulfonate (PFOS) has an especially high bioconcentration factor in fish, due to the stability of PFOS in the e...

  6. Behavior and Fate of PFOA and PFOS in Sandy Aquifer Sediment (journal)

    EPA Science Inventory

    Microcosms were constructed with sediment from beneath a landfill that received waste containing PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate). The microcosms were amended with PFOA and PFOS, and sampled after 91, 210, 343, 463, 574, and 740 days of incubat...

  7. Identification of the source of PFOS and PFOA contamination at a military air base site.

    PubMed

    Arias E, Victor A; Mallavarapu, Megharaj; Naidu, Ravi

    2015-01-01

    Although the use of perfluorooctane sulfonic acid (PFOS)/perfluorooctanoic acid (PFOA)-based aqueous fire-fighting foams (AFFF) has been banned due to their persistence, bioaccumulation and toxicity to biota, PFOS and PFOA are still present at significant levels in the environment due to their past usage. This study investigated the reasons for detection of PFOS and PFOA in an evaporation pond used to collect the wastewater arising from fire-fighting exercises at a military air base despite the replacement of PFOS/PFOA-based foam with no PFOS/PFOA-foam about 6 years ago. Concentrations in the wastewater stored in this pond ranged from 3.6 to 9.7 mg/L for PFOS and between 0.6 and 1.7 mg/L for PFOA. The hypothesis tested in a laboratory study was that PFOS and PFOA have accumulated in the sediments of the pond and can be released into the main body of the water. Concentrations detected in the sediments were 38 and 0.3 mg/g for PFOS and PFOA, respectively. These values exceed the recently reported average global values for sediments (0.2-3.8 ng/g for PFOS and from 0.1 to 0.6 ng/g for PFOA) by a factor of several thousands. PFOS and PFOA distribution coefficients were derived for the organic content of the pond sediment (1.6%). Identification of the source of contamination and knowledge of the partition between soil and aqueous phases are vital first steps in developing a sustainable remediation technology to remove the source from the site. This study clearly suggests that unless the sediment is cleaned of PFOS/PFOA, these chemicals will continue to be detected for a long period in the pond water, with potential adverse impacts on the ecosystem. PMID:25407991

  8. Impact of a perfluorinated organic compound PFOS on the terrestrial pollinator Bombus terrestris (Insecta, Hymenoptera).

    TOXLINE Toxicology Bibliographic Information

    Mommaerts V; Hagenaars A; Meyer J; De Coen W; Swevers L; Mosallanejad H; Smagghe G

    2011-03-01

    Perfluorinated organic chemicals like perfluorooctane sulfonic acid (PFOS) are persistent environmental pollutants that have been measured in a great diversity of wildlife worldwide, especially in the aquatic compartment. However, little information is available on the presence and effects of PFOS in the terrestrial compartment. Therefore, we investigated in this project the risks for effects, bioaccumulation and potential mechanisms of activity of PFOS in the bumblebee Bombus terrestris L. (Hymenoptera: Apidae) that is an important worldwide pollinator in the terrestrial compartment of wildflowers and cultivated crops. The exposure to PFOS occurred orally via the drinking of treated sugar water in a wide range from 1 ?g/l up to 10 mg/l, containing environmentally relevant as well as high concentrations, and this was done with use of microcolonies of B. terrestris in the laboratory. A chronic toxicity assay demonstrated high bumblebee worker mortality (up to 100%) with an LC(50) of 1.01 mg/l (R(2) = 0.98). In addition, PFOS posed strong detrimental reproductive effects, and these concerted with a dramatic reduction in ovarian size. HPLC-MS demonstrated a bioaccumulation factor of 27.9 for PFOS in bumblebee workers fed with sugar water containing 100 ?g/l PFOS during 5 weeks (2184 365 ng/g BW). Finally, potential mechanisms of activity were investigated to explain the significant impact of PFOS on survival and reproduction capacity of B. terrestris. Exposure of bumblebee workers to PFOS resulted in a significant decrease in mitochondrial electron transport activity (p = 0.035) and lipid amounts (p = 0.019), while the respective p-values were 0.58 and 0.12 for protein and glucose amounts. Hence, addition of PFOS to ecdysteroid responsive Drosophila melanogaster S2 cells resulted in a strong antagonistic action on the EcR-b.act.luc reporter construct, demonstrating that PFOS may exert its effects partially through an endocrine disrupting action via the insect molting hormone or ecdysteroid receptor.

  9. Effect of sound frequency and initial concentration on the sonochemical degradation of perfluorooctane sulfonate (PFOS).

    PubMed

    Rodriguez-Freire, Lucia; Balachandran, Rajesh; Sierra-Alvarez, Reyes; Keswani, Manish

    2015-12-30

    Perfluoooctanesulfonic acid (PFOS) is a perfluorinated compound (PFC) highly resistant to conventional advance oxidation processes, which was widely used in industrial activities due to its surfactant nature, olephobic-hydrophobic properties, and chemical inertness. Sonochemical treatment has been suggested as an effective approach to treat aqueous solutions containing minimal levels of PFCs. This study investigates PFOS sonochemical degradation and its dependency on the initial concentration (10-460 μM), and the applied sound frequency (25 and 500 kHz, and 1 MHz). PFOS was degraded by sonochemical treatment at concentrations as high as 460 μM, as demonstrated by fluoride release and total organic content data. PFOS degradation rate was higher at megasonic frequencies (1MHz) compared to ultrasonic frequencies (25-500 kHz). PFOS degradation was controlled by saturation kinetics as indicated by an increase in PFOS degradation rate with increasing PFOS concentration until a maximum, after which the degradation rate was independent of the concentration. The saturation conditions were dependent on the sound frequency, and they were reached at a lower concentration under 1 MHz (100 μM) compared to the 500 kHz frequency (>460 μM). Overall, the results of this study demonstrate that high PFOS concentration can be effectively sonochemically treated using megasonic frequencies. PMID:26282221

  10. Gene expression profiling in the lung and liver of PFOS-exposed mouse fetuses

    EPA Science Inventory

    The industrial surfactants perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are persistent environmental contaminants commonly found in the tissues of humans and wildlife. Both compounds are agonists of peroxisome proliferator-activated receptor α (PPARα) and...

  11. Gene expression profiling in the lung and liver of PFOS-exposed mouse fetuses

    EPA Science Inventory

    The industrial surfactants perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are persistent environmental contaminants commonly found in the tissues of humans and wildlife. Both compounds are agonists of peroxisome proliferator-activated receptor ? (PPAR?) and...

  12. Temporal trends of PFOS and PFOA in guillemot eggs from the Baltic Sea, 1968--2003.

    PubMed

    Holmström, Katrin E; Järnberg, Ulf; Bignert, Anders

    2005-01-01

    Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) have recently been identified as ubiquitous environmental contaminants. Although they have been produced for 50 years, little is known about when they first appeared in the environment and how their concentrations have changed over time, particularly in response to the phase-out of PFOS, which began in 2000. In this study temporal trends in the concentrations of PFOS and PFOA in the Baltic Sea marine environmentwere measured using archived guillemot eggs. Samples collected from Stora Karlsö (Sweden) between 1968 and 2003 were received from an environmental specimen bank and concentrations of PFOS and PFOA were analyzed using HPLC coupled to ESI-MS/MS. PFOA was not detected in any of the samples (LOD 3 ng/g), but there was an almost 30-fold increase in PFOS concentrations in the guillemot eggs during the time period, from 25 ng/g in 1968 to 614 ng/g in 2003 (wet weight). Regression analysis indicated a significant trend, increasing on average between 7 and 11% per year. A sharp peak in PFOS concentrations was observed in 1997 followed by decreasing levels up to 2002, but this cannot be linked to the PFOS phase-out, which occurred at the end of this period. PMID:15667078

  13. Perfluorooctane sulfonate (PFOS) exposure could modify the dopaminergic system in several limbic brain regions.

    PubMed

    Salgado, R; López-Doval, S; Pereiro, N; Lafuente, A

    2016-01-01

    Perfluorooctane sulfonate (PFOS) is the most representative of a rising class of persistent organic pollutants perfluorochemicals. In the present study, its neurotoxicity was examined using adult male rats orally treated with 0.5; 1.0; 3.0 and 6.0 mg of PFOS/kg/day for 28 days. At the end of the treatment, the dopamine concentration and its metabolism expressed like the ratio 3,4-dihydroxyphenylacetic acid (DOPAC)/dopamine and homovanillic acid (HVA)/dopamine were measured in the amygdala, prefrontal cortex and hippocampus. Gene and protein expression of the dopamine receptors D1 and D2 were also determined in these limbic areas. The obtained results suggest that: (1) PFOS can alter the dopamine system by modifying its neuronal activity and/or its D1 and D2 receptors in the studied brain regions; (2) the dopamine concentration and metabolism seem to be more sensitive against PFOS toxicity in the hippocampus than in the other analyzed brain areas; (3) the inhibited gene and protein expression of the D1 receptors induced by PFOS in the amygdala could be related to several changes in the HPA axis activity, and lastly; (4) the observed alterations on the dopamine system induced by PFOS could be a possible neurotoxicity mechanism of PFOS, leading to many neurological diseases. PMID:26529483

  14. Levels of perfluorinated compounds in food and dietary intake of PFOS and PFOA in the Netherlands.

    PubMed

    Noorlander, Cornelle W; van Leeuwen, Stefan P J; Te Biesebeek, Jan Dirk; Mengelers, Marcel J B; Zeilmaker, Marco J

    2011-07-13

    This study presents concentrations of perfluorinated compounds in food and the dietary intake of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in The Netherlands. The concentrations of perfluorinated compounds in food were analyzed in pooled samples of foodstuffs randomly purchased in several Dutch retail store chains with nation-wide coverage. The concentrations analyzed for PFOS and PFOA were used to assess the exposure to these compounds in The Netherlands. As concentrations in drinking water in The Netherlands were missing for these compounds, conservative default concentrations of 7 pg/g for PFOS and 9 pg/g for PFOA, as reported by European Food Safety Authority, were used in the exposure assessment. In food, 6 out of 14 analyzed perfluorinated compounds could be quantified in the majority of the food categories (perfluoroheptanoic acid (PFHpA), PFOA, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoro-1-hexanesulfonate (PFHxS), and PFOS). The highest concentration of the sum of these six compounds was found in crustaceans (825 pg/g product, PFOS: 582 pg/g product) and in lean fish (481 pg/g product, PFOS: 308 pg/g product). Lower concentrations were found in beef, fatty fish, flour, butter, eggs, and cheese (concentrations between 20 and 100 pg/g product; PFOS, 29-82 pg/g product) and milk, pork, bakery products, chicken, vegetable, and industrial oils (concentration lower than 10 pg/g product; PFOS not detected). The median long-term intake for PFOS was 0.3 ng/kg bw/day and for PFOA 0.2 ng/kg bw/day. The corresponding high level intakes (99th percentile) were 0.6 and 0.5 ng/kg bw/day, respectively. These intakes were well below the tolerable daily intake values of both compounds (PFOS, 150 ng/kg bw/day; PFOA, 1500 ng/kg bw/day). The intake calculations quantified the contribution of drinking water to the PFOS and PFOA intake in The Netherlands. Important contributors of PFOA intake were vegetables/fruit and flour. Milk, beef, and lean fish were important contributors of PFOS intake. PMID:21591675

  15. The impact of PFOS on health in the general population: a review.

    PubMed

    Saikat, Sohel; Kreis, Irene; Davies, Bethan; Bridgman, Stephen; Kamanyire, Robie

    2013-02-01

    Perfluorooctane sulphonate (PFOS) is a persistent organic pollutant that is toxic, bioaccumulative and undergoes wide transportation across all environmental media. It has been widely detected in environmental samples but there is limited information about the health effects on humans from environmental exposure. This paper presents the findings of a review of the literature on the impact of PFOS on the health of the general population. Fifteen relevant epidemiological studies were identified that looked at the association between human PFOS exposure and a range of health related outcomes. Small but statistically significant associations have been reported with PFOS and total cholesterol, glucose metabolism, body mass index (BMI), thyroid function, infertility, breast feeding, uric acid and attention deficit/hyperactivity disorder (ADHD). The true significance of these findings is uncertain due to the inconsistencies in some of the study results and the limitations of the literature. The majority of studies were cross-sectional and considered surrogate markers of health (e.g. cholesterol levels). The available literature is also limited in ascertaining the link between PFOS concentrations in the environment, exposure pathways and health effects. We conclude that the current evidence is inconclusive and further large-scale prospective cohort studies would be useful to assess the association between environmental exposure to PFOS, appropriate biomarkers (e.g. serum levels of PFOS) and health outcomes. PMID:25208696

  16. Sonochemical degradation of peerfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in landfill groundwater: environmental matrix effects.

    PubMed

    Cheng, Jie; Vecitis, Chad D; Park, Hyunwoong; Mader, Brian T; Hoffmann, Michael R

    2008-11-01

    Perfluorinated chemicals such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are environmentally persistent and recalcitrant to most conventional chemical and microbial treatment technologies. In this paper, we show that sonolysis is able to decompose PFOS and PFOA present in groundwater beneath a landfill. However, the pseudo first-order rate constant for the sonochemical degradation in the landfill groundwater is reduced by 61 and 56% relative to MilliQ water for PFOS and PFOA, respectively, primarily due to the presence of other organic constituents. In this study, we evaluate the effect of various organic compounds on the sonochemical decomposition rates of PFOS and PFOA. Organic components in environmental matrices may reduce the sonochemical degradation rates of PFOS and PFOA by competitive adsorption onto the bubble-water interface or by lowering the average interfacial temperatures during transient bubble collapse events. The effect of individual organic compounds depends on the Langmuir adsorption constant the Henry's law constant the specific heat capacity, and the overall endothermic heat of dissociation. Volatile organic compounds (VOCs) are identified as the primary cause of the sonochemical rate reduction for PFOS and PFOA in landfill groundwater, whereas the effect of dissolved natural organic matter (DOM) is not significant Finally, a combined process of ozonation and sonolysis is shown to substantially recover the rate loss for PFOS and PFOA in landfill groundwater. PMID:19031902

  17. Perfluorooctane sulfonate (PFOS) depletion in beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perfluorooctane sulfonate (PFOS) is an industrial chemical that is used as a surfactant in several manufactured consumer products but is also a breakdown product from other chemical surfactants. As a result of its extensive use, PFOS is ubiquitous in the environment and is often detected in biosoli...

  18. Behaviour of damselfly larvae (Enallagma cyathigerum) (Insecta, Odonata) after long-term exposure to PFOS.

    PubMed

    Van Gossum, Hans; Bots, Jessica; Snijkers, Tom; Meyer, Johan; Van Wassenbergh, Sam; De Coen, Wim; De Bruyn, Luc

    2009-04-01

    Perfluorooctane sulfonic acid (PFOS) is a persistent and ubiquitous environmental contaminant that has been detected in organisms worldwide. Here, we evaluate whether long-term (1 and 4 months) exposure to PFOS contamination affects the behavioural performance of freshwater larvae of the damselfly Enallagma cyathigerum (Insecta: Odonata). Our results show reduced behavioural performance with increasing PFOS concentration. In 1 month exposed larvae, no observed effect concentrations (NOECs) were 100 microg/L for general activity. In 4 months exposed larvae, NOECs were 10 microg/L, for each behavioural trait, except swimming acceleration of male larvae where the NOEC was 100 microg/L. When faced with PFOS concentrations above the NOEC, E. cyathigerum larvae were less active, less capable to escape a simulated predator attack and less efficient in foraging. Together, our results show that damselfly larvae suffer reduced survival-related behavioural performance. PMID:19110351

  19. Enantiospecific perfluorooctane sulfonate (PFOS) analysis reveals evidence for the source contribution of PFOS-precursors to the Lake Ontario foodweb.

    PubMed

    Asher, Brian J; Wang, Yuan; De Silva, Amila O; Backus, Sean; Muir, Derek C G; Wong, Charles S; Martin, Jonathan W

    2012-07-17

    Exposure to perfluorooctane sulfonate (PFOS) may arise directly, from emission and exposure to PFOS itself, or indirectly via the environmental release and degradation of PFOS-precursors. Human serum enantiomer fractions (EFs) of 1m-PFOS have been shown to be nonracemic, suggesting that PFOS-precursors are a significant source of PFOS in humans, but little is known about the importance of PFOS-precursors in ecosystems. In the current work, concentrations of PFOS, perfluorooctane sulfonamide (PFOSA), PFOS isomer profiles, and EFs of 1m-PFOS were determined in Lake Ontario water, sediment, fishes and invertebrates. Concentrations of PFOS and PFOSA were highest in slimy sculpin and Diporeia, and concentrations of the two compounds were often correlated. 1m-PFOS was racemic in sediment, water, sculpin and rainbow smelt, but nonracemic in the top predator, lake trout, and all invertebrate species. Furthermore, EFs were correlated with the relative concentrations of PFOS and PFOSA in invertebrates. Overall, these empirical observations with a new analytical tool confirm previous suggestions that PFOS-precursors contribute to PFOS in the food web, likely via sediment. Implications are that future PFOS exposures in this ecosystem will be influenced by an in situ source, and that the apparent environmental behavior of PFOS (e.g., bioaccumulation potential) can be confounded by precursors. PMID:22676298

  20. PFOS and PFC releases and associated pollution from a PFC production plant in Minnesota (USA).

    PubMed

    Oliaei, Fardin; Kriens, Don; Weber, Roland; Watson, Alan

    2013-04-01

    Perfluorooctane sulfonate (PFOS) and PFOS-related substances have been listed as persistent organic pollutants in the Stockholm Convention. From August 2012, Parties to the Convention needed to address the use, storage, and disposal of PFOS-including production sites and sites where PFOS wastes have been deposited-in their national implementation plans. The paper describes the pollution in Minnesota (USA) caused by the 3M Company at one of the largest per/polyfluorinated chemical (PFC) production facilities. From early 1950s until the end of 2002, when 3M terminated PFOS and perfluorooctanoic acid (PFOA) production, PFOS, PFOA, and other PFC production wastes were disposed around the plant and in local disposal sites. Discharges from the site and releases from deposits caused widespread contamination of ground and surface waters including local drinking water wells. Fish in the river downstream were contaminated with PFOS to levels that led to fish consumption advisories. Human exposures resulted from ingesting contaminated drinking water, requiring installation of water treatment facilities and alternate water supplies. The critical evaluation of the assessments done revealed a range of gaps in particular of human exposure where relevant exposure pathways including the entire exposure via food have not been taken into consideration. Currently, the exposure assessment of vulnerable groups such as children or Hmong minorities is inadequate and needs to be improved/validated by epidemiological studies. The assessment methodology described for this site may serve-with highlighted improvements-as a model for assessment of other PFOS/PFC production sites in the Stockholm Convention implementation. PMID:23128989

  1. Hazard quotient profiles used as a risk assessment tool for PFOS and PFOA serum levels in three distinctive European populations.

    PubMed

    Ludwicki, Jan K; Góralczyk, Katarzyna; Struciński, Paweł; Wojtyniak, Bogdan; Rabczenko, Daniel; Toft, Gunnar; Lindh, Christian H; Jönsson, Bo A G; Lenters, Virissa; Heederik, Dick; Czaja, Katarzyna; Hernik, Agnieszka; Pedersen, Henning S; Zvyezday, Valentyna; Bonde, Jens Peter

    2015-01-01

    Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) blood levels are commonly used as biomarkers of human environmental exposure to these compounds. Many biomonitoring studies indicate 100% detection for PFOS and PFOA thus justifying a concern of possible risk for the most exposed individuals. This study addresses the predictive value of hazard quotients (HQs) calculated on the basis of serum PFOS and PFOA in male and female populations of reproductive age in Greenland, Poland and Ukraine. Overall, 2026 results of PFOS and PFOA serum concentrations (589 males, 1437 females) were obtained from the INUENDO database. HQs were calculated from the actual biomonitoring results and literature-based animal data linking toxicological outcomes and critical PFOS/PFOA serum levels. HQs for serum PFOS were calculated based on Points of Departure (PoD) at 13μgmL(-1) (cynomolgus monkeys, 183days, changes in THS and T3) and for PFOA at 7.1μgmL(-1) serum (male rats, 90days, hepatocellular necrosis, increased liver weight). Uncertainty factors were applied to reflect interspecies differences and human variability. Serum HQs were expressed as a ratio relative to the point of departure for each PFOS and PFOA. Only in the three cases of males in Greenland were there serum PFOS levels showing HQ values exceeding 1, so indicating that such serum levels may be of concern. The mean serum concentration of PFOS was significantly higher in male than in female populations. Despite significant differences between HQ profiles for PFOS and PFOA in donors from Greenland, Poland and Ukraine, the concentrations of these perfluoroalkylated compounds do not indicate a cause for concern, except for the three aforementioned cases from Greenland. This study demonstrates that the HQ approach can help to interpret human biomonitoring data and thus serve as a valuable tool in further risk assessment priority settings and may also be used as a basis for taking decisions in risk management. PMID:25454227

  2. Development of PBPK Models for PFOA and PFOS for Human Pregnancy and Lactation Life Stages

    PubMed Central

    Loccisano, Anne E.; Longnecker, Matthew P.; Campbell, Jerry L.; Andersen, Melvin E.; Clewell, Harvey J.

    2012-01-01

    Perfluoroalkyl acid carboxylates and sulfonates (PFAAs) have many consumer and industrial applications. Developmental toxicity studies in animals have raised concern about potential reproductive/developmental effects of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS); however, in humans conflicting results have been reported for associations between maternal PFAA levels and these outcomes. Risk assessments and interpretation of available human data during gestation and lactation are hindered due to lack of a framework for understanding and estimating maternal, fetal, and neonatal pharmacokinetics (PK). Physiologically-based pharmacokinetic (PBPK) models were developed for PFOA & PFOS for the gestation and lactation life stages in humans to understand how the physiological changes associated with development affect pharmacokinetics of these compounds in the mother, fetus, and infant. These models were derived from PBPK models for PFOA/PFOS that were previously developed for adult humans and rats during gestation and lactation and from existing human pregnancy and lactation models developed for other chemicals. The models simulated PFOA and PFOS concentrations in fetal, infant, and maternal plasma and milk, were compared to available data in humans, and also used to estimate maternal exposure. The models reported here identified several research needs, which include: 1) the identification of transporters involved in renal resorption to explain the multi-year half-lives of these compounds in humans, 2) factors affecting clearance of PFOA/PFOS during gestation and lactation, and 3) data to estimate clearance of PFOA/PFOS in infants. These models may help address concerns regarding possible adverse health effects due to PFOA/PFOS exposure in the fetus and infant and may be useful in comparing pharmacokinetics across life stages. PMID:23151209

  3. The study of interaction between PFOA/PFOS and uracil by topology quality and spectroscopic analysis

    NASA Astrophysics Data System (ADS)

    Xu, Hui-Ying; Zhu, Jian-Qing; Wang, Wei; Xu, Xiao-Lu; Lu, Yin

    2014-02-01

    It has been established that perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) can be considered as emerging persistent organic pollutants. In recent years, there was increasing distribution of PFOA/PFOS in environmental systems, and accumulation and toxic effects of PFOA/PFOS in human body. In this paper, quantum chemistry methods were employed to study the interaction between perfluorinated organic pollutants and base (uracil). The results showed that there were four stable binding modes between the two perfluorinated compounds with uracil, especially the second mode which caused the most detrimental physiological functional response. NBO analysis showed that reactive hydrogen in the two perfluorinated compounds had the greatest effect on the hydrogen bond. The nature of the hydrogen bond formed between the two perfluorinated compounds and base was investigated using the AIM theory. The changes of spectroscopic properties in complexes were analyzed by IR and NMR spectra.

  4. Connexin 43 mediates PFOS-induced apoptosis in astrocytes.

    PubMed

    Dong, Li; Yang, Xiaoyan; Gu, Wen; Zhao, Kangfeng; Ge, Huizheng; Zhou, Jianjun; Bai, Xuetao

    2015-08-01

    Perfluorooctane sulfonate (PFOS) is a man-made environmental pollutant that is toxic to mammals. However, the neurotoxic effects of PFOS remain largely unexplored. In this study, we determined the role of an astrocyte specific gap junction protein, connexin 43 (Cx43), in PFOS-induced apoptosis. The rate of astrocyte apoptosis was higher in cortex astrocytes after PFOS treatment. These astrocytes also showed up-regulated expression of Cx43 and higher levels of cleaved caspase-3. Elevated ROS accumulation and decreased ??m also confirmed the presence of PFOS-induced apoptosis. However, the exposure of astrocytes to PFOS together with carbenoxolone (CBX) significantly reduced both Cx43 and cleaved caspase-3 levels. These results indicate that Cx43 plays a proapoptotic role in PFOS-induced apoptosis in cortex astrocyte cells. PMID:25770831

  5. Developmental toxicity of PFOS and PFOA in great cormorant (Phalacrocorax carbo sinensis), herring gull (Larus argentatus) and chicken (Gallus gallus domesticus).

    PubMed

    Nordén, Marcus; Berger, Urs; Engwall, Magnus

    2016-06-01

    Perfluoroalkyl acids (PFAAs) are found globally in environmental samples and have been studied in various species. In this study, we compare the sensitivity of three avian species to the toxic effects of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA). Eggs of great cormorant (Phalacrocorax carbo sinensis), herring gull (Larus argentatus) and the domestic White Leghorn chicken (Gallus gallus domesticus) were exposed in ovo by injection into the air sac. Effects on embryo survival were observed following exposure to PFOS and PFOA in chicken and herring gull. Chicken was found to be the most sensitive species with 50 % reduced embryo survival at 8.5 μg/g egg for PFOS and 2.5 μg/g egg for PFOA. Cormorant was shown to be the least sensitive species. The difference in sensitivity between chicken and herring gull was a factor of 2.7 for PFOS and 3.5 for PFOA. Between chicken and great cormorant, the sensitivity difference was 2.6 for PFOS and 8.2 for PFOA. Effects on embryo survival were seen at egg injection doses of PFOS close to levels found in environmental samples from wild birds, indicating that PFOS could be having effects in highly exposed populations of birds. This study also shows that there are differences in species sensitivity to PFOS and PFOA that should be taken into consideration in avian wildlife risk assessment. PMID:26895726

  6. PERFLUOROOCTANE SULFONATE (PFOS) DISRUPTS THE THYROID STATUS IN LABORATORY RODENTS

    EPA Science Inventory

    PERFLUOROOCTANE SULFONATE (PFOS) DISRUPTS THE THYROID STATUS IN LABORATORY RODENTS. C. Lau, J.R. Thibodeaux, R.G. Hanson, B.E. Gray and J.M. Rogers. Reprod. Tox. Div. NHEERL, US EPA, Research Triangle Park, NC.

    PFOS is an environmental contaminant ubiquitously found in h...

  7. Absorption and distribution of perfluorooctane sulfonate (PFOS) in beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perfluorooctane sulfonate (PFOS) is an industrial chemical that is found in biosolids, and the application of these biosolids to pastures has raised concerns about human exposure through the accumulation of PFOS in edible tissues of these animals. The United States Department of Agriculture (USDA) h...

  8. Does perfluorooctane sulfonate (PFOS) act as chemosensitizer in zebrafish embryos?

    PubMed

    Keiter, Susanne; Burkhardt-Medicke, Kathleen; Wellner, Peggy; Kais, Britta; Färber, Harald; Skutlarek, Dirk; Engwall, Magnus; Braunbeck, Thomas; Keiter, Steffen H; Luckenbach, Till

    2016-04-01

    Earlier studies have shown that perfluorooctane sulfonate (PFOS) increases the toxicity of other chemicals by enhancing their uptake by cells and tissues. The present study aimed at testing whether the underlying mechanism of enhanced uptake of chemicals by zebrafish (Danio rerio) embryos in the presence of PFOS is by interference of this compound with the cellular efflux transporter Abcb4. Modifications of uptake/clearance and toxicity of two Abcb4 substrates, the fluorescent dye rhodamine B (RhB) and vinblastine, by PFOS were evaluated using 24 and 48h post-fertilization (hpf) embryos. Upon 90min exposure of 24hpf embryos to 1μM RhB and different PFOS concentrations (3-300μM) accumulation of RhB in zebrafish was increased by up to 11.9-fold compared to controls, whereas RhB increases in verapamil treatments were 1.7-fold. Co-administration of PFOS and vinblastine in exposures from 0 to 48hpf resulted in higher vinblastine-caused mortalities in zebrafish embryos indicating increased uptake of this compound. Interference of PFOS with zebrafish Abcb4 activity was further studied using recombinant protein obtained with the baculovirus expression system. PFOS lead to a concentration-dependent decrease of the verapamil-stimulated Abcb4 ATPase activity; at higher PFOS concentrations (250, 500μM), also the basal ATPase activity was lowered indicating PFOS to be an Abcb4 inhibitor. In exposures of 48hpf embryos to a very high RhB concentration (200μM), accumulation of RhB in embryo tissue and adsorption to the chorion were increased in the presence of 50 or 100μM PFOS. In conclusion, the results indicate that PFOS acts as inhibitor of zebrafish Abcb4; however, the exceptionally large PFOS-caused effect amplitude of RhB accumulation in the 1μM RhB experiments and the clear PFOS effects in the experiments with 200μM RhB suggest that an additional mechanism appears to be responsible for the potential of PFOS to enhance uptake of Abcb4 substrates. PMID:26803730

  9. Elevated levels of PFOS and PFHxS in firefighters exposed to aqueous film forming foam (AFFF).

    PubMed

    Rotander, Anna; Toms, Leisa-Maree L; Aylward, Lesa; Kay, Margaret; Mueller, Jochen F

    2015-09-01

    Exposure to aqueous film forming foam (AFFF) was evaluated in 149 firefighters working at AFFF training facilities in Australia by analysis of PFOS and related compounds in serum. A questionnaire was designed to capture information about basic demographic factors, lifestyle factors and potential occupational exposure (such as work history and self-reported skin contact with foam). The results showed that a number of factors were associated with PFAA serum concentrations. Blood donation was found to be linked to low PFAA levels, and the concentrations of PFOS and PFHxS were found to be positively associated with years of jobs with AFFF contact. The highest levels of PFOS and PFHxS were one order of magnitude higher compared to the general population in Australia and Canada. Study participants who had worked ten years or less had levels of PFOS that were similar to or only slightly above those of the general population. This coincides with the phase out of 3M AFFF from all training facilities in 2003, and suggests that the exposures to PFOS and PFHxS in AFFF have declined in recent years. Self-reporting of skin contact and frequency of contact were used as an index of exposure. Using this index, there was no relationship between PFOS levels and skin exposure. This index of exposure is limited as it relies on self-report and it only considers skin exposure to AFFF, and does not capture other routes of potential exposure. Possible associations between serum PFAA concentrations and five biochemical outcomes were assessed. The outcomes were serum cholesterol, triglycerides, high-density lipoproteins, low density lipoproteins, and uric acid. No statistical associations between any of these endpoints and serum PFAA concentrations were observed. PMID:26001497

  10. Perfluorinated chemicals, PFOS and PFOA, enhance the estrogenic effects of 17β-estradiol in T47D human breast cancer cells.

    PubMed

    Sonthithai, Pacharapan; Suriyo, Tawit; Thiantanawat, Apinya; Watcharasit, Piyajit; Ruchirawat, Mathuros; Satayavivad, Jutamaad

    2016-06-01

    Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the two most popular surfactants among perfluorinated compounds (PFCs), with a wide range of uses. Growing evidence suggests that PFCs have the potential to interfere with estrogen homeostasis, posing a risk of endocrine-disrupting effects. This in vitro study aimed to investigate the estrogenic effect of these compounds on T47D hormone-dependent breast cancer cells. PFOS and PFOA (10(-12) to 10(-4)  M) were not able to induce estrogen response element (ERE) activation in the ERE luciferase reporter assay. The ERE activation was induced when the cells were co-incubated with PFOS (10(-10) to 10(-7)  M) or PFOA (10(-9) to 10(-7)  M) and 1 nM of 17β-estradiol (E2). PFOS and PFOA did not modulate the expression of estrogen-responsive genes, including progesterone (PR) and trefoil factor (pS2), but these compounds enhanced the effect of E2-induced pS2 gene expression. Neither PFOS nor PFOA affected T47D cell viability at any of the tested concentrations. In contrast, co-exposure with PFOS or PFOA and E2 resulted in an increase of E2-induced cell viability, but no effect was found with 10 ng ml(-1) EGF co-exposure. Both compounds also intensified E2-dependent growth in the proliferation assay. ERK1/2 phosphorylation was increased by co-exposure with PFOS or PFOA and E2, but not with EGF. Collectively, this study shows that PFOS and PFOA did not possess estrogenic activity, but they enhanced the effects of E2 on estrogen-responsive gene expression, ERK1/2 activation and the growth of the hormone-deprived T47D cells. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26234195

  11. Contribution to the evaluation of reference values for PFOA and PFOS in plasma of children and adults from Germany.

    PubMed

    Wilhelm, Michael; Angerer, Jürgen; Fromme, Hermann; Hölzer, Jürgen

    2009-01-01

    Perfluorinated compounds (PFC) are a large group of chemicals produced for several decades and widely used for many industrial and consumer applications. Human Biomonitoring studies reveal a background exposure of the general population to perfluorooctanoic acid (PFOA) and pefluorooctane sulfonate (PFOS) in many parts of the world. Reference values for PFOS and PFOA in the German population are currently not available. However, the data of three PFC human biomonitoring studies are taken as basis for deriving a preliminary reference value. The first two studies were performed in southern Germany with 105 (sampling period 2003-2004) and 356 adults (sampling period 2005). The third study was performed in North Rhine-Westphalia (sampling period October and November 2006) in connection with the high PFOA contamination of drinking water in the Sauerland region. Non PFOA exposed control groups comprised of 80 children and 153 females from Siegen and 103 men from Brilon. The whole study which could be taken as a basis for PFOS reference considerations comprised of 170 children, 317 females and 204 men. Though the studies are not representative for the German population, they provide at present the best available data basis for deriving reference values. The 95th percentile values of the studies were used and the following preliminary reference values are recommended: PFOA, 10microg/l for all groups; for PFOS 10microg/l for children at school beginner age, 15microg/l for adult females and 25microg/l for adult males. PMID:18162439

  12. Prenatal exposure to PFOS or PFOA alters motor function in mice in a sex-related manner.

    PubMed

    Onishchenko, Natalia; Fischer, Celia; Wan Ibrahim, Wan Norhamidah; Negri, Sara; Spulber, Stefan; Cottica, Danilo; Ceccatelli, Sandra

    2011-04-01

    Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are organic surfactants widely used in various industrial and consumer applications. Due to their chemical properties, these perfluorinated compounds (PFCs) have also become persistent contaminants. The risk of possible intrauterine and lactational exposure to these chemicals poses a significant health concern for potential developmental effects. In the present study we have found that dietary exposure of mice to 0.3 mg/kg of PFOS or PFOA throughout pregnancy results in different distribution pattern in the offspring brain and liver. In particular, exposure to PFOS led to four times higher accumulation of the chemical in the brains of newborn mice than PFOA. We have used a battery of behavioral tests to evaluate motor function, circadian activity, and emotion-related behavior in the exposed offspring. Exposure to PFOS resulted in decreased locomotion in a novel environment and reduced muscle strength only in male offspring. Prenatal exposure to PFOA was associated with changes in exploratory behavior in male and female offspring, as well as with increased global activity in males in their home cage. The neurobehavioral outcome of prenatal exposure to PFCs in mice is characterized by mild alterations in motor function and it appears to be sex-related. PMID:20512442

  13. Estimating emissions of PFOS and PFOA to the Danube River catchment and evaluating them using a catchment-scale chemical transport and fate model.

    PubMed

    Lindim, C; Cousins, I T; vanGils, J

    2015-12-01

    Novel approaches for estimating the emissions of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) to surface waters are explored. The Danube River catchment is used to investigate emissions contributing to riverine loads of PFOS and PFOA and to verify the accuracy of estimates using a catchment-scale dynamic fugacity-based chemical transport and fate model (STREAM-EU; Spatially and Temporally Resolved Exposure Assessment Model for European basins). Model accuracy evaluation performed by comparing STREAM-EU predicted concentrations and monitoring data for the Danube and its tributaries shows that the best estimates for PFOS and PFOA emissions in the Danube region are obtained by considering the combined contributions of human population, wealth (based on local gross domestic product (GDP)) and wastewater treatment. Human population alone cannot explain the levels of PFOS and PFOA found in the Danube catchment waters. Introducing wealth distribution information in the form of local GDPs improves emission estimates markedly, likely by better representing emissions resulting from consumer trends, industrial and commercial sources. For compounds such as PFOS and PFOA, whose main sink and transport media is the aquatic compartment, a major source to freshwater are wastewater treatment plants. Introducing wastewater treatment information in the emission estimations also further improves emission estimates. PMID:26367703

  14. Pathways and factors for food safety and food security at PFOS contaminated sites within a problem based learning approach.

    PubMed

    Brambilla, Gianfranco; D'Hollander, Wendy; Oliaei, Fardin; Stahl, Thorsten; Weber, Roland

    2015-06-01

    Perfluorooctanesulfonic acid (PFOS) and related substances have been listed in Annex B of the Stockholm Convention. The implementation requires inventories of use, stockpiles, and environmental contamination including contaminated sites and measures for (risk) reduction and phase out. In most countries monitoring capacity is not available and therefore other approaches for assessment of contaminated sites are needed. Available informations about PFOS contamination in hot spot areas and its bio-accumulation in the food webs have been merged to build up a worst-case scenario We model PFOS transfer from 1 to 100ngL(-1) range in water to extensive and free-range food producing animals, also via the spread of contaminated sludges on agriculture soils. The modeling indicates that forages represented 78% of the exposure in ruminants, while soil accounted for >80% in outdoor poultry/eggs and pigs. From the carry-over rates derived from literature, in pork liver, egg, and feral fish computed concentration falls at 101, 28 and 2.7ngg(-1), respectively, under the 1ngL(-1) PFOS scenario. Assuming a major consumption of food produced from a contaminated area, advisories on egg and fish, supported by good agriculture/farming practices could abate 75% of the human food intake. Such advisories would allow people to become resilient in a PFOS contaminated area through an empowerment of the food choices, bringing the alimentary exposure toward the current Tolerable Daily Intake (TDI) of 150ngkg(-1)bodyweightd(-1) proposed by the European Food Safety Authority (EFSA). PMID:25439130

  15. EFFECTS OF PRENATAL PERFLUOROOCTANE SULFONATE (PFOS) EXPOSURE ON LUNG MATURATION IN THE PERINATAL RAT

    EPA Science Inventory

    Background: Perfluorooctane sulfonate (PFOS), found widely in wildlife and humans, is environmentally and metabolically stable. Environmental PFOS may be from its use as a surfactant, hydrolysis of perfluorooctanesulfonyl fluoride, and degradation of N-alkyl-perfluorooctanesulfon...

  16. TOXICITY AND BIOACCUMULATION OF PFOS IN A PARTIAL LIFE CYCLE TEST WITH THE NORTHERN LEOPARD FROG

    EPA Science Inventory

    A number of recent monitoring studies have demonstrated elevated concentrations of perfluorooctane sulfonate (PFOS) in humans and wildlife throughout the world. Although no longer actively manufactured, the global distribution and relative persistence of PFOS indicates a need to...

  17. PFOS and PFOA in environmental and tap water in China.

    PubMed

    Jin, Yi He; Liu, Wei; Sato, Itaru; Nakayama, Shoji F; Sasaki, Kazuaki; Saito, Norimitsu; Tsuda, Shuji

    2009-10-01

    There is a great concern about global contamination with persistent fluoroorganic compounds including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), however, few data are available on the environmental levels of these chemicals in China. In the present study, therefore, environmental or tap water samples collected from various regions of China were assayed for PFOS and PFOA by solid phase extraction and liquid chromatography-mass spectrometry technique. Median concentrations (maximum concentration) of PFOS and PFOA in environmental water were 0.4 (2.4) and 0.1 (1.3) ngL(-1) for the remote area (n=13), 4.0 (14.1) and 3.9 (30.8) ngL(-1) for the urban area (n=22), respectively. Systematic survey was also conducted in the Hun River (n=11) and the Yangtze River (n=34). In the Hun River, the median of PFOS concentration was 4.9ngL(-1), while PFOA was below the limit of quantitation (0.1ngL(-1)) at many of the sampling sites. The Yangtze River was moderately contaminated with both chemicals: median concentration was 4.2ngL(-1) for PFOS and 5.4ngL(-1) for PFOA. Remarkably high concentration of PFOA was found at 2 sampling sites of the Yangtze River (110.6 and 297.5ngL(-1)), but the concentration had declined to the average level at the next sampling site in both cases. Many cities provided tap water with low levels of PFOS and PFOA, however, tap water in Guangzhou and Shenzhen exceeded 10ngL(-1) for both chemicals. This study revealed obvious presence of perfluorinated compounds spread out the entire territory of China, and the levels in urban area of China were almost comparable to those in the US, Europe and Japan. PMID:19775722

  18. Absorption and excretion of 14C- perfluorooctanoic acid (PFOA) in beef cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are industrial chemicals that are environmentally persistent. PFOS has recently been classified as a persistent organic pollutant under the Stockholm Convention. Both PFOS and PFOA can be found in biosolids, and the application of c...

  19. EVALUATION OF PERFLUOROOCTANE SULFONATE (PFOS) IN THE RAT BRAIN

    EPA Science Inventory

    This study examined whether there is a differential distribution of PFOS within the brain, and compares adult rats with neonatal rats at an age when formation of the blood-brain barrier is not yet complete (postnatal day 7). Male and female Sprague-Dawley rats (60-70 day old, 4/...

  20. DEVELOPMENTAL TOXICITY OF PFOS AND PFOA

    EPA Science Inventory

    Perfluoroalkyl acids (PFAA) are fully-fluorinated organic chemicals with a carbon backbone (typically varying from C-4 to C-14) and a functional group (usually carboxylic acid or sulfonic acid). These chemicals are man-made, exceptionally stable to metabolic and environmental de...

  1. Toxicity, uptake kinetics and behavior assessment in zebrafish embryos following exposure to perfluorooctanesulphonicacid (PFOS)

    PubMed Central

    Huang, Haihua; Huang, Changjiang; Wang, Lijun; Ye, Xiaowei; Bai, Chenglian; Simonich, Michael T.; Tanguay, Robert L.; Dong, Qiaoxiang

    2014-01-01

    Perfluorooctanesulphonicacid (PFOS), a persistent organic contaminant, has been widely detected in the environment, wildlife and humans, but few studies have assessed its effect on aquatic organisms. The present study evaluated the effect of PFOS on zebrafish embryos. Zebrafish embryos exhibited bent spine and developmental toxicity after exposure to various PFOS concentrations (0.01-16.0 μM) from 6 to 120 hour post-fertilization (hpf). The LC50 at 120 hpf was 4.39 μM and the EC50 at 120 hpf was 2.23 μM. PFOS induced apoptosis at 24 hpf was consistently located in the brain, eye, and tail region of embryos. PFOS elevated the basal rate of swimming after 4 days of exposure, and larvae exposed to PFOS (0.5-8.0μM) for only 1 h at 6 dpf swam faster with increasing PFOS concentration. Larvae exposed to 16.0 μM PFOS for 24 h periods from 1 to 121 hpf showed the highest incidence of malformations in the 97-121 hpf window. Continuous exposure to PFOS from 1 to 121 hpf resulted in a steady accumulation with no evidence of elimination. Our results further the understanding of the health risks of PFOS to aquatic organisms and identify additional research needed on PFOS toxicology. PMID:20171748

  2. Emission Inventory for PFOS in China: Review of Past Methodologies and Suggestions

    PubMed Central

    Lim, Theodore Chao; Wang, Bin; Huang, Jun; Deng, Shubo; Yu, Gang

    2011-01-01

    Perfluorooctane sulfonate (PFOS) is a persistent, bioaccumulative, and toxic chemical that has the potential for long-range transport in the environment. Its use in a wide variety of consumer products and industrial processes makes a detailed characterization of its emissions sources very challenging. These varied emissions sources all contribute to PFOS' existence within nearly all environmental media. Currently, China is the only country documented to still be producing PFOS, though there is no China PFOS emission inventory available. This study reviews the inventory methodologies for PFOS in other countries to suggest a China-specific methodology framework for a PFOS emission inventory. The suggested framework combines unknowns for PFOS-containing product penetration into the Chinese market with product lifecycle assumptions, centralizing these diverse sources into municipal sewage treatment plants. Releases from industrial sources can be quantified separately using another set of emission factors. Industrial sources likely to be relevant to the Chinese environment are identified. PMID:22125449

  3. Influence of the uncertainty in the validation of PBPK models: A case-study for PFOS and PFOA.

    PubMed

    Fàbrega, Francesc; Nadal, Martí; Schuhmacher, Marta; Domingo, José L; Kumar, Vikas

    2016-06-01

    Physiologically-based pharmacokinetic (PBPK) models are mathematical representations of the human body aimed at describing the time course distribution of chemicals in human tissues. Since parameterization of PBPK models is based on empirical estimation and experimental data, simulation results may have high degree of uncertainty. As a consequence, the reliability of model validation is highly affected. In this study, the parametric uncertainty associated with PBPK models developed for perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) were analyzed and the different validation approaches were discussed for a case-study in Tarragona County (NE of Spain). Physicochemical parameters and dietary intake of PFOS and PFOA were estimated from previous investigations performed in Tarragona County. A sensitivity analysis (SA) was performed to understand the degree of influence of input parameters on the final outcomes. The uncertainty of the PBPK models' outcome was assessed by propagating the parametric uncertainty using the Latin Hypercube Sampling (LHS) technique. The elimination constants (Tm and Kt) as well as the Free fraction and the Intake, were the most influential parameters according to the SA results, being up to 83% for PFOS and 99.9% for PFOA. The validation of the PBPK model, which was performed using different approaches, showed clear discrepancies in the visual validation when compared with the statistical analysis. PMID:26993749

  4. Neonatal mortality from in utero exposure to perfluorooctanesulfonate (PFOS) in Sprague-Dawley rats: dose-response, and biochemical and pharamacokinetic parameters.

    PubMed

    Luebker, Deanna J; York, Raymond G; Hansen, Kristen J; Moore, John A; Butenhoff, John L

    2005-11-01

    Perfluorooctanesulfonate (PFOS) is a widely distributed, environmentally persistent acid found at low levels in human, wildlife, and environmental media samples. Neonatal mortality has been observed following PFOS exposure in a two-generation reproduction study in rats and after dosing pregnant rats and mice during gestation. Objectives of the current study were to better define the dose-response curve for neonatal mortality in rat pups born to PFOS-exposed dams and to investigate biochemical and pharmacokinetic parameters potentially related to the etiology of effects observed in neonatal rat pups. In the current study, additional doses of 0.8, 1.0, 1.2, and 2.0 mg/kg/day were included with original doses used in the two-generation study of 0.4 and 1.6 mg/kg/day in order to obtain data in the critical range of the dose-response curve. Biochemical parameters investigated in dams and litters included: (1) serum lipids, glucose, mevalonic acid, and thyroid hormones; (2) milk cholesterol; and (3) liver lipids. Pharmacokinetic parameters investigated included the interrelationship of administered oral dose of PFOS to maternal body burden of PFOS and the transfer of maternal body burden to the fetus in utero and pup during lactation, as these factors may affect neonatal toxicity. Dosing of dams occurred for 6 weeks prior to mating with untreated breeder males, through confirmed mating, gestation, and day four of lactation. Dose levels for the dose-response and etiological investigation were 0.0, 0.4, 0.8, 1.0, 1.2, 1.6, and 2.0 mg/kg/day PFOS. Statistically significant decreases in gestation length were observed in the 0.8 mg/kg and higher dose groups. Decreases in viability through lactation day 5 were observed in the 0.8 mg/kg and higher dose groups, becoming statistically significant in the 1.6 and 2.0 mg/kg dose groups. Reduced neonatal survival did not appear to be the result of reductions in lipids, glucose utilization, or thyroid hormones. The endpoints of gestation length and decreased viability were positively correlated, suggesting that late-stage fetal development may be affected in pups exposed to PFOS in utero and may contribute to the observed mortality. Benchmark dose (BMD) estimates for decreased gestation length, birth weight, pup weight on lactation day 5, pup weight gain through lactation day 5, and viability resulted in values ranging from 0.27 to 0.89mg/kg/day for the lower 95% confidence limit of the BMD5 (BMDL5). Results of analyses for PFOS in biological matrices indicate a linear proportionality of mean serum PFOS concentration to maternal administered dose prior to mating and through the first two trimesters of gestation. However, at 21 days of gestation, mean serum PFOS concentrations were notably reduced from values measured earlier in gestation. Urinary and fecal elimination was low as expected from prior observations in adult rats. Significant transfer of PFOS from dam to fetus in utero was confirmed, and results suggest that dam and corresponding fetal body burdens, as indicated by serum and liver PFOS levels, correlate with neonatal survival. PMID:16129535

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

    SciTech Connect

    Ehresman, David J.; Froehlich, John W.; Olsen, Geary W. . E-mail: gwolsen@mmm.com; Chang, Shu-Ching; Butenhoff, John L.

    2007-02-15

    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.

  6. Chronic PFOS exposure alters the expression of neuronal development-related human homologues in Eisenia fetida.

    PubMed

    Mayilswami, Srinithi; Krishnan, Kannan; Megharaj, Mallavarapu; Naidu, Ravi

    2014-12-01

    PFOS is a toxic, persistent environmental pollutant which is widespread worldwide. PFOS contamination has entered the food chain and is interfering with normal development in man and is neurotoxic, hepatotoxic and tumorigenic. The earthworm, Eisenia fetida is one of the organisms which can help to diagnose soil health and contamination at lower levels in the food chain. Studying the chronic effects of sub-lethal PFOS exposure in such an organism is therefore appropriate. As PFOS bioaccumulates and is not easily biodegraded, it is biomagnified up the food chain. Gene expression studies will give us information to develop biomarkers for early diagnosis of soil contamination, well before this contaminant passes up the food chain. We have carried out mRNA sequencing of control and chronically PFOS exposed E. fetida and reconstructed the transcripts in silico and identified the differentially expressed genes. Our findings suggest that PFOS up/down regulates neurodegenerative-related human homologues and can cause neuronal damage in E. fetida. This information will help to understand the links between neurodegenerative disorders and environmental pollutants such as PFOS. Furthermore, these up/down regulated genes can be used as biomarkers to detect a sub-lethal presence of PFOS in soil. Neuronal calcium sensor-2, nucleoside diphosphate kinase, polyadenylate-binding protein-1 and mitochondrial Pyruvate dehydrogenase protein-X component, could be potential biomarkers for sub lethal concentrations of PFOS. PMID:25285771

  7. EFFECTS OF PRENATAL PERFLUOROOCTANESULFONATE (PFOS) EXPOSURE ON LUNG MATURATION IN THE PERINATAL RAT

    EPA Science Inventory

    PFOS is an environmentally stable compound that has been detected at 3 ppb -10 ppm in serum samples from the general public and occupationally exposed individuals. We have shown that exposing pregnant rats to PFOS (25, or 50 mg/kg/d on GD 19-20) induces neonatal death in the rat...

  8. Distribution and excretion of perfluorooctane sulfonate (PFOS) in beef cattle (Bos taurus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perfluorooctane sulfonate (PFOS), a perfluoroalkyl surfactant used in many industrial products, is present in industrial wastes and in wastewater treatment plant biosolids. Biosolids are commonly applied to pastures and crops used for animal feed; consequently, PFOS may accumulate in the edible tis...

  9. PFOS Induces Behavioral Alterations, Including Spontaneous Hyperactivity That Is Corrected by Dexamfetamine in Zebrafish Larvae

    PubMed Central

    Spulber, Stefan; Kilian, Pascal; Wan Ibrahim, Wan Norhamidah; Onishchenko, Natalia; Ulhaq, Mazhar; Norrgren, Leif; Negri, Sara; Di Tuccio, Marcello; Ceccatelli, Sandra

    2014-01-01

    Perfluorooctane sulfonate (PFOS) is a widely spread environmental contaminant. It accumulates in the brain and has potential neurotoxic effects. The exposure to PFOS has been associated with higher impulsivity and increased ADHD prevalence. We investigated the effects of developmental exposure to PFOS in zebrafish larvae, focusing on the modulation of activity by the dopaminergic system. We exposed zebrafish embryos to 0.1 or 1 mg/L PFOS (0.186 or 1.858 µM, respectively) and assessed swimming activity at 6 dpf. We analyzed the structure of spontaneous activity, the hyperactivity and the habituation during a brief dark period (visual motor response), and the vibrational startle response. The findings in zebrafish larvae were compared with historical data from 3 months old male mice exposed to 0.3 or 3 mg/kg/day PFOS throughout gestation. Finally, we investigated the effects of dexamfetamine on the alterations in spontaneous activity and startle response in zebrafish larvae. We found that zebrafish larvae exposed to 0.1 mg/L PFOS habituate faster than controls during a dark pulse, while the larvae exposed to 1 mg/L PFOS display a disorganized pattern of spontaneous activity and persistent hyperactivity. Similarly, mice exposed to 0.3 mg/kg/day PFOS habituated faster than controls to a new environment, while mice exposed to 3 mg/kg/day PFOS displayed more intense and disorganized spontaneous activity. Dexamfetamine partly corrected the hyperactive phenotype in zebrafish larvae. In conclusion, developmental exposure to PFOS in zebrafish induces spontaneous hyperactivity mediated by a dopaminergic deficit, which can be partially reversed by dexamfetamine in zebrafish larvae. PMID:24740186

  10. PFOS induces behavioral alterations, including spontaneous hyperactivity that is corrected by dexamfetamine in zebrafish larvae.

    PubMed

    Spulber, Stefan; Kilian, Pascal; Wan Ibrahim, Wan Norhamidah; Onishchenko, Natalia; Ulhaq, Mazhar; Norrgren, Leif; Negri, Sara; Di Tuccio, Marcello; Ceccatelli, Sandra

    2014-01-01

    Perfluorooctane sulfonate (PFOS) is a widely spread environmental contaminant. It accumulates in the brain and has potential neurotoxic effects. The exposure to PFOS has been associated with higher impulsivity and increased ADHD prevalence. We investigated the effects of developmental exposure to PFOS in zebrafish larvae, focusing on the modulation of activity by the dopaminergic system. We exposed zebrafish embryos to 0.1 or 1 mg/L PFOS (0.186 or 1.858 µM, respectively) and assessed swimming activity at 6 dpf. We analyzed the structure of spontaneous activity, the hyperactivity and the habituation during a brief dark period (visual motor response), and the vibrational startle response. The findings in zebrafish larvae were compared with historical data from 3 months old male mice exposed to 0.3 or 3 mg/kg/day PFOS throughout gestation. Finally, we investigated the effects of dexamfetamine on the alterations in spontaneous activity and startle response in zebrafish larvae. We found that zebrafish larvae exposed to 0.1 mg/L PFOS habituate faster than controls during a dark pulse, while the larvae exposed to 1 mg/L PFOS display a disorganized pattern of spontaneous activity and persistent hyperactivity. Similarly, mice exposed to 0.3 mg/kg/day PFOS habituated faster than controls to a new environment, while mice exposed to 3 mg/kg/day PFOS displayed more intense and disorganized spontaneous activity. Dexamfetamine partly corrected the hyperactive phenotype in zebrafish larvae. In conclusion, developmental exposure to PFOS in zebrafish induces spontaneous hyperactivity mediated by a dopaminergic deficit, which can be partially reversed by dexamfetamine in zebrafish larvae. PMID:24740186

  11. PFOS, PFNA, and PFOA sub-lethal exposure to embryonic zebrafish have different toxicity profiles in terms of morphometrics, behavior and gene expression.

    PubMed

    Jantzen, Carrie E; Annunziato, Kate A; Bugel, Sean M; Cooper, Keith R

    2016-06-01

    Polyfluorinated compounds (PFC) are a class of anthropogenic, persistent and toxic chemicals. PFCs are detected worldwide and consist of fluorinated carbon chains of varying length, terminal groups, and industrial uses. Previous zebrafish studies in the literature as well as our own studies have shown that exposure to these chemicals at a low range of concentrations (0.02-2.0μM; 20-2000ppb) resulted in chemical specific developmental defects and reduced post hatch survival. It was hypothesized that sub-lethal embryonic exposure to perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA), or perfluorooctanoic acid (PFOA) would result in different responses with regard to morphometric, behavior, and gene expression in both yolk sac fry and larval zebrafish. Zebrafish were exposed to PFOS, PFOA, and PFNA (0.02, 0.2, 2.0μM) for the first five days post fertilization (dpf) and analyzed for morphometrics (5 dpf, 14 dpf), targeted gene expression (5 dpf, 14 dpf), and locomotive behavior (14 dpf). All three PFCs commonly resulted in a decrease in total body length, increased tfc3a (muscle development) expression and decreased ap1s (protein transport) expression at 5dpf, and hyperactive locomotor activity 14 dpf. All other endpoints measured at both life-stage time points varied between each of the PFCs. PFOS, PFNA, and PFOA exposure resulted in significantly altered responses in terms of morphometric, locomotion, and gene expression endpoints, which could be manifested in field exposed teleosts. PMID:27058923

  12. Developmental Toxicity of Perfluoroalkyl Acid Mixtures in CD-1 Mice

    EPA Science Inventory

    Perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS) and perfluorononanoic acid (PFNA) belong to a family of fluoro-organic compounds known as perfluoroalkyl acids (PFAAs). PFAAs have been widely used in industrial and commercial applications, and have been found to be...

  13. Determinants of plasma PFOA and PFOS levels among 652 Danish men.

    PubMed

    Eriksen, Kirsten T; Sørensen, Mette; McLaughlin, Joseph K; Tjønneland, Anne; Overvad, Kim; Raaschou-Nielsen, Ole

    2011-10-01

    Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) are used in a variety of industrial and consumer products and have been detected worldwide in human blood. The sources for human exposure are not well described, but dietary intake is suggested as an important source. In this study of 652 Danish men from the Diet, Cancer and Health cohort, we examined intake of 10 major dietary groups, tap water drinks, alcohol consumption, cooking method, geographical area, age, smoking status, and BMI as potential determinants of PFOA and PFOS plasma levels. Living in the Aarhus area was associated with higher PFOA and PFOS plasma levels compared with living in the Copenhagen area, and never smokers had higher levels than current smokers. Frying as compared with other cooking methods was a determinant of PFOA and PFOS levels. BMI and alcohol consumption were inversely associated with both compounds. Among the dietary groups, only intake of eggs was significantly positively associated with PFOS plasma levels. In future studies, PFOA and PFOS levels in air, dust and water samples should be measured to elucidate further the sources of exposure; exposure through diet needs to be studied in greater detail. Our finding of a higher body burden of PFOA and PFOS among never smokers also warrants further evaluation. PMID:20939531

  14. Behavior, metabolism and swimming physiology in juvenile Spinibarbus sinensis exposed to PFOS under different temperatures.

    PubMed

    Xia, Ji-Gang; Nie, Li-Juan; Mi, Xia-Mei; Wang, Wei-Zhen; Ma, Yi-Jie; Cao, Zhen-Dong; Fu, Shi-Jian

    2015-10-01

    The harmful effects of perfluorooctane sulfonate (PFOS) are of growing international concern. This paper aimed to gain an integrated understanding of fitness-related ecological end points, such as behavior, metabolism and swimming physiology, in juvenile Spinibarbus sinensis in response to PFOS toxicity at different temperatures. The fish were exposed to a range of PFOS concentrations (0, 0.32, 0.8, 2 and 5 mg/L) at different temperatures (18 and 28 °C) for 30 days. The effects on fish behavior, metabolic characteristics and aerobic swimming performance caused by PFOS at different temperatures were investigated. Our results showed that both PFOS and temperature had important influences on spontaneous swimming behavior, social interactions, routine metabolic rate (RMR), net energetic cost of transport (COTnet) and critical swimming speed (U crit) in fish. The lowest observed effect concentration for both U crit and RMR was 5 and 0.8 mg/L at 18 and 28 °C, respectively. We found that PFOS affected various behavioral and social end points and also appeared to affect metabolic rates and reduced U crit, likely as a result of increased COTnet, and that many of these effects also changed with respect to temperature. Our results further the understanding of the metabolic and behavioral toxicity of PFOS to aquatic organisms. PMID:26077224

  15. Toxicity and DNA methylation changes induced by perfluorooctane sulfonate (PFOS) in sea urchin Glyptocidaris crenularis.

