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Sample records for bioaccumulative hydroxylated pbde

  1. Food Web Bioaccumulation Model for Resident Killer Whales from the Northeastern Pacific Ocean as a Tool for the Derivation of PBDE-Sediment Quality Guidelines.

    Science.gov (United States)

    Alava, Juan José; Ross, Peter S; Gobas, Frank A P C

    2016-01-01

    Resident killer whale populations in the NE Pacific Ocean are at risk due to the accumulation of pollutants, including polybrominated diphenyl ethers (PBDEs). To assess the impact of PBDEs in water and sediments in killer whale critical habitat, we developed a food web bioaccumulation model. The model was designed to estimate PBDE concentrations in killer whales based on PBDE concentrations in sediments and the water column throughout a lifetime of exposure. Calculated and observed PBDE concentrations exceeded the only toxicity reference value available for PBDEs in marine mammals (1500 μg/kg lipid) in southern resident killer whales but not in northern resident killer whales. Temporal trends (1993-2006) for PBDEs observed in southern resident killer whales showed a doubling time of ≈5 years. If current sediment quality guidelines available in Canada for polychlorinated biphenyls are applied to PBDEs, it can be expected that PBDE concentrations in killer whales will exceed available toxicity reference values by a large margin. Model calculations suggest that a PBDE concentration in sediments of approximately 1.0 μg/kg dw produces PBDE concentrations in resident killer whales that are below the current toxicity reference value for 95 % of the population, with this value serving as a precautionary benchmark for a management-based approach to reducing PBDE health risks to killer whales. The food web bioaccumulation model may be a useful risk management tool in support of regulatory protection for killer whales. PMID:26289814

  2. Dietary exposure of juvenile common sole (Solea solea L.) to polybrominated diphenyl ethers (PBDEs): Part 2. Formation, bioaccumulation and elimination of hydroxylated metabolites

    International Nuclear Information System (INIS)

    The uptake, elimination and transformation of six PBDE congeners (BDE-28, -47, -99, -100, -153, -209) were studied in juvenile common sole (Solea solea L.) exposed to spiked contaminated food over a three-month period, and then depurated over a five-month period. Methoxylated (MeO-) and hydroxylated (OH-) PBDEs were determined in fish plasma exposed to PBDEs and compared to those obtained in control fish. While all MeO- and some OH- congeners identified in fish plasma were found to originate from non-metabolic sources, several OH- congeners, i.e., OH-tetraBDEs and OH-pentaBDEs, were found to originate from fish metabolism. Among these, 4'-OH-BDE-49 was identified as a BDE-47 metabolite. Congener 4'-OH-BDE-101, identified here for the first time, may be the result of BDE-99 metabolic transformation. Our results unequivocally showed that PBDEs are metabolised in juvenile sole via the formation of OH- metabolites. However, this was not a major biotransformation route compared to biotransformation through debromination. - Juvenile sole exposed to artificially-contaminated food showed the ability to biotransform PBDEs into hydroxylated metabolites; these meta-bolites accumulated in fish.

  3. Bioaccumulation of hydroxylated polychlorinated biphenyls and pentachlorophenol in the serum of northern elephant seal pups (Mirounga angustirostris)

    Energy Technology Data Exchange (ETDEWEB)

    Louis, Caroline, E-mail: caroline.louis@uclouvain.be [Institut des Sciences de la Vie, UCLouvain, Croix du Sud 2/L7.05.08, 1348 Louvain-la-Neuve (Belgium); Covaci, Adrian [Department of Pharmaceutical Sciences, Toxicological Center, Campus Drie Eiken, Universiteit Antwerpen, Universiteitsplein 1, 2610 Wilrijk (Belgium); Stas, Marie [Institut des Sciences de la Vie, UCLouvain, Croix du Sud 2/L7.05.08, 1348 Louvain-la-Neuve (Belgium); Crocker, Daniel E. [Department of Biology, Sonoma State University, 1801 East Cotati Ave, Rohnert Park, CA 94928 (United States); Malarvannan, Govindan [Department of Pharmaceutical Sciences, Toxicological Center, Campus Drie Eiken, Universiteit Antwerpen, Universiteitsplein 1, 2610 Wilrijk (Belgium); Dirtu, Alin C. [Department of Pharmaceutical Sciences, Toxicological Center, Campus Drie Eiken, Universiteit Antwerpen, Universiteitsplein 1, 2610 Wilrijk (Belgium); Department of Chemistry, “Al. I. Cuza” University of Iasi, 700506 Iasi (Romania); Debier, Cathy [Institut des Sciences de la Vie, UCLouvain, Croix du Sud 2/L7.05.08, 1348 Louvain-la-Neuve (Belgium)