    PubMed

    Ding, Guanghui; Wang, Luyan; Zhang, Jing; Wei, Yuanyuan; Wei, Lie; Li, Yang; Shao, Mihua; Xiong, Deqi

    2015-06-01

    Perfluorooctane sulfonate (PFOS) is an ubiquitous persistent organic pollutant, which can be bioaccumulated and cause adverse effects on organisms. However, there is very limited information about the toxic effects of PFOS to marine organisms and its mechanisms. Therefore, in the present study, adult sea urchins Glyptocidaris crenularis were exposed to PFOS for 21 d, followed by a 7-d depuration period, in order to investigate the toxicity of PFOS to sea urchin and its potential epigenetic mechanisms. Sea urchins dropped spines, and lowered down the motor ability and feeding ability after the PFOS exposure. Superoxide dismutase activities in supernatant of coelomic fluid of sea urchin increased firstly and then dropped down, while the change of the catalase activity took an opposite trend during the exposure period. They both approached to the corresponding activity of the control after the depuration period. The DNA methylation polymorphism, methylation rate and demethylation rate in sea urchin gonad all increased following the prolonged exposure time, and then decreased after the depuration period. The demethylation rates were lower than the corresponding methylation rates, therefore methylation events were dominant during the whole experimental period. This might suggest that sea urchin have strong self-protection mechanisms and can survive from the PFOS exposure presented in this study. Further efforts are needed to more precisely investigate the DNA methylation effects of PFOS and the self-protection mechanism of sea urchin. PMID:25723714

  16. Prenatal exposure to PFOS caused mitochondia-mediated apoptosis in heart of weaned rat.

    PubMed

    Zeng, Huai-Cai; He, Qing-Zhi; Li, Yuan-Yuan; Wu, Cheng-Qiu; Wu, Yi-Mou; Xu, Shun-Qing

    2015-09-01

    Perfluorooctanyl sulfonate (PFOS), a cardiac toxicity compound, has been widely detected in the environment and in organisms. However, the toxic mechanism is not clear. Our previous study indicated that prenatal PFOS exposure led to swollen mitochondrial with vacuolar structure and loss of cristae in offsping's heart. The purpose of this study was to investigate the effect of PFOS on the apoptosis in developing heart and mitochondria-mediated apoptosis pathway. Pregnant Sprague-Dawley (SD) rats were exposed to PFOS at doses of 0.1, 0.6, and 2.0 mg/kg-d and 0.05% Tween 80 as control by gavage from gestation day 2 (GD 2) to GD 21. Apoptosis, as well as expression of apoptosis related genes associated with mitochondrial-mediated apoptosis pathway, including p53, bcl-2, bax, cytochrome c, caspase-9, and caspase-3 were analyzed in heart tissues from weaned (postnatal day 21, PND 21) offspring. The results showed that prenatal PFOS exposure resulted in apoptosis in the offspring's heart. The mRNA and protein expression levels of p53, bax, cytochrome c, caspase-9, and caspase-3 in the offspring's heart were enhanced in various PFOS-treated groups, meanwhile, the bcl-2 expression levels were decreased. Our results indicated that prenatal PFOS exposure induced the apoptosis of weaned offspring rat heart tissue via mitochondria-mediated apoptotic pathway. PMID:24616003

  17. Comparing measured and modelled PFOS concentrations in a UK freshwater catchment and estimating emission rates.

    PubMed

    Earnshaw, Mark R; Paul, Alexander G; Loos, Robert; Tavazzi, Simona; Paracchini, Bruno; Scheringer, Martin; Hungerbühler, Konrad; Jones, Kevin C; Sweetman, Andrew J

    2014-09-01

    The lifecycle, sources and fate of perfluorooctane sulfonate (PFOS) continue to generate scientific and political interest, particularly since PFOS was listed by the Stockholm Convention and largely restricted in Europe. It continues to be detected in aquatic environments, with only limited studies into the on-going sources. This paper explores PFOS emissions discharged by the general population into a small catchment comprising two rivers in the UK. A sampling campaign was undertaken to improve our understanding of population-derived PFOS sources from sewage treatment plants (STPs) and in rivers. A corresponding modelling exercise allowed an emission estimate of 13μg/day/per capita to be derived for the Aire and Calder rivers. PFOS emission was linked to STP discharges bylinear regression of measured and modelled concntrations (R(2)=0.49-0.85). The model was able to accurately estimate the spatial trends of PFOS in the rivers, while predicted concentrations were within a factor of three based on per capita emission values taken from the literature. Measured PFOS concentrations in rivers suggested that emissions from STPs are partially dependent on treatment type, where plants with secondary or tertiary treatment such as activated sludge processes emit less PFOS, possibly due to increased partitioning and retention. With refinements based on the type of treatment at each STP, predictions were further improved. The total PFOS mass discharged annually via rivers from the UK has been estimated to be between 215 and 310kg, based on the per capita emission range derived in this study. PMID:24879369

  18. Estimation of PFOS emission from domestic sources in the eastern coastal region of China.

    PubMed

    Xie, Shuangwei; Lu, Yonglong; Wang, Tieyu; Liu, Shijie; Jones, Kevin; Sweetman, Andy

    2013-09-01

    Perfluorooctane sulfonate (PFOS) and related chemicals (collectively "PFOS equivalents") have been released to the environment through widespread consumer use and disposal of PFOS-containing products like carpet, leather, textiles, paper, food containers, household cleansers, etc. Accordingly, in addition to PFOS-related industries, domestic activities may also considerably contribute to the PFOS emissions in the eastern coastal region of China, which has been characterized by high industrial input. In the present study, domestic emissions of PFOS equivalents derived from municipal wastewater treatment plants were estimated at the county level, using a regression model of domestic emission density with population density and per capita disposable income as independent variables. The total emission load of PFOS equivalents from domestic sources in the eastern coastal region of China was 381kg in 2010, and large cities were prominent as the emission centers. The domestic emission density averaged 0.37g/km(2)·a for the entire study area. Generally, the Beijing-Tianjin area, Pearl River Delta and Yangtze River Delta, as the most populous and economically developed areas in China, showed significantly higher emission density. Geographical variations within individual provinces were noteworthy. The average per capita discharge load of PFOS equivalents arising from domestic activities was 1.91μg/day per capita in the eastern coastal region of China, which is consistent with previous estimates in Korea, but lower than those calculated for developed countries. In comparison, the spatial distributions of provincial PFOS emissions from domestic and industrial sources were similar to each other; however, the latter was much larger for all the provinces. PMID:23892226

  19. Influence of oxic/anoxic condition on sorption behavior of PFOS in sediment.

    PubMed

    Ololade, Isaac Ayodele; Zhou, Qin; Pan, Gang

    2016-05-01

    Sediment components and redox properties change with oxic/anoxic condition, which affect the environmental transport of perfluorooctane sulfonate (PFOS). Herein, the influence of oxic/anoxic condition on the variation of redox and residual components of sediments, where organic matter, iron and manganese oxides are separated from the original sediment collected from Lake Taihu, China, are investigated. Meanwhile, the distinguishing sorption behaviors of PFOS on various residual sediments under oxic and anoxic condition are studied. Sediment after extracting iron and manganese (S-FeMn), which possessed the highest organic carbon (0.99%), had the highest affinity for PFOS under oxic condition. However, anoxic environment resulted in an increase of the pH, dissolving of organic carbon and de-protonation of S-FeMn, which caused the lower sorption capacity of PFOS on S-FeMn. Sediment after extracting manganese (S-Mn) had the higher sorption ability in anoxic environment because the Fe(2+) from S-Mn provided more effective electrostatic sites for anionic PFOS. When the environment changed to oxic condition, the iron existed as trivalent form in S-Mn, which resulted in a block of effective sorption site and reduced the sorption amounts of PFOS. The higher percentage of manganese oxides restrained the sorption of PFOS. Hence, whether or not oxic/anoxic condition promoted the PFOS sorption depended on both the percentage and form of various components in the sediment. The study generated further insight into the environmental transport of PFOS in the sediments with different properties and the wetland system, where oxic/anoxic subsurface flow was constructed. PMID:26350897

  20. All-organic non-PFOS nonionic photoacid generating compounds with functionalized fluoroorganic sulfonate motif for chemically amplified resists

    NASA Astrophysics Data System (ADS)

    Ayothi, Ramakrishnan; Yi, Yi; Ober, Christopher K.; Putna, Steve; Yueh, Wang; Cao, Heidi

    2006-03-01

    Nonionic photoacid generators (PAGs) based on photosensitive fluoroorganic sulfonate esters of imide and nitrobenzyl have been prepared and characterized. These new compounds produce fluoroorganic sulfonic acids that contain very few fluorine atoms (non-PFOS), which make them attractive PAGs for all advanced and emerging lithography. The structural influence of these new PAGs on sensitivity, resolution and line edge roughness (LER) was investigated by using DUV (254 nm) and e-beam lithography with ESCAP and ACRYLIC type positive tone resists. E-beam lithography evaluation indicates that these new fluroorganic sulfonic acids are sensitive and capable of providing image profiles down to 80 nm. The variation observed in sensitivity and LER at e-beam lithography was analyzed in terms of the structures of the photogenerated acids, chromophores and resists.

  1. Thyroid hormone status and pituitary function in adult rats given oral doses of perfluorooctanesulfonate (PFOS)

    EPA Science Inventory

    Perfluorooctanesulfonate (PFOS) is widely distributed and persistent in humans and wildlife. Prior toxicological studies have reported decreased total and free thyroid hormones in serum without a major compensatory rise in thyrotropin (TSH) or altered thyroid gland histology. Alt...

  2. Molecular dynamics simulations of structural transformation of perfluorooctane sulfonate (PFOS) at water/rutile interfaces.

    PubMed

    He, Guangzhi; Zhang, Meiyi; Zhou, Qin; Pan, Gang

    2015-09-01

    Concentration and salinity conditions are the dominant environmental factors affecting the behavior of perfluorinated compounds (PFCs) on the surfaces of a variety of solid matrices (suspended particles, sediments, and natural minerals). However, the mechanism has not yet been examined at molecular scales. Here, the structural transformation of perfluorooctane sulfonate (PFOS) at water/rutile interfaces induced by changes of the concentration level of PFOS and salt condition was investigated using molecular dynamics (MD) simulations. At low and intermediate concentrations all PFOS molecules directly interacted with the rutile (110) surface mainly by the sulfonate headgroups through electrostatic attraction, yielding a typical monolayer structure. As the concentration of PFOS increased, the molecules aggregated in a complex multi-layered structure, where an irregular assembling configuration was adsorbed on the monolayer structure by the van der Waals interactions between the perfluoroalkyl chains. When adding CaCl2 to the system, the multi-layered structure changed to a monolayer again, indicating that the addition of CaCl2 enhanced the critical concentration value to yield PFOS multilayer assemblies. The divalent Ca(2+) substituted for monovalent K(+) as the bridging counterion in PFOS adsorption. MD simulation may trigger wide applications in study of perfluorinated compounds (PFCs) from atomic/molecular scale. PMID:25966457

  3. The partition behavior of perfluorooctanesulfonate (PFOS) and perfluorooctanesulfonamide (FOSA) on microplastics.

    PubMed

    Wang, Fei; Shih, Kai Min; Li, Xiao Yan

    2015-01-01

    Microplastics have been recognized as transport vectors for heavy metals and organic pollutants to marine animals. Thus, the sorption behavior of contaminant on microplastic is crucial to their transport in marine system. In this study, the sorption behavior of PFOS and FOSA (two perfluorochemicals) on three kinds of microplastics (PE, PS, and PVC) are reported. The isotherm study showed that the sorption of PFOS and FOSA on microplastics is highly linear, and it indicated that partition by hydrophobic interaction is the predominant sorption mechanism. The Kd values of FOSA on three kinds of microplastics are all higher than those of PFOS, and the reason is attributed to their different functional groups. The Kd value of FOSA on three types of microplastics followed the order as: PE>PVC>PS. Such finding may indicate that the molecule composition and structure of microplastics play important roles in their sorption processes of organic pollutants. The PFOS sorption levels on PE and PS particles were increased with the increase of NaCl and CaCl2 concentrations, while the ion concentrations have no effect on FOSA sorption. The study on the pH effects on PFOS and FOSA sorption indicated FOSA could partition under various pH conditions on three types of microplastics while PFOS sorption on PE and PS were favored with lower pH. PMID:25222623

  4. Neonatal exposure to PFOS and PFOA in mice results in changes in proteins which are important for neuronal growth and synaptogenesis in the developing brain.

    PubMed

    Johansson, Niclas; Eriksson, Per; Viberg, Henrik

    2009-04-01

    Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) belong to the family of perfluorinated compounds. They are used in industrial and consumer applications, e.g., clothing fabrics, carpets, and food packaging. PFOS and PFOA are present in the environment and are found in dust and human milk, which implies that newborns and toddlers can be directly exposed to these agents during brain development. Recently, we reported that PFOS and PFOA can cause neurobehavioral defects and changes in the cholinergic system, in the adult animal, when given directly to neonatal mice, and thereby showing similarities with other investigated persistent organic pollutants, such as dichloro-diphenyl-trichloroethan, polychlorinated biphenyls, and polybrominated diphenyl ethers (PBDEs). In recent studies, we have also seen that highly brominated PBDEs can affect the levels of proteins that are important for neuronal growth and synaptogenesis in the neonatal mouse brain. The present study shows that a single oral dose of either 21 micromol PFOS or PFOA/kg body weight (11.3 or 8.70 mg), given directly to the neonatal mice on postnatal day 10, significantly increased the levels of CaMKII, GAP-43, and synaptophysin in the hippocampus of the neonatal mouse. Both compounds significantly increased the levels of synaptophysin and tau in cerebral cortex, and PFOA also increased the levels of tau in hippocampus. These proteins are important for normal brain development, and altered levels of these proteins during a critical period of the brain growth spurts could be one of the mechanisms behind earlier reported behavioral defects. PMID:19211617

  5. PFOS Disturbs BDNF-ERK-CREB Signalling in Association with Increased MicroRNA-22 in SH-SY5Y Cells

    PubMed Central

    Li, Wu; He, Qing-zhi; Wu, Cheng-qiu; Pan, Xiao-yuan; Wang, Jing; Tan, Yan; Shan, Xiao-yun; Zeng, Huai-cai

    2015-01-01

    Perfluorooctane sulfonate (PFOS), a ubiquitous environmental pollutant, is neurotoxic to mammalian species. However, the underlying mechanism of its neurotoxicity was unclear. We hypothesized that PFOS suppresses BDNF expression to produce its neurotoxic effects by inhibiting the ERK-CREB pathway. SH-SY5Y human neuroblastoma cells were exposed to various concentrations of PFOS to examine the role of the BDNF-ERK-CREB signalling pathway in PFOS-induced apoptosis and cytotoxicity. Furthermore, to ascertain the mechanism by which PFOS reduces BDNF signalling, we examined the expression levels of miR-16 and miR-22, which potentially regulate BDNF mRNA translation at the posttranscriptional level. Results indicated that PFOS significantly decreased cell viability and induced apoptosis in SH-SY5Y cells. In addition, BDNF and pERK protein levels decreased after PFOS treatment; however, pCREB protein levels were significantly elevated in PFOS treated groups. TrkB protein expression increased in the 10 μM and 50 μM PFOS groups and significantly decreased in the 100 μM PFOS group. Our results demonstrated that PFOS exposure decreased miR-16 expression and increased miR-22 expression, which may represent a possible mechanism by which PFOS decreases BDNF protein levels. PFOS may inhibit BDNF-ERK-CREB signalling by increasing miR-22 levels, which may, in part, explain the mechanism of PFOS neurotoxicity. PMID:26649298

  6. Developmental toxicity of perfluorononanoic acid in the mouse.

    EPA Science Inventory

    Toxicology Curriculum, University of North Carolina, Chapel Hill, NC Perfluorononanoic acid (PFNA) is a persistent environmental contaminant. Although its levels in the environment are lower than those of perfluorooctane sulfonate (PFOS) or perfluorooctanoic acid (PFOA), its pre...

  7. THE DEVELOPMENTAL TOXICITY OF PERFLUOROALKYL ACIDS AND THEIR DERIVATIVES

    EPA Science Inventory

    Abstract

    Perfluoroalkyl acids such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have applications in numerous industrial and consumer products. Although the toxicology of some of these compounds has been investigated in the past, the widespread pr...

  8. Toxicogenomic profiling of perfluorononanoic acid in wild-type and PPARa-null mice

    EPA Science Inventory

    Perfluorononanoic acid (PFNA) is a ubiquitous environmental contaminant and a developmental toxicant in laboratory animals. Like other perfluoroalkyl acids (PFAAs) such as perfluorooctane sulfonate (PFOA) and perfluoroalkyl acid (PFOS), PFNA is a known activator ofperoxisome prol...

  9. In vitro PFOS exposure on immune endpoints in bottlenose dolphins (Tursiops truncatus) and mice.

    PubMed

    Wirth, Jena R; Peden-Adams, Margie M; White, Natasha D; Bossart, Gregory D; Fair, Patricia A

    2014-06-01

    Previous studies in our lab have shown that perfluorooctane sulfonate (PFOS) modulates immune function in mice and correlates with many immune parameters in bottlenose dolphins (Tursiops truncatus). In this study, bottlenose dolphin peripheral blood leukocytes (PBLs) and adult female B6C3F1 mouse splenocytes were exposed to environmentally relevant PFOS concentrations (0-5 µg ml(-1)) in vitro; and natural killer (NK) cell activity and lymphocyte proliferation (T and B cell) were assessed using the parallelogram approach for risk assessment. The objectives were: to corroborate results from the correlative studies in bottlenose dolphins with in vitro PFOS exposures; to evaluate the sensitivity of the mouse model as compared with bottlenose dolphins; and to assess risk using the parallelogram approach. In mouse cells, NK cell activity was decreased at in vitro doses of 0.01, 0.5, 0.1, 0.5 and 1 µg PFOS ml(-1) and increased at 5 µg ml(-1). Additionally, B cell proliferation was not altered, but T cell proliferation was decreased at all in vitro PFOS exposures. In dolphin cells, NK cell activity and T cell proliferation were not altered by in vitro PFOS exposure, but B cell proliferation exhibited a positive association in relation to PFOS dose. Overall, the data indicates that: the in vitro exposures of bottlenose dolphin PBLs exhibited results similar to reported correlative fields studies; that mice were generally more sensitive (for these selected endpoints) than were dolphins; and that the parallelogram approach could be used two-thirds of the time to predict the effects in bottlenose dolphins. PMID:23722986

  10. Alterations in tumor biomarker GSTP gene methylation patterns induced by prenatal exposure to PFOS.

    PubMed

    Wan, Yan-jian; Li, Yuan-yuan; Xia, Wei; Chen, Jun; Lv, Zi-quan; Zeng, Huai-cai; Zhang, Ling; Yang, Wen-jie; Chen, Tian; Lin, Yi; Wei, Jie; Xu, Shun-qing

    2010-01-01

    The adverse environmental exposure in early life may have adverse effects on animals through epigenetic aspects. The current study examined the possibility of early epigenetic alteration in PFOS-exposed rat liver. Pregnant Sprague-Dawley (SD) rats were exposed to perfluorooctane sulfonate (PFOS) at doses of 0.1, 0.6 and 2.0 mg/kg/d and 0.05% Tween 80 as control by gavage from gestation days 2 to 21. The dams were allowed to give birth and liver samples from weaned (postnatal day 21) offspring rats were analyzed for PFOS content, relative liver weight, global DNA methylation, methylation of LINE-1 regulatory region, tumor suppressor gene glutathione S-transferase pi (GSTP) and p16 promoter methylation level, as well as related genes expression level. In PFOS-exposed weaned rats, compared to the control, global DNA methylation and methylation of LINE-1 regulatory region decreased significantly only in the 2.0 mg/kg/d group. Up to 30% of critical CpG sites (+79, 81 and 84) in GSTP promoter region were methylated in the livers of PFOS-treated rats, while p16 promoter methylation was not affected. In addition, the up-regulated expression of GSTP was observed and this increase was associated with its main pathway of transcription regulation: Keap1-Nrf2/MafK. Thus, early-induced changes in critical cytosines within the GSTP gene promoter region may be a biomarker of hepatic PFOS burden, though their direct role in PFOS-induced hepatotoxicity, including its potential carcinogenic action, needs further research. PMID:20621739

  11. Developmental toxicity in white leghorn chickens following in ovo exposure to perfluorooctane sulfonate (PFOS)

    USGS Publications Warehouse

    Peden-Adams, M. M.; Stuckey, Joyce E.; Gaworecki, K.M.; Berger-Ritchie, J.; Bryant, K.; Jodice, P.G.; Scott, T.R.; Ferrario, J.B.; Guan, B.; Vigo, C.; Boone, J.S.; McGuinn, W.D.; DeWitt, J.C.; Keil, D.E.

    2009-01-01

    Studies show that perfluorinated compounds cause various toxicological effects; nevertheless, effects on immune function and developmental endpoints have not been addressed at length. This study examined the effects of perfluorooctane sulfonate (PFOS) in white leghorn hatchlings on various developmental, immunological, and clinical health parameters. In addition, serum PFOS concentrations were determined by LC/MS/MS. Embryonic day (ED) 0 eggs were injected with either safflower oil/10% DMSO (control, 0 mg/kg egg wt) or PFOS in safflower oil/10% DMSO at 1, 2.5, or 5 mg/kg egg wt, and the chicks were grown to post-hatch day (PHD) 14. Treatment with PFOS did not affect hatch rate. Following in ovo exposure chicks exhibited increases in spleen mass at all treatment levels, in liver mass at 2.5 and 5 mg/kg egg wt, and in body length (crown-rump length) at the 5 mg/kg treatment. Right wings were shorter in all treatments compared to control. Increases in the frequency of brain asymmetry were evident in all treatment groups. SRBC-specific immunoglobulin (IgM and IgY combined) titers were decreased significantly at all treatment levels, while plasma lysozyme activity was increased at all treatment levels. The PHA skin test response decreased in relation to increasing PFOS dose. Serum concentrations where significant immunological, morphological, and neurological effects were observed at the lowest dose (1 mg/kg egg wt) averaged 154 ng PFOS/g serum. These concentrations fall within environmental ranges reported in blood samples from wild caught avian species; thereby, verifying that the environmental egg concentrations used for the injections do indeed relate to serum levels in hatchlings that are also environmentally relevant. These data indicate that immune alterations and brain asymmetry can occur in birds following in ovo exposure to environmentally relevant concentrations of PFOS and demonstrates the need for further research on the developmental effects of perfluorinated compounds in various species. ?? 2009 Elsevier Inc.

  12. Reactive oxygen species mediate nitric oxide production through ERK/JNK MAPK signaling in HAPI microglia after PFOS exposure.

    PubMed

    Wang, Cheng; Nie, Xiaoke; Zhang, Yan; Li, Ting; Mao, Jiamin; Liu, Xinhang; Gu, Yiyang; Shi, Jiyun; Xiao, Jing; Wan, Chunhua; Wu, Qiyun

    2015-10-15

    Perfluorooctane sulfonate (PFOS), an emerging persistent contaminant that is commonly encountered during daily life, has been shown to exert toxic effects on the central nervous system (CNS). However, the molecular mechanisms underlying the neurotoxicity of PFOS remain largely unknown. It has been widely acknowledged that the inflammatory mediators released by hyper-activated microglia play vital roles in the pathogenesis of various neurological diseases. In the present study, we examined the impact of PFOS exposure on microglial activation and the release of proinflammatory mediators, including nitric oxide (NO) and reactive oxidative species (ROS). We found that PFOS exposure led to concentration-dependent NO and ROS production by rat HAPI microglia. We also discovered that there was rapid activation of the ERK/JNK MAPK signaling pathway in the HAPI microglia following PFOS treatment. Moreover, the PFOS-induced iNOS expression and NO production were attenuated after the inhibition of ERK or JNK MAPK by their corresponding inhibitors, PD98059 and SP600125. Interestingly, NAC, a ROS inhibitor, blocked iNOS expression, NO production, and activation of ERK and JNK MAPKs, which suggested that PFOS-mediated microglial NO production occurs via a ROS/ERK/JNK MAPK signaling pathway. Finally, by exposing SH-SY5Y cells to PFOS-treated microglia-conditioned medium, we demonstrated that NO was responsible for PFOS-mediated neuronal apoptosis. PMID:26086160

  13. Antioxidative-related genes expression following perfluorooctane sulfonate (PFOS) exposure in the intertidal mud crab, Macrophthalmus japonicus

    NASA Astrophysics Data System (ADS)

    Park, Kiyun; Nikapitiya, Chamilani; Kwak, Tae-Soo; Kwak, Ihn-Sil

    2015-09-01

    Perfluorooctane sulfonate (PFOS) is a persistent environmental contaminant that is used as a surfactant in various industries and consumer products. The intertidal mud crab, Macrophthalmus japonicus, is one of the most abundant macrobenthic creatures. In this study, we have investigated the effect of PFOS on the molecular transcription of antioxidant and detoxification signaling in M. japonicus crab. The selected stress response genes were superoxide dismutases (CuZnSOD and MnSOD), catalase (CAT), glutathione peroxidase (GPx), phospholipid hydroperoxide glutathione peroxidase (PHGPx), peroxiredoxin (Prx), and thioredoxin reductase (TrxR). Significant up-regulation of SODs and CAT was observed after 24 and 96 h exposure to PFOS at different concentrations. The gene expression levels of GPx, PHGPx, and TrXR were significantly up-regulated after exposure to PFOS for 96 h. The transcript levels of CAT and PHGPx were induced in dose- and time-dependent manners after PFOS treatments. However, Prx gene expression was significantly up-regulated in M. japonicus crabs exposed to 10 and 30 μg L-1 PFOS for 96 h. Additionally, PFOS toxicity in M. japonicus induced reduced survival rates at relatively high concentrations of PFOS exposure. Our findings support the contention that exposures to PFOS induced the response of genes related to oxidative stress and detoxification in M. japonicus crabs.

  14. Developmental toxicity and alteration of gene expression in zebrafish embryos exposed to PFOS

    SciTech Connect

    Shi Xiongjie; Du Yongbing; Lam, Paul K.S.; Wu, Rudolf S.S.; Zhou Bingsheng

    2008-07-01

    Perfluorooctanesulfonate (PFOS) is a persistent organic pollutant, the potential toxicity of which is causing great concern. In the present study, we employed zebrafish embryos to investigate the developmental toxicity of this compound. Four-hour post-fertilization (hpf) zebrafish embryos were exposed to 0.1, 0.5, 1, 3 and 5 mg/L PFOS. Hatching was delayed and hatching rates as well as larval survivorship were significantly reduced after the embryos were exposed to 1, 3 and 5 mg/L PFOS until 132 hpf. The fry displayed gross developmental malformations, including epiboly deformities, hypopigmentation, yolk sac edema, tail and heart malformations and spinal curvature upon exposure to PFOS concentrations of 1 mg/L or greater. Growth (body length) was significantly reduced in the 3 and 5 mg/L PFOS-treated groups. To test whether developmental malformation was mediated via apoptosis, flow cytometry analysis of DNA content, acridine orange staining and TUNEL assay was used. These techniques indicated that more apoptotic cells were present in the PFOS-treated embryos than in the control embryos. Certain genes related to cell apoptosis, p53 and Bax, were both significantly up-regulated upon exposure to all the concentrations tested. In addition, we investigated the effects of PFOS on marker genes related to early thyroid development (hhex and pax8) and genes regulating the balance of androgens and estrogens (cyp19a and cyp19b). For thyroid development, the expression of hhex was significantly up-regulated at all concentrations tested, whereas pax8 expression was significantly up-regulated only upon exposure to lower concentrations of PFOS (0.1, 0.5, 1 mg/L). The expression of cyp19a and of cyp19b was significantly down-regulated at all exposure concentrations. The overall results indicated that zebrafish embryos constitute a reliable model for testing the developmental toxicity of PFOS, and the gene expression patterns in the embryos were able to reveal some potential mechanisms of developmental toxicity.

  15. Hepatic miRNA profiles and thyroid hormone homeostasis in rats exposed to dietary potassium perfluorooctanesulfonate (PFOS).

    PubMed

    Dong, Hongyan; Curran, Ivan; Williams, Andrew; Bondy, Genevieve; Yauk, Carole L; Wade, Michael G

    2016-01-01

    Perfluorooctanesulfonate (PFOS) has been widely used in a variety of industrial and commercial applications as a surfactant and stain repellent. PFOS causes liver damage (including liver tumors) in experimental animals, primarily via interaction with PPARα and CAR/PXR. We investigated the involvement of microRNAs (miRNAs) in PFOS-induced hepatotoxicity, and mechanisms involved in abnormal thyroid hormone (TH) homeostasis, in the livers of adult male rats exposed in feed to 50mg PFOS/kg diet for 28 days. PFOS-treated rats exhibited expected histopathological and clinical chemistry changes, and global gene expression changes consistent with the involvement of PPARα and CAR/PXR. Thirty-eight miRNAs were significantly altered. Three members of the miR-200 family were the most increased, while miR-122-5p and miR-21-5p were the most decreased, in PFOS-treated rats. Expression of the miR-23b-3p/27b-3p/24-3p cluster also decreased in PFOS-treated animals. Pathway analysis of miRNAs and associated gene expression changes suggests involvement of epithelial to mesenchymal transition (EMT), which is a primary process of tumor cell motility and cancer metastasis. Our analysis also revealed transcripts that may mediate PFOS-induced effects on TH homeostasis including: activation of the CAR/PXR pathway, phase II/III enzymes, and deiodinase. These changes are consistent with low serum TH due to enhanced metabolic clearance of TH. However, most TH hepatic target genes were not altered in a manner consistent with reduced TH signaling, suggesting that PFOS exposure did not induce functional hypothyroidism. Collectively, the study suggests an important role for miRNAs in PFOS-induced hepatotoxicity and provides insight into the effects of PFOS on TH homeostasis. PMID:26724606

  16. Mechanisms of perfluoroalkyl acid (PFAA) toxicity: Involvement of peroxisome proliferator activator receptor alpha (PPAR) molecular signals.

    EPA Science Inventory

    Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are members of a family of environmentally persistent perfluorinated compounds and are found in the serum of wildlife and humans. PFOS and PFOA are developmentally toxic in rats and mice. Exposure in utero reduces...

  17. Linear and branched perfluorooctane sulfonate (PFOS) isomer patterns differ among several tissues and blood of polar bears.

    PubMed

    Greaves, Alana K; Letcher, Robert J

    2013-09-01

    Perfluorooctane sulfonate (PFOS) is a globally distributed persistent organic pollutant that has been found to bioaccumulate and biomagnify in aquatic food webs. Although principally in its linear isomeric configuration, 21-35% of the PFOS manufactured via electrochemical fluorination is produced as a branched structural isomer. PFOS isomer patterns were investigated in multiple tissues of polar bears (Ursus maritimus) from East Greenland. The liver (n = 9), blood (n = 19), brain (n = 16), muscle (n = 5), and adipose (n = 5) were analyzed for linear PFOS (n-PFOS), as well as multiple mono- and di-trifluoromethyl-substituted branched isomers. n-PFOS accounted for 93.0 ± 0.5% of Σ-PFOS isomer concentrations in the liver, whereas the proportion was significantly lower (p<0.05) in the blood (85.4 ± 0.5%). Branched isomers were quantifiable in the liver and blood, but not in the brain, muscle, or adipose. In both the liver and blood, 6-perfluoromethylheptane sulfonate (P6MHpS) was the dominant branched isomer (2.61 ± 0.10%, and 3.26 ± 0.13% of Σ-PFOS concentrations, respectively). No di-trifluoromethyl-substituted isomers were detectable in any of the tissues analyzed. These tissue-specific isomer patterns suggest isomer-specific pharmacokinetics, perhaps due to differences in protein affinities, and thus differences in protein interactions, as well transport, absorption, and/or metabolism in the body. PMID:23920361

  18. PARTIAL LIFE-CYCLE TOXICITY AND BIOCONCENTRATION MODELLING OF PERFLUOROOCTANE SULFONATE (PFOS) IN THE NORTHERN LEOPARD FROG (RANA PIPIENS)

    EPA Science Inventory

    A number of recent monitoring studies have demonstrated elevated concentrations of perfluorooctane sulfonate (PFOS) in humans and wildlife throughout the world. Although no longer manufactured in the U.S., the global distribution and relative persistence of PFOS indicates a need ...

  19. Investigation on the distribution and fate of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in a sewage-impacted bay.

    PubMed

    Wang, Shiliang; Wang, Hui; Zhao, Wei; Cao, Yuanxin; Wan, Yi

    2015-10-01

    The distribution and fate of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) were investigated in the water and sediment of Bohai Bay, China, during 2011-2013. A total of 360 water samples and 60 sediment samples were collected from 20 locations. The median concentrations of PFOS and PFOA were 4.8 and 12.15 ng/L in the water, and 2.65 and 0.62 ng/g-dry in the sediment, respectively. Significant enrichment were observed for PFOS and PFOA in water of sea surface microlayer. The concentrations of these two compounds showed an apparent gradient from nearshore to offshore stations. The correlation analysis and the distribution tendencies indicated that freshwater inflowing to the bay was the main source of PFOS and PFOA. The salinity of seawater and the total organic carbon (TOC) content of sediment heavily affected the spatial distribution and the partitioning of PFOS and PFOA in the sediment-water system. PMID:26074160

  20. PFOS induced lipid metabolism disturbances in BALB/c mice through inhibition of low density lipoproteins excretion

    NASA Astrophysics Data System (ADS)

    Wang, Ling; Wang, Yu; Liang, Yong; Li, Jia; Liu, Yuchen; Zhang, Jie; Zhang, Aiqian; Fu, Jianjie; Jiang, Guibin

    2014-04-01

    Male BALB/c mice fed with either a regular or high fat diet were exposed to 0, 5 or 20 mg/kg perfluorooctane sulfonate (PFOS) for 14 days. Increased body weight, serum glucose, cholesterol and lipoprotein levels were observed in mice given a high fat diet. However, all PFOS-treated mice got reduced levels of serum lipid and lipoprotein. Decreasing liver glycogen content was also observed, accompanied by reduced serum glucose levels. Histological and ultrastructural examination detected more lipid droplets accumulated in hepatocytes after PFOS exposure. Moreover, transcripitonal activity of lipid metabolism related genes suggests that PFOS toxicity is probably unrelevant to PPARα's transcription. The present study demonstrates a lipid disturbance caused by PFOS and thus point to its role in inhibiting the secretion and normal function of low density lipoproteins.

  1. Potential toxicity of environmentally relevant perfluorooctane sulfonate (PFOS) concentrations to yellow-legged gull Larus michahellis embryos.

    PubMed

    Parolini, Marco; Colombo, Graziano; Valsecchi, Sara; Mazzoni, Michela; Possenti, Cristina Daniela; Caprioli, Manuela; Dalle-Donne, Isabella; Milzani, Aldo; Saino, Nicola; Rubolini, Diego

    2016-01-01

    Perfluooctane sulfonate (PFOS) is considered an emerging pollutant because of its wide distribution in both aquatic and terrestrial ecosystems, as well as its potential toxicity to living organisms. Although PFOS environmental levels and the adverse effects on classical model organisms in toxicological studies are well known, including developmental alterations and alteration of oxidative status, its toxicity to free-living species has been seldom investigated. The aim of this study was to assess the potential toxicity of environmental levels of PFOS to yellow-legged gull (Larus michahellis) embryos under field experimental conditions. In a within-clutch experimental design, we injected two PFOS concentrations (100 ng PFOS/g egg weight and 200 ng PFOS/g egg weight) in ovo soon after laying. Eggs were collected when they reached the cracking stage. We investigated the effects of PFOS treatment, laying order and sex on both morphological and biochemical endpoints of embryos. Specifically, we assessed changes in embryo body mass and tarsus length, as well as in liver and brain mass. Moreover, the imbalance of oxidative status was evaluated in both liver and brain from embryos by measuring total antioxidant capacity (TAC) and total oxidant status (TOS), while the levels of protein carbonyl content (PCO) and DNA fragmentation were measured as oxidative and genetic damage endpoints, respectively. The concentrations of PFOS we tested did not significantly alter the morphological endpoints, independently of laying order and sex. Similarly, embryo oxidative status and oxidative and genetic damage were not significantly affected by PFOS in ovo exposure. These findings suggest that current environmental PFOS levels do not affect early development of yellow-legged gull embryos. PMID:26310703

  2. Exposure to Perfluorononanoic acid during pregnancy: Evaluations of rat and mice model

    EPA Science Inventory

    Perfluorononanoic acid (PFNA) is a persistent environmental contaminant. Although its levels in the environment are lower than those of perfluorooctane sulfonate (PFOS) or perfluorooctanoic acid (PFOA), its presence in humans is rising and is of concern. Previous studies have in...

  3. Exploring the fate, transport and risk of Perfluorooctane Sulfonate (PFOS) in a coastal region of China using a multimedia model.

    PubMed

    Liu, Shijie; Lu, Yonglong; Xie, Shuangwei; Wang, Tieyu; Jones, Kevin C; Sweetman, Andrew J

    2015-12-01

    Perfluorooctane Sulfonate (PFOS) and related substances have been widely applied in both industrial processes and domestic products in China. Exploring the environmental fate and transport of PFOS using modeling methods provides an important link between emission and multimedia diffusion which forms a vital part in the human health risk assessment and chemical management for these substances. In this study, the gridded fugacity based BETR model was modified to make it more suitable to model transfer processes of PFOS in a coastal region, including changes to PFOS partition coefficients to reflect the influence of water salinity on its sorption behavior. The fate and transport of PFOS in the Bohai coastal region of China were simulated under steady state with the modified version of the model. Spatially distributed emissions of PFOS and related substances in 2010 were estimated and used in these simulations. Four different emission scenarios were investigated, in which a range of half-lives for PFOS related substances were considered. Concentrations of PFOS in air, vegetation, soil, fresh water, fresh water sediment and coastal water were derived from the model under the steady-state assumption. The median modeled PFOS concentrations in fresh water, fresh water sediment and soil were 7.20ng/L, 0.39ng/g and 0.21ng/g, respectively, under Emission Scenario 2 (which assumed all PFOS related substances immediately degrade to PFOS) for the whole region, while the maximum concentrations were 47.10ng/L, 4.98ng/g and 2.49ng/g, respectively. Measured concentration data for PFOS in the Bohai coastal region around the year of 2010 were collected from the literature. The reliability of the model results was evaluated by comparing the range of modeled concentrations with the measured data, which generally matched well for the main compartments. Fate and transfer fluxes were derived from the model based on the calculated inventory within the compartments, transfer fluxes between compartments and advection fluxes between sub-regions. It showed that soil and costal water were likely to be the most important sinks of PFOS in the Bohai costal region, in which more than 90% of PFOS was stored. Flows of fresh water were the driving force for spatial transport of PFOS in this region. Influences of the seasonal change of fresh water fluxes on the model results were also analyzed. When only seasonal changes of the fresh water flow rates were considered, concentrations of PFOS in winter and spring were predicted to be higher than that under annual average conditions, while the concentrations in summer and autumn were lower. For PFOS fluxes entering the sea, opposite conclusions were drawn compared to the concentrations. Environmental risks from the presence of PFOS in fresh water were assessed for this region through comparison with available water quality criteria values. The predicted concentrations of PFOS in the Bohai coastal region provided by the model were lower than the water quality criteria published by the United States Environmental Protection Agency and Chinese researchers, while the concentrations in more than 80% of the sampling locations exceeded the European Union Water Framework Directive Environmental Quality Standards values. Seasonal variations of flow rate might cause a significant increase in environmental risks. PMID:26298835

  4. WINDOW OF SUSCEPTIBILITY TO PERFLUOROOCTANE SULFONATE (PFOS)-INDUCED NEONATAL MORTALITY IN THE RAT

    EPA Science Inventory

    GRASTY1, 2, R.C., B.E. GREY1, C.S. LAU1 and J.M. ROGERS1, 2. 1Reproductive Toxicology Division, NHEERL, ORD, US EPA, Research Triangle Park, NC; and 2Curriculum in Toxicology, UNC Chapel Hill, Chapel Hill, NC. Window of susceptibility to perfluorooctane sulfonate (PFOS)-induce...

  5. EFFECTS OF PERFLUOROOCTANE SULFONATE (PFOS) ON MATERNAL AND DEVELOPMENTAL THYROID STATUS IN THE RAT

    EPA Science Inventory

    EFFECTS OF PERFLUOROOCTANE SULFONATE (PFOS) ON MATERNAL AND DEVELOPMENTAL THYROID STATUS IN THE RAT. JR Thibodeaux1, R Hanson1, B Grey1, JM Rogers1, ME Stanton2, and C Lau1. 1Reproductive Toxicology Division; 2Neurotoxicology Division, NHEERL, ORD, US EPA, Research Triangle P...

  6. ANALYTICAL METHODS AND QUALITY ASSURANCE CRITERIA FOR LC/ES/MS DETERMINATION OF PFOS IN FISH

    EPA Science Inventory

    PFOS, perfluorooctanesulfonate, has recently received much attention from environmental researchers. Previous analytical methods were based upon complexing with a strong ion-pairing reagent and extraction into MTBE. Detection was done on a concentrate using negative ion LC/ES/MS/...

  7. HEPATIC GENE EXPRESSION PROFILES OF RATS EXPOSED TO PERFLUOROOCTANE SULFONATE (PFOS) IN UTERO

    EPA Science Inventory

    Hepatic Gene Expression Profiles of Rats Exposed to Perfluorooctanesulfonate (PFOS) in utero.
    J.A. Bjork1, J.M. Berthiaume1, C. Lau2, J. L. Butenhoff3, and K.B. Wallace1

    1Department of Biochemistry & Molecular Biology, University of Minnesota School of Medicine, Dulut...

  8. MATERNAL AND DEVELOPMENTAL TOXICITY OF PERFLUOROOCTANE SULFONATE (PFOS) IN THE MOUSE

    EPA Science Inventory

    MATERNAL AND DEVELOPMENTAL TOXICITY OF PERFLUOROOCTANE SULFONATE (PFOS) IN THE MOUSE. J.R. Thibodeaux1, R.G. Hanson1, B.E. Grey1, B.D. Barbee1, J.H. Richards2, J.L. Butenhoff3, J.M. Rogers1, C. Lau1. 1Reprod. Tox. Div., 2Exp. Tox. Div., NHEERL, ORD, US EPA, Research Triangle Pa...

  9. MATERNAL AND DEVELOPMENTAL TOXICITY OF PERFLUOROOCATANE SULFONATE (PFOS) IN THE RAT

    EPA Science Inventory

    MATERNAL AND DEVELOPMENTAL TOXICITY OF PERFLUOROOCTANE SULFONATE (PFOS) IN THE RAT. C. Lau1, J.M. Rogers1, J.R. Thibodeaux1, R.G. Hanson1, B.E. Grey1, B.D. Barbee1, J.H. Richards2, J.L. Butenoff3. 1Reprod. Tox. Div., 2Exp. Tox. Div., NHEERL, USEPA, Research Triangle Park, NC, 3...

  10. GC AND LC CHROMATOGRAPHIC AND EI, CE, +/- CI, AND ES MASS SPECTRAL CHARACTERISTICS OF SALTS AND AMIDES OF PERFLUOROOCTANESULFONIC ACID

    EPA Science Inventory

    In 1976, fluorine in human blood serum was thought to be present as perfluorooctanic acid; however, in the 1990s it was correctly identified by LC/MS as perfluorooctanesulfonate (PFOS). PFOS was both a commercial product and an end-stage metabolite of numerous substituted amides ...

  11. Gestational and lactational exposure to potassium perfluorooctanesulfonate (K+PFOS) in rats: toxicokinetics, thyroid hormone status, and related gene expression.

    PubMed

    Chang, Shu-Ching; Ehresman, David J; Bjork, James A; Wallace, Kendall B; Parker, George A; Stump, Donald G; Butenhoff, John L

    2009-06-01

    Perfluorooctanesulfonate (PFOS), a persistent and accumulative compound, is widely distributed in humans and wildlife. Human exposure can occur early in development, as evidenced by the detection of PFOS in umbilical cord blood and breast milk. As part of a developmental neurotoxicology study for which developmental endpoints, including those related to the developing nervous system, have been reported separately, groups of 25 pregnant Sprague Dawley rats were given daily oral doses of either vehicle control or potassium PFOS (K(+)PFOS) at 0.1, 0.3, and 1.0mg/kg-d from gestation day (GD) 0 (day positive for mating) through postnatal day (PND) 20. An additional 10 pregnant females per treatment group were treated through GD 19 and sacrificed on GD 20 in order to obtain maternal and fetal serum and tissue samples at the end of gestation. The present paper reports the results of samples of serum, liver, brain, and thyroid glands taken at various times to evaluate: (1) serum, liver, and brain PFOS concentrations by LC-MS/MS to establish the relationship between PFOS concentrations and study outcomes; (2) serum thyrotropin (TSH) concentrations by RIA; (3) thyroid follicular cell proliferation index by Ki-67 immunohistochemical staining; (4) thyroid follicle epithelial cell height and colloidal area by histomorphometric analysis; (5) selected liver mRNA transcripts by quantitative RT-PCR. PFOS concentrations in dam and pup serum, liver, and brain increased across treatment groups in approximate proportion to the proportional increases in maternal K(+)PFOS dose, and sex differences in PFOS concentrations were not apparent in pups on PND 21. In pups from K(+)PFOS maternal dose groups on PND 72, serum PFOS had decreased to about 3 and 11% of PND 21 concentrations in males and females, respectively, and liver PFOS had decreased to about 17% of PND 21 concentrations in both sexes. Liver PFOS concentrations were approximately 0.6-0.8 times serum PFOS in GD 20 fetuses, and increased to about 2-4 times serum concentrations on PND 4 and 21. GD 20 fetal and PND 4 pup brain PFOS concentrations were approximately 33% of the corresponding serum concentrations, dropping to approximately 10% by PND 21, in contrast to dam brain PFOS concentrations, which were approximately 4-9% of serum PFOS concentrations. Compared to controls, Cyp2b2 mRNA was increased (2.8-fold) in the 1.0mg/kg-d treatment-group dams on GD 20. In male pups on PND 21, Cyp4A1, ACoA, and Cyp2b2 were increased 2.1-, 1.5-, and 1.8-fold, respectively, and Cyp7A1 was decreased 3.5-fold. Serum TSH and thyroid follicular morphology were not altered by K(+)PFOS treatment. The mean number of proliferating thyroid follicular cells was increased 2.1-fold over control in GD 20 female fetuses from 1.0mg/kg-d-treated dams, yet the highest individual count was similar to that of controls (116 versus 113 in controls). PMID:19429409

  12. Characterisation of perfluorooctane sulfonate (PFOS) in a terrestrial ecosystem near a fluorochemical plant in Flanders, Belgium.

    PubMed

    D'Hollander, Wendy; De Bruyn, Luc; Hagenaars, An; de Voogt, Pim; Bervoets, Lieven

    2014-10-01

    Bioaccumulation of perfluorooctane sulfonate (PFOS) in a restricted terrestrial food chain was investigated with the omnivorous wood mouse (Apodemus sylvaticus) on top of the studied food chain. The levels detected are very high compared with literature as a result of the presence of fluorochemical plant in the immediate vicinity of the study area. Soil, surface water, fruits of European elder and common blackberry, invertebrates, bank vole and wood mouse were collected at two sites, e.g. Blokkersdijk, adjacent to the fluorochemical plant, and Galgenweel, a reference site 2 km further away. In wood mouse, the highest PFOS concentrations were found in the liver followed by the pancreas, lungs and kidneys, with the spleen having the lowest levels. In the liver, the concentrations ranged from 787 to 22,355 ng/g ww at Blokkersdijk and these were significantly correlated with those detected in the kidneys (13.7-4,226 ng/g ww). If current results are compared to the findings of a previous study conducted in 2002 at the same sites, a significant decrease of PFOS in livers of wood mouse is observed. To the best of our knowledge, so far no studies reported levels of PFOS in terrestrial invertebrates under field conditions. At Blokkersdijk, PFOS was detected in all invertebrate species ranging from 28 to 9,000 ng/g. Soil and water were also contaminated with levels of respectively 68 ng/g and 22 ng/L. Biota-to-soil accumulation factors ranged from 0.11 to 68 for earthworms. Biomagnification factors (BMFs) of liver wood mouse/berries were as high as 302. BMFs for invertebrates were remarkably lower (up to 2). PMID:24385186

  13. Biochemical effect evaluation of perfluorooctane sulfonic acid-contaminated wood mice (Apodemus sylvaticus).

    PubMed Central

    Hoff, Philippe Tony; Scheirs, Jan; Van de Vijver, Kristin; Van Dongen, Walter; Esmans, Eddy Louis; Blust, Ronny; De Coen, Wim

    2004-01-01

    Wood mice (Apodemus sylvaticus) were captured at Blokkersdijk, a nature reserve in the immediate vicinity of a fluorochemical plant in Antwerp, Belgium, and at Galgenweel, 3 kilometers farther away. The liver perfluorooctane sulfonic acid (PFOS) concentrations in the Blokkersdijk mice were extremely high (0.47-178.55 micro g/g wet weight). Perfluorononanoic, perfluorodecanoic, perfluoroundecanoic, and perfluorododecanoic acids were found sporadically in the liver tissue of the Blokkersdijk mice. The liver PFOS concentrations at Galgenweel were significantly lower than those at Blokkersdijk (0.14-1.11 micro g/g wet weight). Further results suggest sex independence of the liver PFOS levels, increased levels of PFOS bioaccumulation in older mice, and maternal PFOS transfer to the young. Several liver end points were significantly elevated in the Blokkersdijk mice: liver weight, relative liver weight, peroxisomal beta-oxidation activity, microsomal lipid peroxidation level, and mitochondrial fraction protein content. For the mitochondrial fraction catalase activity, no significant difference between locations was found. The liver weight, relative liver weight, and liver microsomal lipid peroxidation level increased significantly with the liver PFOS concentration. No indications for PFOS-mediated effects on the serum triglyceride, cholesterol, or potassium levels were obtained. The liver PFOS concentration was negatively related to the serum alanine aminotransferase activity. PMID:15121511

  14. Chronic PFOS exposures induce life stage-specific behavioral deficits in adult zebrafish and produce malformations in F1 offspring

    PubMed Central

    Chen, Jiangfei; Huang, Changjiang; Das, Siba R.; La Du, Jane; Corvi, Margaret M.; Bai, Chenglian; Chen, Yuanhong; Tanguay, Robert L.; Dong, Qiaoxiang

    2014-01-01

    Perfluorooctanesulphonicacid (PFOS) is an organic contaminant that is ubiquitous in the environment, wildlife, and humans. Few studies have assessed the effects of chronic PFOS exposure on central nervous system function in aquatic organisms. The present study defined the behavioral effects of varying life span chronic exposures to low dose PFOS in zebrafish. The zebrafish were treated with vehicle control or 0.5μM PFOS during 1–21, 21–120, or 1–120 day post fertilization (dpf). Chronic PFOS exposure impaired the adult zebrafish behavior mode under the tapping stimulus. The movement speed of 1–120 dpf exposed fish was significantly increased compared with control, while 1–21 and 21–120 dpf exposed groups were not severely affected. PFOS residues in F1 embryos derived from parental exposure during both the 1–120 and 21–120 dpf groups was significantly higher than control, and F1 embryos in these two groups showed obvious malformations, such as uninflated swim bladder (USB) and bent spine (BS). Larvae of the parental exposed to PFOS from 1–21 or 21–120 dpf elicited a higher swim rate than control in both the light and dark periods. Embryos derived from the 1–120 dpf group showed a statistically lower speed in the light period and a higher speed in the dark period as compared with control. Though there is little PFOS residue in 1–21 dpf group, the adverse behavioral effects on both adult and F1 larvae indicate that exposure during the first 21 dpf induce long-term neurobehavior toxicity. Our findings demonstrate that chronic exposure to low dose PFOS in different life stage adversely impacts adult behavior, subsequent offspring malformation, and larval behavior. PMID:23059794

  15. Perfluorooctane sulfonic acid exposure increases cadmium toxicity in early life stage of zebrafish, Danio rerio.

    PubMed

    Kim, Suyoung; Ji, Kyunghee; Lee, Sangwoo; Lee, Jinyoung; Kim, Jungkon; Kim, Sunmi; Kho, Younglim; Choi, Kyungho

    2011-04-01

    Exposure to perfluorooctane sulfonic acid (PFOS) is known to induce thyroid-related adverse effects in aquatic organisms. Because an antioxidant defense mechanism is one of the key functions of the thyroid gland, we examined whether preexposure to PFOS could disrupt thyroid function and enhance cadmium (Cd)-induced oxidative stress in fish. Zebrafish embryos were exposed to control or 0.5 mg/L PFOS for 7 d after fertilization and subsequently exposed to 0.038 mg/L of Cd(2+) or a mixture of the PFOS and Cd for an additional 3 d until 10 d postfertilization (dpf). Survival rates, body length, messenger RNA (mRNA) expressions related to thyroid function and oxidative stress, the levels of thyroid hormones, and malondialdehyde and antioxidant enzyme activities were measured. Significant down-regulation of mRNAs related to thyroid function (thyroid hormone receptor-alpha [THRα], thyroid hormone receptor-beta [THRβ], hematopoietically expressed homeobox [hhex], and paired box gene 8 [pax8]) and decrease of throxine (T4) levels were observed in the PFOS preexposure group, suggesting that PFOS preexposure would influence the performance of thyroid gland in the later stages of life. Certain genes relative to oxidative stress, such as superoxide dismutase 1 (sod1) and heat shock protein 70 (hsp70), in the PFOS preexposure group were significantly up-regulated when the larvae were subsequently exposed to Cd or to the mixture of PFOS and Cd. Glutathione S-transferase activity and malondialdehyde levels of the PFOS-preexposed group were increased significantly by Cd exposure. Significant decrease of the survival rates and body length of fish were observed at 10 dpf among the larvae that were previously exposed to PFOS. These results suggest that preexposure to PFOS could affect antioxidant defense mechanisms and potentially increase the toxicity of Cd on mRNA expression and enzyme activity level responses, as well as on survival or growth of individuals. PMID:21184528

  16. Toxicity of perfluorooctane sulfonate and perfluorooctanoic acid to plants and aquatic invertebrates.

    PubMed

    Li, Mei-Hui

    2009-02-01

    Acute toxicities of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were tested on four freshwater species and three plant species. PFOS was more toxic than PFOA for all species tested in this study. Similar time-response patterns of PFOS and PFOA toxicity were observed for each tested species. Values of the 48-h LC(50) of PFOS for all test species ranged from 27 to 233 mg/L and values of the 96-h LC(50) for three of the species ranged from 10 to 178 mg/L. Values of the 48-h LC(50) of PFOA for all test species ranged from 181 to 732 mg/L and values of the 96-h LC(50) for three of the species ranged from 337 to 672 mg/L. The most sensitive freshwater species to PFOS was green neon shrimp (Neocaridina denticulate) with a 96-h LC(50) of 10 mg/L. Of the aquatic organisms tested, the aquatic snail (Physa acuta) always has the highest resistance to PFOS or PFOA toxicity over each exposure period. Both PFOS and PFOA had no obvious adverse effect on seed germination for all three plant species. Five-day EC(50) of root elongation was more sensitive to LC(50) of seed germination in this study. Based on EC(10), EC(50), and NOECs, the 5-day root elongation sensitivity of test plants to both PFOS and PFOA was in the order of lettuce (Lactuca sativa) > pakchoi (Brassica rapa chinensis) > cucumber (Cucumis sativus). Based on the results of this study and other published literature, it is suggested that current PFOS and PFOA levels in freshwater may have no acute harmful ecological impact on the aquatic environment. However, more research on the long-term ecological effects of PFOS and PFOA on aquatic fauna are needed to provide important information to adequately assess ecological risk of PFOS and PFOA. PMID:18461560

  17. Evidence for the Involvement of Xenobiotic-responsive Nuclear Receptors in Transcriptional Effects Upon Perfluoroalkyl Acid Exposure in Diverse Species.

    EPA Science Inventory

    Humans and other species have detectable body burdens of a number of perfluorinated alkyl acids (PFAA) including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). In mouse and rat liver these compounds elicit transcriptional and phenotypic effects similar to pe...

  18. Evidence for the Involvement of Xenobiotic-response Nuclear Receptors in Transcriptional Effects Upon Perfluroroalkyl Acid Exposure in Diverse Species

    EPA Science Inventory

    Humans and ecological species have been found to have detectable body burdens of a number of perfluorinated alkyl acids (PFAA) including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). In mouse and rat liver these compounds elicit transcriptional and phenotyp...

  19. Serum levels of perfluoroalkyl acids (PFAAs) with isomer analysis and their associations with medical parameters in Chinese pregnant women.

    PubMed

    Jiang, Weiwei; Zhang, Yifeng; Zhu, Lingyan; Deng, Jimin

    2014-03-01

    Perfluoroalkyl acids (PFAAs) are a group of chemicals used for many applications and widely present in the environment and humans. In this study, serum levels of PFAAs and isomers of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) were analyzed in 141 Chinese pregnant women. Among all the samples, total PFOS (∑PFOS, mean concentration 7.32ng/mL) was predominant, followed by ∑PFOA (mean 4.78ng/mL) and perfluorodecanoate (PFDA, mean 1.45ng/mL). On average, the proportion of linear PFOS (n-PFOS) was 66.7% of ∑PFOS, which was higher than the general population, implying that maternal women could excrete branched PFOS isomers to the fetus by transplacental transfer. Moreover, the proportion of n-PFOS decreased significantly with the increasing concentration of ∑PFOS in the serum samples (r=-0.342, p<0.001). The mean proportion of n-PFOA in the serum samples was 99.0%, which was much higher than the technical ECF (electrochemical fluorination) products (ca. 70%). The small proportion of branched isomers of PFOA suggests that there is still a source of ECF PFOA in China. Significant correlations (p<0.005) were observed between the concentrations of some PFAAs with certain medical parameters in the pregnant women. For example, the levels of most perfluorinated carboxylic acids (PFCAs) were found to correlate with albumin significantly, which might be a sign of immunotoxicity of these chemicals. The adverse effects of PFAA exposure to pregnant women may increase the health risk of the fetus. Interestingly, not only the PFAA concentrations but also the percentages of PFOS and PFOA isomers were correlated with certain medical parameters. This implies that the compositions of PFOS or PFOA should be considered in human health risk assessment in the future. PMID:24361923

  20. Mechanisms for removal of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) from drinking water by conventional and enhanced coagulation.