    2015-01-15

    Northern elephant seals (NES) (Mirounga angustirostris) from the Año Nuevo State Reserve (CA, USA) were sampled at 1-, 4-, 7- and 10-week post-weaning. Concentrations of hydroxylated polychlorinated biphenyls (HO-PCBs) and their parent PCBs were measured in the serum of each individual. The ΣHO-PCB concentrations in the serum increased significantly between early and late fast (from 282±20 to 529±31 pg/mL). This increase might result from a mobilisation of HO-PCBs transferred from the mother during gestation and/or lactation and stored in the pup's liver. Food deprivation has been shown to exacerbate biotransformation capacities in mammals, birds and fish. The HO-penta-CBs was the predominant homologue group, followed by HO-hexa-CBs and HO-hepta-CBs. No preferential pathway for the metabolism of HO-PCBs (HO-direct insertion or NIH-shift of a chlorine atom) could be evidenced. The concentrations of pentachlorophenol (PCP) in the serum of weaned NES increased from 103±7 pg/mL at early fast to 246±41 pg/mL at late fast, which is within the range of PCP concentrations usually encountered in marine mammals. - Highlights: • Σ HO-PCB concentrations in serum significantly increased between early and late fast. • The HO-penta-CBs were the predominant homologue group measured in serum. • No preferential pathway for the metabolism of HO-PCBs could be evidenced. • PCP concentrations in serum significantly increased between early and late fast.

  4. Bioaccumulation of hydroxylated polychlorinated biphenyls and pentachlorophenol in the serum of northern elephant seal pups (Mirounga angustirostris)

    International Nuclear Information System (INIS)

    Northern elephant seals (NES) (Mirounga angustirostris) from the Año Nuevo State Reserve (CA, USA) were sampled at 1-, 4-, 7- and 10-week post-weaning. Concentrations of hydroxylated polychlorinated biphenyls (HO-PCBs) and their parent PCBs were measured in the serum of each individual. The ΣHO-PCB concentrations in the serum increased significantly between early and late fast (from 282±20 to 529±31 pg/mL). This increase might result from a mobilisation of HO-PCBs transferred from the mother during gestation and/or lactation and stored in the pup's liver. Food deprivation has been shown to exacerbate biotransformation capacities in mammals, birds and fish. The HO-penta-CBs was the predominant homologue group, followed by HO-hexa-CBs and HO-hepta-CBs. No preferential pathway for the metabolism of HO-PCBs (HO-direct insertion or NIH-shift of a chlorine atom) could be evidenced. The concentrations of pentachlorophenol (PCP) in the serum of weaned NES increased from 103±7 pg/mL at early fast to 246±41 pg/mL at late fast, which is within the range of PCP concentrations usually encountered in marine mammals. - Highlights: • Σ HO-PCB concentrations in serum significantly increased between early and late fast. • The HO-penta-CBs were the predominant homologue group measured in serum. • No preferential pathway for the metabolism of HO-PCBs could be evidenced. • PCP concentrations in serum significantly increased between early and late fast

  5. Anthropogenic (PBDE) and naturally-produced (MeO-PBDE) brominated compounds in cetaceans--a review.

    Science.gov (United States)

    Alonso, Mariana B; Azevedo, Alexandre; Torres, João Paulo M; Dorneles, Paulo R; Eljarrat, Ethel; Barceló, Damià; Lailson-Brito, José; Malm, Olaf

    2014-05-15

    This paper reviews the available data on brominated flame retardants, the polybrominated diphenyl ethers (PBDEs), as well as on the naturally-produced methoxylated polybrominated diphenyl ethers (MeO-PBDEs) in cetacean tissues around the world. Levels and possible sources of both compound classes are discussed. Odontocete cetaceans accumulate higher PBDE concentrations than mysticete species. PBDE contamination was higher in cetaceans from the Northern hemisphere, whereas MeO-PBDE levels were higher in animals from the Southern hemisphere. Southern resident killer whales from NE Pacific presented the highest levels reported in biota, followed by bottlenose dolphins from North Atlantic (U.K. and U.S. coast). Many species presented PBDE concentrations above threshold levels for health effects in odontocetes. Time trend studies indicate that PBDE concentrations in odontocetes from Japan, China, U.S. and Canada coastal zones have increased significantly over the past 30 years. Studies from U.K. waters and NE Atlantic showed a decrease and/or stability of PBDE levels in cetacean tissues in recent decades. The highest MeO-PBDE concentrations were found in dolphins from Tanzania (Indian Ocean), bottlenose dolphins from Queensland, Australia (SW Pacific), and odontocetes from coastal and continental shelf waters off southeastern Brazil (SW Atlantic). The upwelling phenomenon and the presence of coral reef complexes in these tropical oceans may explain the large amounts of the naturally-produced organobromines. Considering that these bioaccumulative chemicals have properties that could cause many deleterious effects in those animals, future studies are required to evaluate the potential ecotoxicological risks. PMID:24636867