    PubMed

    Xiao, Feng; Simcik, Matt F; Gulliver, John S

    2013-01-01

    Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are persistent organic pollutants that have been found to be ubiquitous in the environment. This article, for the first time, delineates removal areas of these polar compounds on a coagulation diagram that associates chemical conditions with different coagulation mechanisms. Variables considered were solution pH, coagulant dosage, coagulants (alum and ferric chloride), natural organic matter (NOM), initial turbidity, and flocculation time. The jar-test results show that conventional coagulation (alum dosage of 10-60 mg/L and final pH of 6.5-8.0) removed ≤20% of PFOS and PFOA. These chemicals tended to be removed better by enhanced coagulation at higher coagulant dosages (>60 mg/L) and (thus) lower final pH (4.5-6.5). A coagulation diagram was developed to define the coagulant dosage and solution pH for PFOS/PFOA removal. The results suggest that the primary PFOS/PFOA removal mechanism is adsorption to fine Al hydroxide flocs freshly formed during the initial stage of coagulation; increasing flocculation time from 2 to 90 min could not further improve PFOS and PFOA removals. Furthermore, the effect of NOM on PFOS/PFOA removal by coagulation was examined, and possible removal mechanisms were discussed. PMID:23123052

  1. Assembling structures and dynamics properties of perfluorooctane sulfonate (PFOS) at water-titanium oxide interfaces.

    PubMed

    He, Guangzhi; Pan, Gang; Zhang, Meiyi

    2013-09-01

    The surface-associated structures and growth modes of perfluorooctane sulfonate (PFOS) at water-rutile TiO2 interfaces were defined by molecular dynamics (MD) simulations. The results showed that a compact PFOS layer was generated at the rutile surfaces, and the assembling structures and dynamic profiles were crystal-face-dependent. PFOS molecules were attached to the (110) and (001) surfaces mainly by the sulfonate headgroups. A well-defined monolayer was formed on the (110) surface with the perfluorinated alkyl chains nearly perpendicular to the substrate, whereas the C-F chains were inclined at an angle (30-75°) and formed a hemicylinder-like configuration on the (001) surface. On the other hand, the perfluorinated amphiphiles interacted with the (100) plane through both the sulfonate headgroups (relatively strong electrostatic attraction) and the C-F tailgroups (weak van der Waals forces) and yielded an irregular assembling pattern. Water molecules were mostly concentrated more than 17.0 Å away from the solid surfaces and formed a continuous solvent layer, suggesting the super hydrophobicity of perfluorinated alkyl chains. A counterion-bridging mechanism suggested in surfactant adsorption was observed at the molecular scale, where the sulfonate headgroups were linked together by the potassium ions at the surfaces and caused the formation of surface aggregates. PMID:23759323

  2. Heat-activated persulfate oxidation of PFOA, 6:2 fluorotelomer sulfonate, and PFOS under conditions suitable for in-situ groundwater remediation.

    PubMed

    Park, Saerom; Lee, Linda S; Medina, Victor F; Zull, Aaron; Waisner, Scott

    2016-02-01

    PFOA (perfluorooctanoic acid) oxidation (0.121-6.04 μM) by heat-activated persulfate was evaluated at 20-60 °C with 4.2-84 mM [Formula: see text] and in the presence of soluble fuel components to assess feasibility for in-situ remediation of groundwater. 6:2 fluorotelomer sulfonic acid/sulfonate (6:2 FTSA) and PFOS (perfluorooctanesulfonic acid) persulfate oxidation was also evaluated in a subset of conditions given their co-occurrence at many sites. High performance liquid chromatography electron spray tandem mass spectrometry was used for organic analysis and fluoride was measured using a fluoride-specific electrode. PFOA pseudo-1st order transformation rates (k1,PFOA) increased with increasing temperature (half-lives from 0.1 to 7 d for 60 to 30 °C) sequentially removing CF2 groups ('unzipping') to shorter chain perfluoroalkyl carboxylic acids (PFCAs) and F(-). At 50 °C, a 5-fold increase in [Formula: see text] led to a 5-fold increase in k1,PFOA after which self-scavenging by sulfate radicals decreased the relative rate of increase with more [Formula: see text] . Benzene, toluene, ethylbenzene and xylene did not affect k1,PFOA even at 40 times higher molar concentrations than PFOA. A modeling approach to explore pathways strongly supported that for 6:2 FTSA, both the ethyl linkage and CF2-CH2 bond of 6:2 FTSA oxidize simultaneously, resulting in a ratio of ∼25/75 PFHpA/PFHxA. The effectiveness of heat-activated [Formula: see text] on PFOA oxidation was reduced in a soil slurry; therefore, repeated persulfate injections are required to efficiently achieve complete oxidation in the field. However, PFOS remained unaltered even at higher activation temperatures, thus limiting the sole use of heat-activated persulfate for perfluoroalkyl substances removal in the field. PMID:26692515

  3. Association between plasma PFOA and PFOS levels and total cholesterol in a middle-aged Danish population.

    PubMed

    Eriksen, Kirsten T; Raaschou-Nielsen, Ole; McLaughlin, Joseph K; Lipworth, Loren; Tjønneland, Anne; Overvad, Kim; Sørensen, Mette

    2013-01-01

    Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) are used in a variety of consumer products and have been detected worldwide in human blood. Recent studies mainly of highly exposed populations have indicated that PFOA and PFOS may affect serum cholesterol levels, but the magnitude of the effect may be inconsistent across exposure levels. The aim of the present cross-sectional study was to investigate the association between plasma PFOA and PFOS and total cholesterol in a general, middle-aged Danish population. The study population comprised 753 individuals (663 men and 90 women), 50-65 years of age, nested within a Danish cohort of 57,053 participants. Blood samples were taken from all cohort members at enrolment (1993-1997) and stored in a biobank at -150°C. Plasma levels of PFOA and PFOS and serum levels of total cholesterol were measured. The associations between plasma PFOA and PFOS levels and total cholesterol levels were analysed by generalized linear models, both crude and adjusted for potential confounders. We observed statistically significant positive associations between both perfluorinated compounds and total cholesterol, e.g. a 4.4 [95% CI  =  1.1-7.8] higher concentration of total cholesterol (mg/dL) per interquartile range of PFOA plasma level. Sex and prevalent diabetes appeared to modify the association between PFOA and PFOS, respectively, and cholesterol. In conclusion, this study indicated positive associations between plasma PFOA and PFOS levels and total cholesterol in a middle-aged Danish population, although whether the observed pattern of results reflects a causal association is unclear. PMID:23441227

  4. Association between Plasma PFOA and PFOS Levels and Total Cholesterol in a Middle-Aged Danish Population

    PubMed Central

    Eriksen, Kirsten T.; Raaschou-Nielsen, Ole; McLaughlin, Joseph K.; Lipworth, Loren; Tjønneland, Anne; Overvad, Kim; Sørensen, Mette

    2013-01-01

    Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) are used in a variety of consumer products and have been detected worldwide in human blood. Recent studies mainly of highly exposed populations have indicated that PFOA and PFOS may affect serum cholesterol levels, but the magnitude of the effect may be inconsistent across exposure levels. The aim of the present cross-sectional study was to investigate the association between plasma PFOA and PFOS and total cholesterol in a general, middle-aged Danish population. The study population comprised 753 individuals (663 men and 90 women), 50–65 years of age, nested within a Danish cohort of 57,053 participants. Blood samples were taken from all cohort members at enrolment (1993–1997) and stored in a biobank at -150°C. Plasma levels of PFOA and PFOS and serum levels of total cholesterol were measured. The associations between plasma PFOA and PFOS levels and total cholesterol levels were analysed by generalized linear models, both crude and adjusted for potential confounders. We observed statistically significant positive associations between both perfluorinated compounds and total cholesterol, e.g. a 4.4 [95% CI  =  1.1–7.8] higher concentration of total cholesterol (mg/dL) per interquartile range of PFOA plasma level. Sex and prevalent diabetes appeared to modify the association between PFOA and PFOS, respectively, and cholesterol. In conclusion, this study indicated positive associations between plasma PFOA and PFOS levels and total cholesterol in a middle-aged Danish population, although whether the observed pattern of results reflects a causal association is unclear. PMID:23441227

  5. The expression of several reproductive hormone receptors can be modified by perfluorooctane sulfonate (PFOS) in adult male rats.

    PubMed

    López-Doval, S; Salgado, R; Lafuente, A

    2016-07-01

    This study was undertaken to evaluate the possible role of several reproductive hormone receptors on the disruption of the hypothalamic-pituitary-testis (HPT) axis activity induced by perfluorooctane sulfonate (PFOS). The studied receptors are the gonadotropin-releasing hormone receptor (GnRHr), luteinizing hormone receptor (LHr), follicle-stimulating hormone receptor (FSHr), and the androgen receptor (Ar). Adult male rats were orally treated with 1.0; 3.0 and 6.0 mg of PFOS kg(-1) d(-1) for 28 days. In general terms, PFOS can modify the relative gene and protein expressions of these receptors in several tissues of the reproductive axis. At the testicular level, apart from the expected inhibition of both gene and protein expressions of FSHr and Ar, PFOS also stimulates the GnRHr protein and the LHr gene expression. The receptors of the main hormones involved in the HPT axis may have an important role in the disruption exerted by PFOS on this axis. PMID:27151425

  6. Is Ongoing Sulfluramid Use in South America a Significant Source of Perfluorooctanesulfonate (PFOS)? Production Inventories, Environmental Fate, and Local Occurrence.

    PubMed

    Löfstedt Gilljam, John; Leonel, Juliana; Cousins, Ian T; Benskin, Jonathan P

    2016-01-19

    Despite international phase-out initiatives, production and use of perfluorooctanesulfonate (PFOS) and related substances continues in some countries. In Brazil, the PFOS-precursor N-ethyl perfluorooctane sulfonamide (EtFOSA) is used in Sulfluramid, a pesticide for controlling leaf-cutting ants. New data on production, environmental fate, and occurrence of Brazilian Sulfluramid are reported herein. From 2003 to 2013, Brazilian Sulfluramid manufacturing increased from 30 to 60 tonnes yr(-1) EtFOSA. During this time <1.3 tonnes yr(-1) were imported, while exports increased from ∼0.3 to 2 tonnes yr(-1). From 2004 to 2015, most EtFOSA was exported to Argentina (7.2 tonnes), Colombia (2.07 tonnes), Costa Rica (1.13 tonnes), Equador (2.16 tonnes), and Venezuela (2.4 tonnes). Within Brazil, sales occurred primarily in the states of Minas Gerais, São Paulo, Mato Grosso do Sul, Espírito Santo, and Bahia. Model simulations predict EtFOSA will partition to soils, while transformation products perfluorooctane sulfonamide (FOSA) and PFOS are sufficiently mobile to leach into surface waters. In support of these predictions, up to 3400 pg L(-1) of FOSA and up to 1100 pg L(-1) of PFOS were measured in Brazilian surface water, while EtFOSA was not detected. The high FOSA/PFOS ratio observed here (up to 14:1) is unprecedented in the scientific literature to our knowledge. Depending on the extent of conversion of EtFOSA, cumulative Brazilian Sulfluramid production and import from 2004 to 2015 may contribute between 167 and 487 tonnes of PFOS/FOSA to the environment. These levels are clearly nontrivial and of concern since production is continuing unabated. PMID:26653085

  7. AROMATASE-B (CYP 19B) EXPRESSION IN FATHEAD MINNOWS (PIMEPHALES PROMELAS) EXPOSED TO PERFLUOROOCTANE (PFOS) AND THE AROMATASE INHIBITOR FADROZOLE

    EPA Science Inventory

    Perfluorooctane sulfonate (PFOS) is a fluorinated organic contaminant that is globally distributed in both humans and wildlife. PFOS belongs to a family of perfluorinated sulfonates that are highly persistent in the environment and have been commercially produced for over 40 year...

  8. Developmental Toxicity of Perfluoronanoic Acid in Mice

    EPA Science Inventory

    Perfluorononanoic acid (PFNA) is a ubiquitous and persistent environmental contaminant. Although its levels in the environment and in humans are lower than those of perfluorooctane sulfonate(PFOS) or perfluorooctanoic acid (PFOA), a steady trend of increases in the general popula...

  9. Comparison of the sorption behaviors and mechanisms of perfluorosulfonates and perfluorocarboxylic acids on three kinds of clay minerals.

    PubMed

    Zhao, Lixia; Bian, Jingna; Zhang, Yahui; Zhu, Lingyan; Liu, Zhengtao

    2014-11-01

    The sorption of four perfluoroalkyl acids (PFAAs) [perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid (PFOA) and perfluorohexanoic acid (PFHxA)] on three typical minerals [montmorillonite (MM), kaolinite (KL) and hematite (HM)] was studied. The sorption of PFOS and PFHxS was much stronger than PFOA and PFHxA. The sorption of each PFAA on the minerals followed an order of HM>KL>MM, even though MM was positively while KL and HM were negatively charged, implying that the sorption is driven by some other interactions besides electrostatic attraction. The sorption decreased with an increase in pH and a decrease in ionic strength of the solution, and their impacts on PFOS were much stronger than other three PFAAs. Surface complexing and hydrogen-bonding could make great contributions to the sorption of PFOS on the minerals. The results are important for understanding the transport and fate of PFAAs in sediment and ground water. PMID:25113183

  10. Induction of p53-mediated apoptosis in splenocytes and thymocytes of C57BL/6 mice exposed to perfluorooctane sulfonate (PFOS)

    SciTech Connect

    Dong, Guang-Hui; Wang, Jing; Zhang, Ying-Hua; Liu, Miao-Miao; Wang, Da; Zheng, Li; Jin, Yi-He; School of Environmental Science and Technology, Dalian University of Technology, Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, Dalian 116024

    2012-10-15

    Perfluorooctane sulfonate (PFOS) is a persistent environmental contaminant found in human and wildlife tissues. It has been reported that PFOS can cause atrophy of the immune organs and apoptosis of immunocytes in rodents. However, the mechanism behind such cause is still unclear. To understand the model of cell death and its mechanism on lymphoid cells in vivo, we conducted a dose/response experiment in which 4 groups of male adult C57BL/6 mice (12 mice per group) were dosed daily by oral gavage with PFOS at 0, 0.0167, 0.0833, or 0.8333 mg/kg/day, yielding targeted Total Administered Dose (TAD) of 0, 1, 5, or 50 mg PFOS/kg, respectively, over 60 days. The results showed that spleen and thymus weight were significantly reduced in the highest PFOS-dose-group (TAD 50 mg PFOS/kg) compared to the control group, whereas liver weight was significantly increased. We analyzed the cell death via apoptosis with an annexin-V/propidium iodide assay by flow cytometry, and observed that both the percentage of apoptosis and the expression of the pro-apoptotic proteins p53 in splenocytes and thymocytes increased in a dose-related manner after PFOS treatment. We also observed that PFOS induced p53-dependent apoptosis through the cooperation between the Bcl-xl down regulation without changing the Bcl-2 and Bax expression. The down regulation of Bcl-xl was strongly indicating mitochondrial involvement in apoptosis. It is confirmed by the release of cytochrome c and activation of caspase-3. All of these findings establish an important role of p53 and mitochondrial function in PFOS induced toxic environment in the host. -- Highlights: ► PFOS immunotoxicity is caused by induction of apoptosis via the p53 activation. ► PFOS exposure can induce down regulation of Bcl-xl. ► Mitochondria are involved in PFOS-induced apoptosis. ► PFOS exposure can cause the release of cytochrome c and activation of caspase-3.

  11. Levels of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) in blood samples from different groups of adults living in Greece.

    PubMed

    Vassiliadou, Irene; Costopoulou, Danae; Ferderigou, Angeliki; Leondiadis, Leondios

    2010-08-01

    The production of perfluorinated compounds which finds application in a wide variety of consumer products has led to their accumulation in the environment. This fact, in combination with their chemical properties of amphiphilicity and chemical stability is the cause of their occurrence in human tissues, which according to reports is widespread, not only in occupationally exposed workers, but also in the general population. In this study, we analyzed 182 blood samples from three different groups of adults living in Greece, in order to evaluate blood levels of two environmentally most common perfluorinated compounds, perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA). The samples examined were from a group of individuals living in Athens, a group of inhabitants of the semi-urban and rural area of Argolida, and a group of cancer patients from the St. Savas Anticancer Hospital in Athens. The latter group was chosen in order to examine the possible relation of PFOS and PFOA levels with cancer incidence in the general population. The analytical results showed the presence of PFOS and PFOA in all samples examined, at levels similar to those reported from other European countries. There was no significant difference between the three groups however there was a significant difference between the levels of men and women in all groups examined. No correlation was found between age and PFOS and PFOA levels. This is the first study of this kind to be conducted in samples from Greece. PMID:20619872

  12. TOXICITY OF PERFLUOROOCTANE SULFONATE (PFOS), PERFLUOROOCTANOIC ACID (PFOA), AND RELATED ORGANIC FLUOROCHEMICALS

    EPA Science Inventory

    A host of organic fluorochemicals increasingly are being used as surfactant coatings for fabrics and paper products, fire-fighting foams, electronic etching baths and insecticides. Concern for the potential toxicological risk of these types of chemicals had been minimal until re...

  13. Identification of Novel Polyfluorinated Ether Sulfonates as PFOS Alternatives in Municipal Sewage Sludge in China.

    PubMed

    Ruan, Ting; Lin, Yongfeng; Wang, Thanh; Liu, Runzeng; Jiang, Guibin

    2015-06-01

    A 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFAES) with the trade name F-53B, is an alternative to perfluorooctanesulfonate (PFOS) in electroplating industry that is uniquely used in China. It was developed as a mist suppressant initially in the 1970s, but the environmental behaviors and potential adverse effects of the 6:2 Cl-PFAES have only recently been investigated. In this work, the occurrence and distribution of perfluoroalkyl sulfonate (PFSA), fluorotelomer sulfonate (FTSA), and PFAES analogues were investigated in municipal sewage sludge samples collected around China. Perfluorobutane, perfluorohexane, perfluorooctane, and perfluorodecanesulfonates, 6:2 and 8:2 FTSAs, and the emerging 6:2 Cl-PFAES were detected. Moreover, 8:2 and 10:2 Cl-PFAESs were identified for the first time as new polyfluorinated contaminants using high resolution mass spectrometry. These fluorinated analytes were further quantified with the aid of commercial and laboratory-purified standards. PFOS was the predominant contaminant with a geometric mean (GM) value of 3.19 ng/g dry weight (d.w.), which was subsequently followed by 6:2 Cl-PFAES and 8:2 Cl-PFAES (GM: 2.15 and 0.50 ng/g d.w., respectively). Both 6:2 and 8:2 Cl-PFAES were positively detected as the major components in the F-53B commercial product, and discrete 6:2 Cl-PFAES/8:2 Cl-PFAES ratios in the product and sludge samples might suggest 8:2 Cl-PFAES had enhanced sorption behavior in the sludge due to the increase in hydrophobicity. PMID:25961764

  14. DISRUPTION OF THYROID HORMONE HOMEOSTASIS BY PERFLUROALKYL ACIDS

    EPA Science Inventory

    Perfluoroalkyl acids (PFAA) are man-made chemicals found ubiquitously in humans and wildlife; the major representatives of these are those with an 8-carbon chain (C-8, perfluorooctane sulfonate, PFOS and perfluorooctanoic acid, PFOA). Presently, we have investigated the effects o...

  15. Perfluorooctanesulfonate (PFOS) Perturbs Male Rat Sertoli Cell Blood-Testis Barrier Function by Affecting F-Actin Organization via p-FAK-Tyr407: An in Vitro Study

    PubMed Central

    Wan, Hin-Ting; Mruk, Dolores D.; Wong, Chris K. C.

    2014-01-01

    Environmental toxicants such as perfluorooctanesulfonate (PFOS) have been implicated in male reproductive dysfunction, including reduced sperm count and semen quality, in humans. However, the underlying mechanism(s) remains unknown. Herein PFOS at 10–20 μM (∼5–10 μg/mL) was found to be more potent than bisphenol A (100 μM) in perturbing the blood-testis barrier (BTB) function by disrupting the Sertoli cell tight junction-permeability barrier without detectable cytotoxicity. We also delineated the underlying molecular mechanism by which PFOS perturbed Sertoli cell BTB function using an in vitro model that mimics the BTB in vivo. First, PFOS perturbed F-actin organization in Sertoli cells, causing truncation of actin filaments at the BTB. Thus, the actin-based cytoskeleton was no longer capable of supporting the distribution and/or localization of actin-regulatory and adhesion proteins at the cell-cell interface necessary to maintain BTB integrity. Second, PFOS was found to perturb inter-Sertoli cell gap junction (GJ) communication based on a dye-transfer assay by down-regulating the expression of connexin-43, a GJ integral membrane protein. Third, phosphorylated focal adhesion kinase (FAK)-Tyr407 was found to protect the BTB from the destructive effects of PFOS as shown in a study via an overexpression of an FAK Y407E phosphomimetic mutant. Also, transfection of Sertoli cells with an FAK-specific microRNA, miR-135b, to knock down the expression of phosphorylated FAK-Tyr407 was found to worsen PFOS-mediated Sertoli cell tight junction disruption. In summary, PFOS-induced BTB disruption is mediated by down-regulating phosphorylated FAK-Tyr407 and connexin-43, which in turn perturbed F-actin organization and GJ-based intercellular communication, leading to mislocalization of actin-regulatory and adhesion proteins at the BTB. PMID:24169556

  16. Developmental retardation, reduced fecundity, and modulated expression of the defensome in the intertidal copepod Tigriopus japonicus exposed to BDE-47 and PFOS.

    PubMed

    Han, Jeonghoon; Won, Eun-Ji; Lee, Min-Chul; Seo, Jung Soo; Lee, Su-Jae; Lee, Jae-Seong

    2015-08-01

    2,2',4,4'-tetrabromodiphenyl ether (BDE-47) and perfluorooctane sulfonate (PFOS) are widely dispersed persistent organic pollutants (POPs) in the marine ecosystem. However, their toxic effects on marine organisms are still poorly understood. In this study, we investigated the effects of BDE-47 and PFOS on development and reproduction at the organismal level and reactive oxygen species (ROS) production and gene expression patterns of the defensome at the cellular level in the intertidal copepod Tigriopus japonicus. In copepods exposed to BDE-47 and PFOS, we observed developmental retardation and reduced fecundity, suggesting repercussions on in vivo endpoints through alterations to the normal molting and reproduction system of T. japonicus. BDE-47 and PFOS increased levels of ROS in T. japonicus in a concentration-dependent manner, indicating that POPs can induce oxidative stress through the generation of ROS. Additionally, transcript profiles of genes related to detoxification (e.g., CYPs), antioxidant functions (e.g., GST- sigma, catalase, MnSOD), apoptosis (e.g., p53, Rb), and cellular proliferation (e.g., PCNA) were modulated over 72h in response to BDE-47 (120μg/L) and PFOS (1000μg/L). These findings indicate that BDE-47 and PFOS can induce oxidative stress-mediated DNA damage repair systems with transcriptional regulation of detoxification, antioxidant, and apoptosis-related genes, resulting in developmental retardation and reduced fecundity in the copepod T. japonicus. PMID:26037098

  17. First report of a Chinese PFOS alternative overlooked for 30 years: its toxicity, persistence, and presence in the environment.

    PubMed

    Wang, Siwen; Huang, Jun; Yang, Yang; Hui, Yamei; Ge, Yuxi; Larssen, Thorjørn; Yu, Gang; Deng, Shubo; Wang, Bin; Harman, Christopher

    2013-09-17

    This is the first report on the environmental occurrence of a chlorinated polyfluorinated ether sulfonate (locally called F-53B, C8ClF16O4SK). It has been widely applied as a mist suppressant by the chrome plating industry in China for decades but has evaded the attention of environmental research and regulation. In this study, F-53B was found in high concentrations (43-78 and 65-112 μg/L for the effluent and influent, respectively) in wastewater from the chrome plating industry in the city of Wenzhou, China. F-53B was not successfully removed by the wastewater treatments in place. Consequently, it was detected in surface water that receives the treated wastewater at similar levels to PFOS (ca. 10-50 ng/L) and the concentration decreased with the increasing distance from the wastewater discharge point along the river. Initial data presented here suggest that F-53B is moderately toxic (Zebrafish LC50-96 h 15.5 mg/L) and is as resistant to degradation as PFOS. While current usage is limited to the chrome plating industry, the increasing demand for PFOS alternatives in other sectors may result in expanded usage. Collectively, the results of this work call for future assessments on the effects of this overlooked contaminant and its presence and fate in the environment. PMID:23952109

  18. Changes in morphometry and association between whole-body fatty acids and steroid hormone profiles in relation to bioaccumulation patterns in salmon larvae exposed to perfluorooctane sulfonic or perfluorooctane carboxylic acids.

    PubMed

    Arukwe, Augustine; Cangialosi, Maria V; Letcher, Robert J; Rocha, Eduardo; Mortensen, Anne S

    2013-04-15

    In the present study, we have used salmon embryos whose continuous exposure to waterborne PFOA or PFOS at 100 μg/L started as freshly fertilized eggs, and lasted for a total of 52 days. PFOS and PFOA were dissolved in methanol (carrier vehicle) whose concentration never exceeded 0.01% of total tank volume. Samples were collected at day 21, 28, 35, 52, 49 and 56 after the start of the exposure. Note that days 49 and 56 represent end of exposure and 1 week after a recovery period, respectively. Tissue bioaccumulations were determined by HPLC/MS/MS, steroid hormones, fatty acids (FAs) and lipids were determined by GC-MS, while mRNA expression levels of genes were determined by qPCR in whole body homogenate. We observed that PFOS and PFOA showed a steady increase in whole body burden during the exposure period, with a slight decrease after the recovery period. Calculated somatic indexes showed that PFOA produced increases in heart-, thymus-, liver- and kidney somatic indexes (HSI, TSI, LSI and KSI). PFOA and PFOS exposure produced significant decreases in whole body dehydroepiandrosterone (DHEA), estrone and testosterone at sampling day 21 and a strong increase of cortisol and cholesterol at the end of recovery period (day 56). PFOA and PFOS effects differed with DHEA and estrone. While PFOS decreased DHEA levels, PFOA produced an increase at day 49, and while PFOS decreased estrone, PFOA produced a slight increase at day 56. We observed changes in FA composition that predominantly involved increases in FA methyl esters (FAMEs), mono- and poly-unsaturated FA (MUFA and PUFA) and a decrease in n-3/n-6 PUFA ratio by both PFOA and PFOS. Particularly, an increase in - pentadecenoic MUFA (15:1), two n-3 PUFAs α-linolenic acid [ALA: 18:3 n3] and eicosapentaenoic acid [EPA: 20:5 n-3] and n-6 PUFA: arachidonic acid [ARA: 20:4 n6], docosapentaenoic acid (DPA) by PFOA and PFOS were observed. These effects were associated with changes in mRNA expression of FA elongase (FAE), Δ5-desaturase (FAD5) and Δ6-desaturase (FAD6) genes. In summary, the changes in hormonal and FA profiles may represent cellular and/or physiological adaptation to continuous PFOS and PFOA exposure by increasing membrane fluidity, and/or overt developmental effects. The present findings provide some potential insights and basis for a better understanding on the possible mechanisms of PFCs toxicity in fish. PMID:23435358

  19. Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in soils and groundwater of a U.S. metropolitan area: migration and implications for human exposure.

    PubMed

    Xiao, Feng; Simcik, Matt F; Halbach, Thomas R; Gulliver, John S

    2015-04-01

    Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are emerging anthropogenic compounds that have recently become the target of global concern due to their ubiquitous presence in the environment, persistence, and bioaccumulative properties. This study was carried out to investigate the migration of PFOS and PFOA in soils and groundwater in a U.S. metropolitan area. We observed elevated levels in surface soils (median: 12.2 ng PFOS/g dw and 8.0 ng PFOA/g dw), which were much higher than the soil-screening levels for groundwater protection developed in this study. The measured levels in subsurface soils show a general increase with depth, suggesting a downward movement toward the groundwater table and a potential risk of aquifer contamination. Furthermore, concentrations of PFOS and PFOA in monitoring wells in the source zone varied insignificantly over 5 years (2009-2013), suggesting limited or no change in either the source or the magnitude of the source. The analysis also shows that natural processes of dispersion and dilution can significantly attenuate the groundwater contamination; the adsorption on aquifer solids, on the other hand, appears to have limited effects on the transport of PFOS and PFOA in the aquifer. The probabilistic exposure assessment indicates that ingestion of contaminated groundwater constitutes a much more important exposure route than ingestion of contaminated soil. Overall, the results suggest that (i) the transport of PFOS and PFOA is retarded in the vadose zone, but not in the aquifer; (ii) the groundwater contamination of PFOS and PFOA often follows their release to surface soils by years, if not decades; and (iii) the aquifer can be a major source of exposure for communities living near point sources. PMID:25455741

  20. Human serum levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in Uyghurs from Sinkiang-Uighur Autonomous Region, China: background levels study.

    PubMed

    Zeng, Xiao-Wen; Qian, Zhengmin; Vaughn, Michael; Xian, Hong; Elder, Keith; Rodemich, Eugene; Bao, Jia; Jin, Yi-He; Dong, Guang-Hui

    2015-03-01

    Perfluorinated compounds (PFCs), such as perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), are a family of commonly used industrial chemicals whose persistence and ubiquity in blood samples of humans and wildlife have become a growing concern. Despite PFOS and PFOA having been found in human blood and tissue samples from occupationally exposed workers and the general worldwide population, little systematic knowledge has accrued with respect to exposure levels in Uyghurs in the Sinkiang-Uighur Autonomous Region of China, which is predominantly agricultural and pastoral. Our goal was to provide background data for biological monitoring in the general population of this region. In this study, 110 self-reported healthy human serum samples were collected from nonoccupationally exposed Uyghurs volunteers and analyzed by microbore HPLC-electrospray tandem mass spectrometry. Among the 110 blood specimens, PFOS was detected in 102 samples (93%) and ranged from the lower limit of quantification of 0.01 to 22.63 μg/L with a median of 1.93 μg/L (interquartile range 1.00-3.43 μg/L). The median was higher among males (2.39 μg/L; interquartile range 1.23-4.40 μg/L) than that among females (1.20 μg/L; interquartile range 0.83-2.77 μg/L). No significant difference was observed with respect to age. The concentration of PFOA was lower than that of PFOS and was found only in seven samples (6%) at concentrations above the limit of quantification. This study is the first investigation to reveal serum PFOS and PFOA levels in the general population of Uyghurs. PFOS and PFOA concentrations found in the present investigation were lower than those found in recent studies consisting of subjects from different geographic locations (PFOS 5.0-44.7 μg/L, PFOA 1.5-10 μg/L). PMID:25339531

  1. Combined effects of perfluorooctane sulfonate (PFOS) and maternal restraint stress on hypothalamus adrenal axis (HPA) function in the offspring of mice

    SciTech Connect

    Ribes, Diana; Fuentes, Silvia; Torrente, Margarita; Colomina, M. Teresa; Domingo, Jose L.

    2010-02-15

    Although it is known that prenatal exposure to perfluorooctane sulfonate (PFOS) can cause developmental adverse effects in mammals, the disruptive effects of this compound on hormonal systems are still controversial. Information concerning the effects of PFOS on hypothalamus adrenal (HPA) axis response to stress and corticosterone levels is not currently available. On the other hand, it is well established that stress can enhance the developmental toxicity of some chemicals. In the present study, we assessed the combined effects of maternal restraint stress and PFOS on HPA axis function in the offspring of mice. Twenty plug-positive female mice were divided in two groups. Animals were given by gavage 0 and 6 mg PFOS/kg/day on gestation days 12-18. One half of the animals in each group were also subjected to restraint stress (30 min/session, 3 sessions/day) during the same period. Five plug-positive females were also included as non-manipulated controls. At 3 months of age, activity in an open-field and the stress response were evaluated in male and female mice by exposing them to 30 min of restraint stress. Male and female offspring were subsequently sacrificed and blood samples were collected to measure changes in corticosterone levels at four different moments related to stress exposure conditions: before stress exposure, immediately after 30 min of stress exposure, and recuperation levels at 60 and 90 min after stress exposure. Results indicate corticosterone levels were lower in mice prenatally exposed to restraint. In general terms, PFOS exposure decreased corticosterone levels, although this effect was only significant in females. The recuperation pattern of corticosterone was mainly affected by prenatal stress. Interactive effects between PFOS and maternal stress were sex dependent. The current results suggest that prenatal PFOS exposure induced long-lasting effects in mice.

  2. Perfluoroalkyl substances (PFAS) including structural PFOS isomers in plasma from elderly men and women from Sweden: Results from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS).

    PubMed

    Salihovic, Samira; Kärrman, Anna; Lind, Lars; Lind, P Monica; Lindström, Gunilla; van Bavel, Bert

    2015-09-01

    Per- and polyfluoroalkyl substances (PFASs) are a class of compounds with unique chemical properties that have been shown useful in a wide variety of applications because they provide materials with reduced surface tension and exceptional non-stick properties. PFASs are commonly found in impregnation materials, coatings of papers and textiles, fire-fighting foams, pesticides, and cleaning agents. The potential for human exposure to PFASs is high because of their widespread distribution. The aim of this study was to investigate levels of PFASs in men and women from Sweden and to assess the influence of gender and parity among women. Levels of 13 PFASs were determined in plasma samples collected during 2001-2004 from 1016 (507 women) 70year-old participants from the population-based Prospective Study of the Vasculature in Uppsala Seniors (PIVUS). The PFASs studied were nine perfluorinated carboxylic acids (PFCAs), four perfluorinated sulfonic acids (PFSAs) and perfluorooctane sulfonamide (PFOSA). In addition, structural isomers of perfluorooctane sulfonic acid (PFOS) were determined in a subset of 398 individuals. The detection rates were high and the majority of the studied compounds were detected in more than 75% of the participants. Levels of the selected analytes were found to be similar to other studies of non-occupationally exposed populations. Gender differences were observed in levels of PFHpA which was higher in men, while PFHxS was higher in women. Parity among women was shown to have a minor effect on PFAS concentrations and we found primi- and multiparous women to have slightly lower levels of PFUnDA when compared to nulliparous women. PMID:26001496

  3. Sonochemical degradation of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in groundwater: kinetic effects of matrix inorganics.

    PubMed

    Cheng, Jie; Vecitis, Chad D; Park, Hyunwoong; Mader, Brian T; Hoffmann, Michael R

    2010-01-01

    Ultrasonic irradiation has been shown to effectively degrade perfluorinated chemicals (PFCs) such as perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in aqueous solution. Reduced PFC sonochemical degradation rates in organic-rich groundwater taken from beneath a landfill, however, testify to the negative kinetic effects of the organic groundwater constituents. In this study, the PFOX (X = S or A) sonochemical degradation rates in a groundwater sample with organic concentrations about 10 times lower than those in the groundwater taken from beneath a landfill are found to be 29.7% and 20.5% lower, respectively, than the rates in Milli-Q water, suggesting that inorganic groundwater constituents also negatively affect PFC sonochemical kinetics. To determine the source of the groundwater matrix effects, we evaluate the effects of various inorganic species on PFOX sonochemical kinetics. Anions over the range of 1-10 mM show Hofmeister effects on the sonochemical degradation rates of PFOX, kClO4(-) (-PFOX) > kNO3(-) (-PFOX) kCl(-) (-)PFOX > or = kMQ-PFOX > kHCO3(-) (-PFOX) kSO42(-) (-PFOX). In contrast, common cations at 5 mM have negligible effects. Initial solution pH enhances the degradation rates of PFOX at 3, but has negligible effects over the range of 4 to 11. The observed inorganic effects on sonochemical kinetics are hypothesized to be due to ions' partitioning to and interaction with the bubble-water interface. Finally, it is shown that the rate reduction in the groundwater in this study is primarily due to the presence of bicarbonate and thus can be fully rectified by pH adjustment prior to sonolysis. PMID:19950930

  4. Pyrene-functionalized oligonucleotides and locked nucleic acids (LNAs): Tools for fundamental research, diagnostics, and materials science†

    PubMed Central

    Østergaard, Michael E.; Hrdlicka, Patrick J.

    2013-01-01

    Pyrene-functionalized oligonucleotides (PFOs) are increasingly explored as tools in fundamental research, diagnostics and materials science. Their popularity is linked to the ability of pyrenes to function as polarity-sensitive and quenchable fluorophores, excimer-generating units, aromatic stacking moieties and nucleic acid duplex intercalators. These characteristics have motivated development of PFOs for detection of complementary DNA/RNA targets, single nucleotide polymorphisms (SNPs), and generation of π-arrays on nucleic acid scaffolds. This Review will highlight the physical properties and applications of PFOs that are likely to provide high degree of positional control of the chromophore in nucleic acid complexes. Particular emphasis will be placed on pyrene-functionalized Locked Nucleic Acids (LNAs) since these materials display distinctive properties such as large fluorescence quantum yields, efficient discrimination of SNPs, and recognition of mixed-sequence double stranded DNA. PMID:21487621

  5. Survey of perfluorinated alkyl acids in Finnish effluents, storm water, landfill leachate and sludge.

    PubMed

    Perkola, Noora; Sainio, Pirjo

    2013-11-01

    The objective of the Control of Hazardous Substances in the Baltic Sea (COHIBA) project is to support the implementation of the HELCOM Baltic Sea Action Plan regarding hazardous substances by developing joint actions to achieve the goal of "a Baltic Sea with life undisturbed by hazardous substances". One aim in the project was to identify the most important sources of 11 hazardous substances of special concern in the Baltic Sea. Among them are perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). In this study, four perfluorinated alkyl acids (PFAAs) were studied: PFOA, PFOS, perfluorohexanoic acid (PFHxA) and perfluorodecanoic acid (PFDA). The occurrence of PFAAs in municipal and industrial wastewater treatment plant effluents (MWWTP1-3, IWWTP1), target industry effluent, storm water, landfill leachate and sludge was studied. Effluents were analysed six times and storm water, leachate and sludge were analysed twice, once in the warm season and once in the cold, during a 1-year sampling campaign. PFOS prevailed in two municipal effluents (MWWTP1 and 3) and industrial effluent (IWWTP1; 7.8-14, 8.0-640 and 320-1,300 ng/l, respectively). However, in one municipal effluent (MWWTP2) PFOA was, in a majority of sampling occasions, the predominant PFAA (9-15 ng/l) followed by PFOS (3.8-20 ng/l). The highest PFAA loads of the municipal effluents were found in the MWWTP3 receiving the biggest portion of industrial wastewater. In storm water the highest concentration was found for PFHxA (17 ng/l). The highest concentration of PFOS and PFOA were 9.9 and 5.1 ng/l, respectively. PFOS, PFOA and PFHxA were detected in every effluent, storm water and landfill leachate sample, whereas PFDA was detected in most of the samples (77%). In the target industry, PFOS concentrations varied between 1,400 and 18,000 μg/l. In addition, on one sampling occasion PFOA and PFHxA were found (0.027 and 0.009 μg/l, respectively). For effluents, PFAA mass flows into the Baltic Sea were calculated. For municipal wastewater treatment plants average mass flows per day varied for PFOS between 1,073 and 38,880 mg/day, for PFOA 960 and 2,700 mg/day, for PFHxA 408 and 1,269 mg/day and for PFDA 84 and 270 mg/day. In IWWTP mass flows for PFOS, PFOA, PFHxA and PFDA were 495 mg/d, 28 mg/d, 23 mg/d and 0.6 mg/g, respectively. PMID:23512237

  6. Evaluation of Perfluoroalkyl Acid Activity Using Primary Mouse and Human Hepatocytes.

    EPA Science Inventory

    While perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been studied at length, less is known about the biological activity of other perfluoroalkyl acids (PFAAs) in the environment. Using a transient transfection assay developed in COS-1 cells, our group h...

  7. EVALUATION OF PERFLUOROALKYL ACID ACTIVITY USING PRIMARY MOUSE AND HUMAN HEPATOCYTES

    EPA Science Inventory

    While perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been studied at length, less is know about the biological activity of other environmental perfluoroalkyl acids (pFAAs). Using a transient transfection assay developed in COS-l cells, our group has previ...

  8. On-line preconcentration of perfluorooctanoic acid and perfluorooctanesulfonic acid by nonaqueous capillary electrophoresis.

    PubMed

    Knob, Radim; Maier, Vítězslav; Petr, Jan; Ranc, Václav; Sevčík, Juraj

    2012-07-01

    Separation of major environmental pollutants as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) by capillary electrophoresis is reported for the first time. It is not possible to resolve the solutes in an aqueous media. However, the use of methanol and acetonitrile as the background electrolyte (BGE) solvents allowed their rapid separation in an uncoated capillary. A major effort was put into BGE optimization in respect to both separation efficiency and detection for further on-line preconcentration. 5 mmol.L⁻¹ naphthalene-1-sulfonic acid and 10 mmol.L⁻¹ triethylamine dissolved in ACN/MeOH (50:50 v/v) provided best separation and detection conditions. Next, the large-volume sample stacking and the field-amplified sample injection were applied and compared. Large-volume sample stacking improved limits of detection (LODs) with regard to the standard injection by 69 times for PFOA and 143 times for PFOS with LODs of 280 and 230 nmol.L⁻¹, respectively. Field-amplified sample injection improved LODs 624 times for PFOAand 806 times for PFOS with LODs 31 and 40 nmol.L⁻¹, respectively. Both preconcentration methods showed repeatabilities of migration times less than 1.2% RSD intraday and 6.6% RSD interday. The method was applied on PFOA and PFOS analysis in a sample of river water treated with solid-phase extraction, which further improved LOD toward 5.6 × 10⁻¹⁰ mol.L⁻¹ for PFOS and 6.4 × 10⁻¹⁰ mol.L⁻¹ for PFOA and allows the method to be used for river water contamination screening or decomposition studies. PMID:22821493

  9. In utero exposure to perfluorooctanoate (PFOA) or perfluorooctane sulfonate (PFOS) did not increase body weight or intestinal tumorigenesis in multiple intestinal neoplasia (Min/+) mice.

    PubMed

    Ngo, Ha Thi; Hetland, Ragna Bogen; Sabaredzovic, Azemira; Haug, Line Småstuen; Steffensen, Inger-Lise

    2014-07-01

    We examined whether perfluorooctanoate (PFOA) or perfluorooctane sulfonate (PFOS) had obesogenic effects and if they increased spontaneous intestinal tumorigenesis in the mouse model C57BL/6J-Min/+ (multiple intestinal neoplasia) after in utero exposure. The dams were exposed to PFOA or PFOS (0.01, 0.1 or 3.0mg/kg bw/day) by po gavage on GD1-17. The Min/+ and wild-type offspring were terminated at week 11 for examination of intestinal tumorigenesis or at week 20 for obesogenic effect, respectively. Body weights of the dams and pups were recorded throughout life. Food intake was determined at week 6 and 10. Blood glucose (non-fasted) was measured at week 6 and 11. No obesogenic effect of PFOA or PFOS was observed up to 20 weeks of age. PFOA or PFOS did not increase the incidence or number of tumors in the small intestine or colon of the Min/+ mice or affect their location along the intestines. Feed intake was not affected. There were some indications of toxicity of PFOA, but not of PFOS. There was lower survival of pups after 3.0mg/kg PFOA, lower body weight in pups after 3.0 and possibly 0.1mg/kg PFOA, and increased relative liver weight after 0.01 and possibly 0.1mg/kg PFOA. Plasma glucose was lower after 0.01 and 0.1mg/kg PFOA. In conclusion, exposure to PFOA and PFOS in utero with the doses used did not have obesogenic effect on either Min/+ or wild-type mice, at least not up to 11 or 20 weeks of age, nor increased intestinal tumorigenesis in Min/+ mice. PMID:24834819

  10. Enhanced cytotoxicity of pentachlorophenol by perfluorooctane sulfonate or perfluorooctanoic acid in HepG2 cells.

    PubMed

    Shan, Guoqiang; Ye, Minqiang; Zhu, Benzhan; Zhu, Lingyan

    2013-11-01

    Chlorinated phenols and perfluoroalkyl acids (PFAAs) are two kinds of pollutants which are widely present in the environment. Considering liver is the primary toxic target organ for these two groups of chemicals, it is interesting to evaluate the possible joint effects of them on liver. In this work, the combined toxicity of pentachlorophenol (PCP) and perfluorooctane sulfonate (PFOS) or perfluorooctanoic acid (PFOA) were investigated using HepG2 cells. The results indicated that PFOS and PFOA could strengthen PCP's hepatotoxicity. Further studies showed that rather than intensify the oxidative stress or promote the biotransformation of PCP, PFOS (or PFOA) might lead to strengthening of the oxidative phosphorylation uncoupling of PCP. By measuring the intracellular PCP concentration and the cell membrane properties, it was suggested that PFOS and PFOA could disrupt the plasma membrane and increase the membrane permeability. Thus, more cellular accessibility of PCP was induced when they were co-exposed to PCP and PFOS (or PFOA), leading to increased cytotoxicity. Further research is warranted to better understand the combined toxicity of PFAAs and other environmental pollutants. PMID:23972907

  11. Persistent perfluorinated acids in seafood collected from two cities of China.

    PubMed

    Gulkowska, Anna; Jiang, Qinting; So, Man Ka; Taniyasu, Sachi; Lam, Paul K S; Yamashita, Nobuyoshi

    2006-06-15

    As an initial survey of human exposure to perfluorinated acids through food consumption in China, seven types of seafood collected from fish markets in two coastal cities were analyzed. Nine perfluorinated compounds were determined using HPLC coupled with ESI-MS/MS. Perfluorooctane sulfonate (PFOS) was the predominant fluorochemical and was found in all 27 seafood samples, including fish, molluscs, crabs, shrimp, oysters, mussels, and clams. Concentrations of PFOS in seafood samples ranged from 0.3 to 13.9 ng/g wet weight, with the highest concentration in mantis shrimp. The hazard ratios of noncancer risk through seafood consumption based on PFOS and perfluorooctanoic acid concentrations were calculated and were less than unity. PMID:16830535

  12. Temporal trends of perfluoroalkane sulfonic acids and their sulfonamide-based precursors in herring from the Swedish west coast 1991-2011 including isomer-specific considerations.

    PubMed

    Ullah, Shahid; Huber, Sandra; Bignert, Anders; Berger, Urs

    2014-04-01

    A method was developed for simultaneous analysis of perfluoroalkane sulfonic acids (PFSAs) and their sulfonamide-based precursors (perfluoroalkane sulfonamidoacetic acids (FASAAs), sulfonamides (FASAs), and sulfonamidoethanols (FASEs)) in fish muscle. Extraction was performed with acetonitrile followed by a clean-up and fractionation step and instrumental analysis by UPLC/MS/MS and GC/MS. Time trends of PFSAs and their precursors in herring muscle samples originating from the Kattegat at the west coast of Sweden were investigated covering the years 1991-2011. The following analytes were detected, all with decreasing or unchanged trends between 1991 and 2011: Perfluorobutane sulfonic acid (PFBS, below the method detection limit (acid (PFHxS, 9-38pg/g), perfluorooctane sulfonic acid (PFOS, 240-930pg/g), perfluorodecane sulfonic acid (PFDS, acid (MeFOSAA and EtFOSAA, 2-39 and 2-31pg/g, respectively) and perfluorooctane sulfonamide (FOSA, 78-920pg/g). The highest concentrations were found for PFOS and FOSA around the turn of the century. Shorter disappearance half-lives were observed for precursors compared to PFSAs. Assuming that these trend differences are representative for fish consumed by the general Swedish population, this observation suggests that the relative contribution of precursors to total human exposure to PFOS via fish intake has decreased in Sweden over the study period. PFOS precursors in fish may have constituted a significant indirect exposure pathway for PFOS in the 1990s. Isomer-specific analysis of PFOS and FOSA revealed <10% relative contributions of branched isomers to total PFOS and total FOSA. Furthermore, the percentage branched isomers decreased over time for both compounds. These findings are contrary to patterns and temporal trends of PFOS isomers commonly found in human serum. In combination with literature data on isomer patterns in other edible fish species and on isomer-specific human toxicokinetics, our results suggest that fish consumption alone cannot account for the PFOS isomer patterns and trends observed in humans. PMID:24468635

  13. Laboratory evaluation of the toxicity of Perfluorooctane Sulfonate (PFOS) on Selenastrum capricornutum, Chlorella vulgaris, Lemna gibba, Daphnia magna, and Daphnia pulicaria.

    PubMed

    Boudreau, T M; Sibley, P K; Mabury, S A; Muir, D G C; Solomon, K R

    2003-04-01

    Perfluorooctane sulfonate (PFOS) is an anthropogenic compound found in trace amounts in many environmental compartments far from areas of production. This, along with the highly persistent nature of PFOS, presents a concern for possible effects in aquatic ecosystems. The objective of this study was to determine the toxicity of PFOS in representative freshwater organisms. Toxicity testing using standard laboratory protocols was performed on the green algae Selenastrum capricornutum and Chlorella vulgaris, the floating macrophyte Lemna gibba, and the invertebrates Daphnia magna and Daphnia pulicaria. No observable effect concentration (NOEC) values were generated from the most sensitive endpoints for all organisms. Autotroph inhibition of growth NOEC values were 5.3, 8.2, and 6.6 mg/L for S. capricornutum, C. vulgaris, and L. gibba, respectively. The 48-h immobility NOEC values for D. magna and D. pulicaria were 0.8 and 13.6 mg/L, respectively. In comparison to immobility, the 21-day lethality NOEC for D. magna was 5.3 mg/L. Based on effect (immobility) values, the most sensitive of all test organisms was D. magna. The most sensitive organism based on 50% inhibition of growth (IC(50)) was L. gibba, with an IC(50) value of 31.1 mg/L determined from wet weight. This is 4.3 times less than the LC(50) for D. pulicaria, which was 134 mg/L. Significant adverse effects (p < or = 0.05) were observed for all organisms in concentrations >134 mg/L. The results indicate that under laboratory conditions PFOS is acutely toxic to freshwater organisms at concentrations at or near 100 mg/L. Based on known environmental concentrations of PFOS, which occur in the low ng/L to low microg/L range, there is no apparent risk to freshwater systems. However, further work is required to investigate long-term effects in these and other freshwater organisms. PMID:12712289

  14. Temporal trends for inflow of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) to Tokyo Bay, Japan, estimated by a receptor-oriented approach.

    PubMed

    Sakurai, Takeo; Serizawa, Shigeko; Kobayashi, Jun; Kodama, Keita; Lee, Jeong-Hoon; Maki, Hideaki; Zushi, Yasuyuki; Sevilla-Nastor, Janice Beltran; Imaizumi, Yoshitaka; Suzuki, Noriyuki; Horiguchi, Toshihiro; Shiraishi, Hiroaki

    2016-01-01

    We estimated inflow rates of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) to Tokyo Bay, Japan, between February 2004 and February 2011 by a receptor-oriented approach based on quarterly samplings of the bay water. Temporal trends in these inflow rates are an important basis for evaluating changes in PFOS and PFOA emissions in the Tokyo Bay catchment basin. A mixing model estimated the average concentrations of these compounds in the freshwater inflow to the bay, which were then multiplied by estimated freshwater inflow rates to obtain the inflow rates of these compounds. The receptor-oriented approach enabled us to comprehensively cover inflow to the bay, including inflow via direct discharge to the bay. On a logarithmic basis, the rate of inflow for PFOS decreased gradually, particularly after 2006, whereas that for PFOA exhibited a marked stepwise decrease from 2006 to 2007. The rate of inflow for PFOS decreased from 730kg/y during 2004-2006 to 160kg/y in 2010, whereas that for PFOA decreased from 2000kg/y during 2004-2006 to 290kg/y in 2010. These reductions probably reflected reductions in the use and emission of these compounds and their precursors in the Tokyo Bay catchment basin. Our estimated per-person inflow rates (i.e., inflow rates divided by the estimated population in the basin) for PFOS were generally comparable to previously reported per-person waterborne emission rates in Japan and other countries, whereas those for PFOA were generally higher than previously reported per-person waterborne emission rates. A comparison with previous estimates of household emission rates of these compounds suggested that our inflow estimates included a considerable contribution from point industrial sources. PMID:26363401

  15. Alterations in gene expression levels provide early indicators of chemical stress during Xenopus laevis embryo development: A case study with perfluorooctane sulfonate (PFOS).

    PubMed

    San-Segundo, Laura; Guimarães, Laura; Fernández Torija, Carlos; Beltrán, Eulalia M; Guilhermino, Lúcia; Pablos, María Victoria

    2016-05-01

    In the present study, Xenopus laevis embryos were exposed to a range of perfluorooctane sulfonate (PFOS) concentrations (0, 0.5, 6, 12, 24, 48 and 96mg/L) for 96h in laboratorial conditions to establish toxicity along with possible gene expression changes. Mortality and deformities were monitored daily and head-tail length was measured at the end of the assay as an indicator of growth. At 24 and 96h post-exposure (hpe), the mRNA expression levels of the genetic markers involved in general stress responses (hsp70, hsp47, crh-a and ucn1), oxidative stress (cat.2 and sod), lipid metabolism (ppard) and apoptosis (tp53 and bax) were analyzed by RT-qPCR. Malformations were significantly higher in the embryos exposed to the highest PFOS concentration (41.8% to 56.4%) compared to controls (5.5%) at 48, 72 and 96hpe. Growth inhibition was observed in the embryos exposed to PFOS concentrations≥48mg/L. At 24 hpe, a statistically significant up-regulation of genes hsp70, hsp47, ppard, tp53 and bax in relation to controls was found. Similar responses were found for genes hsp70, hsp47, crh-a, ucn1, sod and ppard at 96 hpe. Alterations in the mRNA expression levels indicated both a stress response to PFOS exposure during X. laevis embryo development, and alterations in the regulation of oxidative stress, apoptosis, and differentiation. These molecular alterations were detected at an earlier exposure time or at lower concentrations than those producing developmental toxicity. Therefore, these sensitive warning signals could be used together with other biomarkers to supplement alternative methods (i.e. the frog embryo test) for developmental toxicity safety evaluations, and as tools in amphibian risk assessments for PFOS and its potential substitutes. PMID:26802562

  16. Developmental toxicity of perfluorononanoic acid in mice.

    PubMed

    Das, Kaberi P; Grey, Brian E; Rosen, Mitchell B; Wood, Carmen R; Tatum-Gibbs, Katoria R; Zehr, R Daniel; Strynar, Mark J; Lindstrom, Andrew B; Lau, Christopher

    2015-01-01

    Perfluorononanoic acid (PFNA) is a ubiquitous and persistent environmental contaminant. Although its levels in the environment and in humans are lower than those of perfluorooctane sulfonate (PFOS) or perfluorooctanoic acid (PFOA), a steady trend of increases in the general population in recent years has drawn considerable interest and concern. Previous studies with PFOS and PFOA have indicated developmental toxicity in laboratory rodent models. The current study extends the evaluation of these adverse outcomes to PFNA in mice. PFNA was given to timed-pregnant CD-1 mice by oral gavage daily on gestational day 1-17 at 1, 3, 5 or 10mg/kg; controls received water vehicle. Dams given 10mg/kg PFNA could not carry their pregnancy successfully and effects of this dose group were not followed. Similar to PFOS and PFOA, PFNA at 5mg/kg or lower doses produced hepatomegaly in the pregnant dams, but did not affect the number of implantations, fetal viability, or fetal weight. Mouse pups were born alive and postnatal survival in the 1 and 3mg/kg PFNA groups was not different from that in controls. In contrast, although most of the pups were also born alive in the 5mg/kg PFNA group, 80% of these neonates died in the first 10 days of life. The pattern of PFNA-induced neonatal death differed somewhat from those elicited by PFOS or PFOA. A majority of the PFNA-exposed pups survived a few days longer after birth than those exposed to PFOS or PFOA, which typically died within the first 2 days of postnatal life. Surviving neonates exposed to PFNA exhibited dose-dependent delays in eye opening and onset of puberty. In addition, increased liver weight seen in PFNA-exposed offspring persisted into adulthood and was likely related to the persistence of the chemical in the tissue. Evaluation of gene expression in fetal and neonatal livers revealed robust activation of peroxisome proliferator-activated receptor-alpha (PPARα) target genes by PFNA that resembled the responses of PFOA. Our results indicate that developmental toxicity of PFNA in mice is comparable to that of PFOS and PFOA, and that these adverse effects are likely common to perfluoroalkyl acids that persist in the body. PMID:25543169

  17. Surface modification of activated carbon for enhanced adsorption of perfluoroalkyl acids from aqueous solutions.

    PubMed

    Zhi, Yue; Liu, Jinxia

    2016-02-01

    The objective of the research was to examine the effect of increasing carbon surface basicity on uptake of perfluorooctane sulfonic (PFOS) and carboxylic acids (PFOA) by activated carbon. Granular activated carbons made from coal, coconut shell, wood, and phenolic-polymer-based activated carbon fibers were modified through high-temperature and ammonia gas treatments to facilitate systematical evaluation of the impact of basicity of different origins. Comparison of adsorption isotherms and adsorption distribution coefficients showed that the ammonia gas treatment was more effective than the high-temperature treatment in enhancing surface basicity. The resultant higher point of zero charges and total basicity (measured by total HCl uptake) correlated with improved adsorption affinity for PFOS and PFOA. The effectiveness of surface modification to enhance adsorption varied with carbon raw material. Wood-based carbons and activated carbon fibers showed enhancement by one to three orders of magnitudes while other materials could experience reduction in adsorption towards either PFOS or PFOA. PMID:26469934

  18. Inverse association of colorectal cancer prevalence to serum levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in a large Appalachian population

    PubMed Central

    2014-01-01

    Background Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) are persistent environmental contaminants that affect metabolic regulation, inflammation, and other factors implicated in the development and progression of colorectal cancer (CRC). However, the link between these compounds and CRC remains unknown. In this cross-sectional study, we investigated the association of CRC diagnosis to PFOA and PFOS blood levels in a large Appalachian population. Methods Participants were 47,359 adults ≥ 21 years of age and residing in six PFOA-contaminated water districts in the mid-Ohio Valley (N = 47,151 cancer-free adults, 208 cases of primary CRC). All participants completed a comprehensive health survey between 2005 and 2006; serum levels of PFOA, PFOS, and a range of other blood markers were also measured. Medical history was assessed via self report and cancer diagnosis confirmed via chart review. Results CRC showed a strong inverse, dose–response association with PFOS serum levels (odds ratio (OR) adjusted for potential confounders = 0.2, 95% confidence interval (CI) 0.2,0.3) for highest vs. lowest quartile of PFOS, P-trend < 0.00001) and a significant, but more modest inverse association with PFOA (adjusted OR = 0.6 (CI 0.4, 0.9) for highest vs. lowest quartile, P-trend = 0.001). These inverse associations were stronger in those diagnosed within the previous 6 years and resident in the same water district for a minimum of 10–15 years preceding assessment. The relationship between PFOA and CRC was also more pronounced in men and leaner adults, and showed a stronger linear trend at lower exposure levels. Conclusions In this large cross-sectional study, we found a strong, inverse association between PFOS and likelihood of CRC diagnosis and a significant, although more modest inverse association between PFOA and CRC. If confirmed in prospective investigations, these findings may aid in identifying new strategies for CRC prevention and treatment and inform future studies regarding mechanisms underlying CRC pathogenesis. PMID:24468211

  19. Differential accumulation and elimination behavior of perfluoroalkyl Acid isomers in occupational workers in a manufactory in China.

    PubMed

    Gao, Yan; Fu, Jianjie; Cao, Huiming; Wang, Yawei; Zhang, Aiqian; Liang, Yong; Wang, Thanh; Zhao, Chunyan; Jiang, Guibin

    2015-06-01

    In this study, serum and urine samples were collected from 36 occupational workers in a fluorochemical manufacturing plant in China from 2008 to 2012 to evaluate the body burden and possible elimination of linear and branched perfluoroalkyl acids (PFAAs). Indoor dust, total suspended particles (TSP), diet, and drinking water samples were also collected to trace the occupational exposure pathway to PFAA isomers. The geometric mean concentrations of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorohexanesulfonate (PFHxS) isomers in the serum were 1386, 371, and 863 ng mL(-1), respectively. The linear isomer of PFOS, PFOA, and PFHxS was the most predominant PFAA in the serum, with mean proportions of 63.3, 91.1, and 92.7% respectively, which were higher than the proportions in urine. The most important exposure routes to PFAA isomers in the occupational workers were considered to be the intake of indoor dust and TSP. A renal clearance estimation indicated that branched PFAA isomers had a higher renal clearance rate than did the corresponding linear isomers. Molecular docking modeling implied that linear PFOS (n-PFOS) had a stronger interaction with human serum albumin (HSA) than branched isomers did, which could decrease the proportion of n-PFOS in the blood of humans via the transport of HSA. PMID:25927957

  20. Effects of perfluorooctane sulfuric acid on placental PRL-family hormone production and fetal growth retardation in mice.

    PubMed

    Lee, Chae Kwan; Kang, Sung Goo; Lee, Jong Tae; Lee, Soo-Woong; Kim, Jeong Ho; Kim, Dae Hwan; Son, Byung Chul; Kim, Kun Hyung; Suh, Chun Hui; Kim, Se Yeong; Park, Yeong Beom

    2015-02-01

    Perfluorooctane sulfuric acid (PFOS) is a persistent organic pollutant, causes fetal growth retardation but the mechanism is still unclear. This study focused on PFOS-induced toxicity such as placental trophoblast cell histopathological changes, endocrine function (i.e., prolactin (PRL)-family hormone production) and subsequent fetal growth retardation in mice. Maternal body weight gain, placental and fetal weights were significantly decreased in proportion to PFOS dosage. Placental efficiency (fetal weight/placental weight) was significantly reduced dose-dependently. Necrotic changes were observed in PFOS-treated placental tissues, and the area of injury increased dose-dependently. Finally, mRNA levels and maternal serum concentrations of the PRL-family hormones (mPL-II, mPLP-Cα, mPLP-K) were significantly reduced dose-dependently. In addition, the changing pattern between PRL-family hormone concentrations and fetal body weight was positively correlated. These results suggest that gestational PFOS treatment induces placental histopathological changes and disruption of endocrine function, finally may lead to fetal growth retardation in mice. PMID:25449418

  1. Sorption of perfluorooctanoic acid, perfluorooctane sulfonate and perfluoroheptanoic acid on granular activated carbon.

    PubMed

    Zhang, Di; Luo, Qi; Gao, Bin; Chiang, Sheau-Yun Dora; Woodward, David; Huang, Qingguo

    2016-02-01

    The sorption of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and perfluoroheptanoic acid (PFHpA) on granular activated carbon (GAC) was characterized and compared to explore the underlying mechanisms. Sorption of the three perfluoroalkyl acids (PFAAs) on GAC appeared to be a rapid intra-particle diffusion process, which were well represented by the pseudo-second-order rate model with the sorption rate following the order PFOS > PFOA > PFHpA. Sorption isotherm data were well fitted by the Freundlich model with the sorption capacity (Kf) of PFOS, PFOA and PFHpA being 4.45, 2.42 and 1.66 respectively. This suggests that the hydrophilic head group on PFAAs, i.e. sulfonate vs carboxylic, has a strong influence on their sorption. Comparison between PFOA and PFHpA revealed that hydrophobicity could also play a role in the sorption of PFAAs on GAC when the fluorocarbon chain length is different. Analyses using Attenuated Total Reflection (ATR)-Fourier Transform Infrared (FTIR) spectroscopy suggested possible formation of a negative charge-assisted H-bond between PFAAs and the functionalities on GAC surfaces, including non-aromatic ketones, sulfides, and halogenated hydrocarbons. PMID:26606188

  2. Metabolically inert perfluorinated fatty acids directly activate uncoupling protein 1 in brown-fat mitochondria.

    PubMed

    Shabalina, Irina G; Kalinovich, Anastasia V; Cannon, Barbara; Nedergaard, Jan

    2016-05-01

    The metabolically inert perfluorinated fatty acids perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) can display fatty acid-like activity in biological systems. The uncoupling protein 1 (UCP1) in brown adipose tissue is physiologically (re)activated by fatty acids, including octanoate. This leads to bioenergetically uncoupled energy dissipation (heat production, thermogenesis). We have examined here the possibility that PFOA/PFOS can directly (re)activate UCP1 in isolated mouse brown-fat mitochondria. In wild-type brown-fat mitochondria, PFOS and PFOA overcame GDP-inhibited thermogenesis, leading to increased oxygen consumption and dissipated membrane potential. The absence of this effect in brown-fat mitochondria from UCP1-ablated mice indicated that it occurred through activation of UCP1. A competitive type of inhibition by increased GDP concentrations indicated interaction with the same mechanistic site as that utilized by fatty acids. No effect was observed in heart mitochondria, i.e., in mitochondria without UCP1. The stimulatory effect of PFOA/PFOS was not secondary to non-specific mitochondrial membrane permeabilization or to ROS production. Thus, metabolic effects of perfluorinated fatty acids could include direct brown adipose tissue (UCP1) activation. The possibility that this may lead to unwarranted extra heat production and thus extra utilization of food resources, leading to decreased fitness in mammalian wildlife, is discussed, as well as possible negative effects in humans. However, a possibility to utilize PFOA-/PFOS-like substances for activating UCP1 therapeutically in obesity-prone humans may also be envisaged. PMID:26041126

  3. Determination of perfluorooctanoic acid and perfluorooctane sulfonate in cooking oil and pig adipose tissue using reversed-phase liquid-liquid extraction followed by high performance liquid chromatography tandem mass spectrometry.

    PubMed

    Tang, Caiming; Tan, Jianhua; Wang, Chunwei; Peng, Xianzhi

    2014-05-01

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are two perfluorinated compounds (PFCs) ubiquitously present in the environment, which could pose potential adverse effects on human health. Contamination and presence of PFOA and PFOS should be eliminated or rigidly restricted in food stuffs such as cooking oils and lard (from pig adipose tissue). This work describes a rapid, simple, reliable and sensitive method for quantitative analysis of PFOA and PFOS in cooking oils and pig adipose tissue with liquid chromatography tandem mass spectrometry (LC-MS/MS). The pretreatment mainly included a one-step reversed-phase liquid-liquid extraction using the mixture of basified water/methanol as the aqueous system, and dichloromethane (DCM) as the non-polar system. PFOA and PFOS can be successfully separated from the two lipid-rich matrices, i.e., cooking oil and adipose tissue, and extracted into the aqueous system, and then directly analyzed with LC-MS/MS. This method was validated in terms of accuracy (both intra- and inter-batch), precision, recovery, linearity, sensitivity and applicability. The intra-batch accuracies for PFOA and PFOS in cooking oil samples were within 93.9-101.9% with relative standard deviation (RSD) no more than 10.9%, and the inter-batch accuracies were 91.2-96.2% with RSD not exceeding 10.0%. The intra-batch accuracies of the analytes in pig adipose tissue samples were 102.9-113.0% with RSD of 8.8-13.1%. And the quantification ranges of PFOA and PFOS were 0.01-25ng/mL. This method has been applied to the analysis of PFOA and PFOS in real samples collected from local markets in Guangzhou, China. PMID:24679825

  4. Liquid chromatography/mass spectrometry analysis of perfluoroalkyl carboxylic acids and perfluorooctanesulfonate in bivalve shells: extraction method optimization.

    PubMed

    Wang, Lei; Sun, Hongwen; Yang, Lurong; He, Chuan; Wu, Wenling; Sun, Shujuan

    2010-01-22

    Different extraction methods, including extraction by organic solvents with and without acetic acid digestion, and mixed inorganic acid digestion coupled with solid phase extraction (SPE), were developed for the analysis of perfluorinated carboxylic acids (PFCAs) and perfluorooctanesulfonate (PFOS) in bivalve shells. The extracts were separated, identified and quantified by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). The method utilizing mixed acid digestion coupled with SPE performed more efficiently than other extraction methods. Matrix recoveries of the optimized methods ranged from 92% to 104%, with limits of detection of 0.05-0.43ng/g. The optimized method was successfully applied to the analysis of PFCAs and PFOS in shell samples of two bivalves from Bohai Bay, China. PFCAs and PFOS concentrations in the shells ranged from 0.3 ng/g to 4.1 ng/g, 1-50 times lower than those in the soft tissues of bivalves for most target analytes. No relationship between PFCAs and PFOS in shells and in soft tissues was found; this is explained by the different contaminant uptake mechanism of shells and soft tissues. PMID:20015508

  5. The Environmental Pollutants Perfluorooctane Sulfonate and Perfluorooctanoic Acid Upregulate Uncoupling Protein 1 (UCP1) in Brown-Fat Mitochondria Through a UCP1-Dependent Reduction in Food Intake.

    PubMed

    Shabalina, Irina G; Kramarova, Tatiana V; Mattsson, Charlotte L; Petrovic, Natasa; Rahman Qazi, Mousumi; Csikasz, Robert I; Chang, Shu-Ching; Butenhoff, John; DePierre, Joseph W; Cannon, Barbara; Nedergaard, Jan

    2015-08-01

    The environmental pollutants perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) cause a dramatic reduction in the size of the major adipose tissue depots and a general body weight decrease when they are added to the food of mice. We demonstrate here that this is mainly due to a reduction in food intake; this reduction was not due to food aversion. Remarkably and unexpectedly, a large part of the effect of PFOA/PFOS on food intake was dependent on the presence of the uncoupling protein 1 (UCP1) in the mice. Correspondingly, PFOA/PFOS treatment induced recruitment of brown adipose tissue mitochondria: increased oxidative capacity and increased UCP1-mediated oxygen consumption (thermogenesis). In mice pair-fed to the food intake during PFOA/PFOS treatment in wildtype mice, brown-fat mitochondrial recruitment was also induced. We conclude that we have uncovered the existence of a regulatory component of food intake that is dependent upon brown adipose tissue thermogenic activity. The possible environmental consequences of this novel PFOA/PFOS effect (a possible decreased fitness) are noted, as well as the perspectives of this finding on the general understanding of control of food intake control and its possible extension to combatting obesity. PMID:26001964

  6. High levels of perfluoroalkyl acids in sport fish species downstream of a firefighting training facility at Hamilton International Airport, Ontario, Canada.

    PubMed

    Gewurtz, Sarah B; Bhavsar, Satyendra P; Petro, Steve; Mahon, Chris G; Zhao, Xiaoming; Morse, Dave; Reiner, Eric J; Tittlemier, Sheryl A; Braekevelt, Eric; Drouillard, Ken

    2014-06-01

    A recent study reported elevated concentrations of perfluorooctane sulfonic acid (PFOS) and other perfluoroalkyl acids (PFAAs) in surface water, snapping turtles, and amphipods in Lake Niapenco, downstream of Hamilton International Airport, Ontario, Canada. Here, our goals were to 1) determine the extent of PFAA contamination in sport fish species collected downstream of the airport, 2) explore if the airport could be a potential source, and 3) compare fish PFOS concentrations to consumption advisory benchmarks. The PFOS levels in several sport fish collected from the three locations closest to the airport (<40km) were among the highest previously published in the peer-reviewed literature and also tended to exceed consumption benchmarks. The only other fish that had comparable concentrations were collected in a region affected by inputs from a major fluorinated chemical production facility. In contrast, PFOS concentrations in the two most downstream locations (>70km) were comparable to or below the average concentrations in fish as observed in the literature and were generally below the benchmarks. With regards to perfluorocarboxylates (PFCAs), there was no significant decrease in concentrations in fish with distance from the airport and levels were comparable to or below the average concentrations observed in the literature, suggesting that the airport is not a significant source of PFCAs in these fish species. PFOS-based aqueous film-forming foam (AFFF) was used at a firefighting training facility at the airport in the 1980s to mid-1990s. Taken together, our results provide evidence that the historical use of AFFF at the airport has resulted in fish PFOS concentrations that exceed the 95th percentile concentration of values reported in the literature to date. PMID:24632327

  7. Associations between Serum Perfluoroalkyl Acids and LINE-1 DNA Methylation

    PubMed Central

    Watkins, Deborah J.; Wellenius, Gregory A.; Butler, Rondi A.; Bartell, Scott M.; Fletcher, Tony; Kelsey, Karl T.

    2014-01-01

    Perfluoroalkyl acids (PFAAs) are persistent, synthetic compounds that are used in a number of consumer products. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been associated with cardiovascular risk factors, and changes in gene expression and DNA methylation in animals and cellular systems. However, whether PFAA exposure is associated with LINE-1 DNA methylation, a potential marker of cardiovascular risk, in humans remains unknown. We sought to evaluate the cross-sectional associations between serum PFAAs and LINE-1 DNA methylation in a population highly exposed to PFOA. We measured serum PFAAs twice four to five years apart in 685 adult participants (47% male, mean age ± SD=42 ± 11 years). We measured percent LINE-1 DNA methylation in peripheral blood leukocytes at the second time point (follow-up), and estimated absolute differences in LINE-1 methylation associated with an interquartile (IQR) shift in mean PFAA serum levels. IQR increases in mean serum PFOA, PFOS, perfluorononanoic acid (PFNA), and perfluorohexane sulfonate (PFHxS) were associated with differences of −0.04 (p=0.16), 0.20 (p=0.001), 0.06 (p=0.19), and 0.02 (p=0.57), respectively, in % LINE-1 methylation at follow-up after adjustment for potential confounders. We observed a monotonic increase in LINE-1 DNA methylation across tertiles of PFOS and PFNA (ptrend=0.02 for both associations), but not across tertiles of PFOA or PFHxS (ptrend=0.71 and 0.44, respectively). In summary, serum PFOS was associated with LINE-1 methylation, while serum PFOA, PFHxS, and PFNA were not. Additional research is needed to more precisely determine whether these compounds are epigenetically active. PMID:24263140

  8. Perfluorinated Alkyl Acids in Plasma of American Alligators (Alligator Mississippiensis) from Florida and South Carolina

    NASA Technical Reports Server (NTRS)

    Bangma, Jacqueline T.; Bowden, John A.; Brunell, Arnold M.; Christie, Ian; Finnell, Brendan; Guillette, Matthew P.; Jones, Martin; Lowers, Russell H.; Rainwater, Thomas R.; Reiner, Jessica L.; Wilkinson, Philip M.; Guillette, Louis J., Jr.

    2016-01-01

    This study aimed to quantitate fourteen perfluoroalkyl acids (PFAAs) in 125 adult American alligators at twelve sites across the southeastern US. Of those fourteen PFAAs, nine were detected in 65% - 100% of the samples: PFOA, PFNA, PFDA, PFUnA, PFDoA, PFTriA, PFTA, PFHxS, and PFOS. Males (across all sites) showed significantly higher concentrations of four PFAAs: PFOS (p = 0.01), PFDA (p = 0.0003), PFUnA (p = 0.021), and PFTriA (p = 0.021). Concentrations of PFOS, PFHxS, and PFDA in plasma were significantly different among the sites in each sex. Alligators at Merritt Island National Wildlife Refuge and Kiawah Nature Conservancy both exhibited some of the highest PFOS concentrations (medians 99.5 ng/g and 55.8 ng/g respectively) in plasma measured to date in a crocodilian species. A number of positive correlations between PFAAs and snout-vent length (SVL) were observed in both sexes suggesting PFAA body burdens increase with increasing size. In addition, several significant correlations among PFAAs in alligator plasma may suggest conserved sources of PFAAs at each site throughout the greater study area. This study is the first to report PFAAs in American alligators, reveals potential PFAA hot spots in Florida and South Carolina, and provides and additional contaminant of concern when assessing anthropogenic impacts on ecosystem health.

  9. Using blood gene signatures for assessing effects of exposure to perfluoroalkyl acids (PFAAs) in humans: the NOWAC postgenome study

    PubMed Central

    Rylander, Charlotta; Dumeaux, Vanessa; Olsen, Karina Standahl; Waaseth, Marit; Sandanger, Torkjel M; Lund, Eiliv

    2011-01-01

    Perfluoroalkyl acids (PFAAs) are ubiquitously present in human blood samples and the effects of these compounds on human health are not fully characterized. This study was conducted in order to investigate the applicability of peripheral blood gene expressions for exploring the impact of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA) and perfluorohexane sulfonate (PFHxS) exposure on the general population. PFOS, PFOA and PFHxS were analyzed in blood samples from a representative group of 270 healthy, postmenopausal Norwegian women (48-62 years). Gene expression was measured in the same samples using the Applied Biosystems microarray platform. Forty-eight different gene sets, all previously linked to PFAA exposure were explored in relation to the selected PFAAs. Two gene sets, both related to the citric acid cycle, were differentially expressed between the “PFOS high” (>30ng/ml, n=42) and the “PFOS low” (<30ng/ml, n=228) group. Based on the results of this study we believe that blood gene signatures have a large potential for elucidating which biological pathways are being affected by environmental pollutants. To the best of our knowledge, this study is the first assessment of the impact of PFAAs on blood gene expressions in humans from the general population. PMID:21915359

  10. Foodstuff analyses show that seafood and water are major perfluoroalkyl acids (PFAAs) sources to humans in Korea.

    PubMed

    Heo, Jin-Ju; Lee, Ji-Woo; Kim, Seung-Kyu; Oh, Jeong-Eun

    2014-08-30

    We measured concentrations of PFAAs in 397 foods, of 66 types, in Korea, and determined the daily human dietary PFAAs intake and the contribution of each foodstuff to that intake. The PFAAs concentration in the 66 different food types ranged from below the detection limit to 48.3ng/g. Perfluorooctane sulfonate (PFOS) and long-chain perfluorocarboxylic acids (PFCAs) were the dominant PFAAs in fish, shellfish, and processed foods, while perfluorooctanoic acid (PFOA) and short-chain PFCAs dominated dairy foodstuffs and beverages. The Korean adult dietary intake ranges, estimated for a range of scenarios, were 0.60-3.03 and 0.17-1.68ngkg(-1)bwd(-1) for PFOS and PFOA, respectively, which were lower than the total daily intake limits suggested by European Food Safety Authority (PFOS: 150ngkg(-1)bwd(-1); PFOA: 1500ngkg(-1)bwd(-1)). The major contributors to PFAAs dietary exposure varied with subject age and PFAAs. For example, fish was a major contributor of PFOS but dairy foods were major contributors of PFOA. However, tap water was a major contributor to PFOA intake when it was the main source of drinking water (rather than bottled water). PMID:25093550

  11. Efficient Sorption and Removal of Perfluoroalkyl Acids (PFAAs) from Aqueous Solution by Metal Hydroxides Generated in Situ by Electrocoagulation.

    PubMed

    Lin, Hui; Wang, Yujuan; Niu, Junfeng; Yue, Zhihan; Huang, Qingguo

    2015-09-01

    Removal of environmentally persistent perfluoroalkyl acids (PFAAs), that is, perfluorooctanesulfonate (PFOS) and perfluorocarboxylic acids (PFCAs, C4 ∼ C10) were investigated through sorption on four metal hydroxide flocs generated in situ by electrocoagulation in deionized water with 10 mM NaCl as supporting electrolyte. The results indicated that the zinc hydroxide flocs yielded the highest removal efficiency with a wide range concentration of PFOA/PFOS (1.5 μM ∼ 0.5 mM) at the zinc dosage <150 mg L(-1) with the energy consumption <0.18 Wh L(-1). The sorption kinetics indicated that the zinc hydroxide flocs had an equilibrium adsorbed amount (qe) up to 5.74/7.69 mmol g(-1) (Zn) for PFOA/PFOS at the initial concentration of 0.5 mM with an initial sorption rate (v0) of 1.01 × 10(3)/1.81 × 10(3) mmol g(-1) h(-1). The sorption of PFOA/PFOS reached equilibrium within <10 min. The sorption mechanisms of PFAAs on the zinc hydroxide flocs were proposed based on the investigation of various driving forces. The results indicated that the hydrophobic interaction was primarily responsible for the PFAAs sorption. The electrocoagulation process with zinc anode may have a great potential for removing PFAAs from industrial wastewater as well as contaminated environmental waterbody. PMID:26244813

  12. An energy-efficient process for decomposing perfluorooctanoic and perfluorooctane sulfonic acids using dc plasmas generated within gas bubbles

    NASA Astrophysics Data System (ADS)

    Yasuoka, K.; Sasaki, K.; Hayashi, R.

    2011-06-01

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are environmentally harmful and persistent substances. Their decomposition was investigated using dc plasmas generated within small gas bubbles in a solution. The plasma characteristics including discharge voltage, voltage drop in the liquid, plasma shape and the emission spectrum were examined with different gases. The decomposition rate and energy efficiency were evaluated by measuring the concentration of fluoride and sulfate ions released from PFOA/PFOS molecules. The concentration of fluoride ions and energy efficiency in the treatment of a PFOS solution were 17.7 mg l-1 (54.8% of the initial amount of fluorine atoms) and 26 mg kWh-1, respectively, after 240 min of operation. The addition of scavengers of hydroxyl radicals and hydrated electrons showed little effect on the decomposition. The decomposition processes were analyzed with an assumption that positive species reacted with PFOA/PFOS molecules at the boundary of the plasma-solution surface. This type of plasma showed a much higher decomposition energy efficiency compared with energy efficiencies reported in other studies.

  13. Perfluoroalkyl acid contamination and polyunsaturated fatty acid composition of French freshwater and marine fishes.

    PubMed

    Yamada, Ami; Bemrah, Nawel; Veyrand, Bruno; Pollono, Charles; Merlo, Mathilde; Desvignes, Virginie; Sirot, Véronique; Oseredczuk, Marine; Marchand, Philippe; Cariou, Ronan; Antignac, Jean-Phillippe; Le Bizec, Bruno; Leblanc, Jean-Charles

    2014-07-30

    In this study, French marine and freshwater fish perfluoroalkyl acid (PFAA) contamination are presented along with their fatty acid (FA) composition to provide further elements for a risk/benefit balance of fish consumption to be assessed. The 29 most consumed marine fish species were collected in four metropolitan French coastal areas in 2004 to constitute composite samples. Geographical differences in terms of consumed species and contamination level were taken into account. Three hundred and eighty-seven composite samples corresponding to 16 freshwater fish species collected between 2008 and 2010 in the six major French rivers or their tributaries were selected among the French national agency for water and aquatic environments freshwater fish sample library. The raw edible parts were analyzed for FA composition and PFAA contamination. Results show that freshwater fishes are more contaminated by PFAAs than marine fishes and do not share the same contamination profile. Freshwater fish contamination is mostly driven by perfluorooctane sulfonate (PFOS) (75%), whereas marine fish contamination is split between perfluorooctanoic acid (PFOA) (24%), PFOS (20%), perfluorohexanoic acid (PFHxA) (15%), perfluoropentanoic acid (PFHpA) (11%), and perfluorobutanoic acid (PFBA) (11%). Common carp, pike-perch, European perch, thicklip grey mullet, and common roach presented the most unfavorable balance profile due to their high level of PFAAs and low level of n-3 long-chain polyunsaturated fatty acids (LC-PUFAs). These data could be used, if needed, in an updated opinion on fish consumption that takes into account PFAA contamination. PMID:25004121

  14. Serum Perfluorooctanoic Acid and Perfluorooctane Sulfonate Concentrations in Relation to Birth Outcomes in the Mid-Ohio Valley, 2005–2010

    PubMed Central

    Stein, Cheryl R.; Steenland, Kyle

    2013-01-01

    Background: Previous research suggests perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) may be associated with adverse pregnancy outcomes. Objective: We conducted a population-based study of PFOA and PFOS and birth outcomes from 2005 through 2010 in a Mid-Ohio Valley community exposed to high levels of PFOA through drinking-water contamination. Methods: Women provided serum for PFOA and PFOS measurement in 2005–2006 and reported reproductive histories in subsequent follow-up interviews. Reported singleton live births among 1,330 women after 1 January 2005 were linked to birth records (n = 1,630) to identify the outcomes of preterm birth (< 37 weeks gestation), pregnancy-induced hypertension, low birth weight (< 2,500 g), and birth weight (grams) among full-term infants. Results: We observed little or no evidence of association between maternal serum PFOA or PFOS and preterm birth (n = 158) or low birth weight (n = 88). Serum PFOA and PFOS were both positively associated with pregnancy-induced hypertension (n = 106), with adjusted odds ratios (ORs) per log unit increase in PFOA and PFOS of 1.27 (95% CI: 1.05, 1.55) and 1.47 (95% CI: 1.06, 2.04), respectively, but associations did not increase monotonically when categorized by quintiles. Results of subanalyses restricted to pregnancies conceived after blood collection were consistent with the main analyses. There was suggestion of a modest negative association between PFOS and birth weight in full-term infants (–29 g per log unit increase; 95% CI: –66, 7), which became stronger when restricted to births conceived after the blood sample collection (–49 g per log unit increase; 95% CI: –90, –8). Conclusion: Results provide some evidence of positive associations between measured serum perfluorinated compounds and pregnancy-induced hypertension and a negative association between PFOS and birth weight among full-term infants. Citation: Darrow LA, Stein CR, Steenland K. 2013. Serum perfluorooctanoic acid and perfluorooctane sulfonate concentrations in relation to birth outcomes in the Mid-Ohio Valley, 2005–2010. Environ Health Perspect 121:1207–1213; http://dx.doi.org/10.1289/ehp.1206372 PMID:23838280

  15. The Association of Prenatal Exposure to Perfluorinated Chemicals with Maternal Essential and Long-Chain Polyunsaturated Fatty Acids during Pregnancy and the Birth Weight of Their Offspring: The Hokkaido Study

    PubMed Central

    Nakajima, Tamie; Goudarzi, Houman; Kobayashi, Sachiko; Sasaki, Seiko; Okada, Emiko; Miyashita, Chihiro; Itoh, Sachiko; Araki, Atsuko; Ikeno, Tamiko; Iwasaki, Yusuke; Nakazawa, Hiroyuki

    2015-01-01

    Background Fatty acids (FAs) are essential for fetal growth. Exposure to perfluorinated chemicals (PFCs) may disrupt FA homeostasis, but there are no epidemiological data regarding associations of PFCs and FA concentrations. Objectives We estimated associations between perfluorooctane sulfonate (PFOS)/perfluorooctanoate (PFOA) concentrations and maternal levels of FAs and triglyceride (TG) and birth size of the offspring. Methods We analyzed 306 mother–child pairs in this birth cohort between 2002 and 2005 in Japan. The prenatal PFOS and PFOA levels were measured in maternal serum samples by liquid chromatography–tandem mass spectrometry. Maternal blood levels of nine FAs and TG were measured by gas chromatography–mass spectrometry and TG E-Test Wako kits, respectively. Information on infants’ birth size was obtained from participant medical records. Results The median PFOS and PFOA levels were 5.6 and 1.4 ng/mL, respectively. In the fully adjusted model, including maternal age, parity, annual household income, blood sampling period, alcohol consumption, and smoking during pregnancy, PFOS but not PFOA had a negative association with the levels of palmitic, palmitoleic, oleic, linoleic, α-linolenic, and arachidonic acids (p < 0.005) and TG (p-value = 0.016). Female infants weighed 186.6 g less with mothers whose PFOS levels were in the fourth quartile compared with the first quartile (95% CI: –363.4, –9.8). We observed no significant association between maternal levels of PFOS and birth weight of male infants. Conclusions Our data suggest an inverse association between PFOS exposure and polyunsaturated FA levels in pregnant women. We also found a negative association between maternal PFOS levels and female birth weight. Citation Kishi R, Nakajima T, Goudarzi H, Kobayashi S, Sasaki S, Okada E, Miyashita C, Itoh S, Araki A, Ikeno T, Iwasaki Y, Nakazawa H. 2015. The association of prenatal exposure to perfluorinated chemicals with maternal essential and long-chain polyunsaturated fatty acids during pregnancy and the birth weight of their offspring: the Hokkaido Study. Environ Health Perspect 123:1038–1045; http://dx.doi.org/10.1289/ehp.1408834 PMID:25840032

  16. Lipid peroxidation and oxidative stress responses of salmon fed a diet containing perfluorooctane sulfonic- or perfluorooctane carboxylic acids.

    PubMed

    Arukwe, Augustine; Mortensen, Anne S

    2011-11-01

    The present study was conducted to evaluate the effects of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) on lipid β-oxidation and oxidative stress responses in Atlantic salmon liver and kidney tissues. We quantified changes in the expression levels of peroxisome proliferator-activated receptors (PPARs) and acyl-CoA oxidase (ACOX1) enzyme whose transcription is induced by PPARs. In addition, we analyzed gene expression patterns for enzymatic antioxidants (superoxide dismutase: SOD, catalase: CAT and glutathione peroxidase: GPx). Thiobarbituric acid reactive substances (TBARS) were analyzed as a measure for lipid peroxidation. Juvenile Atlantic salmon were repeatedly force-fed food spiked with PFOA or PFOS at 0.2mg/kg, and samples were collected after 0, 2, 5 and 8 days and after a 7 days recovery period. Our data showed that exposure of salmon to PFOS or PFOA produced changes (either increased or decreased) in mRNA expression for PPARs, ACOX1, oxidative stress responses and lipid peroxidation (TBARS) and these responses showed marked organ differences, associated with tissue bioaccumulation patterns and dependent on exposure time. Given that a classical reaction during reactive oxygen species (ROS)-induced damage involves the peroxidation of lipids, our study demonstrates that salmon continuously exposed to dietary PFOS or PFOA dose showed alteration in peroxisomal responses and oxidative stress responses, with higher severity in the kidney, compared to liver. Overall, our data suggest that ROS-mediated oxidative damage maybe a significant and putative toxic effect of PFOA and PFOS in fish as has been reported in mammals. PMID:21742055

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

    PubMed

    Li, Fei; Zhang, Chaojie; Qu, Yan; Chen, Jing; Chen, Ling; Liu, Ying; Zhou, Qi

    2010-01-01

    Perfluorinated acids (PFAs) have been recognized as emerging environmental pollutants because of their widespread occurrences, persistence, and bioaccumulative and toxicological effects. PFAs have been detected in aquatic environment and biota in China, but the occurrences of these chemicals have not been reported in solid matrices in China. In the present study, short- and long-chain PFAs (C2-C14) have been quantitatively determined in solid matrices including sediments, soils and sludge collected in Shanghai, China. The results indicate that sludge contains more PFAs than sediments and soils, and the total PFAs concentrations in sediments, soil and sludge are 62.5-276 ng g(-1), 141-237 ng g(-1) and 413-755 ng g(-1), respectively. In most cases, trifluoroacetic acid was the major PFA and accounted for 22-90% of the total PFAs. Although the levels of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) were not only lower than trifluoroacetic acid, but also lower than some short-chain PFCAs (PFOS were still the major pollution compounds in most cases and they constituted 2-34% and 1-9% of the total PFAs, respectively. Meanwhile, unlike previous studies, PFOS levels were not always higher than PFOA in solids collected in Shanghai, China. Given that some short-chain PFAs such as trifluoroacetic acid are mildly phytotoxic and their higher levels in solid matrices were collected in Shanghai, China, these chemicals should be included in future environmental monitoring efforts. PMID:19896166

  18. Perfluoroalkyl acids in urban stormwater runoff: influence of land use.

    PubMed

    Xiao, Feng; Simcik, Matt F; Gulliver, John S

    2012-12-15

    Perfluoroalkyl acids (PFAAs) are persistent organic pollutants in the environment and have been reported to have nonpoint sources. In this study, six PFAAs with different chain lengths were monitored in stormwater runoff from seven storm events (2009-2011) at various outfall locations corresponding to different watershed land uses. We found PFAA(s) in 100% of stormwater runoff samples. Monitoring results and statistical analysis show that PFAAs in stormwater runoff from residential areas mainly came from rainfall. On the other hand, non-atmospheric sources at both industrial and commercial areas contributed PFAAs in stormwater runoff. The mass flux of PFAAs from stormwater runoff in the Twin Cities (Minneapolis and St. Paul, MN) metropolitan area is estimated to be about 7.86 kg/year. In addition, for the first time, we monitored PFAAs on the particles/debris in stormwater runoff and found high-level PFOS on the particulate matter in runoff collected from both industrial and commercial areas; the levels were so high that the finding could not be explained by the solid-water partitioning or adsorption. PFOS on the particulate matter is suspected to have originated from industrial/commercial products, entering the waste stream as PFOS containing particles. PMID:22154107

  19. Perfluorinated acids in Arctic snow: new evidence for atmospheric formation.

    PubMed

    Young, Cora J; Furdui, Vasile I; Franklin, James; Koerner, Roy M; Muir, Derek C G; Mabury, Scott A

    2007-05-15

    Perfluorinated acids (PFAs) are ubiquitously found in water and biota, including remote regions such as the High Arctic. Under environmental conditions, PFAs exist mainly as anions and are not expected to be subject to long-range atmospheric transport in the gas phase. Fluorinated telomer alcohols (FTOHs) are volatile and can be atmospherically oxidized to form perfluorocarboxylic acids. Analogously, fluorosulfamido alcohols can be oxidized to form perfluorooctane sulfonate (PFOS). High Arctic ice caps experience contamination solely from atmospheric sources. By examining concentrations of PFAs in ice cap samples, it is possible to determine atmospheric fluxes to the Arctic. Ice samples were collected from high Arctic ice caps in the spring of 2005 and 2006. Samples were concentrated using solid-phase extraction and analyzed by LC-MS-MS. PFAs were observed in all samples, dating from 1996 to 2005. Concentrations were in the low-mid pg L(-1) range and exhibited seasonality, with maximum concentrations in the spring-summer. The presence of perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnA) on the ice cap was indicative of atmospheric oxidation as a source. Ratios of PFAs to sodium concentrations were highly variable, signifying PFA concentrations on the ice cap were unrelated to marine chemistry. Fluxes of the PFAs were estimated to the area north of 65 degrees N for the 2005 season, which ranged from 114 to 587 kg year(-1) for perfluorooctanoic acid (PFOA), 73 to 860 kg year(-1) for perfluorononanoic acid (PFNA), 16 to 84 kg year(-1) for PFDA, 26 to 62 kg year(-1) for PFUnA, and 18 to 48 kg year(-1) for PFOS. The PFOA and PFNA fluxes agreed with FTOH modeling estimations. A decrease in PFOS concentrations through time was observed, suggesting a fast response to changes in production. These data suggest that atmospheric oxidation of volatile precursors is a primary source of PFAs to the Arctic. PMID:17547163

  20. Survey of perfluoroalkyl acids (PFAAs) and their precursors present in Japanese consumer products.

    PubMed

    Ye, Feng; Zushi, Yasuyuki; Masunaga, Shigeki

    2015-05-01

    Perfluoroalkyl acids (PFAAs) and their precursors have been used in various consumer products. However, limited information regarding their occurrence and concentration levels in products is available. In this study, we investigated 18 PFAAs and 14 PFAA precursors in various categories of consumer products purchased in Japan. Relatively high total concentrations of PFAAs and their precursors were found in sprays for fabrics and textiles (acid (PFOS), N-methyl perfluorooctane sulfonamidoethanol (MeFOSE) was detected in a higher frequency (8%) and in greater concentrations (PFOS (frequency 4%; concentrationsPFOS precursors in consumer products is required. Furthermore, the amount of PFAAs emitted from consumer products may be underestimated if the occurrence of PFAA precursors is not considered. In addition to PFAA precursors, long chain perfluoroalkyl carboxylic acids (PFCAs) (carbon chain length⩾7) were also detected in greater concentrations than short chain PFCAs (⩽6). This result suggests that consumer products are one of the important sources of long-chain PFCAs in the environment. PMID:25753850

  1. Comparison of in vitro cytotoxicity, estrogenicity and anti-estrogenicity of triclosan, perfluorooctane sulfonate and perfluorooctanoic acid.

    PubMed

    Henry, Natasha D; Fair, Patricia A

    2013-04-01

    Concern with increasing levels of emerging contaminants exists on a global scale. Three commonly observed emerging environmental contaminants: triclosan (2,4,4-trichloro-2'-hydroxydiphenyl ether), a synthetic, broad-spectrum antibacterial agent, and perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), used in stain- and water-resistant treatments, have become distributed ubiquitously across ecosystems and have been detected in wildlife and humans. MCF-7 BOS human breast cancer cells were used to investigate the potential for cytotoxicity, estrogenicity and anti-estrogenicity of these three compounds at environmentally relevant concentrations using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt assay (MTS) and the E-SCREEN bioassay. The doses used were 0.002-200 µg ml(-1) for triclosan and 0.03-30 µg ml(-1) for PFOS and PFOA. Quantitative results from the MTS assay revealed no significant cytotoxicity at lower concentrations for any of the test compounds; however, both triclosan and PFOA were cytotoxic at the highest concentrations examined (100-200 and 30 µg ml(-1), respectively), while PFOS showed no significant cytotoxicity at any of the concentrations tested. Positive estrogenic responses (P < 0.05) were elicited from the E-SCREEN at all concentrations examined for triclosan and PFOA and at 30 µg ml(-1) for PFOS. Further, significant anti-estrogenic activity (P < 0.05) was detected for all compounds tested at all concentrations when cells were co-exposed with 10(-9) m 17-β estradiol (E(2)). The overall results demonstrated that triclosan, PFOS and PFOA have estrogenic activities and that co-exposure to contaminants and E(2) produced anti-estrogenic effects. Each of these compounds could provide a source of xenoestrogens to humans and wildlife in the environment. Published 2011. This article is a US Government work and is in the public domain in the USA. PMID:21935973

  2. Simple, high throughput ultra-high performance liquid chromatography/tandem mass spectrometry trace analysis of perfluorinated alkylated substances in food of animal origin: milk and fish.

    PubMed

    Lacina, Ondrej; Hradkova, Petra; Pulkrabova, Jana; Hajslova, Jana

    2011-07-15

    The present study documents development and validation of a novel approach for determination of 23 perfluorinated alkylated substances (PFASs) in food of animal origin represented by milk and fish. The list of target analytes comprises four classes of PFASs, both ionic and non-ionic: 11 perfluorocarboxylic acids (PFCAs), 4 perfluorosulphonic acids (PFSAs), 5 perfluorosulphonamides (FOSAs) and 3 perfluorophosphonic acids (PFPAs). Fast sample preparation procedure is based on an extraction of target analytes with acetonitrile (MeCN) and their transfer (supported by inorganic salts and acidification) into the organic phase. Removing of matrix co-extracts by a simple dispersive solid phase extraction (SPE) employing ENVI-Carb and C18 sorbents is followed by an efficient sample pre-concentration performed by acetonitrile evaporation and subsequent dilution of residue in a small volume of methanol (matrix equivalent in the final extracts was 16 and 8 g mL(-1), for milk and fish respectively). Using modern instrumentation consisting of ultra-high performance liquid chromatography (UHPLC) hyphenated with a tandem mass spectrometer (MS/MS), limits of quantification (LOQs) as low as 0.001-0.006 μg kg(-1) for milk and 0.002-0.013 μg kg(-1) for fish can be achieved. Under these conditions, a wide spectrum of PFASs, including minor representatives, can be determined which enables collecting data required for human exposure studies. The pilot study employing the new method for examination of milk and canned fish samples was realized. Whereas in majority of canned fish products a wide spectrum of PFCAs, perfluorooctanesulphonic acid (PFOS) and perfluoro-1-octanesulphonamide (PFOSA) was detected, only in a few milk samples very low concentrations (LOQ levels) of PFOS and perfluorooctansulphonic acid (PFDS) were found. PMID:21621213

  3. Promotion of hepatocarcinogenesis by perfluoroalkyl acids in rainbow trout.

    PubMed

    Benninghoff, Abby D; Orner, Gayle A; Buchner, Clarissa H; Hendricks, Jerry D; Duffy, Aaron M; Williams, David E

    2012-01-01

    Previously, we reported that perfluorooctanoic acid (PFOA) promotes liver cancer in a manner similar to that of 17β-estradiol (E2) in rainbow trout. Also, other perfluoroalkyl acids (PFAAs) are weakly estrogenic in trout and bind the trout liver estrogen receptor. The primary objective of this study was to determine whether multiple PFAAs enhance hepatic tumorigenesis in trout, an animal model that represents human insensitivity to peroxisome proliferation. A two-stage chemical carcinogenesis model was employed in trout to evaluate PFOA, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorooctane sulfonate (PFOS), and 8:2 fluorotelomer alcohol (8:2FtOH) as complete carcinogens or promoters of aflatoxin B(1) (AFB(1))- and/or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced liver cancer. A custom trout DNA microarray was used to assess hepatic transcriptional response to these dietary treatments in comparison with E2 and the classic peroxisome proliferator, clofibrate (CLOF). Incidence, multiplicity, and size of liver tumors in trout fed diets containing E2, PFOA, PFNA, and PFDA were significantly higher compared with AFB(1)-initiated animals fed control diet, whereas PFOS caused a minor increase in liver tumor incidence. E2 and PFOA also enhanced MNNG-initiated hepatocarcinogenesis. Pearson correlation analyses, unsupervised hierarchical clustering, and principal components analyses showed that the hepatic gene expression profiles for E2 and PFOA, PFNA, PFDA, and PFOS were overall highly similar, though distinct patterns of gene expression were evident for each treatment, particularly for PFNA. Overall, these data suggest that multiple PFAAs can promote liver cancer and that the mechanism of promotion may be similar to that of E2. PMID:21984479

  4. Promotion of Hepatocarcinogenesis by Perfluoroalkyl Acids in Rainbow Trout

    PubMed Central

    Benninghoff, Abby D.; Orner, Gayle A.; Buchner, Clarissa H.; Hendricks, Jerry D.; Duffy, Aaron M.; Williams, David E.

    2012-01-01

    Previously, we reported that perfluorooctanoic acid (PFOA) promotes liver cancer in a manner similar to that of 17β-estradiol (E2) in rainbow trout. Also, other perfluoroalkyl acids (PFAAs) are weakly estrogenic in trout and bind the trout liver estrogen receptor. The primary objective of this study was to determine whether multiple PFAAs enhance hepatic tumorigenesis in trout, an animal model that represents human insensitivity to peroxisome proliferation. A two-stage chemical carcinogenesis model was employed in trout to evaluate PFOA, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorooctane sulfonate (PFOS), and 8:2 fluorotelomer alcohol (8:2FtOH) as complete carcinogens or promoters of aflatoxin B1 (AFB1)- and/or N-methyl-N′-nitro-N-nitrosoguanidine (MNNG)-induced liver cancer. A custom trout DNA microarray was used to assess hepatic transcriptional response to these dietary treatments in comparison with E2 and the classic peroxisome proliferator, clofibrate (CLOF). Incidence, multiplicity, and size of liver tumors in trout fed diets containing E2, PFOA, PFNA, and PFDA were significantly higher compared with AFB1-initiated animals fed control diet, whereas PFOS caused a minor increase in liver tumor incidence. E2 and PFOA also enhanced MNNG-initiated hepatocarcinogenesis. Pearson correlation analyses, unsupervised hierarchical clustering, and principal components analyses showed that the hepatic gene expression profiles for E2 and PFOA, PFNA, PFDA, and PFOS were overall highly similar, though distinct patterns of gene expression were evident for each treatment, particularly for PFNA. Overall, these data suggest that multiple PFAAs can promote liver cancer and that the mechanism of promotion may be similar to that of E2. PMID:21984479

  5. Response of the zooplankton community and environmental fate of perfluorooctane sulfonic acid in aquatic microcosms.

    PubMed

    Boudreau, Timothy M; Wilson, Christian J; Cheong, Woo Jay; Sibley, Paul K; Mabury, Scott A; Muir, Derek C G; Solomon, Keith R

    2003-11-01

    Little is known regarding perfluorooctane sulfonic acid (PFOS) toxicity to freshwater organisms. This field evaluation aims to assess the toxicological risk associated with exposure to PFOS across levels of biological organization. The analysis of variance study was conducted in replicate (n = 3) 12,000 L outdoor microcosms. Multivariate techniques were used to assess the response of zooplankton community structure and dynamics, as well as a floating macrophyte, Lemna gibba. The zooplankton community was significantly affected (p < 0.05) by the treatment regime given by the Monte Carlo permutations for all sampling times. A community-level no-observable-effect concentration ([NOEC]community) of 3.0 mg/L was determined for the 35-day study, however, longer term studies are recommended. The most sensitive taxonomic groups, Cladocera and Copepoda, were virtually eliminated in 30 mg/L treatments after 7 d. The 42-d 50% inhibition concentration (IC50) for L. gibba frond number was 19.1 mg/L and the NOEC was 0.2 mg/L. Furthermore, we investigated the persistence of PFOS over 285 d in microcosms under natural conditions. Perfluorooctane sulfonic acid concentration showed no drastic reduction in any treatment microcosm over the entire study period, confirming that this compound undergoes little degradation in aquatic systems. Presently, there appears to be little hazard to these freshwater organisms at reported environmental concentrations. PMID:14587916

  6. Mass Balance of Perfluoroalkyl Acids in the Baltic Sea

    PubMed Central

    2013-01-01

    A mass balance was assembled for perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDA), and perfluorooctanesulfonic acid (PFOS) in the Baltic Sea. Inputs (from riverine discharge, atmospheric deposition, coastal wastewater discharges, and the North Sea) and outputs (to sediment burial, transformation of the chemical, and the North Sea), as well as the inventory in the Baltic Sea, were estimated from recently published monitoring data. Formation of the chemicals in the water column from precursors was not considered. River inflow and atmospheric deposition were the dominant inputs, while wastewater treatment plant (WWTP) effluents made a minor contribution (<5%). A mass balance of the Oder River watershed was assembled to explore the sources of the perfluoroalkyl acids (PFAAs) in the river inflow. It indicated that WWTP effluents made only a moderate contribution to riverine discharge (21% for PFOA, 6% for PFOS), while atmospheric deposition to the watershed was 1–2 orders of magnitude greater than WWTP discharges. The input to the Baltic Sea exceeded the output for all four PFAAs, suggesting that inputs were higher during 2005–2010 than during the previous 20 years despite efforts to reduce emissions of PFAAs. One possible explanation is the retention and delayed release of PFAAs from atmospheric deposition in the soils and groundwater of the watershed. PMID:23528236

  7. Perfluorinated alkyl acids in the plasma of South African crocodiles (Crocodylus niloticus).

    PubMed

    Christie, Ian; Reiner, Jessica L; Bowden, John A; Botha, Hannes; Cantu, Theresa M; Govender, Danny; Guillette, Matthew P; Lowers, Russell H; Luus-Powell, Wilmien J; Pienaar, Danie; Smit, Willem J; Guillette, Louis J

    2016-07-01

    Perfluorinated alkyl acids (PFAAs) are environmental contaminants that have been used in many products for over 50 years. Interest and concern has grown since 2000 on the widespread presence of PFAAs, when it was discovered that PFAAs were present in wildlife samples around the northern hemisphere. Since then, several studies have reported PFAAs in wildlife from many locations, including the remote regions of Antarctica and the Arctic. Although there are a multitude of studies, few have reported PFAA concentrations in reptiles and wildlife in the Southern Hemisphere. This study investigated the presence of PFAAs in the plasma of Nile crocodiles (Crocodylus niloticus) from South Africa. Crocodiles were captured from five sites in and around the Kruger National Park, South Africa, and plasma samples examined for PFAAs. Perfluorooctane sulfonate (PFOS) was the most frequent PFAA detected; with median values of 13.5 ng/g wet mass in crocodiles. In addition to PFOS, long chain perfluorinated carboxylic acids were also detected. Correlations between total length and PFAA load were investigated, as were differences in PFAA accumulation between sexes. No correlations were seen between crocodile size, nor were there sex-related differences. Spatial differences were examined and significant differences were observed in samples collected from the different sites (p < 0.05). Flag Boshielo Dam had the highest PFOS measurements, with a median concentration of 50.3 ng/g wet mass, when compared to the other sites (median concentrations at other sites below 14.0 ng/g wet mass). This suggests a point source of PFOS in this area. PMID:27038902

  8. 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.

    PubMed

    Loos, Robert; Wollgast, Jan; Huber, Tania; Hanke, Georg

    2007-02-01

    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

  9. Detection of a cyclic perfluorinated acid, perfluoroethylcyclohexane sulfonate, in the Great Lakes of North America.

    PubMed

    De Silva, Amila O; Spencer, Christine; Scott, Brian F; Backus, Sean; Muir, Derek C G

    2011-10-01

    Perfluoroethylcyclohexanesulfonate (PFECHS) is a cyclic perfluorinated acid (PFA) mainly used as an erosion inhibitor in aircraft hydraulic fluids. It is expected to be as recalcitrant to environmental degradation as aliphatic PFAs including perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS). For the first time, PFECHS is reported in top predator fish (PFOS was the major aliphatic PFA in fish from the Great Lakes. Concentrations of most of the PFAs were not statistically different from previously reported 2004 trout data in Lake Ontario. Shorter chain perfluorocarboxylates were prevalent in surface waters of the Great Lakes, dominated by PFOA (0.65-5.5 ng/L). An impurity in the commercial PFECHS formulation, perfluoromethylcyclohexane sulfonate (PFMeCHS), was also detected in the dissolved phase but not above detection limits in fish tissue. Bioaccumulation factors (BAFs) were estimated by taking the ratio of fish to water concentrations. The mean log BAF values corresponded to 2.8 for PFECHS, 2.1 for PFOA, and 4.5 for PFOS. It is not certain whether the fish-water BAF for PFECHS is an overestimate due to the influence of precursor biotransformation. Further studies are recommended to understand the extent of PFECHS contamination. PMID:21528907

  10. Occurrence of perfluorooctanesulfonate and perfluorooctanoic acid and histopathology in eels from north Italian waters.

    PubMed

    Giari, Luisa; Guerranti, Cristiana; Perra, Guido; Lanzoni, Mattia; Fano, Elisa Anna; Castaldelli, Giuseppe

    2015-01-01

    A perfluorinated alkylated substances (PFAS) biomonitoring study was conducted in European eel (Anguilla anguilla) in Italy for the first time. Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) concentrations were assessed in the organs of 35 wild eels from two locations, the highly impacted Po River and the Comacchio Lagoon along the north-western Adriatic coast. PFAS were extracted by ion-pairing liquid extraction procedure and measured using high performance liquid chromatography with electrospray ionization tandem mass spectrometry. There were no significant differences in mean PFAS concentrations (p>0.05) between samples from the two sites. PFOS and PFOA were detectable (>0.4ngg(-1) wet weight, w.w) in 73% and 31% of the total samples, respectively. PFOS concentrations ranged from <0.4 to 6.28ngg(-1)w.w and PFOA from <0.4 to 92.77ngg(-1)w.w. The highest PFAS levels were observed in blood and the lowest in muscle. Histology showed macrophage aggregates and hepatocytic vacuolation in some liver samples. No tissue anomalies were seen in the gonads, suggesting no reproductive impairment. The PFAS contamination levels observed were comparable to, or lower than, those reported in fish in other European countries, seeming to indicate that PFAS pollution of the study area is not remarkable. PMID:25083944

  11. Liquid chromatography-tandem mass spectrometry analysis of perfluorooctane sulfonate and perfluorooctanoic Acid in fish fillet samples.

    PubMed

    Paiano, Viviana; Fattore, Elena; Carrà, Andrea; Generoso, Caterina; Fanelli, Roberto; Bagnati, Renzo

    2012-01-01

    Perfluorooctane sulfonate (PFOS) and perfluorooctanoic (PFOA) acid are persistent contaminants which can be found in environmental and biological samples. A new and fast analytical method is described here for the analysis of these compounds in the edible part of fish samples. The method uses a simple liquid extraction by sonication, followed by a direct determination using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The linearity of the instrumental response was good, with average regression coefficients of 0.9971 and 0.9979 for PFOS and PFOA, respectively, and the coefficients of variation (CV) of the method ranged from 8% to 20%. Limits of detection (LOD) were 0.04 ng/g for both the analytes and recoveries were 90% for PFOS and 76% for PFOA. The method was applied to samples of homogenized fillets of wild and farmed fish from the Mediterranean Sea. Most of the samples showed little or no contamination by perfluorooctane sulfonate and perfluorooctanoic acid, and the highest concentrations detected among the fish species analyzed were, respectively, 5.96 ng/g and 1.89 ng/g. The developed analytical methodology can be used as a tool to monitor and to assess human exposure to perfluorinated compounds through sea food consumption. PMID:22567564

  12. Occurrence and sources of perfluoroalkyl acids in Italian river basins.

    PubMed

    Valsecchi, Sara; Rusconi, Marianna; Mazzoni, Michela; Viviano, Gaetano; Pagnotta, Romano; Zaghi, Carlo; Serrini, Giuliana; Polesello, Stefano

    2015-06-01

    This paper presents a survey on the occurrence and sources of 11 perfluoroalkyl acids (PFAA) in the main river basins in Italy, covering about 40% of the Italian surface area and 45% of the Italian population. Total concentrations of PFAA ranged fromacids (PFCA), 6% PFOS and 1% long chain PFCA. PFOA and PFOS loads, evaluated in the present work, represent 10% and 2% of the estimated European loads, respectively. In Italy the most important sources of PFAA are two chemical plants which produce fluorinated polymers and intermediates, sited in the basin of rivers Po and Brenta, respectively, whose overall emission represents 57% of the total estimated PFAA load. Both rivers flow into the Adriatic Sea, raising concern for the marine ecosystem also because a significant PFOS load (0.3ty(-1)) is still present. Among the remaining activities, tanneries and textile industries are relevant sources of respectively PFBS and PFOA, together with short chain PFCA. As an example, the total PFAA load (0.12ty(-1)) from the textile district of Prato is equivalent to the estimated domestic emission of the whole population in all the studied basins. PMID:25108894

  13. Evidence for the involvement of xenobiotic-responsive nuclear receptors in transcriptional effects upon perfluoroalkyl acid exposure in diverse species.

    PubMed

    Ren, Hongzu; Vallanat, Beena; Nelson, David M; Yeung, Leo W Y; Guruge, Keerthi S; Lam, Paul K S; Lehman-McKeeman, Lois D; Corton, J Christopher

    2009-06-01

    Humans and ecological species have been found to have detectable body burdens of a number of perfluorinated alkyl acids (PFAA) including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). In mouse and rat liver these compounds elicit transcriptional and phenotypic effects similar to peroxisome proliferator chemicals (PPC) that work through the nuclear receptor peroxisome proliferator-activated receptor alpha (PPAR alpha). Recent studies indicate that along with PPAR alpha other nuclear receptors are required for transcriptional changes in the mouse liver after PFOA exposure including the constitutive activated receptor (CAR) and pregnane X receptor (PXR) that regulate xenobiotic metabolizing enzymes (XME). To determine the potential role of CAR/PXR in mediating effects of PFAAs in rat liver, we performed a meta-analysis of transcript profiles from published studies in which rats were exposed to PFOA or PFOS. We compared the profiles to those produced by exposure to prototypical activators of CAR, (phenobarbital (PB)), PXR (pregnenolone 16 alpha-carbonitrile (PCN)), or PPAR alpha (WY-14,643 (WY)). As expected, PFOA and PFOS elicited transcript profile signatures that included many known PPAR alpha target genes. Numerous XME genes were also altered by PFOA and PFOS but not WY. These genes exhibited expression changes shared with PB or PCN. Reexamination of the transcript profiles from the livers of chicken or fish exposed to PFAAs indicated that PPAR alpha, CAR, and PXR orthologs were not activated. Our results indicate that PFAAs under these experimental conditions activate PPAR alpha, CAR, and PXR in rats but not chicken and fish. Lastly, we discuss evidence that human populations with greater CAR expression have lower body burdens of PFAAs. PMID:19162173

  14. In vivo DNA mismatch repair measurement in zebrafish embryos and its use in screening of environmental carcinogens.

    PubMed

    Chen, Yuanhong; Huang, Changjiang; Bai, Chenglian; Du, Changchun; Liao, Junhua; Dong, Qiaoxiang

    2016-01-25

    Impairment of DNA mismatch repair (MMR) function leads to the development and progression of certain cancers. Many environmental contaminants can target DNA MMR system. Currently, measurement of MMR activity is limited to in vitro or in vivo methods at the cell line level, and reports on measurement of MMR activity at the live organism level are lacking. Here, we report an efficient method to measure DNA MMR activity in zebrafish embryos. A G-T mismatch was introduced into enhanced green fluorescent protein (EGFP) gene. Repair of the G-T mismatch to G-C in the heteroduplex plasmid generates a functional EGFP expression. The heteroduplex plasmid and a similarly constructed homoduplex plasmid were injected in parallel into the same batch of embryos at 1-cell stage and EGFP expression in EGFP positive embryos was quantified at 24 h after injection. MMR efficiency was calculated as the total fluorescence intensity of embryos injected with the heteroduplex construct divided by that of embryos injected with the homoduplex construct. Our results showed 73% reduction of MMR activity in embryos derived from MMR-deficient mlh1 mutant fish (positive control) when compared with embryos from MMR-competent wild type AB line fish, indicating feasibility of in vivo MMR activity measurement in zebrafish embryos. We further applied this novel assay for measurement of MMR efficiency in embryos exposed to environmental chemicals such as cadmium chloride (CdCl2), benzo[a]pyrene (BaP), and perfluorooctanesulphonic acid (PFOS) from 6 hpf to 24 hpf. We observed significant reductions of MMR efficiency in embryos exposed to 0.1 μM CdCl2 (52%) and 0.5 μM BaP (34%), but no effect in embryos exposed to PFOS. Our study for the first time provides a model system for in vivo measurement of DNA MMR activity at the organism level, which has important implications in risk assessment of various environmental carcinogens. PMID:26476317

  15. Historical usage of aqueous film forming foam: a case study of the widespread distribution of perfluoroalkyl acids from a military airport to groundwater, lakes, soils and fish.

    PubMed

    Filipovic, Marko; Woldegiorgis, Andreas; Norström, Karin; Bibi, Momina; Lindberg, Maria; Österås, Ann-Helen

    2015-06-01

    Historical usage of aqueous film forming foams (AFFFs) at military airports is a potential source of perfluoroalkyl acids (PFAAs) to the nearby environment. In this study, the distribution of perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS) and perfluorooctane sulfonate (PFOS) in soil, groundwater, surface water, tap water well, and fish muscle was investigated at a closed down military airfield (F18) and its surroundings in Stockholm, Sweden. The presence of PFOS at AFFF training sites was inventoried. One major finding of the study is that a former airfield, abandoned since 1994, may still be a point source of PFAAs to nearby recipients. PFOS and PFOA were ubiquitous in the soil samples at former AFFF training sites with concentrations ranging from 2.18 to 8520ngg(-1) dry weight and <0.12-287ngg(-1) dry weight respectively. The sum of PFAAs in the groundwater and surface waters ranged from 738 to 51000ngL(-1) and PFOS in European perch ranged from 76.5 to 370ngg(-1)wet weight muscle tissue which is among the highest previously reported worldwide. Our results provide evidence that the historical use of AFFF at the site have contaminated an aquifer (7500 m(3)d(-1)), that will require constant PFAA purification before being used for drinking water production. Despite the fact that the water turnover time in the investigated recipients (of 4-6months) suggest a depletion of PFAA-contaminants over a quarter of a decade, abandoned airfields may still pose an environmental and human health concern. PMID:25262531

  16. Estimation of the total concentration of perfluoroalkyl acids (PFAA) in human serum: Data from NHANES 2005-2012.

    PubMed

    Jain, Ram B

    2015-09-01

    While selected perfluoroalkyl acids/substances (PFAAs) like perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) have been detected and measured in laboratory, a method to estimate the total concentration of PFAAs (?PFAA) in serum has not been developed. Because of the health concerns associated with PFAAs and because of the inability of every laboratory to measure every PFAA as well as because of the non-availability of sensitive enough equipment to be able to detect very small amounts of certain PFAAs, it is of interest to know ?PFAA. We used data from the National Health and Nutrition Examination Survey for the years 2005-2012 to develop regression models to estimate ?PFAA by using the levels of PFOA and PFOS only. While data for 2005-2008 were used to develop regression models, data for 2009-2012 were used to evaluate the accuracy of the developed models. Over 63% of observed values for evaluation data were found to be within 10% of the predicted values. The model so developed can be used with just the knowledge of the age, gender, and concentrations of PFOA and PFOS. While the data used to develop the model were generated in U.S., the model can be used to estimate ?PFAA for data collected in North America and Europe and probably elsewhere in the world. PMID:25981317

  17. Time trends of perfluorinated alkyl acids in serum from Danish pregnant women 2008-2013.

    PubMed

    Bjerregaard-Olesen, Christian; Bach, Cathrine C; Long, Manhai; Ghisari, Mandana; Bossi, Rossana; Bech, Bodil H; Nohr, Ellen A; Henriksen, Tine B; Olsen, Jørn; Bonefeld-Jørgensen, Eva C

    2016-05-01

    We aimed to estimate the levels and time trends of perfluorinated alkyl acids (PFAAs) in serum of 1533 Danish pregnant nulliparous women between 2008 and 2013. The selection criterion of only including nulliparous women was chosen to avoid confounding from parity. The serum samples were analyzed for sixteen PFAAs using solid phase extraction and liquid chromatography tandem mass spectrometry (LC-MS/MS). We investigated the time trends for seven PFAAs, which were detected in more than 50% of the samples: perfluorohexane sulfonate (PFHxS), perfluoroheptane sulfonate (PFHpS), perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnA). We found that the serum levels of all seven PFAAs decreased during the period from 2008 to 2013; on average PFHxS decreased with 7.0% per year, PFHpS with 14.8%, PFOS with 9.3%, PFOA with 9.1%, PFNA with 6.2%, PFDA with 6.3%, and PFUnA with 7.1% per year. Adjustment for maternal age, body mass index (BMI), educational level and gestational age at blood sampling did not change the time trends much. To our knowledge, we are the first to report decreasing trends of PFNA, PFDA and PFUnA since year 2000, thereby indicating that the phase-out of these compounds are beginning to show an effect on human serum levels. PMID:26891270

  18. Perfluoroalkyl sulfonates and carboxylic acids in liver, muscle and adipose tissues of black-footed albatross (Phoebastria nigripes) from Midway Island, North Pacific Ocean.

    PubMed

    Chu, Shaogang; Wang, Jun; Leong, Gladys; Woodward, Lee Ann; Letcher, Robert J; Li, Qing X

    2015-11-01

    The Great Pacific Garbage Patch (GPGP) is a gyre of marine plastic debris in the North Pacific Ocean, and nearby is Midway Atoll which is a focal point for ecological damage. This study investigated 13 C4-C16 perfluorinated carboxylic acids (PFCAs), four (C4, C6, C8 and C10) perfluorinated sulfonates and perfluoro-4-ethylcyclohexane sulfonate [collectively perfluoroalkyl acids (PFAAs)] in black-footed albatross tissues (collected in 2011) from Midway Atoll. Of the 18 PFCAs and PFSAs monitored, most were detectable in the liver, muscle and adipose tissues. The concentrations of PFCAs and PFSAs were higher than those in most seabirds from the arctic environment, but lower than those in most of fish-eating water birds collected in the U.S. mainland. The concentrations of the PFAAs in the albatross livers were 7-fold higher than those in Laysan albatross liver samples from the same location reported in 1994. The concentration ranges of PFOS were 22.91-70.48, 3.01-6.59 and 0.53-8.35 ng g(-1) wet weight (ww), respectively, in the liver, muscle and adipose. In the liver samples PFOS was dominant, followed by longer chain PFUdA (8.04-18.70 ng g(-1) ww), PFTrDA, and then PFNA, PFDA and PFDoA. Short chain PFBA, PFPeA, PFBS and PFODA were below limit of quantification. C8-C13 PFCAs showed much higher composition compared to those found in other wildlife where PFOS typically predominated. The concentrations of PFUdA in all 8 individual albatross muscle samples were even higher than those of PFOS. This phenomenon may be attributable to GPGP as a pollution source as well as PFAA physicochemical properties. PMID:26037817

  19. An optimized method for the determination of perfluorooctanoic acid, perfluorooctane sulfonate and other perfluorochemicals in different matrices using liquid chromatography/ion-trap mass spectrometry.

    PubMed

    Dolman, Sebastiaan; Pelzing, Matthias

    2011-07-15

    Perfluorochemicals (PFC's) are widely spread in the environment and have been detected in blood of wildlife and humans world-wide. Recently, various toxic effects of PFC's in laboratory rats have been demonstrated, resulting in increased government concerns regarding the presence of PFC's in the environment and the implications they have on human health. In the last decade, various analytical methods have been developed for the analysis of PFC's in different matrices whereby the majority of methods have utilised liquid chromatography coupled with mass spectrometry (LC-MS). Here we describe an optimized method for the quantitation of PFC's, including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), in food packaging, polytetrafluoroethylene (PTFE) sealant tape and drinking water. The method involved PFC's extraction via off-line SPE followed by separation using reversed-phase liquid chromatography on a Phenyl-Hexyl column coupled with ion-trap (IT) mass spectrometric detection. The optimized approach minimized ion-suppression effects commonly seen with conventional elution buffers, improving detection limits down to 25 pg/mL and allowed effective quantitation down to 50 pg/mL for PFOA and PFOS. The optimized LC-MS method detected PFOA and other PFC's in microwave popcorn packaging and PFOA in PTFE sealant tape in the low μg/kg. In all samples, PFOS was not detected. PMID:21700512

  20. Prenatal Exposure to Perfluoroalkyl Acids and Serum Testosterone Concentrations at 15 Years of Age in Female ALSPAC Study Participants

    PubMed Central

    Calafat, Antonia M.; Marcus, Michele; Jaakkola, Jouni J.K.; Lashen, Hany

    2015-01-01

    Background Exposure to perfluorooctane sulfonic acid (PFOS) or to perfluorooctanoic acid (PFOA) increases mouse and human peroxisome proliferator–activated receptor alpha (PPARα) subtype activity, which influences lipid metabolism. Because cholesterol is the substrate from which testosterone is synthesized, exposure to these substances has the potential to alter testosterone concentrations. Objectives We explored associations of total testosterone and sex hormone–binding globulin (SHBG) concentrations at age 15 years with prenatal exposures to PFOS, PFOA, perfluorohexane sulfonic acid (PFHxS), and perfluoronanoic acid (PFNA) in females. Methods Prenatal concentrations of the perfluoroalkyl acids (PFAAs) were measured in serum collected from pregnant mothers at enrollment (1991–1992) in the Avon Longitudinal Study of Parents and Children (ALSPAC). The median gestational age when the maternal blood sample was obtained was 16 weeks (interquartile range, 11–28 weeks). Total testosterone and SHBG concentrations were measured in serum obtained from their daughters at 15 years of age. Associations between prenatal PFAAs concentrations and reproductive outcomes were estimated using linear regression models (n = 72). Results Adjusted total testosterone concentrations were on average 0.18-nmol/L (95% CI: 0.01, 0.35) higher in daughters with prenatal PFOS in the upper concentration tertile compared with daughters with prenatal PFOS in the lower tertile. Adjusted total testosterone concentrations were also higher in daughters with prenatal concentrations of PFOA (β = 0.24; 95% CI: 0.05, 0.43) and PFHxS (β = 0.18; 95% CI: 0.00, 0.35) in the upper tertile compared with daughters with concentrations in the lower tertile. We did not find evidence of associations between PFNA and total testosterone or between any of the PFAAs and SHBG. Conclusions Our findings were based on a small study sample and should be interpreted with caution. However, they suggest that prenatal exposure to some PFAAs may alter testosterone concentrations in females. Citation Maisonet M, Calafat AM, Marcus M, Jaakkola JJ, Lashen H. 2015. Prenatal exposure to perfluoroalkyl acids and serum testosterone concentrations at 15 years of age in female ALSPAC study participants. Environ Health Perspect 123:1325–1330; http://dx.doi.org/10.1289/ehp.1408847 PMID:26034840

  1. Dietary exposure to selected perfluoroalkyl acids (PFAAs) in four European regions.

    PubMed

    Klenow, Stefanie; Heinemeyer, Gerhard; Brambilla, Gianfranco; Dellatte, Elena; Herzke, Dorte; de Voogt, Pim

    2013-01-01

    The dietary exposure to selected PFAAs was estimated in four selected European states (Belgium, the Czech Republic, Italy and Norway) representing Western, Southern, Eastern and Northern Europe. The harmonised sampling programme designed in the European Union project PERFOOD was targeted at identifying seven selected PFAAs, including perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), in food items that are most important both in terms of consumption and based on known high contamination patterns. The estimated average dietary exposure for adults (18-64 years) and children (3-9 years) is generally below or close to 1 ng kg⁻¹ BW day⁻¹ for all seven PFAAs. Considering the high consumption of food groups that contribute most to the exposure does not result in estimates exceeding 4 ng kg⁻¹ BW day⁻¹. Thus, based on the TDIs proposed by EFSA for PFOS (150 ng kg⁻¹ BW day⁻¹) and PFOA (1500 ng kg⁻¹ BW day⁻¹), no concern can be identified. There are distinct dietary exposure patterns from region to region as a result of different food consumption and contamination patterns. Foods of plant origin (e.g. fruit and vegetables) are most important for the dietary exposure to PFHxA, PFOA and PFHxS, while the consumption of foods of animal origin (particularly fish and seafood) mostly contributes to the dietary exposure to PFDA and PFUnDA. For the dietary exposure to PFNA and PFOS, food of animal and plant origin contributes with equal importance. In conclusion, region-to-region differences as well as the relative importance of food of different origin for each PFAA should be paid more attention in further research. PMID:24279394

  2. Endocrine and developmental effects in Atlantic salmon (Salmo salar) exposed to perfluorooctane sulfonic or perfluorooctane carboxylic acids.

    PubMed

    Spachmo, Bård; Arukwe, Augustine

    2012-02-01

    In this study, we have investigated the effect of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) on endocrine signalling, growth and development in Atlantic salmon (Salmo salar) embryos and larvae. Expression of genes related to the hypothalamic-pituitary-thyroid (HPT) axis, growth-hormone/insulin-like growth factor (GH/IGF) axis and the steroid hormone axis were used as indicators of endocrine disruption. We also studied bone development in larvae, both by observing skeletal structure formation and by investigating expression of genes involved in ossification process. Atlantic salmon embryos, kept in plastic tanks at 5-7°C, were exposed to 100 μg/L PFOA or PFOS from egg stage for a period of 52 days, followed by one-week recovery period. Sampling was performed at day 21, 35, 49 and 56 representing age 549, 597, 679 and 721 dd (dd or day degrees = number of days × temperature in degree Celsius:°C). Note that day 56 or 721 dd is the end of the 1-week recovery period. Larvae were divided into designated head and body regions for the purpose of gene expression analysis, except for genes that regulate ossification that were analyzed in whole larvae. Expression of thyroid receptor α and β (TRα and TRβ), thyroid-stimulating hormone β (TSHβ), T(4) outer-ring deiodinase (T(4)ORD), growth hormone (GH), insulin-like growth factor-I and II (IGF-I and II), insulin-like growth factor I receptor (IGF-IR), and estrogen receptor α and β (ERα and ERβ) were investigated using quantitative PCR. Both PFOS and PFOA exposure produced non-significant alterations in larvae weight (except after the recovery period when a decrease was observed), while larvae length was unaffected. PFOS and PFOA exposure produced body- and head region-specific alterations in expression of all the investigated gene transcripts. Expression of IGF-I and IGF-IR paralleled that of GH, indicating that perturbation of GH expression is a possible end point for disruption of the GH-IGF axis. We did not observe developmental changes related to angiogenesis, ossification and chondrogenesis after exposure to PFOS and PFOA. Transcriptional abnormalities may serve as indicators of chronic exposure, although the concrete mechanisms causing the observed effects remain ambiguous. The implications of these findings for the complete lifecycle, including other developmental and/or reproductive damage, are areas of future study. PMID:22265611

  3. Occurrence and point source characterization of perfluoroalkyl acids in sewage sludge.

    PubMed

    Alder, Alfredo C; van der Voet, Juergen

    2015-06-01

    The occurrence and levels of perfluoroalkyl acids (PFAAs) emitted from specific pollution sources into the aquatic environment in Switzerland were studied using digested sewage sludges from 45 wastewater treatment plants in catchments containing a wide range of potential industrial emitters. Concentrations of individual PFAAs show a high spatial and temporal variability, which infers different contributions from industrial technologies and activities. Perfluorooctane sulfonic acid (PFOS) was generally the predominant PFAA with concentrations varying between 4 and 2440μgkg(-1) (median 75μgkg(-1)). Elevated emissions were especially observed in catchments capturing discharges from metal plating industries (median 82μgkg(-1)), aqueous firefighting foams (median 215μgkg(-1)) and landfill leachates (median 107μgkg(-1)). Some elevated perfluoroalkyl carboxylic acids (PFCAs) levels could be attributed to emissions from textile finishing industries with concentrations up to 233μgkg(-1) in sewage sludge. Assuming sorption to sludge for PFOS and PFCAs of 15% and 2%, respectively, concentrations in wastewater effluents up to the low μgL(-1) level were estimated. Even if wastewater may be expected to be diluted between 10 and 100 times by the receiving waters, elevated concentrations may be reached at specific locations. Although sewage sludge is a minor compartment for PFAAs in WWTPs, these investigations are helpful for the identification of hot-spots from industrial emitters as well as to estimate monthly average concentrations in wastewater. PMID:25176581

  4. Mass spectral studies towards more reliable measurement of perfluorooctanesulfonic acid and other perfluorinated chemicals (PFCs) in food matrices using liquid chromatography/tandem mass spectrometry.

    PubMed

    Lloyd, Antony S; Bailey, Victoria A; Hird, Simon J; Routledge, Anne; Clarke, Don B

    2009-09-01

    Liquid chromatography/mass spectrometry (LC/MS) experiments are described, leading to a reliable method for the measurement of perfluorooctanesulfonic acid (PFOS) and other perfluorinated chemicals (PFCs) in foods. Separations were performed on new fluorinated stationary phases, RP Octyl (-C(8)F(17)) or propyl-perfluorobenzene (-C(3)H(6)-C(6)F(5)), to ensure resolution of PFOS and interfering taurohydroxycholate isomers. Aqueous ammonium formate (5 mM) and methanol were used as the mobile phases. The mass spectrometer was operated in negative electrospray ionisation mode, recording two transitions for each analyte and one for each internal standard. The purities of the analytical standards for the eleven target perfluoro analytes (C(7) to C(12) carboxylic acids, C(4), C(6) and C(8) sulfonic acids, and octanesulfonamide (PFOSA)) were found to be in close agreement with the supplied values; the lowest purity was 91%. Five candidate internal standards were investigated, (13)C(4)-PFOS, (13)C(4)-perfluorooctanoic acid, (13)C(2)-perfluorodecanoic acid, D(9)-n-ethylperfluorooctanesulfonamidoethanol (D(9)-n-Et-FOSE) and D(3)-n-methylperfluorooctanesulfonamide (D(3)-n-Me-FOSA); the purities were all >98%. The use of tetrahydro-PFOS generated backgrounds (>1 microg/kg) for perfluoroheptanoic acid and perfluorobutanesulfonic acid. Similarly D(9)-n-Et-FOSE was unacceptable and D(3)-n-Me-FOSA was volatile, leaving no clear candidate for normalisation of the measurement of PFOSA. Severe matrix-induced suppression and enhancement effects influenced ionisation, making external calibration and quantification problematic. This was addressed by a parallel standard addition and matrix-matching approach, comparing ionisation in methanol, in procedural blanks and in food-based extracts. The limits of detection (LODs) of 0.001-0.01 microg/kg in solvent and 0.01-1 microg/kg in foods demonstrate that this method is suitable for the determination of PFCs in all food to the required 1 microg/kg reporting level. PMID:19685475

  5. Is indirect exposure a significant contributor to the burden of perfluorinated acids observed in humans?

    PubMed

    D'eon, Jessica C; Mabury, Scott A

    2011-10-01

    In comparison to other persistent organic pollutants, human fluorochemical contamination is relatively complicated. This complication arises at least in part from a disparity between the chemicals used commercially and those measured in the environment and humans. Commercial fluorochemical products are dominated by fluorinated polymers used in textile or carpet applications, or fluorosurfactants used in applications ranging from personal care products, leveling and wetting agents, to greaseproofing food-contact materials. Investigations into environmental and human fluorochemical contamination have focused on perfluorinated acids (PFAs), either the perfluorinated carboxylates (PFCAs) or sulfonates (PFSAs). In this review we will present an overview of data related to human fluorochemical exposure including a discussion of fluorochemical production, concentrations in exposure media, biotransformation processes producing PFAs, and trends in human sera. These data will be presented in the context of how they can inform sources of human PFA contamination, specifically whether the contamination results from direct PFA exposure or indirect exposure via the biotransformation of commercial fluorochemicals or their residuals. Concentrations of both perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) began to decrease in human sera around the year 2000, a change that mirrored the 2000-2002 phase-out of perfluorooctane sulfonyl fluoride (POSF) production. These temporal trends suggest exposure to current-use POSF-based materials was a significant source of PFOA and PFOS exposure prior to 2000. Relatively slow PFOA elimination and increasing concentrations of the C9 and C10 PFCAs in human sera suggest continued PFCA exposure, without similar exposure to PFOS, which is consistent with indirect exposure via the biotransformation of fluorotelomer-based materials. Conversely, human exposure models have suggested direct exposure to PFAs present in food items is the major source of human contamination. The data set presented here cannot unequivocally delineate between direct and indirect human exposure, however temporal trends in human sera and exposure media are consistent with indirect exposure representing a significant portion of observed human PFA contamination. PMID:21630688

  6. Exploring the Use of Molecular Docking to Identify Bioaccumulative Perfluorinated Alkyl Acids (PFAAs).

    PubMed

    Ng, Carla A; Hungerbuehler, Konrad

    2015-10-20

    Methods to predict the bioaccumulation potential of per- and polyfluorinated alkyl substances (PFAS) are sorely needed, given the proliferation of these substances and lack of data on their properties and behavior. Here, we test whether molecular docking, a technique where interactions between proteins and ligands are simulated to predict both bound conformation and interaction affinity, can be used to predict PFAS binding strength and biological half-life. We show that an easy-to-implement docking program, Autodock Vina, can successfully redock perfluorooctanesulfonate (PFOS) to human serum albumin with deviations smaller than 2 Å. Furthermore, predicted binding strengths largely fall within one standard deviation of measured values for perfluorinated alkyl acids (PFAAs). Correlations with half-lives suggest both membrane partitioning and protein interactions are important, and that serum albumin is only one of a number of proteins controlling the fate of these chemicals in organisms. However, few data are available for validation of our approach as a broad screening tool, and available data are highly variable. We therefore call for collection of new data, particularly including proteins other than serum albumin and substances beyond perfluorooctanoic acid (PFOA) and PFOS. The methods we discuss in this work can serve as a framework for guiding such data collection. PMID:26393377

  7. Spatial distribution and partition of perfluoroalkyl acids (PFAAs) in rivers of the Pearl River Delta, southern China.

    PubMed

    Liu, Baolin; Zhang, Hong; Xie, Liuwei; Li, Juying; Wang, Xinxuan; Zhao, Liang; Wang, Yanping; Yang, Bo

    2015-08-15

    This study investigated the occurrence of perfluoroalkyl acids (PFAAs) in surface water from 67 sampling sites along rivers of the Pearl River Delta in southern China. Sixteen PFAAs, including perfluoroalkyl carboxylic acids (PFCAs, C5-14, C16 and C18) and perfluoroalkyl sulfonic acids (PFSAs, C4, C6, C8 and C10) were determined by high performance liquid chromatography-negative electrospray ionization-tandem mass spectrometry (HPLC/ESI-MS/MS). Total PFAA concentrations (? PFAAs) in the surface water ranged from 1.53 to 33.5 ngL(-1) with an average of 7.58 ngL(-1). Perfluorobutane sulfonic acid (PFBS), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS) were the three most abundant PFAAs and on average accounted for 28%, 16% and 10% of ? PFAAs, respectively. Higher concentrations of ? PFAAs were found in the samples collected from Jiangmen section of Xijiang River, Dongguan section of Dongjiang River and the Pearl River flowing the cities which had very well-developed manufacturing industries. PCA model was employed to quantitatively calculate the contributions of extracted sources. Factor 1 (72.48% of the total variance) had high loading for perfluorohexanoic acid (PFHxA), perfluoropentanoic acid (PFPeA), PFBS and PFOS. For factor 2 (10.93% of the total variance), perfluorononanoic acid (PFNA) and perfluoroundecanoic acid (PFUdA) got high loading. The sorption of PFCAs on suspended particulate matter (SPM) increased by approximately 0.1 log units for each additional CF2 moiety and that on sediment was approximately 0.8 log units lower than the SPM logKd values. In addition, the differences in the partition coefficients were influenced by the structure discrepancy of absorbents and influx of fresh river water. These data are essential for modeling the transport and environmental fate of PFAAs. PMID:25889539

  8. Footprints of Urban Micro-Pollution in Protected Areas: Investigating the Longitudinal Distribution of Perfluoroalkyl Acids in Wildlife Preserves

    PubMed Central

    Rodriguez-Jorquera, Ignacio A.; Silva-Sanchez, Cecilia; Strynar, Mark; Denslow, Nancy D.; Toor, Gurpal S.

    2016-01-01

    Current approaches to protect biodiversity by establishing protected areas usually gloss over water pollution as a threat. Our objective was to determine the longitudinal and seasonal distribution of perfluoroalkyl acids (PFAAs) in water column and sediments from a wastewater dominated stream that enters preservation areas. Water samples were collected along the longitudinal section (six sites, 1000 m away from each other) of the stream during the dry and wet seasons. Sediments were collected from three sites along the stream from three depths. Water and sediments were analyzed for PFAAs using high performance liquid chromatography-tandem mass spectrometry. Eleven PFAAs with 5 to 14 carbon atoms were detected in the water column at all sampling points, with a minor reduction at the last point suggesting a dilution effect. The most detected PFAAs was PFOS, followed by perfluorooctanoic acid (PFOA), and perfluorohexanoic acid (PFHxA). Seasonal differences in PFAAs concentrations suggested contribution of stormwater runoff during the wet season. All analyzed PFAAs in sediments were under the limit of quantification, likely due to the high proportion of sand and low organic matter. However, high concentrations of PFAAs were detected in the water column inside the protected areas, which includes PFOS in concentrations considered not safe for avian wildlife. Water samples appear to be more relevant than sediments to determine PFAAs micro-pollution in water bodies with sandy sediments. Inclusion of a management plans on micro-pollution research, monitoring, and mitigation is recommended for protected areas. PMID:26909512

  9. Footprints of Urban Micro-Pollution in Protected Areas: Investigating the Longitudinal Distribution of Perfluoroalkyl Acids in Wildlife Preserves.

    PubMed

    Rodriguez-Jorquera, Ignacio A; Silva-Sanchez, Cecilia; Strynar, Mark; Denslow, Nancy D; Toor, Gurpal S

    2016-01-01

    Current approaches to protect biodiversity by establishing protected areas usually gloss over water pollution as a threat. Our objective was to determine the longitudinal and seasonal distribution of perfluoroalkyl acids (PFAAs) in water column and sediments from a wastewater dominated stream that enters preservation areas. Water samples were collected along the longitudinal section (six sites, 1000 m away from each other) of the stream during the dry and wet seasons. Sediments were collected from three sites along the stream from three depths. Water and sediments were analyzed for PFAAs using high performance liquid chromatography-tandem mass spectrometry. Eleven PFAAs with 5 to 14 carbon atoms were detected in the water column at all sampling points, with a minor reduction at the last point suggesting a dilution effect. The most detected PFAAs was PFOS, followed by perfluorooctanoic acid (PFOA), and perfluorohexanoic acid (PFHxA). Seasonal differences in PFAAs concentrations suggested contribution of stormwater runoff during the wet season. All analyzed PFAAs in sediments were under the limit of quantification, likely due to the high proportion of sand and low organic matter. However, high concentrations of PFAAs were detected in the water column inside the protected areas, which includes PFOS in concentrations considered not safe for avian wildlife. Water samples appear to be more relevant than sediments to determine PFAAs micro-pollution in water bodies with sandy sediments. Inclusion of a management plans on micro-pollution research, monitoring, and mitigation is recommended for protected areas. PMID:26909512

  10. Perfluoroalkyl acids in the Canadian environment: multi-media assessment of current status and trends.

    PubMed

    Gewurtz, Sarah B; Backus, Sean M; De Silva, Amila O; Ahrens, Lutz; Armellin, Alain; Evans, Marlene; Fraser, Susan; Gledhill, Melissa; Guerra, Paula; Harner, Tom; Helm, Paul A; Hung, Hayley; Khera, Nav; Kim, Min Gu; King, Martha; Lee, Sum Chi; Letcher, Robert J; Martin, Pamela; Marvin, Chris; McGoldrick, Daryl J; Myers, Anne L; Pelletier, Magella; Pomeroy, Joe; Reiner, Eric J; Rondeau, Myriam; Sauve, Marie-Claude; Sekela, Mark; Shoeib, Mahiba; Smith, Daniel W; Smyth, Shirley Anne; Struger, John; Spry, Doug; Syrgiannis, Jim; Waltho, Jasmine

    2013-09-01

    In Canada, perfluoroalkyl acids (PFAAs) have been the focus of several monitoring programs and research and surveillance studies. Here, we integrate recent data and perform a multi-media assessment to examine the current status and ongoing trends of PFAAs in Canada. Concentrations of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and other long-chain perfluorocarboxylates (PFCAs) in air, water, sediment, fish, and birds across Canada are generally related to urbanization, with elevated concentrations observed around cities, especially in southern Ontario. PFOS levels in water, fish tissue, and bird eggs were below their respective Draft Federal Environmental Quality Guidelines, suggesting there is low potential for adverse effects to the environment/organisms examined. However, PFOS in fish and bird eggs tended to exceed guidelines for the protection of mammalian and avian consumers, suggesting a potential risk to their wildlife predators, although wildlife population health assessments are needed to determine whether negative impacts are actually occurring. Long-term temporal trends of PFOS in suspended sediment, sediment cores, Lake Trout (Salvelinus namaycush), and Herring Gull (Larus argentatus) eggs collected from Lake Ontario increased consistently from the start of data collection until the 1990s. However, after this time, the trends varied by media, with concentrations stabilizing in Lake Trout and Herring Gull eggs, and decreasing and increasing in suspended sediment and the sediment cores, respectively. For PFCAs, concentrations in suspended sediment, sediment cores, and Herring Gulls generally increased from the start of data collection until present and concentrations in Lake Trout increased until the late 1990s and subsequently stabilized. A multimedia comparison of PFAA profiles provided evidence that unexpected patterns in biota of some of the lakes were due to unique source patterns rather than internal lake processes. High concentrations of PFAAs in the leachate and air of landfill sites, in the wastewater influent/effluent, biosolids, and air at wastewater treatment plants, and in indoor air and dust highlight the waste sector and current-use products (used primarily indoors) as ongoing sources of PFAAs to the Canadian environment. The results of this study demonstrate the utility of integrating data from different media. Simultaneous evaluation of spatial and temporal trends in multiple media allows inferences that would be impossible with data on only one medium. As such, more co-ordination among monitoring sites for different media is suggested for future sampling, especially at the northern sites. We emphasize the importance of continued monitoring of multiple-media for determining future responses of environmental PFAA concentrations to voluntary and regulatory actions. PMID:23831544

  11. Perfluoroalkyl acids in blood serum samples from children in Taiwan.

    PubMed

    Bao, Jia; Lee, Yungling Leo; Chen, Pau-Chung; Jin, Yi-He; Dong, Guang-Hui

    2014-06-01

    Severe perfluoroalkyl acid (PFAA) contamination resulting from the fast-growing semiconductor, electrochemical, and optoelectronic industries has been determined in the river water in the vicinity of the Taipei area, Taiwan, during recent years. However, little is known about body burdens of the PFAA contaminations in local residents, especially children living in the Taipei area recently. In this study, ten target PFAA analytes consisted of three perfluorosulfonates (PFSAs) and seven perfluorocarboxylates (PFCAs) in the blood serum samples, collected from 225 healthy children with an average age of 13.6 years in the Taipei area from 2009 to 2010, were analyzed via high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). As the dominant PFAA contaminant in the blood serum samples from Taiwanese children, perfluorooctane sulfonate (PFOS) contributed 86% of all the target PFAA analytes, while the other nine analytes contributed less than 5% individually. PFOS showed the highest median up to 29 ng/mL, ranging from 0.03 to 148 ng/mL, which was higher than that observed in the serum samples collected from Taiwanese children between 2006 and 2008. Statistically, serum concentrations of perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), and perfluorooctanoic acid (PFOA) had significantly positive correlations with ages of children (p < 0.05). Furthermore, serum PFBS, PFHxS, and PFOA concentrations in the male children were considerably higher than those in the female children (p = 0.049, p = 0.000, p = 0.000). PMID:24622984

  12. Impact of Microbial Growth on Subsurface Perfluoroalkyl Acid Transport

    NASA Astrophysics Data System (ADS)

    Weathers, T. S.; Higgins, C. P.; Sharp, J.

    2014-12-01

    The fate and transport of poly and perfluoroalkyl substances (PFASs) in the presence of active microbial communities has not been widely investigated. These emerging contaminants are commonly utilized in aqueous film-forming foams (AFFF) and have often been detected in groundwater. This study explores the transport of a suite of perfluorocarboxylic acids and perfluoroalkylsulfonates, including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), in microbially active settings. Single point organic carbon normalized sorption coefficients derived by exposing inactive cellular material to PFASs result in more than an order of magnitude increase in sorption compared to soil organic carbon sorption coefficients found in literature. For example, the sorption coefficients for PFOS are 4.05±0.07 L/kg and 2.80±0.08 L/kg for cellular organic carbon and soil organic carbon respectively. This increase in sorption, coupled with enhanced extracellular polymeric substance production observed during growth of a common hydrocarbon degrading soil microbe exposed to source-level concentrations of PFASs (10 mg/L of 11 analytes, 110 mg/L total) may result in PFAS retardation in situ. To address the upscaling of this phenomenon, flow-through columns packed with low-organic carbon sediment and biostimulated with 10 mg/L glucose were exposed to PFAS concentrations from 15 μg/L to 10 mg/L of each 11 analytes. Breakthrough and tailing of each analyte was measured and modeled with Hydrus-1D to explore sorption coefficients over time for microbially active columns.

  13. Case-control study on perfluorinated alkyl acids (PFAAs) and the risk of prostate cancer.

    PubMed

    Hardell, Elin; Kärrman, Anna; van Bavel, Bert; Bao, Jia; Carlberg, Michael; Hardell, Lennart

    2014-02-01

    Perfluorinated alkyl acids (PFAAs) are emerging environmental contaminants. Possible health effects for humans include increased risk for cancer but the knowledge is limited. In this study serum concentrations of certain perfluorinated sulfonates (PFHxS and PFOS) and carboxylates (PFOA, PFNA, PFDA, PFUnDA) were analyzed among 201 cases with prostate cancer and 186 population based control subjects. All blood samples were collected during 2007-2011 and no case had been treated with radio- or chemotherapy before enrolment in the study. The blood concentrations did not differ statistically significant between cases and controls except for PFDA with higher concentration among the cases (p=0.03). Analyses based on Gleason score and prostate specific antigen (PSA) level did not change the results. Heredity was a risk factor for prostate cancer yielding odds ratio (OR)=1.8, 95% confidence interval (CI)=1.01-3.1. The analyzed PFAAs yielded statistically significant higher ORs in cases with a first degree relative reporting prostate cancer, e.g., PFOA gave OR=2.6, 95% CI=1.2-6.0 and PFOS gave OR=2.7, 95% CI=1.04-6.8. The results showed a higher risk for prostate cancer in cases with heredity as a risk factor. In further studies interaction between gene and environment should be considered. PMID:24246240

  14. Bioaccumulation of perfluoroalkyl acids in dairy cows in a naturally contaminated environment.

    PubMed

    Vestergren, Robin; Orata, Francis; Berger, Urs; Cousins, Ian T

    2013-11-01

    Beef and dairy products may be important vectors of human exposure to perfluoroalkyl acids (PFAAs), but the understanding of how PFAAs are accumulated and transferred through agricultural food chains is very limited. Here, the bioaccumulation of PFAAs in dairy cows receiving naturally contaminated feed and drinking water was investigated by conducting a mass balance of PFAAs for a herd of dairy cows in a barn on a typical Swedish dairy farm. It was assumed that the cows were able to reach steady state with their dietary intake of PFAAs. Perfluorooctane sulfonic acid (PFOS) and perfluoroalkyl carboxylic acids (PFCAs) with 8 to 12 carbons were detected in cow tissue samples (liver, muscle, and blood) at concentrations up to 130 ng kg(-1). Mass balance calculations demonstrated an agreement between total intake and excretion within a factor of 1.5 and consumption of silage was identified as the dominant intake pathway for all PFAAs. Biomagnification factors (BMFs) were highly tissue and homologue specific. While BMFs of PFOS and PFCAs with 9 and 10 fluorinated carbons in liver ranged from 10 to 20, perfluorooctanoic acid (PFOA) was not biomagnified (BMF<1) in any of the investigated tissues. Biotransfer factors (BTFs; defined as the concentration in tissue divided by the total daily intake) were calculated for muscle and milk. Log BTFs ranged from -1.95 to -1.15 day kg(-1) with the highest BTF observed for PFOS in muscle. Overall, the results of this study suggest that long-chain PFAAs have a relatively high potential for transfer to milk and beef from the diet of dairy cows. However, a low input of PFAAs to terrestrial systems via atmospheric deposition and low bioavailability of PFAAs in soil limits the amount of PFAAs that enter terrestrial agricultural food chains in background contaminated environments and makes this pathway less important than aquatic exposure pathways. The BTFs estimated here provide a useful tool for predicting human exposure to PFAAs via milk and beef under different contamination scenarios. PMID:23644948

  15. Evaluating the additivity of perfluoroalkyl acids in binary combinations on peroxisome proliferator-activated receptor-? activation.

    PubMed

    Wolf, Cynthia J; Rider, Cynthia V; Lau, Christopher; Abbott, Barbara D

    2014-02-28

    Perfluoroalkyl acids (PFAAs) are found globally in the environment, detected in humans and wildlife, and are typically present as mixtures of PFAA congeners. Mechanistic studies have found that responses to PFAAs are mediated in part by PPAR?. Our previous studies showed that individual PFAAs activate PPAR? transfected into COS-1 cells. The goal of the current study was to determine if binary combinations of perfluorooctanoic acid (PFOA) and another PFAA act in an additive fashion to activate PPAR? in the mouse one-hybrid in vitro model. COS-1 cells were transiently transfected with mouse PPAR? luciferase reporter construct and exposed to either vehicle control (0.1% DMSO or water), PPAR? agonist (WY14643, 10 ?M), PFOA at 1-128?M, perfluorononanoic acid (PFNA) at 1-128 ?M, perfluorohexanoic acid (PFHxA) at 8-1024 ?M, perfluorooctane sulfonate (PFOS) at 4-384 ?M or perfluorohexane sulfonate (PFHxS) at 8-2048 ?M to generate sigmoidal concentration-response curves. In addition, cells were exposed to binary combinations of PFOA+either PFNA, PFHxA, PFOS or PFHxS in an 88 factorial design. The concentration-response data for individual chemicals were fit to sigmoidal curves and analyzed with nonlinear regression to generate EC??s and Hillslopes, which were used in response-addition and concentration-addition models to calculate predicted responses for mixtures in the same plate. All PFOA+PFAA combinations produced concentration-response curves that were closely aligned with the predicted curves for both response addition and concentration addition at low concentrations. However, at higher concentrations of all chemicals, the observed response curves deviated from the predicted models of additivity. We conclude that binary combinations of PFAAs behave additively at the lower concentration ranges in activating PPAR? in this in vitro system. PMID:24374136

  16. Aspartic acid

    MedlinePlus

    Aspartic acid is a nonessential amino acids . Amino acids are building blocks of proteins. "Nonessential" means that our ... this amino acid from the food we eat. Aspartic acid is also called asparaginic acid. Aspartic acid helps ...

  17. Occurrence of selected perfluorinated alkyl acids in lunch meals served at school canteens in Italy and their relevance for children's intake.

    PubMed

    Dellatte, Elena; Brambilla, Gianfranco; De Filippis, Stefania Paola; di Domenico, Alessandro; Pulkrabova, Jana; Eschauzier, Christian; Klenow, Stefanie; Heinemeyer, Gerhard; de Voogt, Pim

    2013-01-01

    Ready-to-eat servings may be more contaminated with perfluorinated alkyl acids (PFAAs) than the corresponding unprocessed foods due to the presence of PFAAs in and transfer from food contact materials (FCM) and cookware. Therefore, the presence of selected PFAAs in meals served weekly at lunch time in six Italian school canteens was assessed. Five towns were selected representing different areas with local water and food supply. Daily lunch menus were sampled and pooled to form a composite. Analyses were carried out on the weekly composite from each canteen. UPLC-MS/MS quantification limits were in the 6.0-12 pg g⁻¹ range for the selected PFAAs (PFHxA, PFOA, PFNA, PFDA, PFUnDA, PFHxS, branched and non-branched PFOS). Non-branched PFOS was quantified in four out of six composites, with levels ranging from 14 to 25 pg g⁻¹, while PFOA and PFDA were determined in two out of six in the range 6.5-8.2 pg g⁻¹. Theoretical estimates and analytical results in the same order of magnitude indicate a negligible contribution from food processing and serving to meal contamination. When composite analytical data are transposed into dietary estimates, it is shown that Italian school-age children have intakes in the range of 0.3-1.1 and 0.5-1.4 ng kg⁻¹ bw day⁻¹ for PFOA and PFOS respectively, well below the corresponding tolerable daily intakes (TDIs). PMID:23859821

  18. Highly elevated levels of perfluorooctane sulfonate and other perfluorinated acids found in biota and surface water downstream of an international airport, Hamilton, Ontario, Canada.

    PubMed

    de Solla, S R; De Silva, A O; Letcher, R J

    2012-02-01

    Per- and poly-fluorinated compounds (PFCs), which include perfluorinated carboxylates (PFCAs) and sulfonates (PFSAs) and various precursors, are used in a wide variety of industrial, commercial and domestic products. This includes aqueous film forming foam (AFFF), which is used by military and commercial airports as fire suppressants. In a preliminary assessment prior to this study, very high concentrations (>1 ppm wet weight) of the PFSA, perfluorooctane sulfonate (PFOS), were discovered in the plasma of snapping turtles (Chelydra serpentina) collected in 2008 from Lake Niapenco in southern Ontario, Canada. We presently report on a suite of C(6) to C(15) PFCAs, C(4), C(6), C(8) and C(10) PFSAs, several PFC precursors (e.g. perfluorooctane sulfonamide, PFOSA), and a cyclic perfluorinated acid used in aircraft hydraulic fluid, perfluoroethylcyclohexane sulfonate (PFECHS) in surface water from the Welland River and Lake Niapenco, downstream of the John C. Munro International Airport, Hamilton, Ontario, Canada. Amphipods, shrimp, and water were sampled from the Welland River and Lake Niapenco, as well as local references. The same suite of PFCs in turtle plasma from Lake Niapenco was compared to those from other southern Ontario sites. PFOS dominated the sum PFCs in all substrates (e.g., >99% in plasma of turtles downstream the Hamilton Airport, and 72.1 to 94.1% at all other sites). PFOS averaged 2223(±247.1SE) ng/g in turtle plasma from Lake Niapenco, and ranged from 9.0 to 171.4 elsewhere. Mean PFOS in amphipods and in water were 518.1(±83.8)ng/g and 130.3(±43.6) ng/L downstream of the airport, and 19.1(±2.7) ng/g and 6.8(±0.5) ng/L at reference sites, respectively. Concentrations of selected PFCs declined with distance downstream from the airport. Although there was no known spill event or publicly reported use of AFFF associated with a fire event at the Hamilton airport, the airport is a likely major source of PFC contamination in the Welland River. PMID:22208739

  19. Photo-generated Acid Diffusion in Polymer Photoresist Thin Films

    NASA Astrophysics Data System (ADS)

    Lin, Eric; Soles, Christopher; Wu, Wen-Li; Lin, Qinghuang

    2000-03-01

    Advanced photoresist formulations make use of photosensitive molecules, photoacid generators (PAGs), which decompose to form acids after illumination with UV radiation. The photo-generated acids then catalytically alter the solubility of the resist polymer during a post-exposure bake so that the exposed areas of an image can be removed with an appropriate solvent. One of the limitations in resist performance is the diffusion of small molecules such as the photoacid generators (PAG), photo-generated acids (PGAs), solvents, and performance enhancing additives, in the photoresist formulation. We utilize the high spatial resolution of neutron reflectometry over length scales relevant to line width broadening (10 nm to 20 nm) to measure the diffusion rates of PAGs, PGAs, and polymers in model resist materials. In this study, the model polymer matrix material is monodisperse poly(hydroxystyrene)(PHS) and the photoacid generator is bis(p-tert-butylphenyl) iodonium perfluorooctanesulfonate (PFOS). By measuring the profiles of the PGAs in the PHS layer and into an overlaying poly(methyl methacrylate) layer as a function of post-exposure bake temperature and time, the initial rates of diffusion may be determined.

  20. High levels of perfluoroalkyl acids in eggs and embryo livers of great cormorant (Phalacrocorax carbo sinensis) and herring gull (Larus argentatus) from Lake Vänern, Sweden.

    PubMed

    Nordén, Marcus; Berger, Urs; Engwall, Magnus

    2013-11-01

    In the eggs and developing chick livers in the two wild bird species, great cormorant and herring gull, the concentrations of a range of 15 perfluoroalkyl acids (PFAAs) were determined. Eggs of the two species were collected from Lake Vänern, Sweden, and analysed either as undeveloped egg (whole egg or separated into yolk and albumen) or incubated until start of the hatching process when the chick liver was removed and analysed. High levels of PFAAs were found in all matrixes except albumen. The predominant PFAA was perfluorooctane sulfonate (PFOS), which was found in the μg/g wet weight (ww) range in some samples of cormorant whole egg, yolk and liver and herring gull egg yolk and liver. The average concentration in yolk was 1,506 ng/g ww in cormorant and 589 ng/g ww in herring gull. The average liver concentrations of PFOS were 583 ng/g ww in cormorant and 508 ng/g ww in herring gull. At these concentrations, biochemical effects in the developing embryo or effects on embryo survival cannot be ruled out. For perfluoroalkyl carboxylates (PFCAs), the liver/egg and liver/yolk concentration ratios increased with PFCA chain length in cormorant but not in herring gull, indicating that chain length could possibly affect egg-to-liver transfer of PFCAs and that species differences may exist. PMID:23463275

  1. Estrogen-Like Activity of Perfluoroalkyl Acids In Vivo and Interaction with Human and Rainbow Trout Estrogen Receptors In Vitro

    PubMed Central

    Benninghoff, Abby D.; Bisson, William H.; Koch, Daniel C.; Ehresman, David J.; Kolluri, Siva K.; Williams, David E.

    2011-01-01

    The objectives of this study were to determine the structural characteristics of perfluoroalkyl acids (PFAAs) that confer estrogen-like activity in vivo using juvenile rainbow trout (Oncorhynchus mykiss) as an animal model and to determine whether these chemicals interact directly with the estrogen receptor (ER) using in vitro and in silico species comparison approaches. Perfluorooctanoic (PFOA), perfluorononanoic (PFNA), perfluorodecanoic (PFDA), and perfluoroundecanoic (PFUnDA) acids were all potent inducers of the estrogen-responsive biomarker protein vitellogenin (Vtg) in vivo, although at fairly high dietary exposures. A structure-activity relationship for PFAAs was observed, where eight to ten fluorinated carbons and a carboxylic acid end group were optimal for maximal Vtg induction. These in vivo findings were corroborated by in vitro mechanistic assays for trout and human ER. All PFAAs tested weakly bound to trout liver ER with half maximal inhibitory concentration (IC50) values of 15.2–289μM. Additionally, PFOA, PFNA, PFDA, PFUnDA, and perlfuorooctane sulfonate (PFOS) significantly enhanced human ERα-dependent transcriptional activation at concentrations ranging from 10–1000nM. Finally, we employed an in silico computational model based upon the crystal structure for the human ERα ligand-binding domain complexed with E2 to structurally investigate binding of these putative ligands to human, mouse, and trout ERα. PFOA, PFNA, PFDA, and PFOS all efficiently docked with ERα from different species and formed a hydrogen bond at residue Arg394/398/407 (human/mouse/trout) in a manner similar to the environmental estrogens bisphenol A and nonylphenol. Overall, these data support the contention that several PFAAs are weak environmental xenoestrogens of potential concern. PMID:21163906

  2. Tissue Distribution and Whole Body Burden of the Chlorinated Polyfluoroalkyl Ether Sulfonic Acid F-53B in Crucian Carp (Carassius carassius): Evidence for a Highly Bioaccumulative Contaminant of Emerging Concern.

    PubMed

    Shi, Yali; Vestergren, Robin; Zhou, Zhen; Song, Xiaowei; Xu, Lin; Liang, Yong; Cai, Yaqi

    2015-12-15

    Following the global actions to phase out perfluoroctanesulfonic acid (PFOS) a large number of alternative per- and polyfluoroalkyl substances, with poorly defined hazard properties, are being used in increasing quantities. Here, we report on the first detection of the chlorinated polyfluoroalkyl ether sulfonic acid F-53B in biological samples and determine the tissue distribution and whole body bioaccumulation factors (BAFwhole body) in crucian carp (Carassius carassius). Analysis of fish samples from Xiaoqing River (XR) and Tangxun Lake (TL) demonstrated a similar level of F-53B contamination with median concentrations in blood of 41.9 and 20.9 ng/g, respectively. Tissue/blood ratios showed that distribution of F-53B primarily occurs to the kidney (TL: 0.48, XR: 0.54), gonad (TL: 0.36, XR: 0.54), liver (TL: 0.38, XR: 0.53), and heart (TL: 0.47, XR: 0.47). Median Log BAFwhole body values for F-53B (XR: 4.124, TL: 4.322) exceeded regulatory bioaccumulation criterion and were significantly higher than those of PFOS in the same data sets (XR: 3.430, TL: 3.279). On the basis of its apparent omnipresence and strong bioaccumulation propensity, it is hypothesized that F-53B could explain a significant fraction of previously unidentified organofluorine in biological samples from China, and regulatory actions for this compound are encouraged. PMID:26560673

  3. [Spatial distribution of perfluorooctanoic acids and perfluorinate sulphonates in surface water of East Lake].

    PubMed

    Chen, Jing; Wang, Lin-ling; Zhu, Hu-di; Wang, Bei-bei; Liu, Huang-cheng; Cao, Meng-hua; Miao, Zhu; Hu, Li; Lu, Xiao-hua; Liu, Guang-hong

    2012-08-01

    Concentrations and spatial distribution of PFOS and PFOA in surface water from East Lake in Wuhan, Hubei, China were studied. The total concentration of PFCs ranged from 31.1 to 237 ng x L(-1), and the mean value was 115 ng x L(-1), revealing lake-wide contamination in East Lake. PFOS and PFOA were detected in all samples with maximum values of 132 ng x L(-1) and 158 ng x L(-1), respectively, whereas the mean values of PFOS and PFOA were 60.4 and 55.0 ng x L(-1), respectively. The highest concentrations of PFOS and PFOA were found in the eastern area of lake, followed by the southern area of lake, and the western and northern areas of East Lake were the least contaminated regions. The specific distribution and composition profile of PFOS and PFOA, and the lack of significant correlation between PFOS and PFOA, suggested that there were various sources of PFCs. The PFOS concentrations at 30 sample sites (63%) were greater than 43 ng x L(-1), which was used to estimate an avian wildlife value for PFOS. The PFOA concentrations at 20 sample sites (42%) were greater than 40 ng x L(-1), which was a health-based guidance level recommended by the State of New Jersey for PFOA. PMID:23213877

  4. Amino acids

    MedlinePlus

    Amino acids are organic compounds that combine to form proteins . Amino acids and proteins are the building blocks of life. When proteins are digested or broken down, amino acids are left. The human body uses amino acids ...

  5. Perfluorooctanoic acid (PFOA) acts as a tumor promoter on Syrian hamster embryo (SHE) cells.

    PubMed

    Jacquet, N; Maire, M A; Rast, C; Bonnard, M; Vasseur, P

    2011-08-01

    Perfluorooctane sulfonate (PFOS) (C(8)F(17)SO(3)) and perfluorooctanoic acid (PFOA) (C(8)HF(15)O(2)) are synthetic chemicals widely used in industrial applications for their hydrophobic and oleophobic properties. They are persistent, bioaccumulative, and toxic to mammalian species. Their widespread distribution on earth and contamination of human serum raised concerns about long-term side effects. They are suspected to be carcinogenic through a nongenotoxic mode of action, a mechanism supported by recent findings that PFOS induced cell transformation but no genotoxicity in Syrian hamster embryo (SHE) cells. In the present study, we evaluated carcinogenic potential of PFOA using the cell transformation assay on SHE cells. The chemical was applied alone or in combination with a nontransformant concentration of benzo[a]pyrene (BaP, 0.4 μM) in order to detect PFOA ability to act as tumor initiator or tumor promoter. The results showed that PFOA tested alone in the range 3.7 × 10(-5) to 300 μM did not induce SHE cell transformation frequency in a 7-day treatment. On the other side, the combination BaP/PFOA induced cell transformation at all PFOA concentrations tested, which revealed synergistic effects. No genotoxicity of PFOA on SHE cells was detected using the comet assay after 5 and 24 h of exposure. No significant increase in DNA breakage was found in BaP-initiated cells exposed to PFOA in a 7-day treatment. The whole results showed that PFOA acts as a tumor promoter and a nongenotoxic carcinogen. Cell transformation in initiated cells was observed at concentrations equivalent to the ones found in human serum of nonoccupationally and occupationally exposed populations. An involvement of PFOA in increased incidence of cancer recorded in occupationally exposed population cannot be ruled out. PMID:22828883

  6. Spatial distribution and importance of potential perfluoroalkyl acid precursors in urban rivers and sewage treatment plant effluent--case study of Tama River, Japan.

    PubMed

    Ye, Feng; Tokumura, Masahiro; Islam, Md Saiful; Zushi, Yasuyuki; Oh, Jungkeun; Masunaga, Shigeki

    2014-12-15

    Production and use of perfluorooctane sulfonate (PFOS) is regulated worldwide. However, numerous potential precursors that eventually decompose into PFOS and other perfluoroalkyl acids (PFAAs) such as perfluorooctanoic acid (PFOA) are still being used and have not been studied in detail. Therefore, knowledge about the levels and sources of the precursors is essential. We investigated the total concentration of potential PFAA precursors in the Tama River, which is one of the major rivers flowing into the Tokyo Bay, by converting all the perfluorinated carboxylic acid (PFCA) and perfluoroalkyl sulfonic acid (PFSA) precursors into PFCAs by chemical oxidation. The importance of controlling PFAA precursors was determined by calculating the ratios of PFCAs formed by oxidation to the PFAAs originally present (ΣΔ[PFCAC4-C12]/Σ[PFAAs]before oxidation) (average = 0.28 and 0.69 for main and tributary branch rivers, respectively). Higher total concentrations of Δ[PFCAs] were found in sewage treatment plant (STP) effluents. However, the ratios found in the effluents were lower (average = 0.21) than those found in the river water samples, which implies the decomposition of some precursors into PFAAs during the treatment process. On the other hand, higher ratios were observed in the upstream water samples and the existence of emission sources other than the STP effluents was indicated. This study showed that although the treatment process converting a part of the PFAA precursors into PFAAs, STPs were important sources of precursors to the Tama River. To reduce the levels of PFAAs in the aquatic environment, it is necessary to reduce the emission of the PFAA precursors as well. PMID:25262552

  7. Exposure to Perfluoroalkyl Acids and Markers of Kidney Function among Children and Adolescents Living near a Chemical Plant

    PubMed Central

    Josson, Jyoti; Elston, Beth; Bartell, Scott M.; Shin, Hyeong-Moo; Vieira, Veronica M.; Savitz, David A.; Fletcher, Tony; Wellenius, Gregory A.

    2013-01-01

    Background: Serum levels of perfluorooctanoic acid (PFOA) have been associated with decreased renal function in cross-sectional analyses, but the direction of the association is unclear. Objectives: We examined the association of measured and model-predicted serum PFOA concentrations with estimated glomerular filtration rate (eGFR), a marker of kidney function, in a highly exposed population (median serum PFOA, 28.3 ng/mL). Methods: We measured serum creatinine, PFOA, perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonate (PFHxS) and calculated eGFR in 9,660 children 1 to < 18 years of age at study enrollment. We predicted concurrent and historical serum PFOA concentrations using a validated environmental, exposure, and pharmacokinetic model based on individual residential histories, and used linear regression to estimate the association between eGFR and measured and predicted serum PFOA concentrations. We hypothesized that predicted serum PFOA levels would be less susceptible to reverse causation than measured levels. Results: An interquartile range increase in measured serum PFOA concentrations [IQR ln(PFOA) = 1.63] was associated with a decrease in eGFR of 0.75 mL/min/1.73 m2 (95% CI: –1.41, –0.10; p = 0.02). Measured serum levels of PFOS, PFNA, and PFHxS were also cross-sectionally associated with decreased eGFR. In contrast, predicted serum PFOA concentrations at the time of enrollment were not associated with eGFR (–0.10; 95% CI: –0.80, 0.60; p = 0.78). Additionally, predicted serum PFOA levels at birth and during the first ten years of life were not related to eGFR. Conclusions: Our findings suggest that the cross-sectional association between eGFR and serum PFOA observed in this and prior studies may be a consequence of, rather than a cause of, decreased kidney function. PMID:23482063

  8. 40 CFR 63.341 - Definitions and nomenclature.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... entrained from the packed-bed section. Perfluorooctane sulfonic acid (PFOS)-based fume suppressant means a fume suppressant that contains 1 percent or greater PFOS by weight. Research or laboratory...

  9. 40 CFR 63.341 - Definitions and nomenclature.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... entrained from the packed-bed section. Perfluorooctane sulfonic acid (PFOS)-based fume suppressant means a fume suppressant that contains 1 percent or greater PFOS by weight. Research or laboratory...

  10. Pipping success and liver mRNA expression in chicken embryos exposed in ovo to C8 and C11 perfluorinated carboxylic acids and C10 perfluorinated sulfonate.

    PubMed

    O'Brien, Jason M; Crump, Doug; Mundy, Lukas J; Chu, Shaogang; McLaren, Kristina K; Vongphachan, Viengtha; Letcher, Robert J; Kennedy, Sean W

    2009-10-28

    Several perfluoroalkyl compounds (PFCs) are ubiquitous environmental contaminants that can biomagnify in species at high trophic levels including wild birds. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have been detected in wild birds and are known to reduce hatching success of laboratory-exposed chicken embryos at environmentally relevant concentrations. Limited toxicity data are available regarding avian exposure to PFCs of chain lengths greater than C(8), which are of increasing environmental relevance following the recent phase-out of PFOS and PFOA. In this study, linear PFOA, perfluoroundecanoic acid (PFUdA) and perfluorodecane sulfonate (PFDS) were injected into the air cell of white leghorn chicken eggs (Gallus gallus domesticus) prior to incubation to determine effects on embryo pipping success. Furthermore, mRNA expression of key genes involved in pathways implicated in PFC toxicity was monitored in liver tissue. PFOA, PFUdA or PFDS had no effect on embryonic pipping success at concentrations up to 10 microg/g. All PFCs accumulated in the liver to concentrations greater than the initial whole-egg concentration as determined by HPLC/MS/MS. Hepatic accumulation was highest for PFOA (4.5 times) compared to PFUdA and PFDS. Cytochrome P450 1A4 and liver fatty acid binding protein mRNA expression increased after exposure to PFUdA but was only statistically significant at 10 microg/g; several orders of magnitude higher than levels found in wild bird eggs. Based on the present results for white leghorn chickens, current environmental concentrations of PFOA, PFUdA and PFDS are unlikely to affect the hatching success of wild birds. PMID:19595750

  11. Occurrence of perfluoroalkyl acids in environmental waters in Vietnam.

    PubMed

    Duong, Hanh Thi; Kadokami, Kiwao; Shirasaka, Hanako; Hidaka, Rento; Chau, Hong Thi Cam; Kong, Lingxiao; Nguyen, Trung Quang; Nguyen, Thao Thanh

    2015-03-01

    This is the first nationwide study of perfluoroalkyl acids (PFAAs) in environmental waters in Vietnam. Twenty-eight river water and 22 groundwater samples collected in four major cities and 14 river water samples from the Red River were screened to investigate the occurrence and sources of 16 PFAAs. Perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were the most prevalent of 11 detected PFAAs with maximum concentrations in urban river water of 5.3, 18 and 0.93ngL(-1), respectively, and in groundwater of 8.2, 4.5 and 0.45ngL(-1), respectively. PFAAs in the Red River water were detected at low levels. PFAA concentrations in river water were higher in the rainy season than in the dry season, possibly due to storm water runoff, a common phenomenon in Southeast Asian countries. The highest concentrations of PFAAs in river water were observed in samples from highly populated and industrialized areas, perhaps sourced from sewage. The PFAA concentrations observed were similar to those in other Southeast Asian countries, but lower than in developed nations. From the composition profiles of PFAAs, industrial products containing PFAAs imported from China and Japan might be one of the major sources of PFAAs in the Vietnamese aquatic environment. According to the health-based values and advisory issued by the United States Environmental Protection Agency (USEPA), the concentrations of detected PFAAs in this study do not pose an immediate health risk to humans and aquatic organisms. PMID:25496738

  12. Acid Rain

    MedlinePlus

    ... damaging to lakes, streams, and forests and the plants and animals that live in these ecosystems. This Web site provides information about the following: What causes acid rain The effects of acid rain How we measure acid rain ...

  13. Folic Acid

    MedlinePlus

    Folic acid is used to treat or prevent folic acid deficiency. It is a B-complex vitamin needed by ... Folic acid comes in tablets. It usually is taken once a day. Follow the directions on your prescription label ...

  14. Folic Acid

    MedlinePlus

    Folic acid is a B vitamin. It helps the body make healthy new cells. Everyone needs folic acid. For women who may get pregnant, it is really important. Getting enough folic acid before and during pregnancy can prevent major birth ...

  15. Acid Rain.

    ERIC Educational Resources Information Center

    Openshaw, Peter

    1987-01-01

    Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)

  16. Phlebotomy Treatment for Elimination of Perfluoroalkyl Acids in a Highly Exposed Family: A Retrospective Case-Series

    PubMed Central

    Genuis, Stephen J.; Liu, Yanna; Genuis, Quentin I. T.; Martin, Jonathan W.

    2014-01-01

    Background Perfluoroalkyl acids (PFAAs) are a family of commonly used synthetic chemicals that have become widespread environmental contaminants. In human serum, perfluorohexane sulfonate (PFHxS), perflurooctane sulfonate (PFOS), and perfluorooctanoate (PFOA) are most frequently detected, in part owing to their long elimination half-lives of between 3.8 yrs (PFOA) and 8.5 yrs (PFHxS). These PFAAs also cross the placenta and have been associated with developmental toxicity, and some are considered likely human carcinogens. Interventions to eliminate PFAAs in highly contaminated individuals would reduce future health risks, but minimal research has been conducted on methods to facilitate accelerated human clearance of these persistent substances. Methods Six patients with elevated serum concentrations from a single family were treated by intermittent phlebotomy over a 4–5 year period at intervals similar to, or less frequent than what is done for routine blood donation at Canadian Blood Services. The apparent elimination half-life (HLapp) for PFHxS, PFOS, and PFOA in this treated population was calculated in each patient and compared to the intrinsic elimination half-lives (HLin) from a literature reference population of untreated fluorochemical manufacturing plant retirees (n = 26, age >55 yrs). Results For all three PFAAs monitored during phlebotomy, HLapp in each of the family members (except the mother, who had a low rate of venesection) was significantly shorter than the geometric mean HL measured in the reference population, and in some cases were even shorter compared to the fastest eliminator in the reference population. Conclusion This study suggests significantly accelerated PFAA clearance with regular phlebotomy treatment, but the small sample size and the lack of controls in this clinical intervention precludes drawing firm conclusions. Given the minimal risks of intermittent phlebotomy, this may be an effective and safe clinical intervention to diminish the body burden of PFAAs in highly exposed people. PMID:25504057

  17. A review of sources, multimedia distribution and health risks of perfluoroalkyl acids (PFAAs) in China.

    PubMed

    Wang, Tieyu; Wang, Pei; Meng, Jing; Liu, Shijie; Lu, Yonglong; Khim, Jong Seong; Giesy, John P

    2015-06-01

    Perfluoroalkyl acids (PFAAs) have been recognized as emerging pollutants because of their ubiquitous occurrence in the environment, biota and humans. In order to investigate their sources, fate and environmental effects, a great number of surveys have been carried out over the past several years. In the present review, we summarized the status of sources and emission, concentration, distribution and risks of PFAAs in China. Concentrations of PFAAs, especially perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in various environmental media including water, sediment, soil, rain, snow and organisms, as well as human tissues are summarized based on the available data. Concentrations of PFAAs in aquatic systems are higher in relatively more industrialized and urbanized areas than those from the less populated and remote regions in China, indicating that their emission and distribution are closely related to regional urbanization and industrialization. PFAAs and related products have been widely used over the past several decades, which have brought about high concentrations detected in environmental matrixes, biota and even local residents. Ecological risk assessment of PFAAs is still less developed in China. Most existing studies compared concentrations of PFAAs to guideline values derived for single species to evaluate the risk. In order to reveal the transport, partitioning and degradation of PFAAs in the environment, further studies on their behavior, fate, bioaccumulation and adverse effects in different trophic levels should be conducted. PMID:25262946

  18. Major perfluoroalkyl acid (PFAA) concentrations and influence of food consumption among the general population of Daegu, Korea.

    PubMed

    Ji, Kyunghee; Kim, Sunmi; Kho, Younglim; Sakong, Joon; Paek, Domyung; Choi, Kyungho

    2012-11-01

    Perfluoroalkyl acids (PFAAs) have been used in various industrial and consumer products for decades, and have consequently been detected in human blood worldwide. In the present study, general adult population in Daegu, Korea (n=140, >20 years of old) was recruited, collected for serum, and analyzed for 13 major PFAAs. The influence of dietary and water consumption on serum PFAA levels was also evaluated. Perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonic acid (PFHxS) were frequently detected with relatively higher concentrations in blood serum. Most PFAA concentrations except for PFOA were detected in higher concentrations among males, and were positively correlated with age and body mass index (BMI). PFOA concentrations were relatively higher among the female of childbearing age, e.g., 20-49years old, raising concerns on potential impacts on fetus through transplacental transfer or lactation. In addition, the concentrations of PFOA in Daegu population were higher than other areas of Korea, suggesting a presence of distinctive sources in the area. Among food items, potato consumption was identified to be significant contributor to serum PFOA. For PFUnDA and PFTrDA levels, intake of fish/shellfish was positively associated. The results of this study will be useful in developing public health management options for PFAAs. PMID:22964400

  19. Acid rain

    SciTech Connect

    Stensland, G.J.

    1983-11-01

    A series of definitions for the field of acid rain studies are presented. Protocols for acid rain sampling and monitoring are also presented. A procedure for calculatory precipitation pH is discussed. 11 references, 1 table.

  20. Aminocaproic Acid

    MedlinePlus

    Aminocaproic acid is used to control bleeding that occurs when blood clots are broken down too quickly. This type ... the baby is ready to be born). Aminocaproic acid is also used to control bleeding in the ...

  1. GENE EXPRESSION PROFILING IN WILD-TYPE AND PPARa-NULL MICE EXPOSED TO PERFLUOROOCTANE SULFONATE REVEALS PPARa-INDEPENDENT EFFECTS

    EPA Science Inventory

    Perfluorooctane sulfonate (PFOS) is a perfluoroalky1 acid (PFAA) and a persistent environmental contaminant found in the tissues of humans and wildlife. Although blood levels of PFOS have begun to decline, health concerns remain because of the long half-life of PFOS in humans. Li...

  2. Short- and long-chain perfluorinated acids in sewage sludge from Shanghai, China.

    PubMed

    Yan, Hong; Zhang, Chao-Jie; Zhou, Qi; Chen, Ling; Meng, Xiang-Zhou

    2012-09-01

    Perfluorinated acids (PFAs) are the subject of increasingly intense environmental research. In this study, sewage sludge samples were collected from 25 wastewater treatment plants (WWTPs) in Shanghai, China to evaluate the levels and profile of C3-C14 PFAs. The results showed a ubiquitous PFAs contamination of sewage sludge in Shanghai with the total PFAs (∑PFAs) range of 126-809 ng g(-1)dw. Perfluorooctanoic acid (PFOA) was found to be the dominant PFA pollutant and its concentration ranged from 23.2 to 298 ng g(-1)dw, much higher than the levels in other countries. Moreover, concentrations of short-chain PFAs (PFOS) are predicted to be 1.08 and 7.53 ng g(-1)dw, respectively, much lower than the corresponding US EPA standards. Nevertheless, further studies are needed to explore the fate of PFAs in sludge-amended soils due to the persistence and bioaccumulation potential of these compounds. PMID:22546628

  3. Firefighters' exposure to perfluoroalkyl acids and 2-butoxyethanol present in firefighting foams.

    PubMed

    Laitinen, Juha Ari; Koponen, Jani; Koikkalainen, Janne; Kiviranta, Hannu

    2014-12-01

    The aim of this study was to assess eight firefighters' exposure to Sthamex 3% AFFF (aqueous film forming foam) in the simulation of aircraft accidents at Oulu airport in Finland. Study was conducted in 2010 before limitation for the use of PFOA and PFOS in AFFFs. Due to prospective limitation also eight commercially available AFFFs were evaluated from occupational and environmental point of view to find substitutive AFFFs for future. The firefighters' exposure to twelve perfluoroalkyl acids (PFAS) was analyzed in order to observe the signs of accumulation during three consecutive training sessions. The firefighters' short-term exposure to 2-butoxyethanol (EGBE) was analyzed by urinalysis of 2-butoxyacetic acid (2-BAA). For the background information also the concentration of PFAS in used AFFF-liquid was analyzed. Fire fighters' serum PFHxS and PFNA concentrations seemed to increase during the three training sessions although they were not the main PFAS in used AFFF. The statistical significance for the elevations was not able to test due to limited size of test group. In two training sessions, the average urinary excretions of 2-BAA exceeded the reference limit of the occupationally unexposed population. In the evaluations of the firefighting foams, non-fluorine based products were favored and the alcohol resistance properties of foams were recommended for consideration due to the increasing use of biofuels. PMID:25447453

  4. Elevated levels of perfluoroalkyl acids in family members of occupationally exposed workers: the importance of dust transfer

    NASA Astrophysics Data System (ADS)

    Fu, Jianjie; Gao, Yan; Wang, Thanh; Liang, Yong; Zhang, Aiqian; Wang, Yawei; Jiang, Guibin

    2015-03-01

    The exposure pathways of perfluoroalkyl acids (PFAAs) to humans are still not clear because of the complex living environment, and few studies have simultaneously investigated the bioaccumulative behaviour of different PFAAs in humans. In this study, serum, dust, duplicate diet, and other matrices were collected around a manufacturing plant in China, and homologous series of PFAAs were analysed. PFAA levels in dust and serum of local residents in this area were considerably higher than those in non-polluted area. Although dietary intake was the major exposure pathway in the present study, dust ingestion played an important role in this case. Serum PFAAs in local residents was significantly correlated with dust PFAAs levels in their living or working microenvironment. Serum PFAAs and dust PFAAs were significantly higher in family members of occupational workers (FM) than in ordinary residents (OR) (p < 0.01). After a careful analysis of the PFAAs exposure pathway, a potential pathway in addition to direct dust ingestion was suggested: PFAAs might transferred from occupational worker's clothes to dinners via cooking processes. The bioaccumulative potential of PFHxS and PFOS were higher than other PFAAs, which suggested a substantial difference between the bioaccumulative ability of perfluorinated sulfonic acids and perfluorinated carboxylic acids.

  5. Acid Deposition

    EPA Science Inventory

    This indicator presents acid deposition trends in the contiguous U.S. from 1989 to 2007. Data are broken down by wet and dry deposition and deposition of nitrogen and sulfur compounds. Acid deposition is particularly damaging to lakes, streams, and forests and the plants and a...

  6. Acid rain

    SciTech Connect

    Elsworth, S.

    1985-01-01

    This book was written in a concise and readable style for the lay public. It's purpose was to make the public aware of the damage caused by acid rain and to mobilize public opinion to favor the elimination of the causes of acid rain.

  7. How Acidic Is Carbonic Acid?

    PubMed

    Pines, Dina; Ditkovich, Julia; Mukra, Tzach; Miller, Yifat; Kiefer, Philip M; Daschakraborty, Snehasis; Hynes, James T; Pines, Ehud

    2016-03-10

    Carbonic, lactic, and pyruvic acids have been generated in aqueous solution by the transient protonation of their corresponding conjugate bases by a tailor-made photoacid, the 6-hydroxy-1-sulfonate pyrene sodium salt molecule. A particular goal is to establish the pKa of carbonic acid H2CO3. The on-contact proton transfer (PT) reaction rate from the optically excited photoacid to the carboxylic bases was derived, with unprecedented precision, from time-correlated single-photon-counting measurements of the fluorescence lifetime of the photoacid in the presence of the proton acceptors. The time-dependent diffusion-assisted PT rate was analyzed using the Szabo-Collins-Kimball equation with a radiation boundary condition. The on-contact PT rates were found to follow the acidity order of the carboxylic acids: the stronger was the acid, the slower was the PT reaction to its conjugate base. The pKa of carbonic acid was found to be 3.49 ± 0.05 using both the Marcus and Kiefer-Hynes free energy correlations. This establishes H2CO3 as being 0.37 pKa units stronger and about 1 pKa unit weaker, respectively, than the physiologically important lactic and pyruvic acids. The considerable acid strength of intact carbonic acid indicates that it is an important protonation agent under physiological conditions. PMID:26862781

  8. Acid rain

    SciTech Connect

    Sweet, W.

    1980-06-20

    Acid precipitation includes not only rain but also acidified snow, hail and frost, as well as sulfur and nitrogen dust. The principal source of acid precipitation is pollution emitted by power plants and smelters. Sulfur and nitrogen compounds contained in the emissions combine with moisture to form droplets with a high acid content - sometimes as acidic as vinegar. When sufficiently concentrated, these acids can kill fish and damage material structures. Under certain circumstances they may reduce crop and forest yields and cause or aggravate respiratory diseases in humans. During the summer, especially, pollutants tend to collect over the Great Lakes in high pressure systems. Since winds typically are westerly and rotate clockwise around high pressure systems, the pollutants gradually are dispersed throughout the eastern part of the continent.

  9. Asparagusic acid.

    PubMed

    Mitchell, Stephen C; Waring, Rosemary H

    2014-01-01

    Asparagusic acid (1,2-dithiolane-4-carboxylic acid) is a simple sulphur-containing 5-membered heterocyclic compound that appears unique to asparagus, though other dithiolane derivatives have been identified in non-food species. This molecule, apparently innocuous toxicologically to man, is the most probable culprit responsible for the curious excretion of odorous urine following asparagus ingestion. The presence of the two adjacent sulphur atoms leads to an enhanced chemical reactivity, endowing it with biological properties including the ability to substitute potentially for α-lipoic acid in α-keto-acid oxidation systems. This brief review collects the scattered data available in the literature concerning asparagusic acid and highlights its properties, intermediary metabolism and exploratory applications. PMID:24099657

  10. [Gastric Acid].

    PubMed

    Ruíz Chávez, R

    1996-01-01

    Gastric acid, a product of parietal cells secretion, full fills multiple biological roles which are absolutely necessary to keep corporal homeostasis. The production of the acid depends upon an effector cellular process represented in the first step by histamine, acetilcholine and gastrin, first messengers of the process. These interact with specific receptors than in sequence activate second messengers -cAMP and the calcium-calmodulin system- which afterwards activate a kinase. An specific protein is then phosphorilated by this enzyme, being the crucial factor that starts the production of acid. Finally, a proton bomb, extrudes the acid towards the gastric lumen. The secretion process mentioned above, is progressive lyactivated in three steps, two of which are stimulators -cephalic and gastric phases- and the other one inhibitor or intestinal phase. These stages are started by mental and neurological phenomena -thought, sight, smell or memory-; by food, drugs or other ingested substances; and by products of digestion. Changes in regulation of acid secretion, in the structure of gastro-duodenal mucosal barrier by a wide spectrum of factors and agents including food, drugs and H. pylori, are the basis of acid-peptic disease, entity in which gastric acid plays a fundamental role. From the therapeutic point of view, so at the theoretical as at the practical levels, t is possible to interfere with the secretion of acid by neutralization of some of the steps of the effector cellular process. An adequate knowledge of the basics related to gastric acid, allows to create strategies for the clinical handling of associated pathology, specifically in relation to peptic acid disease in all of the known clinical forms. PMID:12165790

  11. Acid Precipitation

    ERIC Educational Resources Information Center

    Likens, Gene E.

    1976-01-01

    Discusses the fact that the acidity of rain and snow falling on parts of the U.S. and Europe has been rising. The reasons are still not entirely clear and the consequences have yet to be well evaluated. (MLH)

  12. Mefenamic Acid

    MedlinePlus

    ... as mefenamic acid may cause ulcers, bleeding, or holes in the stomach or intestine. These problems may ... like coffee grounds, blood in the stool, or black and tarry stools.Keep all appointments with your ...

  13. Carnosic acid.

    PubMed

    Birtić, Simona; Dussort, Pierre; Pierre, François-Xavier; Bily, Antoine C; Roller, Marc

    2015-07-01

    Carnosic acid (salvin), which possesses antioxidative and antimicrobial properties, is increasingly exploited within the food, nutritional health and cosmetics industries. Since its first extraction from a Salvia species (∼70 years ago) and its identification (∼50 years ago), numerous articles and patents (∼400) have been published on specific food and medicinal applications of Rosmarinus and Salvia plant extracts abundant in carnosic acid. In contrast, relevant biochemical, physiological or molecular studies in planta have remained rare. In this overview, recent advances in understanding of carnosic acid distribution, biosynthesis, accumulation and role in planta, and its applications are summarised. We also discuss the deficiencies in our understanding of the relevant biochemical processes, and suggest the molecular targets of carnosic acid. Finally, future perspectives and studies related to its potential roles are highlighted. PMID:25639596

  14. Tranexamic Acid

    MedlinePlus

    ... is used to treat heavy bleeding during the menstrual cycle (monthly periods) in women. Tranexamic acid is in ... tablets for more than 5 days in a menstrual cycle or take more than 6 tablets in a ...

  15. Acidic precipitation

    SciTech Connect

    Martin, H.C.

    1987-01-01

    At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).

  16. Bioaccumulation characteristics of perfluoroalkyl acids (PFAAs) in coastal organisms from the west coast of South Korea.

    PubMed

    Hong, Seongjin; Khim, Jong Seong; Wang, Tieyu; Naile, Jonathan E; Park, Jinsoon; Kwon, Bong-Oh; Song, Sung Joon; Ryu, Jongseong; Codling, Garry; Jones, Paul D; Lu, Yonglong; Giesy, John P

    2015-06-01

    Year-round monitoring for perfluoroalkyl acids (PFAAs) along the west coast of South Korea targeting long-term changes in water and coastal organisms has been conducted since 2008. In this study, we present the most recent 5-years of accumulated data and scrutinize the relationship between concentrations in water and biota highlighting bioaccumulation characteristics. Twelve individual PFAAs in samples of water (n=43) and biota (n=59) were quantified by use of HPLC-MS/MS after solid phase extraction. In recent years, concentrations of PFAAs in water have been generally decreasing, but profiles of relative concentrations of individual PFAAs vary among location and year. Bioaccumulation of PFAAs in various organisms including fishes, bivalves, crabs, gastropods, shrimps, starfish, and polychaetes varied among species. However, overall bioaccumulation of PFAAs was dependent on corresponding concentrations of PFAAs in water within an area. In organ-specific distributions of PFAAs, greater concentrations of PFAAs were found in intestine of fish (green eel goby). This result suggests that PFAAs are mainly accumulated via dietary exposure, while greater concentrations were found in gill and intestine of bivalve (oyster) which suggests both waterborne and dietary exposures to these organisms. Concentrations of PFAAs in biota did not decrease over time (2008-2010), indicating that continuing bioaccumulation followed by slow degradation or excretion of PFAAs accumulated in biota. Overall, spatio-temporal distributions of PFAAs in water and bioaccumulation characteristics seemed to be associated with recent restrictions of PFOS-based products and uses of PFBS-based substitutes. PMID:25015225

  17. Salicylic acids

    PubMed Central

    Hayat, Shamsul; Irfan, Mohd; Wani, Arif; Nasser, Alyemeni; Ahmad, Aqil

    2012-01-01

    Salicylic acid is well known phytohormone, emerging recently as a new paradigm of an array of manifestations of growth regulators. The area unleashed yet encompassed the applied agriculture sector to find the roles to strengthen the crops against plethora of abiotic and biotic stresses. The skipped part of integrated picture, however, was the evolutionary insight of salicylic acid to either allow or discard the microbial invasion depending upon various internal factors of two interactants under the prevailing external conditions. The metabolic status that allows the host invasion either as pathogenesis or symbiosis with possible intermediary stages in close systems has been tried to underpin here. PMID:22301975

  18. Trichloroacetic acid

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 09 / 003F www.epa.gov / iris TOXICOLOGICAL REVIEW OF TRICHLOROACETIC ACID ( CAS No . 76 - 03 - 9 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) September 2011 U.S . Environmental Protection Agency Washington , DC ii DISCLAIMER This document has

  19. Ethacrynic Acid

    MedlinePlus

    ... ethacrynic acid once a day, take it with breakfast in the morning. If you take it twice ... a daily exercise program, a low-salt or low-sodium diet, potassium supplements, and increased amounts of potassium-rich foods (e.g., bananas, prunes, raisins, and orange juice) in your diet.

  20. Folic Acid

    MedlinePlus

    ... doctor what vitamins and supplements you might need. Return to top More information on folic acid For more information about folic ... Bifida Association of America Phone: 800-621-3141 Return to top Share this information! The information on our website is provided by ...

  1. Stearic Acid

    ERIC Educational Resources Information Center

    Young, Jay A.

    2004-01-01

    A chemical laboratory information profile (CLIP) is presented for the chemical, stearic acid. The profile lists the chemical's physical and harmful characteristics, exposure limits, and symptoms of major exposure, for the benefit of teachers and students, who use the chemical in the laboratory.

  2. Acrylic acid

    Integrated Risk Information System (IRIS)

    Acrylic acid ( CASRN 79 - 10 - 7 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  3. Formic acid

    Integrated Risk Information System (IRIS)

    Formic acid ; CASRN 64 - 18 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  4. Cacodylic acid

    Integrated Risk Information System (IRIS)

    Cacodylic acid ; CASRN 75 - 60 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  5. Phosphoric acid

    Integrated Risk Information System (IRIS)

    Phosphoric acid ; CASRN 7664 - 38 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  6. Dichloroacetic acid

    Integrated Risk Information System (IRIS)

    Dichloroacetic acid ; CASRN 79 - 43 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  7. Benzoic acid

    Integrated Risk Information System (IRIS)

    Benzoic acid ; CASRN 65 - 85 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effec

  8. Selenious acid

    Integrated Risk Information System (IRIS)

    Selenious acid ; CASRN 7783 - 00 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  9. Carbonate acidizing

    SciTech Connect

    Daccord, G.; Touboul, E.; Lenormand, R.

    1989-02-01

    The authors present the first quantitative study and complete model of the wormholing phenomenon, leading to a means of predicting and optimizing carbonate acidizing treatments. Laboratory experiments on a gypsum model system and computer simulations show that for a given geometry, wormholes can be quantified by a unique parameter, their equivalent hydraulic length. The behavior of this quantifying parameter vs. all the system parameters is studied and allows the quantitative prediction of the efficiency of an acidizing treatment. This study highlights the fractal nature of the phenomenon, which is accounted for in the equations, and the strong effect of the sample geometry. Three types of etching can be obtained: compact, wormhole type, or homogeneous. The optimum conditions for achieving the best skin decrease correspond to the creation of wormholes and can then be defined in terms of fluid reactivity and injection rate.

  10. Hydroxycarboxylic acids and salts

    SciTech Connect

    Kiely, Donald E; Hash, Kirk R; Kramer-Presta, Kylie; Smith, Tyler N

    2015-02-24

    Compositions which inhibit corrosion and alter the physical properties of concrete (admixtures) are prepared from salt mixtures of hydroxycarboxylic acids, carboxylic acids, and nitric acid. The salt mixtures are prepared by neutralizing acid product mixtures from the oxidation of polyols using nitric acid and oxygen as the oxidizing agents. Nitric acid is removed from the hydroxycarboxylic acids by evaporation and diffusion dialysis.

  11. Association between thyroid profile and perfluoroalkyl acids: Data from NHNAES 2007–2008

    SciTech Connect

    Jain, Ram B.

    2013-10-15

    The effect of six perfluoroalkyl acids (PFAAs), namely, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDE), perfluorohexane sulfonic acid (PFHxS), 2-(N-methyl-perfluorooctane sulfonamide) acetic acid (MPAH), and perfluorononanoic acid (PFNA) on the levels of six thyroid function variables, namely, thyroid stimulating hormone (TSH), free and total thyroxine (FT4, TT4), free and total triiodothyronine (FT3, TT3), and thyroglobulin (TGN) was evaluated. Data from National Health and Nutrition Examination Survey for the years 2007–2008 were used for this evaluation. TSH levels increased with increase in levels of PFOA (p<0.01). There were no statistically significant associations between the levels of FT3, and FT4 with the levels of any of the six PFAAs. Levels of TT3 were found to increase with the levels of PFOA (p=0.01) and TT4 levels were found to increase with increase in PFHxS levels (p<0.01). Males had statistically significantly higher levels of FT3 than females and females had statistically significantly higher levels of TT4 than males. As compared to non-Hispanics whites and Hispanics, non-Hispanic blacks had lower levels of TSH, FT3, TT3, and TT4 but Hispanics had the lowest levels of TGN. Age was negatively associated with FT3 and TT3 but positively associated with FT4 and TT4. Non-smokers had higher levels of TSH and TT4 than smokers and smokers had higher levels of FT3 and TGN than non-smokers. Iodine deficiency was associated with increased levels of TSH, TT3, TT4, and TGN. -- Highlights: • Levels of total triiodothyronine were found to increase with the levels of PFOA. • Total thyroxine increased with increase in levels of perfluorohexane sulfonic acid. • There was a positive association between the levels of PFOA and TSH. • Iodine deficiency was associated with elevated levels of TSH, total T3 and T4. • Iodine deficiency was associated with elevated levels of thyroglobulin.

  12. Presence and sources of anthropogenic perfluoroalkyl acids in high-consumption tap-water based beverages.

    PubMed

    Eschauzier, Christian; Hoppe, Maria; Schlummer, Martin; de Voogt, Pim

    2013-01-01

    This study investigates the presence and sources of perfluorinated alkyl acids (PFAAs) in tap water and corresponding tap-water based beverages such as coffee and cola collected in the city of Amsterdam, The Netherlands. Exposure pathways studies have shown that low concentrations of PFAA in tap water already may pose a high contribution to daily human exposure. Tap water samples (n=4) had higher concentrations of PFAAs than the corresponding post-mixed cola (n=4). The lower PFAA levels in the cola were attributed to the pre-treatment of tap water in the mixing machines and dilution with cola syrup. In coffee samples from a coffee machine perfluorooctanoic acid (PFOA) at 4 ng L(-1) was the dominating analyte (n=12). The concentrations of PFHpA, PFOA and non branched PFOS were found to be significantly higher in manually (self) brewed coffee than in the corresponding tap water (n=4). The contribution from short-chain PFAA analogs could not be quantified due to low recoveries. Leaching experiments at different temperatures were performed with fluoropolymers-containing tubes to investigate the potential of leaching from tubes used in beverage preparation (n=16). Fluoropolymer tubes showed leaching of PFAAs at high (80°C) temperature but its relevance for contamination of beverages in practice is small. The specific contribution from perfluoropolymer tubing inside the beverage preparation machines could not be assessed since no information was available from the manufacturers. The present study shows that although different beverage preparation processes possibly affect the concentrations of PFAAs encountered in the final consumed product, the water used for preparation remains the most important source of PFAAs. This in turn has implications for areas where drinking water is contaminated. Tap-water based beverages will possibly be an additional source of human exposure to PFAAs and need to be considered in exposure modeling. PMID:22939265

  13. Investigating sources and pathways of perfluoroalkyl acids (PFAAs) in aquifers in Tokyo using multiple tracers.

    PubMed

    Kuroda, Keisuke; Murakami, Michio; Oguma, Kumiko; Takada, Hideshige; Takizawa, Satoshi

    2014-08-01

    We employed a multi-tracer approach to investigate sources and pathways of perfluoroalkyl acids (PFAAs) in urban groundwater, based on 53 groundwater samples taken from confined aquifers and unconfined aquifers in Tokyo. While the median concentrations of groundwater PFAAs were several ng/L, the maximum concentrations of perfluorooctane sulfonate (PFOS, 990 ng/L), perfluorooctanoate (PFOA, 1800 ng/L) and perfluorononanoate (PFNA, 620 ng/L) in groundwater were several times higher than those of wastewater and street runoff reported in the literature. PFAAs were more frequently detected than sewage tracers (carbamazepine and crotamiton), presumably owing to the higher persistence of PFAAs, the multiple sources of PFAAs beyond sewage (e.g., surface runoff, point sources) and the formation of PFAAs from their precursors. Use of multiple methods of source apportionment including principal component analysis-multiple linear regression (PCA-MLR) and perfluoroalkyl carboxylic acid ratio analysis highlighted sewage and point sources as the primary sources of PFAAs in the most severely polluted groundwater samples, with street runoff being a minor source (44.6% sewage, 45.7% point sources and 9.7% street runoff, by PCA-MLR). Tritium analysis indicated that, while young groundwater (recharged during or after the 1970s, when PFAAs were already in commercial use) in shallow aquifers (<50 m depth) was naturally highly vulnerable to PFAA pollution, PFAAs were also found in old groundwater (recharged before the 1950s, when PFAAs were not in use) in deep aquifers (50-500 m depth). This study demonstrated the utility of multiple uses of tracers (pharmaceuticals and personal care products; PPCPs, tritium) and source apportionment methods in investigating sources and pathways of PFAAs in multiple aquifer systems. PMID:24814036

  14. Methylmalonic acid blood test

    MedlinePlus

    ... acid is a substance produced when proteins, called amino acids, in the body break down. The health care ... Cederbaum S, Berry GT. Inborn errors of carbohydrate, ammonia, amino acid, and organic acid metabolism. In: Gleason CA, Devaskar ...

  15. Brain region-specific perfluoroalkylated sulfonate (PFSA) and carboxylic acid (PFCA) accumulation and neurochemical biomarker responses in east Greenland polar bears (Ursus maritimus).

    PubMed

    Eggers Pedersen, Kathrine; Basu, Niladri; Letcher, Robert; Greaves, Alana K; Sonne, Christian; Dietz, Rune; Styrishave, Bjarne

    2015-04-01

    Perfluoroalkyl substances (PFASs) is a growing class of contaminants in the Arctic environment, and include the established perfluorinated sulfonates (PFSAs; especially perfluorooctane sulfonate (PFOS)) and carboxylic acids (PFCAs). PFSAs and PFCAs of varying chain length have been reported to bioaccumulate in lipid rich tissues of the brain among other tissues such as liver, and can reach high concentrations in top predators including the polar bear. PFCA and PFSA bioaccummulation in the brain has the potential to pose neurotoxic effects and therefore we conducted a study to investigate if variations in neurochemical transmitter systems i.e. the cholinergic, glutaminergic, dopaminergic and GABAergic, could be related to brain-specific bioaccumulation of PFASs in East Greenland polar bears. Nine brain regions from nine polar bears were analyzed for enzyme activity (monoamine oxidase (MAO), acetylcholinesterase (AChE) and glutamine synthetase (GS)) and receptor density (dopamine-2 (D2), muscarinic cholinergic (mAChR) and gamma-butyric acid type A (GABA-A)) along with PFSA and PFCA concentrations. Average brain ∑PFSA concentration was 25ng/g ww where PFOS accounted for 91%. Average ∑PFCA concentration was 88ng/g ww where PFUnDA, PFDoDA and PFTrDA combined accounted for 79%. The highest concentrations of PFASs were measured in brain stem, cerebellum and hippocampus. Correlative analyses were performed both across and within brain regions. Significant positive correlations were found between PFASs and MAO activity in occipital lobe (e.g. ∑PFCA; rp=0.83, p=0.041, n=6) and across brain regions (e.g. ∑PFCA; rp=0.47, p=0.001, ∑PFSA; rp=0.44, p>0.001; n=50). GABA-A receptor density was positively correlated with two PFASs across brain regions (PFOS; rp=0.33, p=0.02 and PFDoDA; rp=0.34, p=0.014; n=52). Significant negative correlations were found between mAChR density and PFASs in cerebellum (e.g. ∑PFCA; rp=-0.95, p=0.013, n=5) and across brain regions (e.g. ∑PFCA; rp=-0.40, p=0.003, ∑PFSA; rp=-0.37, p=0.007; n=52). AChE activity and D2 density were negatively correlated with single PFCAs in several brain regions, whereas GS activity was positively correlated with PFASs primarily in occipital lobe. Results from the present study support the hypothesis that PFAS concentrations in polar bears from East Greenland have exceeded the threshold limits for neurochemical alterations. It is not known whether the observed alterations in neurochemical signaling are currently having negative effects on neurochemistry in East Greenland polar bears. However given the importance of these systems in cognitive processes and motor function, the present results indicate an urgent need for a better understanding of neurochemical effects of PFAS exposure to wildlife. PMID:25682255

  16. Sorption of PFOA and PFOS to Ground Water Sediment

    EPA Science Inventory

    During its years of operation, the Washington County Sanitary Landfill near St. Paul, Minnesota accepted both municipal and industrial solid waste. Several years of ground water monitoring performed by the MPCA indicates that, some of the waste disposed of at this landfill contai...

  17. Sorption of PFOA and PFOS to Aquifer Sediment

    EPA Science Inventory

    During its years of operation, the Washington County Sanitary Landfill near St. Paul, Minnesota accepted both municipal and industrial solid waste. Several years of ground water monitoring performed by the MPCA indicates that, some of the waste disposed of at this landfill contai...

  18. Understanding Acid Rain

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

  19. New bioactive fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many oxygenated fatty acids are bioactive compounds. Nocardia cholesterolicum and Flavobacterium DS5 convert oleic acid to 10 hydroxy stearic acid and linoleic acid to 10-hydroxy-12(Z)-octadecanoic acid. Pseudomonas aeruginosa PR3 converts oleic acid to the new compounds, 7,10-dihydroxy-8(E)-octad...

  20. New Bioactive Fatty Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many oxygenated fatty acids are bioactive compounds. Nocardia cholesterolicum and Flavobacterium DS5 convert oleic acid to 10 hydroxy stearic acid and linoleic acid to 10-hydroxy-12(Z)-octadecanoic acid. Pseudomonas aeruginosa PR3 converts oleic acid to new compounds, 7,10-dihydroxy-8(E)-octadecen...

  1. Understanding Acid Rain

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH

  2. Acid rain

    SciTech Connect

    Boyle, R.H.; Boyle, R.A.

    1983-01-01

    Acid rain, says Boyle is a chemical leprosy eating into the face of North America and Europe, perhaps the major ecological problem of our time. Boyle describes the causes and scope of the phenomenon; the effects on man, wildlife, water, and our cultural heritage. He probes the delays of politicians and the frequent self-serving arguments advanced by industry in the face of what scientists have proved. The solutions he offers are to strengthen the Clean Air Act and require emission reductions that can be accomplished by establishing emission standards on a regional or bubble basis, burn low-sulfur coal, install scrubbers at critical plants, and invest in alternative energy sources. 73 references, 1 figure.

  3. Determination of perfluorinated alkyl acids in corn, popcorn and popcorn bags before and after cooking by focused ultrasound solid-liquid extraction, liquid chromatography and quadrupole-time of flight mass spectrometry.

    PubMed

    Moreta, Cristina; Tena, Mara Teresa

    2014-08-15

    An analytical method is proposed to determine ten perfluorinated alkyl acids (PFAAs) [nine perfluorocarboxylic acids (PFCAs) and perfluorooctane sulfonate (PFOS)] in corn, popcorn and microwave popcorn packaging by focused ultrasound solid-liquid extraction (FUSLE) and ultra high performance liquid chromatography (UHPLC) coupled to quadrupole-time of flight mass spectrometry (QTOF-MS/MS). Selected PFAAs were extracted efficiently in only one 10-s cycle by FUSLE, a simple, safe and inexpensive technique. The developed method was validated for microwave popcorn bags matrix as well as corn and popcorn matrices in terms of linearity, matrix effect error, detection and quantification limits, repeatability and recovery values. The method showed good accuracy with recovery values around 100% except for the lowest chain length PFAAs, satisfactory reproducibility with RSDs under 16%, and sensitivity with limits of detection in the order of hundreds picograms per gram of sample (between 0.2 and 0.7ng/g). This method was also applied to the analysis of six microwave popcorn bags and the popcorn inside before and after cooking. PFCAs contents between 3.50ng/g and 750ng/g were found in bags, being PFHxA (perfluorohexanoic acid) the most abundant of them. However, no PFAAs were detected either corn or popcorn, therefore no migration was assumed. PMID:24986069

  4. Identification of long-chain perfluorinated acids in biota from the Canadian Arctic.

    PubMed

    Martin, Jonathan W; Smithwick, Marla M; Braune, Birgit M; Hoekstra, Paul F; Muir, Derek C G; Mabury, Scott A

    2004-01-15

    Recently it was discovered that humans and animals from various urban and remote global locations contained a novel class of persistent fluorinated contaminants, the most pervasive of which was perfluorooctane sulfonate (PFOS). Lower concentrations of perfluorooctanoate, perfluorohexane sulfonate, and heptadecafluorooctane sulfonamide have also been detected in various samples. Although longer perfluoroalkyl carboxylates (PFCAs) are used in industry and have been detected in fish following a spill of aqueous film forming foam, no studies have been conducted to examine the widespread occurrence of long-chain PFCAs (e.g., CF3(CF2)xCOO-, where x > 6). To provide a preliminary assessment of fluorinated contaminants, including PFCAs, in the Canadian Arctic, polar bears, ringed seals, arctic fox, mink, common loons, northern fulmars, black guillemots, and fish were collected at various locations in the circumpolar region. PFOS was the major contaminant detected in most samples and in polar bear liver was the most prominent organohalogen (mean PFOS = 3.1 microg/g wet weight) compared to individual polychlorinated biphenyl congeners, chlordane, or hexachlorocyclohexane-related chemicals in fat. Using two independent mass spectral techniques, it was confirmed that all samples also contained ng/g concentrations of a homologous series of PFCAs, ranging in length from 9 to 15 carbons. Sum concentrations of PFCAs (sum(PFCAs)) were lower than total PFOS equivalents (sum(PFOS)) in all samples except for mink. In mink, perfluorononanoate (PFNA) concentrations exceeded PFOS concentrations, indicating that PFNA and other PFCAs should be considered in future risk assessments. Mammals feeding at higher trophic levels had greater concentrations of PFOS and PFCAs than mammals feeding at lower trophic positions. In general, odd-length PFCAs exceeded the concentration of even-length PFCAs, and concentrations decreased with increasing chain length in mammals. PFOS and PFCA concentrations were much lower for animals living in the Canadian Arctic than for the same species living in mid-latitude regions of the United States. Future studies should continue to monitor all fluorinated contaminants and examine the absolute and relative toxicities for this novel suite of PFCAs. PMID:14750710

  5. Effects of perfluorooctane sulfonate on the immune responses and expression of immune-related genes in Chinese mitten-handed crab Eriocheir sinensis.

    PubMed

    Zhang, Fan; Wei, Jianjun; Li, Qi; Jiang, Runlan; Yu, Na; Qin, Jianguang; Chen, Liqiao

    2015-01-01

    Perfluorooctane sulfonate (PFOS) has been widely studied due to its global distribution, slow degradation, high bioaccumulation and toxicological effects on vertebrates. However, the potential toxicity of PFOS to crustaceans is little known. The present study investigated the effects of PFOS on the immune responses and expression of immune-related genes in the Chinese mitten-handed crab Eriocheir sinensis. Crabs were exposed to 0, 0.01, 0.1, 1.0 and 10mg/L of PFOS, and sampled on 1, 4, 7, 14 and 21days respectively. The total hemocyte count and lysozyme activity in PFOS-treated crab were significantly lower than in the control. The exposure to 10mg/L of PFOS led to a marked inhibition in phenoloxidase and superoxide dismutase activities. At other PFOS levels, phenoloxidase and superoxide dismutase showed an initial increase and a subsequent decrease over time. The alkaline and acid phosphatase activities were stimulated in 10mg/L PFOS until 21days. The mRNA expression of immune related genes including hepatopancreas-specific C-type lectin and prophenoloxidase activating factors were up-regulated after the exposure to the concentrations of 1 and 10mg/L of PFOS, while the expression of lysozyme gene was up-regulated only in the crab exposed to 0.1mg/L PFOS. The results demonstrate that the high dose of PFOS leads to immune toxicity and the hepatopancreas is a major target organ for PFOS accumulation and immunotoxicity. Hemocyte counts, phenoloxidase and acid phosphatase are useful biomarkers for the risk assessment of PFOS toxicity to crustaceans. PMID:25900200

  6. Bioactive Fatty Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxygenated fatty acids are useful as specialty chemicals, plasticizers, and biomedicals. Microbial enzymes convert fatty acids to mono-, di-, and trihydroxy fatty acid products. Among them, Bacillus megaterium ALA2 converted n-6 and n-3 PUFAs to many new oxygenated fatty acids. Linoleic acid was ...

  7. Identification of perfluorooctane sulfonate binding protein in the plasma of tiger pufferfish Takifugu rubripes.

    PubMed

    Honda, Masato; Muta, Akemi; Akasaka, Taiki; Inoue, Yoshiyuki; Shimasaki, Yohei; Kannan, Kurunthachalam; Okino, Nozomu; Oshima, Yuji

    2014-06-01

    It is well known that perfluorooctane sulfonate (PFOS) preferentially accumulates in the plasma of wildlife and humans. Although earlier studies have suggested that this was due to binding of PFOS to a plasma protein, definite characterization of the protein in in vivo exposure studies was not conducted thus far. In this study, we conducted both in vitro and in vivo experiments to identify PFOS binding protein in the plasma of fish. For the in vivo studies, PFOS was administered intraperitoneally to tiger pufferfish, Takifugu rubripes, and the plasma was separated by ammonium sulfate fractionation. High concentrations of PFOS were found in the 65-70 percent ammonium sulfate fraction (190ng/mL). After SDS-PAGE and N-terminal amino acid sequence analysis, the PFOS-binding protein was identified as an apolipoprotein A-I, which was confirmed on the basis of a significant correlation to the PFOS concentration in each fraction. The plasma samples fractionated by ammonium sulfate from untreated pufferfish were subjected to PFOS binding assay by the equilibrium dialysis method. The results further confirmed that the 60-65 percent ammonium sulfate fraction showed a high PFOS-binding ratio, similar to that found from in vivo studies. We demonstrated that PFOS is likely bound to an apolipoprotein A-I in the plasma of tiger pufferfish in in vivo and in vitro studies. PMID:24635910

  8. Experimental and molecular dynamic simulation study of perfluorooctane sulfonate adsorption on soil and sediment components.

    PubMed

    Zhang, Ruiming; Yan, Wei; Jing, Chuanyong

    2015-03-01

    Soil and sediment play a crucial role in the fate and transport of perfluorooctane sulfonate (PFOS) in the environment. However, the molecular mechanisms of major soil/sediment components on PFOS adsorption remain unclear. This study experimentally isolated three major components in soil/sediment: humin/kerogen, humic/fulvic acid (HA/FA), and inorganic component after removing organics, and explored their contributions to PFOS adsorption using batch adsorption experiments and molecular dynamic simulations. The results suggest that the humin/kerogen component dominated the PFOS adsorption due to its aliphatic features where hydrophobic effect and phase transfer are the primary adsorption mechanism. Compared with the humin/kerogen, the HA/FA component contributed less to the PFOS adsorption because of its hydrophilic and polar characteristics. The electrostatic repulsion between the polar groups of HA/FA and PFOS anions was attributable to the reduced PFOS adsorption. When the soil organic matter was extracted, the inorganic component also plays a non-negligible role because PFOS molecules might form surface complexes on SiO2 surface. The findings obtained in this study illustrate the contribution of organic matters in soils and sediments to PFOS adsorption and provided new perspective to understanding the adsorption process of PFOS on micro-interface in the environment. PMID:25766021

  9. Uric acid test (image)

    MedlinePlus

    Uric acid urine test is performed to check for the amount of uric acid in urine. Urine is collected over a 24 ... testing. The most common reason for measuring uric acid levels is in the diagnosis or treatment of ...

  10. Contribution of diffuse inputs to the aqueous mass load of perfluoroalkyl acids in river and stream catchments in Korea.

    PubMed

    Kim, Seung-Kyu; Li, Dong-Hao; Shoeib, Mahiba; Zoh, Kyung-Duk

    2014-02-01

    Recent studies disagree regarding the contributions of point versus non-point sources to the aqueous mass loads of perfluoroalkyl acids (PFAAs). This study investigated the longitudinal change in PFAA mass load from upstream to downstream stations along rivers and/or streams to assess the relative contributions of point versus nonpoint inputs. With concentrations 10 to 100 times higher than running water, point sources such as wastewater treatment plants (WWTPs) effluent and airport ditch-outlet (ADO) water were separated from neighboring upstream and downstream running waters using principal component analysis. Source waters were characterized by certain predominant components [e.g., perfluorobutylsulfonate (PFBS) and perfluorooctanoic acid (PFOA) in WWTP effluent and perfluorohexylsulfonate (PFHxS) and perfluorooctylsulfonate (PFOS) in ADO water], which were minor components of running water. From a mass balance assessment of PFAA mass load, certain compounds such as PFOA and PFBS dominated the contribution of point sources to the mass load in the running water at downstream stations or in small catchment basins with high levels of industrial activity. Most of the mass load in the investigated catchments was attributable to upstream running water with a minor influence from industrial, commercial, and domestic human activities. Furthermore, the negative relationship of per capita emission factors (hereafter, EFs) with population density and a lower contribution of PFAA from WWTPs (~30% on average) compared to the running water-derived mass load at the national level indicated that diffuse inputs were more important contributors to aqueous PFAA contamination in each catchment basin as well as the entire watershed of the country (Korea). Volatile precursor compounds, which are readily dispersed to neighboring basins and transformed to PFAAs in the ambient environment, can be an important source of these diffuse inputs and will become more significant over time. PMID:23849806

  11. PPAR involvement in PFAA developmental toxicity

    EPA Science Inventory

    Perfluoroalkyl acids (PFAAs) are found in the environment and in serum of wildlife and humans. Perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorooctane sulfonate (PFOS) are developmentally toxic in rodents. The effects of in utero exposure include increas...

  12. Acid tolerance in amphibians

    SciTech Connect

    Pierce, B.A.

    1985-04-01

    Studies of amphibian acid tolerance provide information about the potential effects of acid deposition on amphibian communities. Amphibians as a group appear to be relatively acid tolerant, with many species suffering increased mortality only below pH 4. However, amphibians exhibit much intraspecific variation in acid tolerance, and some species are sensitive to even low levels of acidity. Furthermore, nonlethal effects, including depression of growth rates and increases in developmental abnormalities, can occur at higher pH.

  13. Acid Thunder: Acid Rain and Ancient Mesoamerica

    ERIC Educational Resources Information Center

    Kahl, Jonathan D. W.; Berg, Craig A.

    2006-01-01

    Much of Mesoamerica's rich cultural heritage is slowly eroding because of acid rain. Just as water dissolves an Alka-Seltzer tablet, acid rain erodes the limestone surfaces of Mexican archaeological sites at a rate of about one-half millimeter per century (Bravo et al. 2003). A half-millimeter may not seem like much, but at this pace, a few…

  14. Acid Thunder: Acid Rain and Ancient Mesoamerica

    ERIC Educational Resources Information Center

    Kahl, Jonathan D. W.; Berg, Craig A.

    2006-01-01

    Much of Mesoamerica's rich cultural heritage is slowly eroding because of acid rain. Just as water dissolves an Alka-Seltzer tablet, acid rain erodes the limestone surfaces of Mexican archaeological sites at a rate of about one-half millimeter per century (Bravo et al. 2003). A half-millimeter may not seem like much, but at this pace, a few

  15. Lactic acid test

    MedlinePlus

    Lactate test ... test. Exercise can cause a temporary increase in lactic acid levels. ... not getting enough oxygen. Conditions that can increase lactic acid levels include: Heart failure Liver disease Lung disease ...

  16. Facts about Folic Acid

    MedlinePlus

    ... Partners About Us Information For... Media Policy Makers Facts About Folic Acid Language: English Español (Spanish) Recommend ... a woman needs 400 micrograms (mcg) every day. Facts About Folic Acid Download and print this fact ...

  17. Fatty acid analogs

    DOEpatents

    Elmaleh, David R.; Livni, Eli

    1985-01-01

    In one aspect, a radioactively labeled analog of a fatty acid which is capable of being taken up by mammalian tissue and which exhibits an in vivo beta-oxidation rate below that with a corresponding radioactively labeled fatty acid.

  18. Deoxycholic Acid Injection

    MedlinePlus

    Deoxycholic acid injection is used to improve the appearance and profile of moderate to severe submental fat ('double chin'; fatty tissue located under the chin). Deoxycholic acid injection is in a class of medications called ...

  19. Omega-3 Fatty Acids

    MedlinePlus

    Omega-3 fatty acids are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the amount ... the blood in people with very high triglycerides. Omega-3 fatty acids are in a class of medications ...

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

    PubMed

    Sinclair, Ewan; Mayack, David T; Roblee, Kenneth; Yamashita, Nobuyoshi; Kannan, Kurunthachalam

    2006-04-01

    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. PMID:16435086

  1. GENE PROFILING IN WILD-TYPE AND PPAR?-NULL MICE EXPOSED TO PERFLUOROOCTANE SULFONATE

    EPA Science Inventory

    Perfluorooctane sulfonate (PFOS), a perfluoroalkyl acid (PFAA), is a persistent environmental contaminant found in the tissues of humans and wildlife. Over the last decade, health concerns have been raised, in part, because of the long half-life of PFOS and other PFAAs in humans,...

  2. GENE PROFILING IN WILD-TYPE AND PPARα-NULL MICE EXPOSED TO PERFLUOROOCTANE SULFONATE

    EPA Science Inventory

    Perfluorooctane sulfonate (PFOS), a perfluoroalkyl acid (PFAA), is a persistent environmental contaminant found in the tissues of humans and wildlife. Over the last decade, health concerns have been raised, in part, because of the long half-life of PFOS and other PFAAs in humans,...

  3. PRODUCTION OF TRIFLUOROACETIC ACID

    DOEpatents

    Haworth, W.N.; Stacey, M.

    1949-07-19

    A method is given for the production of improved yields of trifluoroacetic acid. The compound is prepared by oxidizing m-aminobenzotrifluoride with an alkali metal or alkaline earth metal permanganate at a temperature in the range of 80 deg C to 100 deg C while dissolved ln a mixture of water with glacial acetic acid and/or trifluoroacetic acid. Preferably a mixture of water and trifluoroacetic acid ls used as the solvent.

  4. Plant fatty acid hydroxylases

    DOEpatents

    Somerville, Chris; Broun, Pierre; van de Loo, Frank

    2001-01-01

    This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.

  5. An eosin Y-based "turn-on" fluorescent sensor for detection of perfluorooctane sulfonate.

    PubMed

    Liang, Jiaman; Deng, Xiaoyan; Tan, Kejun

    2015-11-01

    In this paper, a novel sensing method with a higher sensitivity of perfluorooctane sulfonate (PFOS) than perfluorooctanoic acid (PFOA) has been proposed detection of PFOS in aqueous solution replying on the "off-on" switch of eosin Y/polyethyleneimine (PEI)/PFOS fluorescence system due to the higher affinity of PEI to PFOS than eosin Y. In pH 7.0 Britton-Robinson buffer solution, eosin Y reacts with protonated PEI to form complex by electrostatic attraction, which leads to a strong fluorescence quenching of the eosin Y. When PFOS presents, the fluorescence of eosin Y is recover due to the electrostatic and hydrophobic interactions between PFOS and PEI. The recovered fluorescence intensity is proportional to the concentration of PFOS in the ranging from 0 to 2.0×10(-6) mol/L with the limit of detection (LOD, 3σ) being 1.5×10(-8) mol/L without preconcentration. In this study, the optimum reaction conditions and the interferences of foreign substances were investigated. In addition, the effects of PFOA, the analog of PFOS, on the fluorescence recovery of the system were also studied. The presented approach has been successfully used to detect PFOS in real samples with RSD ⩽2.9%. PMID:26103430

  6. The Acid Rain Reader.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.; And Others

    A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)

  7. What Is Acid Rain?

    ERIC Educational Resources Information Center

    Likens, Gene E.

    2004-01-01

    Acid rain is the collective term for any type of acidified precipitation: rain, snow, sleet, and hail, as well as the presence of acidifying gases, particles, cloud water, and fog in the atmosphere. The increased acidity, primarily from sulfuric and nitric acids, is generated as a by-product of the combustion of fossil fuels such as coal and oil.

  8. The Acid Rain Reader.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.; And Others

    A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…

  9. [alpha]-Oxocarboxylic Acids

    ERIC Educational Resources Information Center

    Kerber, Robert C.; Fernando, Marian S.

    2010-01-01

    Several [alpha]-oxocarboxylic acids play key roles in metabolism in plants and animals. However, there are inconsistencies between the structures as commonly portrayed and the reported acid ionization constants, which result because the acids are predominantly hydrated in aqueous solution; that is, the predominant form is RC(OH)[subscript 2]COOH…

  10. What Is Acid Rain?

    ERIC Educational Resources Information Center

    Likens, Gene E.

    2004-01-01

    Acid rain is the collective term for any type of acidified precipitation: rain, snow, sleet, and hail, as well as the presence of acidifying gases, particles, cloud water, and fog in the atmosphere. The increased acidity, primarily from sulfuric and nitric acids, is generated as a by-product of the combustion of fossil fuels such as coal and oil.…

  11. [alpha]-Oxocarboxylic Acids

    ERIC Educational Resources Information Center

    Kerber, Robert C.; Fernando, Marian S.

    2010-01-01

    Several [alpha]-oxocarboxylic acids play key roles in metabolism in plants and animals. However, there are inconsistencies between the structures as commonly portrayed and the reported acid ionization constants, which result because the acids are predominantly hydrated in aqueous solution; that is, the predominant form is RC(OH)[subscript 2]COOH

  12. Acid Rain Study Guide.

    ERIC Educational Resources Information Center

    Hunger, Carolyn; And Others

    Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

  13. Cleavage of nucleic acids

    SciTech Connect

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor L.; Brow, Mary Ann D.; Dahlberg, James E.

    2007-12-11

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  14. Nucleic acid detection assays

    SciTech Connect

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann; Dahlberg, James E.

    2005-04-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  15. Cleavage of nucleic acids

    SciTech Connect

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann D.; Dahlberg, James E.

    2000-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  16. Editorial: Acid precipitation

    SciTech Connect

    1995-09-01

    This editorial focuses on acid rain and the history of public and governmental response to acid rain. Comments on a book by Gwineth Howell `Acid Rain and Acid Waters` are included. The editor feels that Howells has provide a service to the environmental scientific community, with a textbook useful to a range of people, as well as a call for decision makers to learn from the acid rain issue and use it as a model for more sweeping global environmental issues. A balance is needed among several parameters such as level of evidence, probability that the evidence will lead to a specific direction and the cost to the global community. 1 tab.

  17. Nucleic acid detection compositions

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann; Dahlberg, James L.

    2008-08-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  18. Amino acid analysis

    NASA Technical Reports Server (NTRS)

    Winitz, M.; Graff, J. (Inventor)

    1974-01-01

    The process and apparatus for qualitative and quantitative analysis of the amino acid content of a biological sample are presented. The sample is deposited on a cation exchange resin and then is washed with suitable solvents. The amino acids and various cations and organic material with a basic function remain on the resin. The resin is eluted with an acid eluant, and the eluate containing the amino acids is transferred to a reaction vessel where the eluant is removed. Final analysis of the purified acylated amino acid esters is accomplished by gas-liquid chromatographic techniques.

  19. Cleavage of nucleic acids

    SciTech Connect

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow; Mary Ann D.; Dahlberg, James E.

    2010-11-09

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  20. Nucleic acid detection kits

    DOEpatents

    Hall, Jeff G.; Lyamichev, Victor I.; Mast, Andrea L.; Brow, Mary Ann; Kwiatkowski, Robert W.; Vavra, Stephanie H.

    2005-03-29

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based on charge. The present invention also provides methods for the detection of non-target cleavage products via the formation of a complete and activated protein binding region. The invention further provides sensitive and specific methods for the detection of nucleic acid from various viruses in a sample.

  1. Acidic Ionic Liquids.

    PubMed

    Amarasekara, Ananda S

    2016-05-25

    Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition. PMID:27175515

  2. Process for the preparation of lactic acid and glyceric acid

    DOEpatents

    Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI

    2008-12-02

    Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.

  3. Developmental Toxicity

    EPA Science Inventory

    This chapter provides an overview the developmental toxicity resulting from exposure to perfluorinated alkyl acids (PFAAs). The majority of studies of PFAA-induced developmental toxicity have examined effects of perfluorooctane sulfonate (PFOS) or perfluorooctanoic acid (PFOA) a...

  4. Perfluorinated Compounds in House Dust from Ohio and North Carolina, USA

    EPA Science Inventory

    The perfluoroalkyl acids (PFAAs), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), have come under increasing scrutiny due to their persistence in the environment, global distribution, and animal toxicity. Given that human exposure routes for these c...

  5. Microorganisms for producing organic acids

    SciTech Connect

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-09-30

    Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

  6. Acid-Base Homeostasis

    PubMed Central

    Nakhoul, Nazih; Hering-Smith, Kathleen S.

    2015-01-01

    Acid-base homeostasis and pH regulation are critical for both normal physiology and cell metabolism and function. The importance of this regulation is evidenced by a variety of physiologic derangements that occur when plasma pH is either high or low. The kidneys have the predominant role in regulating the systemic bicarbonate concentration and hence, the metabolic component of acid-base balance. This function of the kidneys has two components: reabsorption of virtually all of the filtered HCO3− and production of new bicarbonate to replace that consumed by normal or pathologic acids. This production or generation of new HCO3− is done by net acid excretion. Under normal conditions, approximately one-third to one-half of net acid excretion by the kidneys is in the form of titratable acid. The other one-half to two-thirds is the excretion of ammonium. The capacity to excrete ammonium under conditions of acid loads is quantitatively much greater than the capacity to increase titratable acid. Multiple, often redundant pathways and processes exist to regulate these renal functions. Derangements in acid-base homeostasis, however, are common in clinical medicine and can often be related to the systems involved in acid-base transport in the kidneys. PMID:26597304

  7. Recovery of organic acids

    DOEpatents

    Verser, Dan W.; Eggeman, Timothy J.

    2011-11-01

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  8. Recovery of organic acids

    DOEpatents

    Verser, Dan W.; Eggeman, Timothy J.

    2009-10-13

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  9. USGS Tracks Acid Rain

    USGS Publications Warehouse

    Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.

    1995-01-01

    The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.

  10. THIN-LAYER SEPARATION OF CITRIC ACID CYCLE INTERMEDIATES, LACTIC ACID, AND THE AMINO ACID TAURINE

    EPA Science Inventory

    This paper describes a two-dimensional mixed-layer method for separating citric acid cycle intermediates, lactic acid and the amino acid taurine. The method cleanly separates all citric acid cycle intermediates tested, excepting citric acid and isocitric acid. The solvents are in...

  11. Structure of Acid phosphatases.

    PubMed

    Araujo, Csar L; Vihko, Pirkko T

    2013-01-01

    Acid phosphatases are enzymes that have been studied extensively due to the fact that their dysregulation is associated with pathophysiological conditions. This characteristic has been exploited for the development of diagnostic and therapeutic methods. As an example, prostatic acid phosphatase was the first marker for metastatic prostate cancer diagnosis and the dysregulation of tartrate resistant acid phosphatase is associated with abnormal bone resorption linked to osteoporosis. The pioneering crystallization studies on prostatic acid phosphatase and mammalian tartrate-resistant acid phosphatase conformed significant milestones towards the elucidation of the mechanisms followed by these enzymes (Schneider et al., EMBO J 12:2609-2615, 1993). Acid phosphatases are also found in nonmammalian species such as bacteria, fungi, parasites, and plants, and most of them share structural similarities with mammalian acid phosphatase enzymes. Acid phosphatase (EC 3.1.3.2) enzymes catalyze the hydrolysis of phosphate monoesters following the general equation. Phosphate monoester + H2O -->/<-- alcohol + phosphate. The general classification "acid phosphatase" relies only on the optimum acidic pH for the enzymatic activity in assay conditions using non-physiological substrates. These enzymes accept a wide range of substrates in vitro, ranging from small organic molecules to phosphoproteins, constituting a heterogeneous group of enzymes from the structural point of view. These structural differences account for the divergence in cofactor dependences and behavior against substrates, inhibitors, and activators. In this group only the tartrate-resistant acid phosphatase is a metallo-enzyme whereas the other members do not require metal-ion binding for their catalytic activity. In addition, tartrate-resistant acid phosphatase and erythrocytic acid phosphatase are not inhibited by L-(+)-tartrate ion while the prostatic acid phosphatase is tartrate-sensitive. This is an important difference that can be exploited in in vitro assays to differentiate between different kinds of phosphatase activity. The search for more sensitive and specific methods of detection in clinical laboratory applications led to the development of radioimmunoassays (RIA) for determination of prostatic acid phosphatase in serum. These methods permit the direct quantification of the enzyme regardless of its activity status. Therefore, an independent structural classification exists that helps to group these enzymes according to their structural features and mechanisms. Based on this we can distinguish the histidine acid phosphatases (Van Etten, Ann N Y Acad Sci 390:27-51, 1982), the low molecular weight protein tyrosine acid phosphatases and the metal-ion dependent phosphatases. A note of caution is worthwhile mentioning here. The nomenclature of acid phosphatases has not been particularly easy for those new to the subject. Unfortunately, the acronym PAP is very common in the literature about purple acid phosphatases and prostatic acid phosphatase. In addition, LPAP is the acronym chosen to refer to the lysophosphatidic acid phosphatase which is a different enzyme. It is important to bear in mind this distinction while reviewing the literature to avoid confusion. PMID:23860654

  12. Aminocaproic Acid Injection

    MedlinePlus

    Amicar® Injection ... Aminocaproic acid injection is used to control bleeding that occurs when blood clots are broken down too quickly. This type of ... baby is ready to be born). Aminocaproic acid injection is also used to control bleeding in the ...

  13. Mutant fatty acid desaturase

    DOEpatents

    Shanklin, John; Cahoon, Edgar B.

    2004-02-03

    The present invention relates to a method for producing mutants of a fatty acid desaturase having a substantially increased activity towards fatty acid substrates with chains containing fewer than 18 carbons relative to an unmutagenized precursor desaturase having an 18 carbon atom chain length substrate specificity. The method involves inducing one or more mutations in the nucleic acid sequence encoding the precursor desaturase, transforming the mutated sequence into an unsaturated fatty acid auxotroph cell such as MH13 E. coli, culturing the cells in the absence of supplemental unsaturated fatty acids, thereby selecting for recipient cells which have received and which express a mutant fatty acid desaturase with an elevated specificity for fatty acid substrates having chain lengths of less than 18 carbon atoms. A variety of mutants having 16 or fewer carbon atom chain length substrate specificities are produced by this method. Mutant desaturases produced by this method can be introduced via expression vectors into prokaryotic and eukaryotic cells and can also be used in the production of transgenic plants which may be used to produce specific fatty acid products.

  14. EXPOSURES TO ACIDIC AEROSOLS

    EPA Science Inventory

    Ambient monitoring of acid aerosol in four U.S. cities and in a rural region of southern Ontario clearly show distinct periods of strong acidity. easurements made in Kingston, TN, and Stuebenville, OH, resulted in 24-hr H+ ion concentrations exceeding 100 nmole/m3 more than 10 ti...

  15. Amino Acid Crossword Puzzle

    ERIC Educational Resources Information Center

    Sims, Paul A.

    2011-01-01

    Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;

  16. Pantothenic acid and biotin

    MedlinePlus

    Pantothenic acid and biotin are types of B vitamins. They are water-soluble, which means that the body can't store them. If ... Pantothenic acid and biotin are needed for growth. They help the body break down and use food. This is called metabolism . They are ...

  17. Toxicology of Perfluoroalkyl acids

    EPA Science Inventory

    The Perfluoroalkyl acids(PFAAs) area a family of organic chemicals consisting of a perflurinated carbon backbone (4-12in length) and a acidic functional moiety (Carboxylate or sulfonate). These compounds have excellent surface-tension reducing properties and have numerous industr...

  18. Analysis of Organic Acids.

    ERIC Educational Resources Information Center

    Griswold, John R.; Rauner, Richard A.

    1990-01-01

    Presented are the procedures and a discussion of the results for an experiment in which students select unknown carboxylic acids, determine their melting points, and investigate their solubility behavior in water and ethanol. A table of selected carboxylic acids is included. (CW)

  19. Toxicology of Perfluoroalkyl Acids*

    EPA Science Inventory

    The perfluoroalkyl acids (PFAAs) are a family of organic chemicals consisting of a perfluorinated carbon backbone (4-12 in length) and an acidic functional moiety (carboxylate or sulfonate). These compounds are chemically stable, have excellent surface-tension reducing properties...

  20. Amino Acid Crossword Puzzle

    ERIC Educational Resources Information Center

    Sims, Paul A.

    2011-01-01

    Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…

  1. Fats and fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The absolute fat requirement of the human species is the amount of essential fatty acids needed to maintain optimal fatty acid composition of all tissues and normal eicosanoid synthesis. At most, this requirement is no more than about 5% of an adequate energy intake. However, fat accounts for appro...

  2. Bile acid transporters

    PubMed Central

    Dawson, Paul A.; Lan, Tian; Rao, Anuradha

    2009-01-01

    In liver and intestine, transporters play a critical role in maintaining the enterohepatic circulation and bile acid homeostasis. Over the past two decades, there has been significant progress toward identifying the individual membrane transporters and unraveling their complex regulation. In the liver, bile acids are efficiently transported across the sinusoidal membrane by the Na+ taurocholate cotransporting polypeptide with assistance by members of the organic anion transporting polypeptide family. The bile acids are then secreted in an ATP-dependent fashion across the canalicular membrane by the bile salt export pump. Following their movement with bile into the lumen of the small intestine, bile acids are almost quantitatively reclaimed in the ileum by the apical sodium-dependent bile acid transporter. The bile acids are shuttled across the enterocyte to the basolateral membrane and effluxed into the portal circulation by the recently indentified heteromeric organic solute transporter, OSTα-OSTβ. In addition to the hepatocyte and enterocyte, subgroups of these bile acid transporters are expressed by the biliary, renal, and colonic epithelium where they contribute to maintaining bile acid homeostasis and play important cytoprotective roles. This article will review our current understanding of the physiological role and regulation of these important carriers. PMID:19498215

  3. Proteins and Amino Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteins are the most abundant substances in living organisms and cells. All proteins are constructed from the same twenty amino acids that are linked together by covalent bonds. Shorter chains of two or more amino acids can be linked by covalent bonds to form polypeptides. There are twenty amino...

  4. Conjugated Fatty Acid Synthesis

    PubMed Central

    Rawat, Richa; Yu, Xiao-Hong; Sweet, Marie; Shanklin, John

    2012-01-01

    Conjugated linolenic acids (CLNs), 18:3 ?9,11,13, lack the methylene groups found between the double bonds of linolenic acid (18:3 ?9,12,15). CLNs are produced by conjugase enzymes that are homologs of the oleate desaturases FAD2. The goal of this study was to map the domain(s) within the Momordica charantia conjugase (FADX) responsible for CLN formation. To achieve this, a series of Momordica FADX-Arabidopsis FAD2 chimeras were expressed in the Arabidopsis fad3fae1 mutant, and the transformed seeds were analyzed for the accumulation of CLN. These experiments identified helix 2 and the first histidine box as a determinant of conjugase product partitioning into punicic acid (18:3 ?9cis,11trans,13cis) or ?-eleostearic acid (18:3 ?9cis,11trans,13trans). This was confirmed by analysis of a FADX mutant containing six substitutions in which the sequence of helix 2 and first histidine box was converted to that of FAD2. Each of the six FAD2 substitutions was individually converted back to the FADX equivalent identifying residues 111 and 115, adjacent to the first histidine box, as key determinants of conjugase product partitioning. Additionally, expression of FADX G111V and FADX G111V/D115E resulted in an approximate doubling of eleostearic acid accumulation to 20.4% and 21.2%, respectively, compared with 9.9% upon expression of the native Momordica FADX. Like the Momordica conjugase, FADX G111V and FADX D115E produced predominantly ?-eleostearic acid and little punicic acid, but the FADX G111V/D115E double mutant produced approximately equal amounts of ?-eleostearic acid and its isomer, punicic acid, implicating an interactive effect of residues 111 and 115 in punicic acid formation. PMID:22451660

  5. Total syntheses of cis-cyclopropane fatty acids: dihydromalvalic acid, dihydrosterculic acid, lactobacillic acid, and 9,10-methylenehexadecanoic acid.

    PubMed

    Shah, Sayali; White, Jonathan M; Williams, Spencer J

    2014-12-14

    cis-Cyclopropane fatty acids (cis-CFAs) are widespread constituents of the seed oils of subtropical plants, membrane components of bacteria and protozoa, and the fats and phospholipids of animals. We describe a systematic approach to the synthesis of enantiomeric pairs of four cis-CFAs: cis-9,10-methylenehexadecanoic acid, lactobacillic acid, dihydromalvalic acid, and dihydrosterculic acid. The approach commences with Rh2(OAc)4-catalyzed cyclopropenation of 1-octyne and 1-decyne, and hinges on the preparative scale chromatographic resolution of racemic 2-alkylcycloprop-2-ene-1-carboxylic acids using a homochiral Evan's auxiliary. Saturation of the individual diastereomeric N-cycloprop-2-ene-1-carbonylacyloxazolidines, followed by elaboration to alkylcyclopropylmethylsulfones, allowed Julia-Kocienski olefination with various ?-aldehyde-esters. Finally, saponification and diimide reduction afforded the individual cis-CFA enantiomers. PMID:25321346

  6. Sulfuric Acid on Europa

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft. The brightest areas, where the yellow is most intense, represent regions of high frozen sulfuric acid concentration. Sulfuric acid is found in battery acid and in Earth's acid rain.

    This image is based on data gathered by Galileo's near infrared mapping spectrometer.

    Europa's leading hemisphere is toward the bottom right, and there are enhanced concentrations of sulfuric acid in the trailing side of Europa (the upper left side of the image). This is the face of Europa that is struck by sulfur ions coming from Jupiter's innermost moon, Io. The long, narrow features that crisscross Europa also show sulfuric acid that may be from sulfurous material extruded in cracks.

    Galileo, launched in 1989, has been orbiting Jupiter and its moons since December 1995. JPL manages the Galileo mission for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  7. Trans Fatty Acids

    NASA Astrophysics Data System (ADS)

    Doyle, Ellin

    1997-09-01

    Fats and their various fatty acid components seem to be a perennial concern of nutritionists and persons concerned with healthful diets. Advice on the consumption of saturated, polyunsaturated, monounsaturated, and total fat bombards us from magazines and newspapers. One of the newer players in this field is the group of trans fatty acids found predominantly in partially hydrogenated fats such as margarines and cooking fats. The controversy concerning dietary trans fatty acids was recently addressed in an American Heart Association (AHA) science advisory (1) and in a position paper from the American Society of Clinical Nutrition/American Institute of Nutrition (ASCN/AIN) (2). Both reports emphasize that the best preventive strategy for reducing risk for cardiovascular disease and some types of cancer is a reduction in total and saturated fats in the diet, but a reduction in the intake of trans fatty acids was also recommended. Although the actual health effects of trans fatty acids remain uncertain, experimental evidence indicates that consumption of trans fatty acids adversely affects serum lipid levels. Since elevated levels of serum cholesterol and triacylglycerols are associated with increased risk of cardiovascular disease, it follows that intake of trans fatty acids should be minimized.

  8. Strongly Acidic Auxin Indole-3-Methanesulfonic Acid

    PubMed Central

    Cohen, Jerry D.; Baldi, Bruce G.; Bialek, Krystyna

    1985-01-01

    A radiochemical synthesis is described for [14C]indole-3-methanesulfonic acid (IMS), a strongly acidic auxin analog. Techniques were developed for fractionation and purification of IMS using normal and reverse phase chromatography. In addition, the utility of both Fourier transform infrared spectrometry and fast atom bombardment mass spectrometry for analysis of IMS has been demonstrated. IMS was shown to be an active auxin, stimulating soybean hypocotyl elongation, bean first internode curvature, and ethylene production. IMS uptake by thin sections of soybean hypocotyl was essentially independent of solution pH and, when applied at a 100 micromolar concentration, IMS exhibited a basipetal polarity in its transport in both corn coleoptile and soybean hypocotyl sections. [14C]IMS should, therefore, be a useful compound to study fundamental processes related to the movement of auxins in plant tissues and organelles. PMID:16664007

  9. Understanding Acid Base Disorders.

    PubMed

    Gomez, Hernando; Kellum, John A

    2015-10-01

    The concentration of hydrogen ions is regulated in biologic solutions. There are currently 3 recognized approaches to assess changes in acid base status. First is the traditional Henderson-Hasselbalch approach, also called the physiologic approach, which uses the relationship between HCO3(-) and Pco2; the second is the standard base excess approach based on the Van Slyke equation. The third approach is the quantitative or Stewart approach, which uses the strong ion difference and the total weak acids. This article explores the origins of the current concepts framing the existing methods to analyze acid base balance. PMID:26410149

  10. Understanding acid rain

    SciTech Connect

    Budiansky, S.

    1981-06-01

    The complexities of the phenomenon of acid rain are described. Many factors, including meteorology, geology, chemistry, and biology, all play parts. Varying weather, varying soils, the presence of other pollutants and species differences all act to blur the connections between industrial emissions, acid rain, and environmental damage. Some experts believe that the greatest pH shock to lakes occurs during snow melt and runoff in the spring; others believe that much of the plant damage ascribed to acid rain is actually due to the effects of ozone. Much work needs to be done in the area of sampling. Historical data are lacking and sampling methods are not sufficiently accurate. (JMT)

  11. Associations of serum perfluoroalkyl acid levels with T-helper cell-specific cytokines in children: By gender and asthma status.

    PubMed

    Zhu, Yu; Qin, Xiao-Di; Zeng, Xiao-Wen; Paul, Gunther; Morawska, Lidia; Su, Ming-Wei; Tsai, Ching-Hui; Wang, Si-Quan; Lee, Yungling Leo; Dong, Guang-Hui

    2016-07-15

    Perfluoroalkyl acids (PFAAs) are a group of common chemicals that ubiquitously exist in wildlife and humans. Experimental data suggest that they may alter T-lymphocyte functioning in situ by preferentially enhancing the development of T-helper 2 (TH2)- and inhibiting TH1-lymphocyte development and might increase allergic inflammation, but few human studies have been conducted. To evaluate the association between serum PFAAs concentrations and T-lymphocyte-related immunological markers of asthma in children, and further to assess whether gender modified this association, 231 asthmatic children and 225 non-asthmatic control children from Northern Taiwan were recruited into the Genetic and Biomarker study for Childhood Asthma. Serum concentrations of ten PFAAs and levels of TH1 [interferon (IFN)-γ, interleukin (IL)-2] and TH2 (IL-4 and IL-5) cytokines were measured. The results showed that asthmatics had significantly higher serum PFAAs concentrations compared with the healthy controls. When stratified by gender, a greater number of significant associations between PFAAs and asthma outcomes were found in males than in females. Among males, adjusted odds ratios for asthma among those with the highest versus lowest quartile of PFAAs exposure ranged from 2.59 (95% CI: 1.14, 5.87) for the perfluorobutanesulfonate (PFBS) to 4.38 (95% CI: 2.02, 9.50) for perfluorooctanesulfonate (PFOS); and serum PFAAs were associated positively with TH2 cytokines and inversely with TH1 cytokines among male asthmatics. Among females, no significant associations between PFAAs and TH2 cytokines could be detected. In conclusion, increased serum PFAAs levels may promote TH cell dysregulation and alter the availability of key TH1 and TH2 cytokines, ultimately contributing to the development of asthma that may differentially impact males to a greater degree than females. These results have potential relevance in asthma prevention. PMID:27060656

  12. WASTE ACID DETOXIFICATION AND RECLAMATION

    EPA Science Inventory

    This Environmental Security Technology Certification Program (ESTCP) project demonstrated the Waste Acid Detoxification and Reclamation (WADR) systems ability to recover waste electropolish acid solutions generated during the manufacturing of gun-tubes, and reuse the clean acid. ...

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

    USGS Publications Warehouse

    Kannan, K.; Perrotta, E.; Thomas, N.J.

    2006-01-01

    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 1992a??2002. Concentrations of PFOS and PFOA were in the ranges of <1a??884 and <5a??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 affect the concentrations of perfluorochemicals in livers. Concentrations of PFOA increased significantly from 1992 to 2002, whereas PFOS concentrations increased from 1992 to 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.

  14. Exposure to perfluorinated compounds: in vitro study on thyroid cells.

    PubMed

    Coperchini, Francesca; Pignatti, Patrizia; Lacerenza, Serena; Negri, Sara; Sideri, Riccardo; Testoni, Claudia; de Martinis, Luca; Cottica, Danilo; Magri, Flavia; Imbriani, Marcello; Rotondi, Mario; Chiovato, Luca

    2015-02-01

    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are widely used perfluorinated chemicals (PFCs). Previous studies detected PFOA and PFOS in human tissues including the thyroid gland. There are no studies on the in vitro effects of PFOA and PFOS on thyroid cells. Our study was aimed at evaluating the effect of the in vitro exposure to PFOA and PFOS on thyroid cell proliferation and viability. These objectives were investigated using Fisher rat thyroid line-5 (FRTL-5) cells. FRTL-5 cells cultured in the presence of PFOA and PFOS at concentrations up to 10(4) nM do not display changes in their viability and proliferation rate, while at a concentration of 10(5) nM of either PFCs, a significant inhibition of cell proliferation, mainly due to increased cell death, was found. PFOA and PFOS were detected in FRTL-5 cell pellets after 72 h of incubation with PFCs but not in control cultures. When FRTL-5 were incubated with PFCs then washed in PBS and re-cultured for 72 h without PFCs in the medium, no detectable concentrations of PFOA and PFOS were measured in the cell pellet. This indicates that PFOA and PFOS enter thyroid cells by a gradient-based passive diffusion mechanism. Future studies are required to evaluate the potential toxic effect resulting from prolonged in vivo exposure to even lower concentrations of PFCs. PMID:25182428

  15. Polymers for acid thickening

    SciTech Connect

    Dixon, K.W.

    1980-09-30

    Acids, thickened with branched emulsion or suspension polymers of diallyldimethylammonium chloride are useful as oil well drilling and fracturing fluids for stimulating well production and in other applications, such as thickeners for cosmetics, paints, adhesives, textiles and printing inks.

  16. Difficult Decisions: Acid Rain.

    ERIC Educational Resources Information Center

    Miller, John A.; Slesnick, Irwin L.

    1989-01-01

    Discusses some of the contributing factors and chemical reactions involved in the production of acid rain, its effects, and political issues pertaining to who should pay for the clean up. Supplies questions for consideration and discussion. (RT)

  17. Folic acid - test

    MedlinePlus

    ... folic acid before and during pregnancy helps prevent neural tube defects, such as spina bifida. Women who are pregnant ... take more if they have a history of neural tube defects in earlier pregnancies. Ask your provider how much ...

  18. Suberanilohydroxamic Acid. Aton Pharma.

    PubMed

    Johnstone, Ricky W

    2004-07-01

    Aton Pharma Inc, under license from the Memorial Sloan-Kettering Cancer Center, is developing suberanilohydroxamic acid (SAHA), a cytodifferentiating agent and histone deacetylase inhibitor, as a potential cancer chemopreventive. PMID:15243870

  19. Nucleic Acids for Computation

    NASA Astrophysics Data System (ADS)

    MacDonald, Joanne; Stojanovic, Milan N.

    Nucleic acids have many features that are ideal for molecular computation. Using nucleic acids, we have constructed a full set of molecular logic gates, with modular stem-loop-controlled deoxyribozymes as switches and single-stranded oligonucleotides as inputs and outputs. These gates have been combined to form basic computational circuits, including a half- and a full-adder, and can also be assembled into automata to perform complex computational tasks such as game playing. Our most advanced automaton to-date integrates more than 100 nucleic acid logic gates to play a complete game of tic-tac-toe encompassing 76 possible game plays. Inputs and outputs can also be coupled with upstream and downstream components, such as aptamers, sensors, secondary gate activation, and small-molecule release, indicating the potential for nucleic acid computation in the engineering of autonomous therapeutic and diagnostic molecular devices.

  20. (Acid rain workshop)

    SciTech Connect

    Turner, R.S.

    1990-12-05

    The traveler presented a paper entitled Susceptibility of Asian Ecosystems to Soil-Mediated Acid Rain Damage'' at the Second Workshop on Acid Rain in Asia. The workshop was organized by the Asian Institute of Technology (Bangkok, Thailand), Argonne National Laboratory (Argonne, Illinois), and Resource Management Associates (Madison, Wisconsin) and was sponsored by the US Department of Energy, the United Nations Environment Program, the United Nations Economic and Social Commission for Asia and the Pacific, and the World Bank. Papers presented on the first day discussed how the experience gained with acid rain in North America and Europe might be applied to the Asian situation. Papers describing energy use projections, sulfur emissions, and effects of acid rain in several Asian countries were presented on the second day. The remaining time was allotted to discussion, planning, and writing plans for a future research program.

  1. Alpha Hydroxy Acids

    MedlinePlus

    ... cancer cells associated with exposure to light) in mice, and that salicyclic acid had a photoprotective effect (protected against the effects of light) in mice. The complete results of this study are available ...

  2. Amino Acids and Chirality

    NASA Technical Reports Server (NTRS)

    Cook, Jamie E.

    2012-01-01

    Amino acids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of amino acids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral amino acids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the amino acids in carbonaceous chondritcs and their relevance to the origin of life.

  3. Citric acid urine test

    MedlinePlus

    ... used to diagnose renal tubular acidosis and evaluate kidney stone disease. ... tubular acidosis and a tendency to form calcium kidney stones. The following may decrease urine citric acid levels: ...

  4. Omega-6 Fatty Acids

    MedlinePlus

    ... 3 fatty acids for 3 months can improve reading, spelling, and behavior, but not coordination or movement in children with DCD. Laser eye surgery. Early research suggests that taking a tablet that contains an ...

  5. Stomach acid test

    MedlinePlus

    Gastric acid secretion test ... The test is done after you have not eaten for a while so fluid is all that remains in ... injected into your body. This is done to test the ability of the cells in the stomach ...

  6. Methylmalonic Acid Test

    MedlinePlus

    ... MMA Formal name: Methylmalonic Acid Related tests: Vitamin B12 and Folate , Homocysteine , Intrinsic Factor Antibody , Complete Blood ... to help diagnose an early or mild vitamin B12 deficiency . It may be ordered by itself or ...

  7. Aminolevulinic Acid Topical

    MedlinePlus

    ... in combination with photodynamic therapy (PDT; special blue light) to treat actinic keratoses (small crusty or scaly ... photosensitizing agents. When aminolevulinic acid is activated by light, it damages the cells of actinic keratosis lesions.

  8. Amoxicillin and Clavulanic Acid

    MedlinePlus

    ... is used to treat certain infections caused by bacteria, including infections of the ears, lungs, sinus, skin, ... antibiotics. It works by stopping the growth of bacteria. Clavulanic acid is in a class of medications ...

  9. Trans fatty acids (image)

    MedlinePlus

    Trans fatty acids are manufactured fats created during a process called hydrogenation, which is aimed at stabilizing polyunsaturated oils to prevent them from becoming rancid and to keep them solid at room temperature. They may be particularly dangerous for ...

  10. Salicylic Acid Topical

    MedlinePlus

    ... Topical salicylic acid is also used to treat skin conditions that involve scaling or overgrowth of skin cells ... to allow pimples to shrink. It treats other skin conditions by softening and loosening dry, scaly, or thickened ...

  11. Acid-base chemistry

    SciTech Connect

    Hand, C.W.; Blewit, H.L.

    1985-01-01

    The book is not a research compendium and there are no references to the literature. It is a teaching text covering the entire range of undergraduate subject matter dealing with acid-base chemistry (some of it remotely) as taught in inorganic, analytical, and organic chemistry courses. The excellent chapters VII through IX deal in detail with the quantitative aspects of aqueous acid-base equilibria (salt hydrolysis and buffer, titrations, polyprotic and amphoteric substances).

  12. Neutron Nucleic Acid Crystallography.

    PubMed

    Chatake, Toshiyuki

    2016-01-01

    The hydration shells surrounding nucleic acids and hydrogen-bonding networks involving water molecules and nucleic acids are essential interactions for the structural stability and function of nucleic acids. Water molecules in the hydration shells influence various conformations of DNA and RNA by specific hydrogen-bonding networks, which often contribute to the chemical reactivity and molecular recognition of nucleic acids. However, X-ray crystallography could not provide a complete description of structural information with respect to hydrogen bonds. Indeed, X-ray crystallography is a powerful tool for determining the locations of water molecules, i.e., the location of the oxygen atom of H2O; however, it is very difficult to determine the orientation of the water molecules, i.e., the orientation of the two hydrogen atoms of H2O, because X-ray scattering from the hydrogen atom is very small.Neutron crystallography is a specialized tool for determining the positions of hydrogen atoms. Neutrons are not diffracted by electrons, but are diffracted by atomic nuclei; accordingly, neutron scattering lengths of hydrogen and its isotopes are comparable to those of non-hydrogen atoms. Therefore, neutron crystallography can determine both of the locations and orientations of water molecules. This chapter describes the current status of neutron nucleic acid crystallographic research as well as the basic principles of neutron diffraction experiments performed on nucleic acid crystals: materials, crystallization, diffraction experiments, and structure determination. PMID:26227050

  13. Studies on bile acids

    PubMed Central

    Okishio, Tatsuo; Nair, Padmanabhan P.; Gordon, Maureen

    1967-01-01

    1. A method is described for the quantitative isolation of bile acids from cellular material. Homogenates of rat liver are freeze-dried and extracted exhaustively with 95% (v/v) ethanol containing 0·1% (v/v) of aq. ammonia (sp.gr. 0·88) and purified by anion-exchange chromatography on Amberlyst A-26. 2. The extracted bile acid conjugates are subjected to either of two hydrolytic procedures, one involving chemical and the other enzymic agents. A unique feature in this study is the introduction of an enzyme, a clostridial peptide-bond hydrolase, for the rapid cleavage of bile acid conjugates, replacing the classical drastic chemical hydrolysis with strong alkali. 3. After hydrolysis, free bile acids are methylated and converted into their trifluoroacetates for final determination by gas–liquid chromatography on a triple component column, FS-1265–SE30–NGS. 4. For the purpose of identification of peaks, bile acid methyl esters are converted into their trimethylsilyl ethers by allowing the methyl esters to react with a new and potent silyl donor, bis(trimethylsilyl)acetamide. 5. The technique affords us a means of studying the metabolism of bile acids at the cellular and subcellular levels in tissues. PMID:16742477

  14. Method for isolating nucleic acids

    DOEpatents

    Hurt, Jr., Richard Ashley; Elias, Dwayne A.

    2015-09-29

    The current disclosure provides methods and kits for isolating nucleic acid from an environmental sample. The current methods and compositions further provide methods for isolating nucleic acids by reducing adsorption of nucleic acids by charged ions and particles within an environmental sample. The methods of the current disclosure provide methods for isolating nucleic acids by releasing adsorbed nucleic acids from charged particles during the nucleic acid isolation process. The current disclosure facilitates the isolation of nucleic acids of sufficient quality and quantity to enable one of ordinary skill in the art to utilize or analyze the isolated nucleic acids for a wide variety of applications including, sequencing or species population analysis.

  15. Acidification and Acid Rain

    NASA Astrophysics Data System (ADS)

    Norton, S. A.; Veselã½, J.

    2003-12-01

    Air pollution by acids has been known as a problem for centuries (Ducros, 1845; Smith, 1872; Camuffo, 1992; Brimblecombe, 1992). Only in the mid-1900s did it become clear that it was a problem for more than just industrially developed areas, and that precipitation quality can affect aquatic resources ( Gorham, 1955). The last three decades of the twentieth century saw tremendous progress in the documentation of the chemistry of the atmosphere, precipitation, and the systems impacted by acid atmospheric deposition. Chronic acidification of ecosystems results in chemical changes to soil and to surface waters and groundwater as a result of reduction of base cation supply or an increase in acid (H+) supply, or both. The most fundamental changes during chronic acidification are an increase in exchangeable H+ or Al3+ (aluminum) in soils, an increase in H+ activity (˜concentration) in water in contact with soil, and a decrease in alkalinity in waters draining watersheds. Water draining from the soil is acidified and has a lower pH (=-log [H+]). As systems acidify, their biotic community changes.Acidic surface waters occur in many parts of the world as a consequence of natural processes and also due to atmospheric deposition of strong acid (e.g., Canada, Jeffries et al. (1986); the United Kingdom, Evans and Monteith (2001); Sweden, Swedish Environmental Protection Board (1986); Finland, Forsius et al. (1990); Norway, Henriksen et al. (1988a); and the United States (USA), Brakke et al. (1988)). Concern over acidification in the temperate regions of the northern hemisphere has been driven by the potential for accelerating natural acidification by pollution of the atmosphere with acidic or acidifying compounds. Atmospheric pollution ( Figure 1) has resulted in an increased flux of acid to and through ecosystems. Depending on the ability of an ecosystem to neutralize the increased flux of acidity, acidification may increase only imperceptibly or be accelerated at a rate that endangers the existing biota. Concerns about acid (or acidic) rain in its modern sense were publicized by the Swedish soil scientist Svante Odén (1968). He argued, initially in the Swedish press, that long-term increases in the atmospheric deposition of acid could lower the pH of surface waters, cause a decline in fish stocks, deplete soils of nutrients, and accelerate damage to materials. By the 1970s, acidification of surface waters was reported in many countries in Europe as well as in North America. The late twentieth-century rush to understand the impact of acid rain was driven by: (i) reports of damaged or threatened freshwater fisheries and (ii) damaged forests. Perhaps the earliest linkage between acidic surface water and damage to fish was made by Dahl (1921) in southern Norway. There, spring runoff was sufficiently acidic to kill trout. It was not until the 1970s that a strong link was established between depressed pH, mobilization of aluminum from soil, and fish status ( Schofield and Trojnar,1980). The relationship between acidification of soils and forest health started with hypotheses in the 1960s and has slowly developed. Acid rain enhances the availability of some nutrients (e.g., nitrogen), and may either enhance or diminish the availability of others (e.g., calcium, magnesium, potassium, and phosphorus). Damage to anthropogenic structures, human health, and visibility have also raised concerns. The history of these early developments was summarized by Cowling (1982). Since the 1970s, sulfur and nitrogen emissions to the atmosphere have been reduced by 50-85% and 0-30%, respectively, both in North America and Europe. The emission reductions have occurred as a consequence of knowledge gained and economic factors. While recovery of water quality is underway in some areas, problems of acidification persist, and are now complicated by the effects of climate change ( Schindler, 1997).

  16. Discovery of essential fatty acids

    PubMed Central

    Spector, Arthur A.; Kim, Hee-Yong

    2015-01-01

    Dietary fat was recognized as a good source of energy and fat-soluble vitamins by the first part of the 20th century, but fatty acids were not considered to be essential nutrients because they could be synthesized from dietary carbohydrate. This well-established view was challenged in 1929 by George and Mildred Burr who reported that dietary fatty acid was required to prevent a deficiency disease that occurred in rats fed a fat-free diet. They concluded that fatty acids were essential nutrients and showed that linoleic acid prevented the disease and is an essential fatty acid. The Burrs surmised that other unsaturated fatty acids were essential and subsequently demonstrated that linolenic acid, the omega-3 fatty acid analog of linoleic acid, is also an essential fatty acid. The discovery of essential fatty acids was a paradigm-changing finding, and it is now considered to be one of the landmark discoveries in lipid research. PMID:25339684

  17. Acid Rain, pH & Acidity: A Common Misinterpretation.

    ERIC Educational Resources Information Center

    Clark, David B.; Thompson, Ronald E.

    1989-01-01

    Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

  18. Amino-acid contamination of aqueous hydrochloric acid.

    NASA Technical Reports Server (NTRS)

    Wolman, Y.; Miller, S. L.

    1971-01-01

    Considerable amino-acid contamination in commercially available analytical grade hydrochloric acid (37% HCl) was found. One bottle contained 8,300 nmol of amino-acids per liter. A bottle from another supplier contained 6,700 nmol per liter. The contaminants were mostly protein amino-acids and several unknowns. Data on the volatility of the amino-acids during HCl distillation were also obtained.

  19. Domoic acid epileptic disease.

    PubMed

    Ramsdell, John S; Gulland, Frances M

    2014-03-01

    Domoic acid epileptic disease is characterized by spontaneous recurrent seizures weeks to months after domoic acid exposure. The potential for this disease was first recognized in a human case study of temporal lobe epilepsy after the 1987 amnesic shellfish-poisoning event in Quebec, and was characterized as a chronic epileptic syndrome in California sea lions through investigation of a series of domoic acid poisoning cases between 1998 and 2006. The sea lion study provided a breadth of insight into clinical presentations, unusual behaviors, brain pathology, and epidemiology. A rat model that replicates key observations of the chronic epileptic syndrome in sea lions has been applied to identify the progression of the epileptic disease state, its relationship to behavioral manifestations, and to define the neural systems involved in these behavioral disorders. Here, we present the concept of domoic acid epileptic disease as a delayed manifestation of domoic acid poisoning and review the state of knowledge for this disease state in affected humans and sea lions. We discuss causative mechanisms and neural underpinnings of disease maturation revealed by the rat model to present the concept for olfactory origin of an epileptic disease; triggered in dendodendritic synapases of the olfactory bulb and maturing in the olfactory cortex. We conclude with updated information on populations at risk, medical diagnosis, treatment, and prognosis. PMID:24663110

  20. Optical high acidity sensor

    SciTech Connect

    Jorgensen, B.S.; Nekimken, H.L.; Carey, W.P.; O`Rourke, P.E.

    1997-07-22

    An apparatus and method for determining acid concentrations in solutions having acid concentrations of from about 0.1 Molar to about 16 Molar is disclosed. The apparatus includes a chamber for interrogation of the sample solution, a fiber optic light source for passing light transversely through the chamber, a fiber optic collector for receiving the collimated light after transmission through the chamber, a coating of an acid resistant polymeric composition upon at least one fiber end or lens, the polymeric composition in contact with the sample solution within the chamber and having a detectable response to acid concentrations within the range of from about 0.1 Molar to about 16 Molar, a measurer for the response of the polymeric composition in contact with the sample solution, and a comparer of the measured response to predetermined standards whereby the acid molarity of the sample solution within the chamber can be determined. Preferably, a first lens is attached to the end of the fiber optic light source, the first lens adapted to collimate light from the fiber optic light source, and a second lens is attached to the end of the fiber optic collector for focusing the collimated light after transmission through the chamber. 10 figs.

  1. Optical high acidity sensor

    DOEpatents

    Jorgensen, Betty S.; Nekimken, Howard L.; Carey, W. Patrick; O'Rourke, Patrick E.

    1997-01-01

    An apparatus and method for determining acid concentrations in solutions having acid concentrations of from about 0.1 Molar to about 16 Molar is disclosed. The apparatus includes a chamber for interrogation of the sample solution, a fiber optic light source for passing light transversely through the chamber, a fiber optic collector for receiving the collimated light after transmission through the chamber, a coating of an acid resistant polymeric composition upon at least one fiber end or lens, the polymeric composition in contact with the sample solution within the chamber and having a detectable response to acid concentrations within the range of from about 0.1 Molar to about 16 Molar, a measurer for the response of the polymeric composition in contact with the sample solution, and, a comparer of the measured response to predetermined standards whereby the acid molarity of the sample solution within the chamber can be determined. Preferably, a first lens is attached to the end of the fiber optic light source, the first lens adapted to collimate light from the fiber optic light source, and a second lens is attached to the end of the fiber optic collector for focusing the collimated light after transmission through the chamber.

  2. Domoic Acid Epileptic Disease

    PubMed Central

    Ramsdell, John S.; Gulland, Frances M.

    2014-01-01

    Domoic acid epileptic disease is characterized by spontaneous recurrent seizures weeks to months after domoic acid exposure. The potential for this disease was first recognized in a human case study of temporal lobe epilepsy after the 1987 amnesic shellfish-poisoning event in Quebec, and was characterized as a chronic epileptic syndrome in California sea lions through investigation of a series of domoic acid poisoning cases between 1998 and 2006. The sea lion study provided a breadth of insight into clinical presentations, unusual behaviors, brain pathology, and epidemiology. A rat model that replicates key observations of the chronic epileptic syndrome in sea lions has been applied to identify the progression of the epileptic disease state, its relationship to behavioral manifestations, and to define the neural systems involved in these behavioral disorders. Here, we present the concept of domoic acid epileptic disease as a delayed manifestation of domoic acid poisoning and review the state of knowledge for this disease state in affected humans and sea lions. We discuss causative mechanisms and neural underpinnings of disease maturation revealed by the rat model to present the concept for olfactory origin of an epileptic disease; triggered in dendodendritic synapases of the olfactory bulb and maturing in the olfactory cortex. We conclude with updated information on populations at risk, medical diagnosis, treatment, and prognosis. PMID:24663110

  3. Pelargonic acid weed control parameters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Producers and researchers are interested in pelargonic acid (nonanoic acid) as a broad-spectrum post-emergence or burn-down herbicide. Pelargonic acid is a fatty acid naturally occurring in many plants and animals, and present in many foods we consume. The objective of this research was to determine...

  4. Corrosion inhibitors used in acidizing

    SciTech Connect

    Cizek, A. . Aquaness Chemical Division)

    1994-01-01

    The history of the development of oil well acidizing and acid corrosion inhibitors used by this industry is reviewed. As deeper and hotter wells were drilled, stimulation acids were exposed to hotter conditions and the organic inhibitors required intensifiers. High-temperature acid corrosion inhibitors are also discussed.

  5. A Demonstration of Acid Rain

    ERIC Educational Resources Information Center

    Fong, Man Wai

    2004-01-01

    A demonstration showing acid rain formation is described. Oxides of sulfur and nitrogen that result from the burning of fossil fuels are the major pollutants of acid rain. In this demonstration, SO[subscript 2] gas is produced by the burning of matches. An acid-base indicator will show that the dissolved gas turns an aqueous solution acidic.

  6. The biosynthesis of ricinoleic acid

    PubMed Central

    James, A. T.; Hadaway, H. C.; Webb, Joan P. W.

    1965-01-01

    1. Ricinoleic acid is shown to be synthesized in the immature castor bean seed only after 3–4 weeks from the time of fertilization. 2. Synthesis occurs both in the isolated embryo and the endosperm. 3. Linoleic acid does not act as precursor of ricinoleic acid in the isolated bean embryo. 4. Oleic acid is shown to be the direct precursor of ricinoleic acid. 5. The reaction does not use molecular oxygen. This suggests that ricinoleic acid is not a precursor of linoleic acid. PMID:14340094

  7. Polyfluorinated Compounds: Past, Present, and Future

    EPA Science Inventory

    Interest and concern about polyfluorinated compounds (PFCs), such as perfluorooctane sulfonate (PFOS), erfluorooctanoic acid (PFOA), and an increasing number of other related compounds is growing as more is learned about these ubiquitous anthropogenic substances. Many of these co...

  8. Determination of Perfluorinated Compounds in the Upper Mississippi River Basin

    EPA Science Inventory

    Despite ongoing efforts to develop robust analytical methods for the determination of perfluorinated compounds (PFCs) such as perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) in surface water, comparatively little has been published on method performance, and the...

  9. Application of WWTP Biosolids and Resulting Perfluorinated Compound Contamination of Surface and Well Water in Decatur, Alabama, USA

    EPA Science Inventory

    Perfluorinated chemicals (PFCs) such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been produced and used in a wide range of industrial and consumer products for many decades. Their resistance to degradation has led to their widespread distribution in...

  10. REGULATORY ACTIONS - COMMUNITY RIGHT TO KNOW - PERFLUORINATED COMPOUNDS (PFCS)

    EPA Science Inventory

    Increasing worldwide attention is being focused on a group of persistent organic pollutants known as the perfluorinated compounds (PFCs). This class of compounds includes the now well known perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), but it also includes ...

  11. Multi-Platform Metabolomic Analyses of Rat Urine Following Exposure to Perfluorinated Chemicals (PFCs)

    EPA Science Inventory

    Perfluorinated chemicals (PFCs), namely perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), represent an emerging class of persistent and bioaccumulative compounds. Global occurrence of these fluorochemicals, coupled with probable human exposure, has prompted inv...

  12. Determination of Ten Perfluorinated Compounds in Bluegill Sunfish (Lepomis macrochirus) Fillets

    EPA Science Inventory

    Limited information is known about the environmental distributions of the perfluorinated compounds (PFCs) such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), in part due to a lack of well characterized analytical methods that can be used to accurately mea...

  13. Oleanolic acid ethanol monosolvate

    PubMed Central

    Froelich, Anna; Gzella, Andrzej K.

    2010-01-01

    Crystals of the title compound (systematic name: 3β-hy­droxy­olean-12-en-28-oic acid ethanol monosolvate), C30H48O3·C2H5OH, were obtained from unsuccessful co-crystallization trials. The asymmetric unit contains two symmetry-independent oleanolic acid mol­ecules, as well as two ethanol solvent mol­ecules. Inter­molecular O—H⋯O hydrogen bonds stabilize the crystal packing. In the oleanolic acid mol­ecules, ring C has a slightly distorted envelope conformation, while rings A, B, D and E adopt chair conformations and rings D and E are cis-fused. Both independent ethanol mol­ecules are orientationally disordered [occupancy ratios of 0.742 (8):0.258 (8) and 0.632 (12):0.368 (12). PMID:21588987

  14. Acid rain in Asia

    NASA Astrophysics Data System (ADS)

    Bhatti, Neeloo; Streets, David G.; Foell, Wesley K.

    1992-07-01

    Acid rain has been an issue of great concern in North America and Europe during the past several decades. However, due to the passage of a number of recent regulations, most notably the Clean Air Act in the United States in 1990, there is an emerging perception that the problem in these Western nations is nearing solution. The situation in the developing world, particularly in Asia, is much bleaker. Given the policies of many Asian nations to achieve levels of development comparable with the industrialized world—which necessitate a significant expansion of energy consumption (most derived from indigenous coal reserves)—the potential for the formation of, and damage from, acid deposition in these developing countries is very high. This article delineates and assesses the emissions patterns, meteorology, physical geology, and biological and cultural resources present in various Asian nations. Based on this analysis and the risk factors to acidification, it is concluded that a number of areas in Asia are currently vulnerable to acid rain. These regions include Japan, North and South Korea, southern China, and the mountainous portions of Southeast Asia and southwestern India. Furthermore, with accelerated development (and its attendant increase in energy use and production of emissions of acid deposition precursors) in many nations of Asia, it is likely that other regions will also be affected by acidification in the near future. Based on the results of this overview, it is clear that acid deposition has significant potential to impact the Asian region. However, empirical evidence is urgently needed to confirm this and to provide early warning of increases in the magnitude and spread of acid deposition and its effects throughout this part of the world.

  15. Ethylenediaminetetraacetic acid in endodontics.

    PubMed

    Mohammadi, Zahed; Shalavi, Sousan; Jafarzadeh, Hamid

    2013-09-01

    Ethylenediaminetetraacetic acid (EDTA) is a chelating agent can bind to metals via four carboxylate and two amine groups. It is a polyamino carboxylic acid and a colorless, water-soluble solid, which is widely used to dissolve lime scale. It is produced as several salts, notably disodium EDTA and calcium disodium EDTA. EDTA reacts with the calcium ions in dentine and forms soluble calcium chelates. A review of the literature and a discussion of the different indications and considerations for its usage are presented. PMID:24966721

  16. NITRIC ACID PICKLING PROCESS

    DOEpatents

    Boller, E.R.; Eubank, L.D.

    1958-08-19

    An improved process is described for the treatment of metallic uranium surfaces preparatory to being given hot dip coatings. The process consists in first pickling the uraniunn surInce with aqueous 50% to 70% nitric acid, at 60 to 70 deg C, for about 5 minutes, rinsing the acid solution from the uranium article, promptly drying and then passing it through a molten alkali-metal halide flux consisting of 42% LiCl, 53% KCla and 5% NaCl into a molten metal bath consisting of 85 parts by weight of zinc and 15 parts by weight of aluminum

  17. The Acid-Base Titration of a Very Weak Acid: Boric Acid

    ERIC Educational Resources Information Center

    Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.

    2012-01-01

    A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the

  18. The Acid-Base Titration of a Very Weak Acid: Boric Acid

    ERIC Educational Resources Information Center

    Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.

    2012-01-01

    A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the…

  19. Comparison of Buffer Effect of Different Acids During Sandstone Acidizing

    NASA Astrophysics Data System (ADS)

    Umer Shafiq, Mian; Khaled Ben Mahmud, Hisham; Hamid, Mohamed Ali

    2015-04-01

    The most important concern of sandstone matrix acidizing is to increase the formation permeability by removing the silica particles. To accomplish this, the mud acid (HF: HCl) has been utilized successfully for many years to stimulate the sandstone formations, but still it has many complexities. This paper presents the results of laboratory investigations of different acid combinations (HF: HCl, HF: H3PO4 and HF: HCOOH). Hydrofluoric acid and fluoboric acid are used to dissolve clays and feldspar. Phosphoric and formic acids are added as a buffer to maintain the pH of the solution; also it allows the maximum penetration of acid into the core sample. Different tests have been performed on the core samples before and after the acidizing to do the comparative study on the buffer effect of these acids. The analysis consists of permeability, porosity, color change and pH value tests. There is more increase in permeability and porosity while less change in pH when phosphoric and formic acids were used compared to mud acid. From these results it has been found that the buffer effect of phosphoric acid and formic acid is better than hydrochloric acid.

  20. In vitro evaluation of the immunotoxic potential of perfluorinated compounds (PFCs)

    SciTech Connect

    Corsini, Emanuela; Avogadro, Anna; Galbiati, Valentina; Dell'Agli, Mario; Marinovich, Marina; Galli, Corrado L.; Germolec, Dori R.

    2011-01-15

    There is evidence from both epidemiology and laboratory studies that perfluorinated compounds may be immunotoxic, affecting both cell-mediated and humoral immunity. The overall goal of this study was to investigate the mechanisms underlying the immunotoxic effects of perfluorooctane sulfonate (PFOS) and perfluorooctane acid (PFOA), using in vitro assays. The release of the pro-inflammatory cytokines IL-6, IL-8, and TNF-{alpha} was evaluated in lipolysaccharide (LPS)-stimulated human peripheral blood leukocytes and in the human promyelocytic cell line THP-1, while the release of IL-4, IL-10 and IFN-{gamma} was evaluated in phytohaemagglutinin (PHA)-stimulated peripheral blood leukocytes. PFOA and PFOS suppressed LPS-induced TNF-{alpha} production in primary human cultures and THP-1 cells, while IL-8 was suppressed only in THP-1 cells. IL-6 release was decreased only by PFOS. Both PFOA and PFOS decreased T-cell derived, PHA-induced IL-4 and IL-10 release, while IFN-{gamma} release was affected only by PFOS. In all instances, PFOS was more potent than PFOA. Mechanistic investigations carried out in THP-1 cells demonstrated that the effect on cytokine release was pre-transcriptional, as assessed by a reduction in LPS-induced TNF-{alpha} mRNA expression. Using siRNA, a role for PPAR-{alpha} could be demonstrated for PFOA-induced immunotoxicity, while an inhibitory effect on LPS-induced I-{kappa}B degradation could explain the immunomodulatory effect of PFOS. The dissimilar role of PPAR-{alpha} in PFOA and PFOS-induced immunotoxicity was consistent with the differing effects observed on LPS-induced MMP-9 release: PFOA, as the PPAR-{alpha} agonist fenofibrate, modulated the release, while PFOS had no effect. Overall, these studies suggest that PFCs directly suppress cytokine secretion by immune cells, and that PFOA and PFOS have different mechanisms of action.

  1. [Studies on interaction of acid-treated nanotube titanic acid and amino acids].

    PubMed

    Zhang, Huqin; Chen, Xuemei; Jin, Zhensheng; Liao, Guangxi; Wu, Xiaoming; Du, Jianqiang; Cao, Xiang

    2010-06-01

    Nanotube titanic acid (NTA) has distinct optical and electrical character, and has photocatalysis character. In accordance with these qualities, NTA was treated with acid so as to enhance its surface activity. Surface structures and surface groups of acid-treated NTA were characterized and analyzed by Transmission Electron Microscope (TEM) and Fourier Transform Infrared Spectrometry (FT-IR). The interaction between acid-treated NTA and amino acids was investigated. Analysis results showed that the lengths of acid-treated NTA became obviously shorter. The diameters of nanotube bundles did not change obviously with acid-treating. Meanwhile, the surface of acid-treated NTA was cross-linked with carboxyl or esterfunction. In addition, acid-treated NTA can catch amino acid residues easily, and then form close combination. PMID:20649031

  2. Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

    1992-01-01

    Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

  3. A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

    SciTech Connect

    Arceo, Elena; Ellman, Jonathan; Bergman, Robert

    2010-05-03

    An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

  4. Docosahexaenoic acid and lactation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Docosahexaenoic acid (DHA) is an important component of membrane phospholipids in the retina, and brain, and accumulates rapidly in these tissues during early infancy. DHA is present in human milk, but the amount varies considerably and is largely dependent on maternal diet. This article reviews dat...

  5. Water surface is acidic

    PubMed Central

    Buch, Victoria; Milet, Anne; Vácha, Robert; Jungwirth, Pavel; Devlin, J. Paul

    2007-01-01

    Water autoionization reaction 2H2O → H3O− + OH− is a textbook process of basic importance, resulting in pH = 7 for pure water. However, pH of pure water surface is shown to be significantly lower, the reduction being caused by proton stabilization at the surface. The evidence presented here includes ab initio and classical molecular dynamics simulations of water slabs with solvated H3O+ and OH− ions, density functional studies of (H2O)48H+ clusters, and spectroscopic isotopic-exchange data for D2O substitutional impurities at the surface and in the interior of ice nanocrystals. Because H3O+ does, but OH− does not, display preference for surface sites, the H2O surface is predicted to be acidic with pH < 4.8. For similar reasons, the strength of some weak acids, such as carbonic acid, is expected to increase at the surface. Enhanced surface acidity can have a significant impact on aqueous surface chemistry, e.g., in the atmosphere. PMID:17452650

  6. The Acid Rain Debate.

    ERIC Educational Resources Information Center

    Bybee, Rodger; And Others

    1984-01-01

    Describes an activity which provides opportunities for role-playing as industrialists, ecologists, and government officials. The activity involves forming an international commission on acid rain, taking testimony, and, based on the testimony, making recommendations to governments on specific ways to solve the problem. Includes suggestions for

  7. The Acid Rain Game.

    ERIC Educational Resources Information Center

    Rakow, Steven J.; Glenn, Allen

    1982-01-01

    Provides rationale for and description of an acid rain game (designed for two players), a problem-solving model for elementary students. Although complete instructions are provided, including a copy of the game board, the game is also available for Apple II microcomputers. Information for the computer program is available from the author.

  8. Acid rain bibliography

    SciTech Connect

    Sayers, C.S.

    1983-09-01

    This bibliography identifies 900 citations on various aspects of Acid Rain, covering published bibliographies, books, reports, conference and symposium proceedings, audio visual materials, pamphlets and newsletters. It includes five sections: citations index (complete record of author, title, source, order number); KWIC index; title index; author index; and source index. 900 references.

  9. The Acid Rain Debate.

    ERIC Educational Resources Information Center

    Bybee, Rodger; And Others

    1984-01-01

    Describes an activity which provides opportunities for role-playing as industrialists, ecologists, and government officials. The activity involves forming an international commission on acid rain, taking testimony, and, based on the testimony, making recommendations to governments on specific ways to solve the problem. Includes suggestions for…

  10. The Acid Rain Game.

    ERIC Educational Resources Information Center

    Rakow, Steven J.; Glenn, Allen

    1982-01-01

    Provides rationale for and description of an acid rain game (designed for two players), a problem-solving model for elementary students. Although complete instructions are provided, including a copy of the game board, the game is also available for Apple II microcomputers. Information for the computer program is available from the author.…

  11. The Acid Rain Debate.

    ERIC Educational Resources Information Center

    Oates-Bockenstedt, Catherine

    1997-01-01

    Details an activity designed to motivate students by incorporating science-related issues into a classroom debate. Includes "The Acid Rain Bill" and "Position Guides" for student roles as committee members, consumers, governors, industry owners, tourism professionals, senators, and debate directors. (DKM)

  12. Acid Rain Investigations.

    ERIC Educational Resources Information Center

    Hugo, John C.

    1992-01-01

    Presents an activity in which students investigate the formation of solid ammonium chloride aerosol particles to help students better understand the concept of acid rain. Provides activity objectives, procedures, sample data, clean-up instructions, and questions and answers to help interpret the data. (MDH)

  13. Acid Rain Classroom Projects.

    ERIC Educational Resources Information Center

    Demchik, Michael J.

    2000-01-01

    Describes a curriculum plan in which students learn about acid rain through instructional media, research and class presentations, lab activities, simulations, design, and design implementation. Describes the simulation activity in detail and includes materials, procedures, instructions, examples, results, and discussion sections. (SAH)

  14. Acid Rain: Science Projects.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.

    1989-01-01

    Presented is a science activity designed to help students monitor the pH of rainfall. Materials, procedures and follow-up activities are listed. A list of domestic and foreign sources of information is provided. Topics which relate to acid precipitation are outlined. (CW)

  15. Plant fatty acid hydroxylase

    SciTech Connect

    Somerville, C.; Loo, F. van de

    2000-02-22

    The present invention relates to the identification of nucleic acid sequences and constructs, and methods related to the use of these sequences and constructs to produce genetically modified plants for the purpose of altering the composition of plant oils, waxes and related compounds.

  16. Uric Acid Test

    MedlinePlus

    ... services. Advertising & Sponsorship: Policy | Opportunities PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and ... page helpful? Also known as: Serum Urate; UA Formal name: Uric Acid Related tests: Synovial Fluid Analysis , Kidney Stone Analysis , Kidney Stone Risk Panel At ...

  17. Folic Acid Quiz

    MedlinePlus

    ... half of all the pregnancies in the United States are unplanned. Remember, neural tube defects occur before many women know that they are pregnant. Close × Answer: A CORRECT: While it's important to eat a healthy diet, the EASIEST way to get the right amount of folic acid everyday is to take ...

  18. ACID AEROSOL MEASUREMENT WORKSHOP

    EPA Science Inventory

    This report documents the discussion and results of the U.S. EPA Acid Aerosol Measurement Workshop, conducted February 1-3, 1989, in Research Triangle Park, North Carolina. t was held in response to recommendations by the Clean Air Scientific Advisory Committee (CASAC) regarding ...

  19. Lake and Stream Acidity

    EPA Science Inventory

    This indicator presents trends in the percentage of lakes and streams in selected regions in the Northeast and mid-Atlantic states that have been considered chronically acidic between 1987 and 2007. This information describes how the extent of acidification, a serious danger t...

  20. Mefenamic acid enteropathy.

    PubMed Central

    Isaacs, P E; Sladen, G E; Filipe, I

    1987-01-01

    The clinical, radiological, and histological features of two patients with severe intestinal damage induced by mefenamic acid and mimicking coeliac disease are described. Symptoms rapidly reverted on withdrawal of the drug, and in one case, did not relapse during treatment with other non-steroidal anti-inflammatory drugs. Images Fig 3 Fig 4 Fig 1 Fig 2 Fig 5 Fig 6 PMID:3680546

  1. Spermatotoxicity of dichloroacetic acid

    EPA Science Inventory

    The testicular toxicity of dichloroacetic acid (DCA), a disinfection byproduct of drinking water, was evaluated in adult male rats given both single and multiple (up to 14 d) oral doses. Delayed spermiation and altered resorption of residual bodies were observed in rats given sin...

  2. Plant fatty acid hydroxylase

    DOEpatents

    Somerville, Chris; van de Loo, Frank

    2000-01-01

    The present invention relates to the identification of nucleic acid sequences and constructs, and methods related thereto, and the use of these sequences and constructs to produce genetically modified plants for the purpose of altering the composition of plant oils, waxes and related compounds.

  3. Synthesis of acid addition salt of delta-aminolevulinic acid from 5-bromo levulinic acid esters

    DOEpatents

    Moens, Luc

    2003-06-24

    A process of preparing an acid addition salt of delta-aminolevulinc acid comprising: a) dissolving a lower alkyl 5-bromolevulinate and hexamethylenetetramine in a solvent selected from the group consisting of water, ethyl acetate, chloroform, acetone, ethanol, tetrahydrofuran and acetonitrile, to form a quaternary ammonium salt of the lower alkyl 5-bromolevulinate; and b) hydrolyzing the quaternary ammonium salt with an inorganic acid to form an acid addition salt of delta-aminolevulinic acid.

  4. Effects of acidic precipitation and acidity on soil microbial processes

    SciTech Connect

    Francis, A.J.

    1981-01-01

    Effects of oil acidity on microbial decomposition of organic matter and transformation of nitrogen in an acid forest soil were investigated. In the oak-leaf-amended pH-adjusted acid soils, CO/sub 2/ production in 14- and 150-day preincubated samples decreased by about 6 and 37%, respectively. In the control (unamended) acidified soils, reductions in CO/sub 2/ production of 14% in 14-day preincubated samples and 52% in 150-day samples were observed. Ammonia formation in the pH-adjusted acid soil was about 50% less than in the naturally acid soil. Increased rates of ammonification and nitrification were observed in the pH-adjusted neutral soil. Little autotrophic and heterotrophic nitrifying activity was detected in naturally acid and acidified forest soils. The rate of denitrification was rather slow in acid soils, and at greater acidities N/sub 2/O was the predominant end product. The abundance of nitrogen-fixing free-living bacteria was very low in acidic and acidified forest soils, and nitrogen gains by asymbiotic bacterial fixation in an acid forest ecosystem may be insignificant. These results suggest that further acidification of acid forest soils by addition of sulfuric acid or by acid precipitation may lead to significant reductions in the leaf litter decomposition, ammonification, nitrification, and denitrification and thus reduce nutrient recycling in the forest ecosystem.

  5. Fatty acid-producing hosts

    SciTech Connect

    Pfleger, Brian F; Lennen, Rebecca M

    2013-12-31

    Described are hosts for overproducing a fatty acid product such as a fatty acid. The hosts include an exogenous nucleic acid encoding a thioesterase and, optionally, an exogenous nucleic acid encoding an acetyl-CoA carboxylase, wherein an acyl-CoA synthetase in the hosts are functionally delected. The hosts prefereably include the nucleic acid encoding the thioesterase at an intermediate copy number. The hosts are preferably recominantly stable and growth-competent at 37.degree. C. Methods of producing a fatty acid product comprising culturing such hosts at 37.degree. C. are also described.

  6. Acid Earth--The Global Threat of Acid Pollution.

    ERIC Educational Resources Information Center

    McCormick, John

    Acid pollution is a major international problem, but the debate it has elicited has often clouded the distinction between myth and facts. This publication attempts to concerning the acid pollution situation. This publication attempts to identify available facts. It is the first global review of the problem of acid pollution and the first to…

  7. SPECTROFLUOROMETRIC ASSAY FOR HYPOHALITE AND PEROXYACETIC ACID USING KOJIC ACID

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hypochlorite reacted with kojic acid to form an intensely fluorescent product with excitation and emission wavelengths at 395 and 495 nm, respectively. Hypobromite, generated by reaction of hypochlorite or peroxyacetic acid with NaBr, also reacted with kojic acid to generate an identical fluorescen...

  8. Acid Earth--The Global Threat of Acid Pollution.

    ERIC Educational Resources Information Center

    McCormick, John

    Acid pollution is a major international problem, but the debate it has elicited has often clouded the distinction between myth and facts. This publication attempts to concerning the acid pollution situation. This publication attempts to identify available facts. It is the first global review of the problem of acid pollution and the first to

  9. Circulating folic acid in plasma: relation to folic acid fortification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The implementation of folic acid fortification in the United States has resulted in unprecedented amounts of this synthetic form of folate in the American diet. Folic acid in circulation may be a useful measure of physiologic exposure to synthetic folic acid, and there is a potential for elevated co...

  10. NAPAP (National Acid Precipitation Assessment Program) results on acid rain

    SciTech Connect

    Not Available

    1990-06-01

    The National Acid Precipitation Assessment Program (NAPAP) was mandated by Congress in 1980 to study the effects of acid rain. The results of 10 years of research on the effect of acid deposition and ozone on forests, particularly high elevation spruce and fir, southern pines, eastern hardwoods and western conifers, will be published this year.

  11. College Chemistry Students' Mental Models of Acids and Acid Strength

    ERIC Educational Resources Information Center

    McClary, LaKeisha; Talanquer, Vicente

    2011-01-01

    The central goal of this study was to characterize the mental models of acids and acid strength expressed by advanced college chemistry students when engaged in prediction, explanation, and justification tasks that asked them to rank chemical compounds based on their relative acid strength. For that purpose we completed a qualitative research…

  12. (Radioiodinated free fatty acids)

    SciTech Connect

    Knapp, Jr., F. F.

    1987-12-11

    The traveler participated in the Second International Workshop on Radioiodinated Free Fatty Acids in Amsterdam, The Netherlands where he presented an invited paper describing the pioneering work at the Oak Ridge National Laboratory (ORNL) involving the design, development and testing of new radioiodinated methyl-branched fatty acids for evaluation of heart disease. He also chaired a technical session on the testing of new agents in various in vitro and in vivo systems. He also visited the Institute for Clinical and Experimental Nuclear Medicine in Bonn, West Germany, to review, discuss, plan and coordinate collaborative investigations with that institution. In addition, he visited the Cyclotron Research Center in Liege, Belgium, to discuss continuing collaborative studies with the Osmium-191/Iridium-191m radionuclide generator system, and to complete manuscripts and plan future studies.

  13. Perfluorooctanoic acid and environmental risks

    EPA Science Inventory

    Perfluorooctanoic acid (PFOA) is a member of the perfluoroalkyl acids (PFAA) family of chemicals, which consist of a carbon backbone typically four to fourteen carbons in length and a charged functional moiety.

  14. Immunomodulatory spherical nucleic acids.

    PubMed

    Radovic-Moreno, Aleksandar F; Chernyak, Natalia; Mader, Christopher C; Nallagatla, Subbarao; Kang, Richard S; Hao, Liangliang; Walker, David A; Halo, Tiffany L; Merkel, Timothy J; Rische, Clayton H; Anantatmula, Sagar; Burkhart, Merideth; Mirkin, Chad A; Gryaznov, Sergei M

    2015-03-31

    Immunomodulatory nucleic acids have extraordinary promise for treating disease, yet clinical progress has been limited by a lack of tools to safely increase activity in patients. Immunomodulatory nucleic acids act by agonizing or antagonizing endosomal toll-like receptors (TLR3, TLR7/8, and TLR9), proteins involved in innate immune signaling. Immunomodulatory spherical nucleic acids (SNAs) that stimulate (immunostimulatory, IS-SNA) or regulate (immunoregulatory, IR-SNA) immunity by engaging TLRs have been designed, synthesized, and characterized. Compared with free oligonucleotides, IS-SNAs exhibit up to 80-fold increases in potency, 700-fold higher antibody titers, 400-fold higher cellular responses to a model antigen, and improved treatment of mice with lymphomas. IR-SNAs exhibit up to eightfold increases in potency and 30% greater reduction in fibrosis score in mice with nonalcoholic steatohepatitis (NASH). Given the clinical potential of SNAs due to their potency, defined chemical nature, and good tolerability, SNAs are attractive new modalities for developing immunotherapies. PMID:25775582

  15. Acid rain: Reign of controversy

    SciTech Connect

    Kahan, A.M.

    1986-01-01

    Acid Rain is a primer on the science and politics of acid rain. Several introductory chapters describe in simple terms the relevant principles of water chemistry, soil chemistry, and plant physiology and discuss the demonstrated or postulated effects of acid rain on fresh waters and forests as well as on statuary and other exposed objects. There follow discussions on the economic and social implications of acid rain (for example, possible health effects) and on the sources, transport, and distribution of air pollutants.

  16. Protonation Equilibrium of 4-Substituted Benzohydroxamic Acids in Mineral Acids.

    PubMed

    Ghosh, Kallol K.; Tamrakar, Pankaj; Rajput, Surendra K.

    1999-04-30

    The protonation equilibria of some 4-substituted benzohydroxamic acids 4-X(C(6)H(4)CONHOH) (X = H, OMe, Cl) have been investigated in aqueous sulfuric, perchloric, and hydrochloric acids at 25 degrees C UV spectrophotometrically. The Hammett acidity function method, the Bunnett-Olsen method, Cox-Yates excess acidity function method, and Marziano-Cimino-Passerini method have been compared in order to rationalize the differences observed between pK(BH)()+ values determined by each method. An attempt has been made to apply multivariate analysis to separate the effect of protonation from the medium effect for benzohydroxamic acid. PMID:11674401

  17. Carboxylic acid sorption regeneration process

    DOEpatents

    King, C.J.; Poole, L.J.

    1995-05-02

    Carboxylic acids are sorbed from aqueous feedstocks into an organic liquid phase or onto a solid adsorbent. The acids are freed from the sorbent phase by treating it with aqueous alkylamine thus forming an alkylammonium carboxylate which is dewatered and decomposed to the desired carboxylic acid and the alkylamine. 10 figs.

  18. Carboxylic acid sorption regeneration process

    DOEpatents

    King, C. Judson; Poole, Loree J.

    1995-01-01

    Carboxylic acids are sorbed from aqueous feedstocks into an organic liquid phase or onto a solid adsorbent. The acids are freed from the sorbent phase by treating it with aqueous alkylamine thus forming an alkylammonium carboxylate which is dewatered and decomposed to the desired carboxylic acid and the alkylamine.

  19. An Umbrella for Acid Rain.

    ERIC Educational Resources Information Center

    Randal, Judith

    1979-01-01

    The Environmental Protection Agency has awarded several grants to study effects of and possible solutions to the problem of "acid rain"; pollution from atmospheric nitric and sulfuric acids. The research program is administered through North Carolina State University at Raleigh and will focus on biological effects of acid rain. (JMF)

  20. Oxy acids of halogens HOHal

    NASA Astrophysics Data System (ADS)

    Nikitin, Igor V.

    2004-06-01

    The key methods for the synthesis of the acids HOF, HOCl, HOBr and HOI are considered. The results of investigations of the structures and properties of these acids are described. Possible participation of the HOHal acids in the destruction of stratospheric ozone is discussed.

  1. Scientists Puzzle Over Acid Rain

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1975

    1975-01-01

    Reports on a growing concern over increased acidity in atmospheric percipitation. Explores possible causes of the increased acidity, identifies chemical components of precipitation in various parts of the world, and presents environmental changes that might be attributed to the acidity. (GS)

  2. Pantothenic acid biosynthesis in zymomonas

    DOEpatents

    Tao, Luan; Tomb, Jean-Francois; Viitanen, Paul V.

    2014-07-01

    Zymomonas is unable to synthesize pantothenic acid and requires this essential vitamin in growth medium. Zymomonas strains transformed with an operon for expression of 2-dehydropantoate reductase and aspartate 1-decarboxylase were able to grow in medium lacking pantothenic acid. These strains may be used for ethanol production without pantothenic acid supplementation in seed culture and fermentation media.

  3. Biological effects of transfatty acids.

    PubMed

    Kaunitz, H

    1976-03-01

    Transfatty acids are geometrical isomers of the naturally occurring cis-fatty acids, and their molecular configuration is more like that of the corresponding saturated fatty acid. In view of the large amounts of trans-acids in commercially prepared margarines, metabolic studies with trans-acids have received a great deal of attention. Although there are differences in the absorption and digestion of trans-acids and although considerable amounts are deposited in various tissues, no definite signs of toxicity have been observed. An important finding is the increased requirement for essential fatty acids in animals fed high levels of trans-acids. In recent work carried out in Kummerow's laboratory, aortic lesions were found in swine fed large amounts of trans-acids. Evaluation of the data suggests that factors other than trans-acids, per se, may have been responsible for the occurrence of the lesions. As yet, there does not seem to be any valid reason why trans-acids should be excluded from the diet as long as their intake is associated with a high enough level of essential fatty acids in the diet. PMID:960788

  4. Regulation of bile acid synthesis.

    PubMed

    Chiang, J Y

    1998-02-15

    Bile acids are important physiological agents required for disposal of cholesterol and absorption of vitamins and fats. Bile acids are synthesized from cholesterol in the liver. Enterohepatic circulation of bile acids is very efficient and plays an important physiological role in lipid absorption and secretion, and regulation of bile acid biosynthesis and cholesterol homeostasis. Conversion of cholesterol to bile acids requires 15 different enzymatic steps. Four cytochrome P450 enzymes play important roles in bile acid biosynthesis. The classic bile acid biosynthesis pathway starts with modification of the sterol ring and followed by side chain cleavage reactions to synthesize cholic acid (CA) and chenodeoxycholic acid (CDCA), the primary bile acids in most species. The first and rate-limiting enzyme in this pathway is cholesterol 7alpha -hydroxylase, a microsomal cytochrome P450, CYP7A. Another microsomal cytochrome P450 sterol 12alpha-hydroxylase (CYP12) is required for the synthesis of cholic acid. Mitochondrial cytochrome P450 sterol 27-hydroxylase (CYP27) catalyzes sterol side chain oxidation to convert C27 sterol to C24 bile acids. An alternative bile acid biosynthesis pathway (acidic) has been known for sometime but only recently has attracted much attention. In this pathway, side chain oxidation precedes modification of the sterol ring. Mitochondrial sterol 27-hydroxylase (CYP27) catalyzes the first reaction and followed by 7alpha-hydroxylation catalyzed by a microsomal oxysterol 7alpha-hydroxylase (CYP7B). Recent advances in purification and cloning of these major enzymes in the pathways have led to better understanding the molecular basis of regulation of bile acid synthesis and physiological role of the alternative pathways. PMID:9450986

  5. Composition for nucleic acid sequencing

    DOEpatents

    Korlach, Jonas; Webb, Watt W.; Levene, Michael; Turner, Stephen; Craighead, Harold G.; Foquet, Mathieu

    2008-08-26

    The present invention is directed to a method of sequencing a target nucleic acid molecule having a plurality of bases. In its principle, the temporal order of base additions during the polymerization reaction is measured on a molecule of nucleic acid, i.e. the activity of a nucleic acid polymerizing enzyme on the template nucleic acid molecule to be sequenced is followed in real time. The sequence is deduced by identifying which base is being incorporated into the growing complementary strand of the target nucleic acid by the catalytic activity of the nucleic acid polymerizing enzyme at each step in the sequence of base additions. A polymerase on the target nucleic acid molecule complex is provided in a position suitable to move along the target nucleic acid molecule and extend the oligonucleotide primer at an active site. A plurality of labelled types of nucleotide analogs are provided proximate to the active site, with each distinguishable type of nucleotide analog being complementary to a different nucleotide in the target nucleic acid sequence. The growing nucleic acid strand is extended by using the polymerase to add a nucleotide analog to the nucleic acid strand at the active site, where the nucleotide analog being added is complementary to the nucleotide of the target nucleic acid at the active site. The nucleotide analog added to the oligonucleotide primer as a result of the polymerizing step is identified. The steps of providing labelled nucleotide analogs, polymerizing the growing nucleic acid strand, and identifying the added nucleotide analog are repeated so that the nucleic acid strand is further extended and the sequence of the target nucleic acid is determined.

  6. Evolution of rosmarinic acid biosynthesis.

    PubMed

    Petersen, Maike; Abdullah, Yana; Benner, Johannes; Eberle, David; Gehlen, Katja; Hücherig, Stephanie; Janiak, Verena; Kim, Kyung Hee; Sander, Marion; Weitzel, Corinna; Wolters, Stefan

    2009-01-01

    Rosmarinic acid and chlorogenic acid are caffeic acid esters widely found in the plant kingdom and presumably accumulated as defense compounds. In a survey, more than 240 plant species have been screened for the presence of rosmarinic and chlorogenic acids. Several rosmarinic acid-containing species have been detected. The rosmarinic acid accumulation in species of the Marantaceae has not been known before. Rosmarinic acid is found in hornworts, in the fern family Blechnaceae and in species of several orders of mono- and dicotyledonous angiosperms. The biosyntheses of caffeoylshikimate, chlorogenic acid and rosmarinic acid use 4-coumaroyl-CoA from the general phenylpropanoid pathway as hydroxycinnamoyl donor. The hydroxycinnamoyl acceptor substrate comes from the shikimate pathway: shikimic acid, quinic acid and hydroxyphenyllactic acid derived from l-tyrosine. Similar steps are involved in the biosyntheses of rosmarinic, chlorogenic and caffeoylshikimic acids: the transfer of the 4-coumaroyl moiety to an acceptor molecule by a hydroxycinnamoyltransferase from the BAHD acyltransferase family and the meta-hydroxylation of the 4-coumaroyl moiety in the ester by a cytochrome P450 monooxygenase from the CYP98A family. The hydroxycinnamoyltransferases as well as the meta-hydroxylases show high sequence similarities and thus seem to be closely related. The hydroxycinnamoyltransferase and CYP98A14 from Coleus blumei (Lamiaceae) are nevertheless specific for substrates involved in RA biosynthesis showing an evolutionary diversification in phenolic ester metabolism. Our current view is that only a few enzymes had to be "invented" for rosmarinic acid biosynthesis probably on the basis of genes needed for the formation of chlorogenic and caffeoylshikimic acid while further biosynthetic steps might have been recruited from phenylpropanoid metabolism, tocopherol/plastoquinone biosynthesis and photorespiration. PMID:19560175

  7. Invasive cleavage of nucleic acids

    SciTech Connect

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann D.; Dahlberg, James E.

    2002-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  8. Invasive cleavage of nucleic acids

    SciTech Connect

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann D.; Dahlberg, James E.

    1999-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  9. The politics of acid rain

    SciTech Connect

    Wilcher, M.E. )

    1989-01-01

    This work examines and compares the acid rain policies through the different political systems of Canada, Great Britain and the United States. Because the flow of acid rain can transcend national boundaries, acid rain has become a crucial international problem. According to the author, because of differences in governmental institutions and structure, the extent of governmental intervention in the industrial economy, the degree of reliance on coal for power generation, and the extent of acid rain damage, national responses to the acid rain problem have varied.

  10. Perfluoroalkyl and polyfluoroalkyl substances (PFASs) in consumer products in Norway - a pilot study.

    PubMed

    Herzke, Dorte; Olsson, Elisabeth; Posner, Stefan

    2012-08-01

    Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are used in numerous industrial and consumer products because of their special chemical properties, for instance the ability to repel both water and oil. A broad variety of PFAS have been introduced into the Norwegian market through industrial use (e.g. via fire fighting foams and paints) as well as in treated customer products such as textiles and coated paper. Our present knowledge of the exact chemical PFAS compositions in preparations using perfluorinated compounds is limited. This lack of knowledge means that it is difficult to provide an accurate assessment of human exposure to these compounds or to the amount of waste that may contain treated products. It is a growing concern that these potentially harmful compounds can now be found throughout the global environment. Samples of consumer products and preparations were collected in Norway, with supplemental samples from Sweden. In 27 of the 30 analyzed consumer products and preparations a number of polyfluorinated substances that were analyzed were detected but this does not exclude the occurrence of unknown PFAS. Notable was that perfluorooctanesulphonate (PFOS), which has been strictly regulated in Norway since 2007, was found in amounts close to or exceeding the EU regulatory level in 4 of the 30 analyzed products, all within the leather or carpet product groups. High amounts of fluorotelomer alcohols (FTOHs) were found in waterproofing agents, carpets and textiles, consistent with earlier findings by Fiedler et al. (2010). The presence of PFAS in a broad range of consumer products can give rise to a constant diffuse human exposure that might eventually result in harm to humans. PMID:22483730

  11. Tested Demonstrations: Color Oscillations in the Formic Acid-Nitric Acid-Sulfuric Acid System.

    ERIC Educational Resources Information Center

    Raw, C. J. G.; And Others

    1983-01-01

    Presented are procedures for demonstrating the production of color oscillations when nitric acid is added to a formic acid/concentrated sulfuric acid mixture. Because of safety considerations, "Super-8" home movie of the color changes was found to be satisfactory for demonstration purposes. (JN)

  12. Amino acids in Arctic aerosols

    NASA Astrophysics Data System (ADS)

    Scalabrin, E.; Zangrando, R.; Barbaro, E.; Kehrwald, N. M.; Gabrieli, J.; Barbante, C.; Gambaro, A.

    2012-07-01

    Amino acids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of amino acid reactivities suggest that amino acids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess amino acid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of amino acid compounds in the global atmosphere, we determined free amino acids (FAAs) in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS) to analyze 20 amino acids to quantify compounds at fmol m-3 levels. Mean total FAA concentration was 1070 fmol m-3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45-60% of the total amino acid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m-3. The higher amino acid concentrations were present in the ultrafine aerosol fraction (<0.49 ?m) and accounted for the majority of the total amino acid content. Local marine sources dominate the boreal summer amino acid concentrations, with the exception of the regional input from Icelandic volcanics.

  13. Amino acids in Arctic aerosols

    NASA Astrophysics Data System (ADS)

    Scalabrin, E.; Zangrando, R.; Barbaro, E.; Kehrwald, N. M.; Gabrieli, J.; Barbante, C.; Gambaro, A.

    2012-11-01

    Amino acids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of amino acid reactivities suggest that amino acids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess amino acid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of amino acid compounds in the global atmosphere, we determined free amino acids (FAAs) in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS) to analyze 20 amino acids and quantify compounds at fmol m-3 levels. Mean total FAA concentration was 1070 fmol m-3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45-60% of the total amino acid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m-3. The higher amino acid concentrations were present in the ultrafine aerosol fraction (< 0.49 ?m) and accounted for the majority of the total amino acid content. Local marine sources dominate the boreal summer amino acid concentrations, with the exception of the regional input from Icelandic volcanic emissions.

  14. Amino Acid Catabolism in Plants.

    PubMed

    Hildebrandt, Tatjana M; Nunes Nesi, Adriano; Araújo, Wagner L; Braun, Hans-Peter

    2015-11-01

    Amino acids have various prominent functions in plants. Besides their usage during protein biosynthesis, they also represent building blocks for several other biosynthesis pathways and play pivotal roles during signaling processes as well as in plant stress response. In general, pool sizes of the 20 amino acids differ strongly and change dynamically depending on the developmental and physiological state of the plant cell. Besides amino acid biosynthesis, which has already been investigated in great detail, the catabolism of amino acids is of central importance for adjusting their pool sizes but so far has drawn much less attention. The degradation of amino acids can also contribute substantially to the energy state of plant cells under certain physiological conditions, e.g. carbon starvation. In this review, we discuss the biological role of amino acid catabolism and summarize current knowledge on amino acid degradation pathways and their regulation in the context of plant cell physiology. PMID:26384576

  15. Twinning of dodecanedicarboxylic acid

    NASA Technical Reports Server (NTRS)

    Sen, R.; Wilcox, W. R.

    1986-01-01

    Twinning of 1,10-dodecanedicarboxyl acid (DDA) was observed in 0.1 mm thick films with a polarizing microscope. Twins originated from polycrystalline regions which tended to nucleate on twin faces, and terminated by intersection gone another. Twinning increased dramatically with addition of organic compounds with a similar molecular size and shape. Increasing the freezing rate, increasing the temperature gradient, and addition of silica particles increased twinning. It is proposed that twins nucleate with polycrystals and sometimes anneal out before they become observable. The impurities may enhance twinning either by lowering the twin energy or by adsorbing on growing faces.

  16. Alpha-1-acid glycoprotein.

    PubMed

    Fournier, T; Medjoubi-N, N; Porquet, D

    2000-10-18

    Alpha-1-acid glycoprotein (AGP) or orosomucoid (ORM) is a 41-43-kDa glycoprotein with a pI of 2.8-3.8. The peptide moiety is a single chain of 183 amino acids (human) or 187 amino acids (rat) with two and one disulfide bridges in humans and rats,respectively. The carbohydrate content represents 45% of the molecular weight attached in the form of five to six highly sialylated complex-type-N-linked glycans. AGP is one of the major acute phase proteins in humans, rats, mice and other species. As most acute phase proteins, its serum concentration increases in response to systemic tissue injury, inflammation or infection, and these changes in serum protein concentrations have been correlated with increases in hepatic synthesis. Expression of the AGP gene is controlled by a combination of the major regulatory mediators, i.e. glucocorticoids and a cytokine network involving mainly interleukin-1 beta (IL-1 beta), tumour necrosis factor-alpha (TNF alpha), interleukin-6 and IL-6 related cytokines. It is now well established that the acute phase response may take place in extra-hepatic cell types, and may be regulated by inflammatory mediators as observed in hepatocytes. The biological function of AGP remains unknown; however,a number of activities of possible physiological significance, such as various immunomodulating effects, have been described. AGP also has the ability to bind and to carry numerous basic and neutral lipophilic drugs from endogenous (steroid hormones) and exogenous origin; one to seven binding sites have been described. AGP can also bind acidic drugs such as phenobarbital. The immunomodulatory as well as the binding activities of AGP have been shown to be mostly dependent on carbohydrate composition. Finally, the use of AGP transgenic animals enabled to address in vivo, functionality of responsive elements and tissue specificity, as well as the effects of drugs that bind to AGP and will be an useful tool to determine the physiological role of AGP. PMID:11058758

  17. Synthesis of amino acids

    DOEpatents

    Davis, J.W. Jr.

    1979-09-21

    A method is described for synthesizing amino acids preceding through novel intermediates of the formulas: R/sub 1/R/sub 2/C(OSOC1)CN, R/sub 1/R/sub 2/C(C1)CN and (R/sub 1/R/sub 2/C(CN)O)/sub 2/SO wherein R/sub 1/ and R/sub 2/ are each selected from hydrogen and monovalent hydrocarbon radicals of 1 to 10 carbon atoms. The use of these intermediates allows the synthesis steps to be exothermic and results in an overall synthesis method which is faster than the synthesis methods of the prior art.

  18. Nucleic Acid Detection Methods

    DOEpatents

    Smith, Cassandra L.; Yaar, Ron; Szafranski, Przemyslaw; Cantor, Charles R.

    1998-05-19

    The invention relates to methods for rapidly determining the sequence and/or length a target sequence. The target sequence may be a series of known or unknown repeat sequences which are hybridized to an array of probes. The hybridized array is digested with a single-strand nuclease and free 3'-hydroxyl groups extended with a nucleic acid polymerase. Nuclease cleaved heteroduplexes can be easily distinguish from nuclease uncleaved heteroduplexes by differential labeling. Probes and target can be differentially labeled with detectable labels. Matched target can be detected by cleaving resulting loops from the hybridized target and creating free 3-hydroxyl groups. These groups are recognized and extended by polymerases added into the reaction system which also adds or releases one label into solution. Analysis of the resulting products using either solid phase or solution. These methods can be used to detect characteristic nucleic acid sequences, to determine target sequence and to screen for genetic defects and disorders. Assays can be conducted on solid surfaces allowing for multiple reactions to be conducted in parallel and, if desired, automated.

  19. [Suicide with acetylsalicylic acid].

    PubMed

    Wollersen, Heike; Preuss, Johanna; Thierauf, Annette; Musshoff, Frank; Madea, Burkhard

    2007-01-01

    The authors report on a suicide of a 41-year-old man with acetylsalicylic acid. According to his own statement the man had taken about 200 tablets of Aspirin (65 g acetylsalicylic acid) and initially showed no symptoms of intoxication. 4-5 hours after ingestion he vomited twice, but clear intoxication symptoms like convulsions and cardiac arrhythmia occurred not earlier than 11 hours after ingestion. Resuscitation by the emergency physician was not successful. The chemical-toxicological analysis (HPLC-DAD) of blood samples taken in the hospital approximately 12 h after ingestion showed salicylate in concentrations of 475 mg/L to 557 mg/L. The post-mortem concentrations of salicylate were within the lethal-toxic range, i.e. 762 mg/L in heart blood and 215 mg/L in femoral blood. All tested organs contained equally lethal salicylate levels (e.g. 503 mg/L in the liver and 251 mg/L in the brain). PMID:17539592

  20. Nucleic acid detection methods

    DOEpatents

    Smith, C.L.; Yaar, R.; Szafranski, P.; Cantor, C.R.

    1998-05-19

    The invention relates to methods for rapidly determining the sequence and/or length a target sequence. The target sequence may be a series of known or unknown repeat sequences which are hybridized to an array of probes. The hybridized array is digested with a single-strand nuclease and free 3{prime}-hydroxyl groups extended with a nucleic acid polymerase. Nuclease cleaved heteroduplexes can be easily distinguish from nuclease uncleaved heteroduplexes by differential labeling. Probes and target can be differentially labeled with detectable labels. Matched target can be detected by cleaving resulting loops from the hybridized target and creating free 3-hydroxyl groups. These groups are recognized and extended by polymerases added into the reaction system which also adds or releases one label into solution. Analysis of the resulting products using either solid phase or solution. These methods can be used to detect characteristic nucleic acid sequences, to determine target sequence and to screen for genetic defects and disorders. Assays can be conducted on solid surfaces allowing for multiple reactions to be conducted in parallel and, if desired, automated. 18 figs.

  1. Cryoprotection from lipoteichoic acid

    NASA Astrophysics Data System (ADS)

    Rice, Charles V.; Middaugh, Amy; Wickham, Jason R.; Friedline, Anthony; Thomas, Kieth J.; Johnson, Karen; Zachariah, Malcolm; Garimella, Ravindranth

    2012-10-01

    Numerous chemical additives lower the freezing point of water, but life at sub-zero temperatures is sustained by a limited number of biological cryoprotectants. Antifreeze proteins in fish, plants, and insects provide protection to a few degrees below freezing. Microbes have been found to survive at even lower temperatures, and with a few exceptions, antifreeze proteins are missing. Survival has been attributed to external factors, such as the high salt concentration of brine veins and adhesion to particulates or ice crystal defects. We have discovered an endogenous cryoprotectant in the cell wall of bacteria, lipoteichoic acid biopolymers. Adding 1% LTA to bacteria cultures immediately prior to freezing provides 50% survival rate, similar to the results obtained with 1% glycerol. In the absence of an additive, bacterial survival is negligible as measured with the resazurin cell viability assay. The mode of action for LTA cryoprotection is unknown. With a molecular weight of 3-5 kDa, it is unlikely to enter the cell cytoplasm. Our observations suggest that teichoic acids could provide a shell of liquid water around biofilms and planktonic bacteria, removing the need for brine veins to prevent bacterial freezing.

  2. Solid-phase extraction of acidic herbicides.

    PubMed

    Wells, M J; Yu, L Z

    2000-07-14

    A discussion of solid-phase extraction method development for acidic herbicides is presented that reviews sample matrix modification, extraction sorbent selection, derivatization procedures for gas chromatographic analysis, and clean-up procedures for high-performance liquid chromatographic analysis. Acidic herbicides are families of compounds that include derivatives of phenol (dinoseb, dinoterb and pentachlorophenol), benzoic acid (acifluorfen, chloramben, dicamba, 3,5-dichlorobenzoic acid and dacthal--a dibenzoic acid derivative), acetic acid [2,4-dichlorophenoxyacetic acid (2,4-D), 4-chloro-2-methylphenoxyacetic acid (MCPA) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)], propanoic acid [dichlorprop, fluazifop, haloxyfop, 2-(4-chloro-2-methylphenoxy)propanoic acid (MCPP) and silvex], butanoic acid [4-(2,4-dichlorophenoxy)butanoic acid (2,4-DB) and 4-(4-chloro-2-methylphenoxy)butanoic acid (MCPB)], and other miscellaneous acids such as pyridinecarboxylic acid (picloram) and thiadiazine dioxide (bentazon). PMID:10941675

  3. The gas phase acidities of substituted silanoic acids

    NASA Astrophysics Data System (ADS)

    Remko, Milan

    Ab initio molecular orbital methods at the CBS-Q level of theory have been used to study the structure, gas phase acidities and vibrational spectra of silanoic acid, HSiO2H, and several of its derivatives RSiO2H (R = F, Cl, NH2, OH and CH3). Geometry optimizations were performed at the MP2(FC)/6-31G(†) level of theory. The syn forms always are more stable than the anti. The silanoic acid derivatives are more acidic than their parent oxygen acid analogues. The fundamental vibrational frequencies have been computed using the MP2(Full)/6-31G(d) method. The ν(Si=O) = 1261 cm-1 value agrees with the experimentally determined normal mode (1249 cm-1) in silanoic acid.

  4. Growth of nitric acid hydrates on thin sulfuric acid films

    NASA Technical Reports Server (NTRS)

    Iraci, Laura T.; Middlebrook, Ann M.; Wilson, Margaret A.; Tolbert, Margaret A.

    1994-01-01

    Type I polar stratospheric clouds (PSCs) are thought to nucleate and grow on stratospheric sulfate aerosols (SSAs). To model this system, thin sulfuric acid films were exposed to water and nitric acid vapors (1-3 x 10(exp -4) Torr H2O and 1-2.5 x 10(exp -6) Torr HNO3) and subjected to cooling and heating cycles. Fourier Transform Infrared (FTIR) spectroscopy was used to probe the phase of the sulfuric acid and to identify the HNO3/H2O films that condensed. Nitric acid trihydrate (NAT) was observed to grow on crystalline sulfuric acid tetrahydrate (SAT) films. NAT also condensed in/on supercooled H2SO4 films without causing crystallization of the sulfuric acid. This growth is consistent with NAT nucleation from ternary solutions as the first step in PSC formation.

  5. Therapeutic targeting of bile acids.

    PubMed

    Camilleri, Michael; Gores, Gregory J

    2015-08-15

    The first objectives of this article are to review the structure, chemistry, and physiology of bile acids and the types of bile acid malabsorption observed in clinical practice. The second major theme addresses the classical or known properties of bile acids, such as the role of bile acid sequestration in the treatment of hyperlipidemia; the use of ursodeoxycholic acid in therapeutics, from traditional oriental medicine to being, until recently, the drug of choice in cholestatic liver diseases; and the potential for normalizing diverse bowel dysfunctions in irritable bowel syndrome, either by sequestering intraluminal bile acids for diarrhea or by delivering more bile acids to the colon to relieve constipation. The final objective addresses novel concepts and therapeutic opportunities such as the interaction of bile acids and the microbiome to control colonic infections, as in Clostridium difficile-associated colitis, and bile acid targeting of the farnesoid X receptor and G protein-coupled bile acid receptor 1 with consequent effects on energy expenditure, fat metabolism, and glycemic control. PMID:26138466

  6. Bile Acid Metabolism and Signaling

    PubMed Central

    Chiang, John Y. L.

    2015-01-01

    Bile acids are important physiological agents for intestinal nutrient absorption and biliary secretion of lipids, toxic metabolites, and xenobiotics. Bile acids also are signaling molecules and metabolic regulators that activate nuclear receptors and G protein-coupled receptor (GPCR) signaling to regulate hepatic lipid, glucose, and energy homeostasis and maintain metabolic homeostasis. Conversion of cholesterol to bile acids is critical for maintaining cholesterol homeostasis and preventing accumulation of cholesterol, triglycerides, and toxic metabolites, and injury in the liver and other organs. Enterohepatic circulation of bile acids from the liver to intestine and back to the liver plays a central role in nutrient absorption and distribution, and metabolic regulation and homeostasis. This physiological process is regulated by a complex membrane transport system in the liver and intestine regulated by nuclear receptors. Toxic bile acids may cause inflammation, apoptosis, and cell death. On the other hand, bile acid-activated nuclear and GPCR signaling protects against inflammation in liver, intestine, and macrophages. Disorders in bile acid metabolism cause cholestatic liver diseases, dyslipidemia, fatty liver diseases, cardiovascular diseases, and diabetes. Bile acids, bile acid derivatives, and bile acid sequestrants are therapeutic agents for treating chronic liver diseases, obesity, and diabetes in humans. PMID:23897684

  7. Acidizing: A well completion reference

    SciTech Connect

    1997-11-01

    Acidizing removes near-wellbore formation damage by dissolving or bypassing drilling mud, completion fluid or other restrictions. These treatments include matrix pump rate jobs, washes and chemical injection. Matrix stimulation techniques are performed without fracturing reservoir rock. Acid is used to remove drilling, completion, workover or production damage. Solvents and surfactants like crude, condensate, diesel or mutual solvents are used to change pore fluid or formation wettability characteristics. Washes remove scale and other dispersible or soluble material from formations, perforations and casing. The purpose of the above methods is to improve well productivity by removing or mitigating formation damage. Hydrofluoric (HF) acid dissolves clay and fine particles in sandstones. Hydrochloric (HCl) acid etches wormholes that bypass damage in carbonates. Products are subdivided into groups that have similar function and performance. Where applicable, groups have been subdivided to reflect significant differences in additive chemical nature to emphasize uniqueness in the product lines of each company. Products and additives are grouped in 28 categories: water-base completion fluids; water-base polymers; friction reducers; fluid loss; diverting agents; polymer plugs; acid inhibitors; acid retarders; emulsifiers; clay stabilizers; surfactants; non-emulsifiers; fines suspender; anti-sludge agent; foamers; scale inhibitors; iron (Fe) control; oxygen scavenger; mutual solvents; corrosion inhibitors; paraffin control; miscellaneous products; acid systems; retarded acid system; mud acid plus surfactants; mud acid plus alcohol; SGMA; and retarded HF.

  8. Acid rain: Rhetoric and reality

    SciTech Connect

    Park, C.C.

    1987-01-01

    Acid rain is now one of the most serious environmental problems in developed countries. Emissions and fallout were previously extremely localized, but since the introduction of tall stacks policies in both Britain and the US - pardoxically to disperse particulate pollutants and hence reduce local damage - emissions are now lifted into the upper air currents and carried long distances downwind. The acid rain debate now embraces many western countries - including Canada, the US, England, Scotland, Wales, Sweden, Norway, Denmark, West Germany, the Netherlands, Austria, Switzerland - and a growing number of eastern countries - including the Soviet Union, Poland, East Germany, and Czechoslovakia. The problem of acid rain arises, strictly speaking, not so much from the rainfall itself as from its effects on the environment. Runoff affects surface water and groundwater, as well as soils and vegetation. Consequently changes in rainfall acidity can trigger off a range of impacts on the chemistry and ecology of lakes and rivers, soil chemistry and processes, the health and productivity of plants, and building materials, and metallic structures. The most suitable solutions to the problems of acid rain require prevention rather than cure, and there is broad agreement in both the political scientific communities on the need to reduce emissions of sulfur and nitrogen oxides to the atmosphere. Book divisions discuss: the problem of acid rain, the science of acid rain, the technology of acid rain, and the politics of acid rain, in an effort to evaluate this growing global problem of acid rain.

  9. Electrolytic nature of aqueous sulfuric acid. 2. Acidity.

    PubMed

    Fraenkel, Dan

    2012-09-27

    In part 1 of this study, I reported that the Debye-Hückel limiting law and the smaller-ion shell (SiS) model of strong electrolyte solutions fit nicely with the experimental mean ionic activity coefficient (γ(±)) of aqueous sulfuric acid as a function of concentration and of temperature when the acid is assumed to be a strong 1-3 electrolyte. Here, I report that the SiS-derived activity coefficient of H(+), γ(H(+)), of the 1-3 acid is comparable to that of aqueous HCl. This agrees with titration curves showing, as well-known, that sulfuric acid in water is parallel in strength to aqueous HCl. The calculated pH is in good accord with the Hammett acidity function, H(0), of aqueous sulfuric acid at low concentration, and differences between the two functions at high concentration are discussed and explained. This pH-H(0) relation is consistent with the literature showing that the H(0) of sulfuric acid (in the 1-9 M range) is similar to those of HCl and the other strong mineral monoprotic acids. The titration of aqueous sulfuric acid with NaOH does not agree with the known second dissociation constant of 0.010 23; rather, the constant is found to be ~0.32 and the acid behaves upon neutralization as a strong diprotic acid practically dissociating in one step. A plausible reaction pathway is offered to explain how the acid may transform, upon base neutralization, from a dissociated H(4)SO(5) (as 3H(+) and HSO(5)(3-)) to a dissociated H(2)SO(4) even though the equilibrium constant of the reaction H(+) + HSO(5)(3-) ↔ SO(4)(2-) + H(2)O, at 25 °C, is 10(-37) (part 1). PMID:22924595

  10. Bile acid interactions with cholangiocytes

    PubMed Central

    Xia, Xuefeng; Francis, Heather; Glaser, Shannon; Alpini, Gianfranco; LeSage, Gene

    2006-01-01

    Cholangiocytes are exposed to high concentrations of bile acids at their apical membrane. A selective transporter for bile acids, the Apical Sodium Bile Acid Cotransporter (ASBT) (also referred to as Ibat; gene name Slc10a2) is localized on the cholangiocyte apical membrane. On the basolateral membrane, four transport systems have been identified (t-ASBT, multidrug resistance (MDR)3, an unidentified anion exchanger system and organic solute transporter (Ost) heteromeric transporter, Ostα-Ostβ. Together, these transporters unidirectionally move bile acids from ductal bile to the circulation. Bile acids absorbed by cholangiocytes recycle via the peribiliary plexus back to hepatocytes for re-secretion into bile. This recycling of bile acids between hepatocytes and cholangiocytes is referred to as the cholehepatic shunt pathway. Recent studies suggest that the cholehepatic shunt pathway may contribute in overall hepatobiliary transport of bile acids and to the adaptation to chronic cholestasis due to extrahepatic obstruction. ASBT is acutely regulated by an adenosine 3', 5’-monophosphate (cAMP)-dependent translocation to the apical membrane and by phosphorylation-dependent ubiquitination and proteasome degradation. ASBT is chronically regulated by changes in gene expression in response to biliary bile acid concentration and inflammatory cytokines. Another potential function of cholangiocyte ASBT is to allow cholangiocytes to sample biliary bile acids in order to activate intracellular signaling pathways. Bile acids trigger changes in intracellular calcium, protein kinase C (PKC), phosphoinositide 3-kinase (PI3K), mitogen-activated protein (MAP) kinase and extracellular signal-regulated protein kinase (ERK) intracellular signals. Bile acids significantly alter cholangiocyte secretion, proliferation and survival. Different bile acids have differential effects on cholangiocyte intracellular signals, and in some instances trigger opposing effects on cholangiocyte secretion, proliferation and survival. Based upon these concepts and observations, the cholangiocyte has been proposed to be the principle target cell for bile acids in the liver. PMID:16773712

  11. Acidity of Strong Acids in Water and Dimethyl Sulfoxide.

    PubMed

    Trummal, Aleksander; Lipping, Lauri; Kaljurand, Ivari; Koppel, Ilmar A; Leito, Ivo

    2016-05-26

    Careful analysis and comparison of the available acidity data of HCl, HBr, HI, HClO4, and CF3SO3H in water, dimethyl sulfoxide (DMSO), and gas-phase has been carried out. The data include experimental and computational pKa and gas-phase acidity data from the literature, as well as high-level computations using different approaches (including the W1 theory) carried out in this work. As a result of the analysis, for every acid in every medium, a recommended acidity value is presented. In some cases, the currently accepted pKa values were revised by more than 10 orders of magnitude. PMID:27115918

  12. 49 CFR 173.158 - Nitric acid.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... material. (b) Nitric acid in any concentration which does not contain sulfuric acid or hydrochloric acid as... sulfuric acid or hydrochloric acid as impurities, when offered for transportation or transported by rail... 49 Transportation 2 2010-10-01 2010-10-01 false Nitric acid. 173.158 Section...

  13. Fatty acids and cardiovascular disease.

    PubMed

    Lecerf, Jean-Michel

    2009-05-01

    Fatty acids have been classified into "good" or "bad" groups according to their degree of unsaturation or whether they are "animal fat" or "vegetable fat". Today, it appears that the effects of fatty acids are complex and vary greatly according to the dose and the nature of the molecule. Monounsaturated fatty acids are still considered as having a "neutral" status, but any benefits may be related to the chemical environment of the source food or the associated overall food pattern. Controversy surrounds omega-6 polyunsaturated fatty acids, because even though they lower LDL cholesterol levels, excessive intakes do not appear to be correlated with cardiovascular benefit. The omega-3 fatty acids are known to exert cardiovascular protective effects. Dairy fat and its cardiovascular impact are being evaluated. This review examines the existing literature on the relationships between the different fatty acids and cardiovascular disease. PMID:19386031

  14. Acid rain degradation of nylon

    SciTech Connect

    Kyllo, K.E.

    1984-01-01

    Acid rain, precipitation with a pH less than 5.6, is known to damage lakes, vegetation and buildings. Degradation of outdoor textiles by acid rain is strongly suspected but not well documented. This study reports the effects of sunlight, aqueous acid, heat and humidity (acid rain conditions) on spun delustered nylon 6,6 fabric. Untreated nylon and nylon treated with sulfuric acid of pH 2.0, 3.0, and 4.4 were exposed to light in an Atlas Xenon-arc fadeometer at 63/sup 0/C and 65% R.H. for up to 640 AATCC Fading Units. The untreated and acid treated nylon fabrics were also exposed to similar temperature and humidity condition without light. Nylon degradation was determined by changes in breaking strength, elongation, molecular weight, color, amino end group concentration (NH/sub 2/) and /sup 13/C NMR spectra. Physical damage was assessed using SEM.

  15. Butyric acid in functional constipation

    PubMed Central

    Pituch, Aleksandra; Walkowiak, Jarosław

    2013-01-01

    Butyric acid, a short-chain fatty acid, is a major energy source for colonocytes. It occurs in small quantities in some foods, and in the human body, it is produced in the large intestine by intestinalkacteria. This production can be reduced in some cases, for which butyric acid supplementation may be useful. So far, the use of butyric acid in the treatment of gastrointestinal disorders has been limited because of its specific characteristics such as its rancid smell and rapid absorption in the upper gastrointestinal tract. In the Polish market, sodium butyrate has been recently made available, produced by the modern technology of microencapsulation, which allows the active substance to reach the small and large intestines, where butyrate easily dissociates into butyric acid. This article presents the potential beneficial mechanisms of action of butyric acid in defecation disorders, which are primarily associated with reductions in pain during defecation and inflammation in the gut, among others. PMID:24868272

  16. Butyric acid in functional constipation.

    PubMed

    Pituch, Aleksandra; Walkowiak, Jarosław; Banaszkiewicz, Aleksandra

    2013-01-01

    Butyric acid, a short-chain fatty acid, is a major energy source for colonocytes. It occurs in small quantities in some foods, and in the human body, it is produced in the large intestine by intestinalkacteria. This production can be reduced in some cases, for which butyric acid supplementation may be useful. So far, the use of butyric acid in the treatment of gastrointestinal disorders has been limited because of its specific characteristics such as its rancid smell and rapid absorption in the upper gastrointestinal tract. In the Polish market, sodium butyrate has been recently made available, produced by the modern technology of microencapsulation, which allows the active substance to reach the small and large intestines, where butyrate easily dissociates into butyric acid. This article presents the potential beneficial mechanisms of action of butyric acid in defecation disorders, which are primarily associated with reductions in pain during defecation and inflammation in the gut, among others. PMID:24868272

  17. A Simpler Nucleic Acid

    NASA Technical Reports Server (NTRS)

    Orgel, Leslie

    2000-01-01

    It has been supposed that for a nucleic acid analog to pair with RNA it must, like RNA, have a backbone with at least a sixatom repeat; a shorter backbone presumably would not stretch far enough to bind RNA properly. The Eschenmoser group has shown, however, that this first impression is incorrect.As they report in their new paper, Eschenmoser and co-workers ( I ) have now synthesized a substantial number of these polymers, which are called (L)-a-threofuranosyl oligonucleotides or TNAs. They are composed of bases linked to a threose sugar-phosphate backbone, with phosphodiester bonds connecting the nucleotides. The investigators discovered that pairs of complementary TNAs do indeed form stable Watson-Crick double helices and, perhaps more importantly, that TNAs form stable double helices with complementary RNAs and DNAs.

  18. Intestinal metabolism of fatty acids

    PubMed Central

    Enser, M.

    1965-01-01

    1. The effect of concentration on the oxidation and incorporation into lipids of lauric acid and linoleic acid by rings of rat small intestine has been studied in vitro. 2. In the absence of glucose, the oxidation of lauric acid in the range 0·01–5·0mm showed a maximum at 0·1mm. In the presence of glucose the maximum was at 0·5mm. The oxidation of linoleic acid in the presence of glucose increased throughout the concentration range 0·01–5·0mm. 3. The incorporation of lauric acid into lipids was maximal at 0·5–0·6mm in the presence of glucose, but at 10mm in the absence of glucose. At 0·8mm-lauric acid, in the presence of glucose, over 75% of the incorporated lauric acid was in triglycerides, but at 10mm they only contained 30%. The incorporation of glucose carbon into glycerides paralleled the incorporation of lauric acid. 4. In the range 0·01–2·5mm-linoleic acid the quantity incorporated into lipids increased. In the range 0·01–0·4mm linoleic acid was incorporated predominantly into triglycerides, but between 0·4 and 1·0mm most was in diglycerides, and between 2·5 and 5·0mm most was in monoglycerides. 5. The relationship of fatty acid concentration to the mechanism of absorption is discussed, together with the correlation between the distribution of the absorbed fatty acids within the tissue lipids and the lipase activity of intestinal mucosa. PMID:5837779

  19. Mixed acid-base disorders.

    PubMed

    Adams, L G; Polzin, D J

    1989-03-01

    Mixed acid-base disturbances are combinations of two or more primary acid-base disturbances. Mixed acid-base disturbances may be suspected on the basis of findings obtained from the medical history, physical examination, serum electrolytes and chemistries, and anion gap. The history, physical examination, and serum biochemical profile may reveal disease processes commonly associated with acid-base disturbances. Changes in serum total CO2, serum potassium and chloride concentrations, or increased anion gap may provide clues to the existence of acid-base disorders. Blood gas analysis is usually required to confirm mixed acid-base disorders. To identify mixed acid-base disorders, blood gas analysis is used to identify primary acid-base disturbance and determine if an appropriate compensatory response has developed. Inappropriate compensatory responses (inadequate or excessive) are evidence of a mixed respiratory and metabolic disorder. The anion gap is also of value in detecting mixed acid-base disturbances. In high anion gap metabolic acidosis, the change in the anion gap should approximate the change in serum bicarbonate. Absence of this relationship should prompt consideration of a mixed metabolic acid-base disorder. Finding an elevated anion gap, regardless of serum bicarbonate concentration, suggests metabolic acidosis. In some instances, elevated anion gap is the only evidence of metabolic acidosis. In patients with hyperchloremic metabolic acidosis, increases in the serum chloride concentration should approximate the reduction in the serum bicarbonate concentration. Significant alterations from this relationship also indicate that a mixed metabolic disorder may be present. In treatment of mixed acid-base disorders, careful consideration should be given to the potential impact of therapeutically altering one acid-base disorder without correcting others. PMID:2494782

  20. Ghrelin and gastric acid secretion

    PubMed Central

    Yakabi, Koji; Kawashima, Junichi; Kato, Shingo

    2008-01-01

    Ghrelin, a novel growth hormone-releasing peptide, was originally isolated from rat and human stomach. Ghrelin has been known to increase the secretion of growth hormone (GH), food intake, and body weight gain when administered peripherally or centrally. Ghrelin is also known to stimulate the gastric motility and the secretion of gastric acid. In the previous studies, the action of ghrelin on acid secretion was shown to be as strong as that of histamine and gastrin in in-vivo experiment. In the studies, the mechanism for the action of ghrelin was also investigated. It was shown that vagotomy completely inhibited the action of ghrelin on the secretion of gastric acid suggesting that vagal nerve is involved in the mechanism for the action of ghrelin on acid secretion. As famotidine did not inhibit ghrelin-induced acid secretion in the study by Masuda et al, they concluded that histamine was not involved in the action of ghrelin on acid secretion. However, we have shown that famotidine completely inhibited ghrelin-induced acid secretion and histidine decarboxylase (HDC) mRNA was increased in gastric mucosa by ghrelin injection which is inhibited by vagotomy Our results indicate that histamine is involved in the action of ghrelin on acid secretion. Furthermore synergistic action of gastrin and ghrelin on gastric acid secretion was shown. Although gastrin has important roles in postprandial secretion of gastric acid, ghrelin may be related to acid secretion during fasting period or at night. However, further studies are needed to elucidate the physiological role of ghrelin in acid secretion. PMID:19009648

  1. [Total synthesis of nordihydroguaiaretic acid].

    PubMed

    Wu, A X; Zhao, Y R; Chen, N; Pan, X F

    1997-04-01

    beta-Keto ester(5) was obtained from vanilin through etherification, oxidation and condensation with acetoacetic ester, (5) on oxidative coupling reaction by NaOEt/I2 produced dimer (6) in high yield. Acid catalyzed cyclodehydration of (6) gave the furan derivative(7), and by a series of selective hydrogenation nordihydroguaiaretic acid, furoguaiacin dimethyl ether and dihydroguaiaretic acid dimethyl ether were synthesized. PMID:11499030

  2. All-trans retinoic acid regulates hepatic bile acid homeostasis

    PubMed Central

    Yang, Fan; He, Yuqi; Liu, Hui-Xin; Tsuei, Jessica; Jiang, Xiaoyue; Yang, Li; Wang, Zheng-Tao; Wan, Yu-Jui Yvonne

    2014-01-01

    Retinoic acid (RA) and bile acids share common roles in regulating lipid homeostasis and insulin sensitivity. In addition, the receptor for RA (retinoid x receptor) is a permissive partner of the receptor for bile acids, farnesoid x receptor (FXR/NR1H4). Thus, RA can activate the FXR-mediated pathway as well. The current study was designed to understand the effect of all-trans RA on bile acid homeostasis. Mice were fed an all-trans RA-supplemented diet and the expression of 46 genes that participate in regulating bile acid homeostasis was studied. The data showed that all-trans RA has a profound effect in regulating genes involved in synthesis and transport of bile acids. All-trans RA treatment reduced the gene expression levels of Cyp7a1, Cyp8b1, and Akr1d1, which are involved in bile acid synthesis. All-trans RA also decreased the hepatic mRNA levels of Lrh-1 (Nr5a2) and Hnf4α (Nr2a1), which positively regulate the gene expression of Cyp7a1 and Cyp8b1. Moreover, all-trans RA induced the gene expression levels of negative regulators of bile acid synthesis including hepatic Fgfr4, Fxr, and Shp (Nr0b2) as well as ileal Fgf15. All-trans RA also decreased the expression of Abcb11 and Slc51b, which have a role in bile acid transport. Consistently, all-trans RA reduced hepatic bile acid levels and the ratio of CA/CDCA, as demonstrated by liquid chromatography-mass spectrometry. The data suggest that all-trans RA-induced SHP may contribute to the inhibition of CYP7A1 and CYP8B1, which in turn reduces bile acid synthesis and affects lipid absorption in the gastrointestinal tract. PMID:25175738

  3. Preparation and characterization Al3+-bentonite Turen Malang for esterification fatty acid (palmitic acid, oleic acid and linoleic acid)

    NASA Astrophysics Data System (ADS)

    Abdulloh, Abdulloh; Aminah, Nanik Siti; Triyono, Mudasir, Trisunaryanti, Wega

    2016-03-01

    Catalyst preparation and characterization of Al3+-bentonite for esterification of palmitic acid, oleic acid and linoleic acid has been done. Al3+-bentonite catalyst was prepared from natural bentonite of Turen Malang through cation exchange reaction using AlCl3 solution. The catalysts obtained were characterized by XRD, XRF, pyridine-FTIR and surface area analyser using the BET method. Catalyst activity test of Al3+-bentonite for esterification reaction was done at 65°C using molar ratio of metanol-fatty acid of 30:1 and 0.25 g of Al3+-bentonite catalyst for the period of ½, 1, 2, 3, 4 and 5 hours. Based on the characterization results, the Al3+-bentonite Turen Malang catalyst has a d-spacing of 15.63 Ǻ, acid sites of Brönsted and Lewis respectively of 230.79 µmol/g and 99.39 µmol/g, surface area of 507.3 m2/g and the average of radius pore of 20.09 Å. GC-MS analysis results of the oil phase after esterification reaction showed the formation of biodiesel (FAME: Fatty acid methyl ester), namely methyl palmitate, methyl oleate and methyl linoleate. The number of conversions resulted in esterification reaction using Al3+-bentonite Turen Malang catalyst was 74.61%, 37.75%, and 20, 93% for the esterification of palmitic acid, oleic acid and linoleic acid respectively.

  4. Acidic gas capture by diamines

    SciTech Connect

    Rochelle, Gary; Hilliard, Marcus

    2011-05-10

    Compositions and methods related to the removal of acidic gas. In particular, the present disclosure relates to a composition and method for the removal of acidic gas from a gas mixture using a solvent comprising a diamine (e.g., piperazine) and carbon dioxide. One example of a method may involve a method for removing acidic gas comprising contacting a gas mixture having an acidic gas with a solvent, wherein the solvent comprises piperazine in an amount of from about 4 to about 20 moles/kg of water, and carbon dioxide in an amount of from about 0.3 to about 0.9 moles per mole of piperazine.

  5. Fatty acid-amino acid conjugates diversification in Lepidopteran caterpillars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatty acid amino acid conjugates (FACs) have been found in Noctuid as well as Sphingid caterpillar oral secretions and especially volicitin [N-(17-hydroxylinolenoyl)-L-Glutamine] and its biochemical precursor, N-linolenoyl-L-glutamine, are known elicitors of induced volatile emissions in corn plants...

  6. Fatty Acid Desaturases, Polyunsaturated Fatty Acid Regulation, and Biotechnological Advances.

    PubMed

    Lee, Je Min; Lee, Hyungjae; Kang, SeokBeom; Park, Woo Jung

    2016-01-01

    Polyunsaturated fatty acids (PUFAs) are considered to be critical nutrients to regulate human health and development, and numerous fatty acid desaturases play key roles in synthesizing PUFAs. Given the lack of delta-12 and -15 desaturases and the low levels of conversion to PUFAs, humans must consume some omega-3 and omega-6 fatty acids in their diet. Many studies on fatty acid desaturases as well as PUFAs have shown that fatty acid desaturase genes are closely related to different human physiological conditions. Since the first front-end desaturases from cyanobacteria were cloned, numerous desaturase genes have been identified and animals and plants have been genetically engineered to produce PUFAs such as eicosapentaenoic acid and docosahexaenoic acid. Recently, a biotechnological approach has been used to develop clinical treatments for human physiological conditions, including cancers and neurogenetic disorders. Thus, understanding the functions and regulation of PUFAs associated with human health and development by using biotechnology may facilitate the engineering of more advanced PUFA production and provide new insights into the complexity of fatty acid metabolism. PMID:26742061

  7. Fatty Acid Desaturases, Polyunsaturated Fatty Acid Regulation, and Biotechnological Advances

    PubMed Central

    Lee, Je Min; Lee, Hyungjae; Kang, SeokBeom; Park, Woo Jung

    2016-01-01

    Polyunsaturated fatty acids (PUFAs) are considered to be critical nutrients to regulate human health and development, and numerous fatty acid desaturases play key roles in synthesizing PUFAs. Given the lack of delta-12 and -15 desaturases and the low levels of conversion to PUFAs, humans must consume some omega-3 and omega-6 fatty acids in their diet. Many studies on fatty acid desaturases as well as PUFAs have shown that fatty acid desaturase genes are closely related to different human physiological conditions. Since the first front-end desaturases from cyanobacteria were cloned, numerous desaturase genes have been identified and animals and plants have been genetically engineered to produce PUFAs such as eicosapentaenoic acid and docosahexaenoic acid. Recently, a biotechnological approach has been used to develop clinical treatments for human physiological conditions, including cancers and neurogenetic disorders. Thus, understanding the functions and regulation of PUFAs associated with human health and development by using biotechnology may facilitate the engineering of more advanced PUFA production and provide new insights into the complexity of fatty acid metabolism. PMID:26742061

  8. A comparison of chromic acid and sulfuric acid anodizing

    NASA Technical Reports Server (NTRS)

    Danford, M. D.

    1992-01-01

    Because of federal and state mandates restricting the use of hexavalent chromium, it was deemed worthwhile to compare the corrosion protection afforded 2219-T87 aluminum alloy by both Type I chromic acid and Type II sulfuric acid anodizing per MIL-A-8625. Corrosion measurements were made on large, flat 2219-T87 aluminum alloy sheet material with an area of 1 cm(exp 2) exposed to a corrosive medium of 3.5-percent sodium chloride at pH 5.5. Both ac electrochemical impedance spectroscopy and the dc polarization resistance techniques were employed. The results clearly indicate that the corrosion protection obtained by Type II sulfuric acid anodizing is superior, and no problems should result by substituting Type II sulfuric acid anodizing for Type I chromic acid anodizing.

  9. Carbonic Acid Retreatment of Biomass

    SciTech Connect

    Baylor university

    2003-06-01

    This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. (1) Solidify the theoretical understanding of the binary CO{sub 2}/H{sub 2}O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. (2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. (3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. (4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. (5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic acid compared to water alone. (6) Determine optimal conditions for carbonic acid pretreatment of aspen wood. Optimal severities appeared to be in the mid range tested. ASPEN-Plus modeling and economic analysis of the process indicate that the process could be cost competitive with sulfuric acid if the concentration of solids in the pretreatment is maintained very high ({approx}50%). Lower solids concentrations result in larger reactors that become expensive to construct for high pressure applications.

  10. Carbonic Acid Pretreatment of Biomass

    SciTech Connect

    G. Peter van Walsum; Kemantha Jayawardhana; Damon Yourchisin; Robert McWilliams; Vanessa Castleberry

    2003-05-31

    This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. 1) Solidify the theoretical understanding of the binary CO2/H2O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. 2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. 3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. 4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. 5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic acid compared to water alone. 6) Determine optimal conditions for carbonic acid pretreatment of aspen wood. Optimal severities appeared to be in the mid range tested. ASPEN-Plus modeling and economic analysis of the process indicate that the process could be cost competitive with sulfuric acid if the concentration of solids in the pretreatment is maintained very high (~50%). Lower solids concentrations result in larger reactors that become expensive to construct for high pressure applications.

  11. The acidic amino acids of tulip: isolation of γ-ethylideneglutamic acid

    PubMed Central

    Fowden, L.

    1966-01-01

    1. γ-Ethylideneglutamic acid has been isolated from fruit capsules of tulip plants. 2. The assigned structure was indicated by examining the products formed after oxidation and catalytic hydrogenation and was confirmed by nuclear-magnetic-resonance spectroscopy and by synthesis of γ-ethylglutamic acid. 3. The ability of γ-ethylideneglutamic acid to participate in transamination and decarboxylation reactions was examined. PMID:5938664

  12. DEVELOPMENTAL TOXICITY OF PERFLUOROOCATANE SULFONATE (PFOS) IN THE RAT AND MOUSE

    EPA Science Inventory

    1Lau, C., 1J.M. Rogers, 1R.G. Hanson*, 1B.D. Barbee*, 1M.G. Narotsky, 1J.E. Schmid* and 2J.H. Richards*. 1Reproductive Toxicology Division, and 2Environmental Toxicology Division, NHEERL, US EPA, Research Triangle Park, North Carolina. Developmental toxicity of Perfluorooctane ...

  13. PFOS and PFOSA in Bottlenose Dolphins: An Investigation into Two High Mortality Epizootics (NRMMSTSN2009)

    EPA Science Inventory

    Along the Atlantic coast of the United States during 1987 and 1988, bottlenose dolphins (Tursiops truncatus) suffered one of this country's largest marine mammal mass mortality events. An estimated 50% of all near-shore bottlenose died during this short period. Two years later a ...

  14. PFOS and PFOSA in Bottlenose Dolphins: An Investigation into Two Unusually High Mortality Epizootics

    EPA Science Inventory

    Along the Atlantic coast of the United States during 1987 and 1988, bottlenose dolphins (Tursiops truncatus) suffered one of this country's largest marine mammal mass mortality events. An estimated 50% of all near-shore bottlenose died during this short period. Two years later a ...

  15. PFOS and PFOSA in Bottlenose Dolphins: An Investigation into Two Unusual Mortality Epizootics (WDA)

    EPA Science Inventory

    Along the Atlantic coast of the United States during 1987 and 1988, bottlenose dolphins (Tursiops truncatus) suffered one of this country's largest marine mammal mass mortality events. An estimated 50% of all near-shore bottlenose died during this short period. Two years later a ...

  16. PFOS and PFOSA in Bottlenose Dolphins: An Investigation into Two Unusually High Mortality Events

    EPA Science Inventory

    Along the Atlantic coast of the United States during 1987 and 1988, bottlenose dolphins (Tursiops truncatus) suffered one of this country's largest marine mammal mass mortality events. An estimated 50% of all near-shore bottlenose died during this short period. Two years later a ...

  17. Synthesis of new kojic acid based unnatural α-amino acid derivatives.

    PubMed

    Balakrishna, C; Payili, Nagaraju; Yennam, Satyanarayana; Devi, P Uma; Behera, Manoranjan

    2015-11-01

    An efficient method for the preparation of kojic acid based α-amino acid derivatives by alkylation of glycinate schiff base with bromokojic acids have been described. Using this method, mono as well as di alkylated kojic acid-amino acid conjugates have been prepared. This is the first synthesis of C-linked kojic acid-amino acid conjugate where kojic acid is directly linked to amino acid through a C-C bond. PMID:26318994

  18. SOIL REACTION AND ACIDIC DEPOSITION

    EPA Science Inventory

    This chapter discusses the major chemical processes by which acidic deposition interacts with soils. he focus is on forest soils, as the effects of acidic deposition on soils used for production of food and fiber are generally small compared to effects of agricultural practices s...

  19. ACID DEPOSITION AND FOREST DECLINE

    EPA Science Inventory

    The location, topography and other characteristics of the high-elevation forests of eastern North America cause them to be receptors of high levels of acid deposition and airborn trace metals. No other major forested areas in the U.S. are subjected to such intensely acid cloud mo...

  20. SIMULATED ACID RAIN ON CROPS

    EPA Science Inventory

    In 1981, simulated H2SO4 acid rain was applied to alfalfa and tall fescue and a 2:1 ratio of H2SO4:HNO3 acid rain was applied to alfalfa, tall fescue, barley, wheat, potato, tomato, radish, and corn crops growing in the open field at Corvallis, Oregon. Careful attention was given...