  6. Study of the toxic effects of flame retardant PBDE-47 on the clam Chamelea gallina (Linnaeus, 1758

    Directory of Open Access Journals (Sweden)

    Salvatora Angela Angioni

    2013-03-01

    Full Text Available The purpose of the study is to evaluate the effects of 2,2',4,4'-tetrabromodiphenylether (PBDE-47 on the Chamelea gallina clam (according to current commercial regulations: Venus gallina. PBDEs, which are used as flame retardants in various industrial products, are classed as hazardous substances by Directive 2011/65/EU. They are bioaccumulative compounds, considered to be endocrine disruptors, genotoxic, neurotoxic and practically ubiquitous, and their concentration in the environment has considerably increased in recent years. The aim of this study is to establish the effects of PBDE-47 on Chamelea gallina: toxic power and any harmful effects on the gonads, bioaccumulation capacity in the tissues, and possible entry into the food chain. The research used 96-hour and 21-day experimental tests on clams housed in filtered seawater. The tests were preceded by a period of acclimatisation of the molluscs lasting five to seven days. The clams were fed on seaweed (Dunaliella tertiolecta. The choice of the toxic compound PBDE-47 was based on the high concentration, among the congeners of PBDE, found in some aquatic species. The study demonstrated that the concentration of the contaminant used did not alter the vital functions, cause significant levels of mortality or lead to evident alteration in the gonads of Chamelea gallina. However, the research demonstrated the bioaccumulation capacity of the bivalve mollusc, allowing PBDE-47 to enter the food chain.

  7. Advances in the study of current-use non-PBDE brominated flame retardants and dechlorane plus in the environment and humans

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The fate of the high production volume,currently in use,and not regulated non-polybrominated diphenyl ether(PBDE) flame retardants,such as tetrabromobisphenol A(TBBPA) ,hexabromocyclododecane(HBCD) and dechlorane plus(DP),and the alternative flame retardants of PBDE,such as BTBPE and DBDPE,in the environment has attracted increasing attention and aroused concern due to the increasing regulation and phasing-out of PBDEs.This paper reviews the distribution,bioaccumulation,human exposure and environmental behavior of those non-PBDE flame retardants in various environmental compartments.The data gaps and needs for future research are discussed.

  8. Black carbon inclusive multichemical modeling of PBDE and PCB biomagnification and -transformation in estuarine food webs.

    Science.gov (United States)

    Di Paolo, Carolina; Gandhi, Nilima; Bhavsar, Satyendra P; Van den Heuvel-Greve, Martine; Koelmans, Albert A

    2010-10-01

    Bioavailability and bioaccumulation of polybrominated diphenylethers (PBDEs) are affected by adsorption on black carbon (BC) and metabolism in biota, respectively. Recent studies have addressed these two processes separately, illustrating their importance in assessing contaminant dynamics. In order to properly examine biomagnification of polychlorinated biphenyls (PCBs) and PBDEs in an estuarine food-web, here we set up a black carbon inclusive multichemical model. A dual domain sorption model, which accounted for sorption to organic matter (OM) and black carbon (BC), was used to estimate aqueous phase concentrations from the measured chemical concentrations in suspended solids. We adapted a previously published multichemical model that tracks the movement of a parent compound and its metabolites in each organism and within its food web. First, the model was calibrated for seven PCB congeners assuming negligible metabolism. Subsequently, PBDE biomagnification was modeled, including biotransformation and bioformation of PBDE congeners, keeping the other model parameters the same. The integrated model was capable of predicting trophic magnification factors (TMF) within error limits. PBDE metabolic half-lives ranged 21-415 days and agreed to literature data. The results showed importance of including BC as an adsorbing phase, and biotransformation and bioformation of PBDEs for a proper assessment of their dynamics in aquatic systems. PMID:20828201

  9. Sex-dependent behavioral changes in rat offspring after in utero administration of a single low dose PBDE 47

    Energy Technology Data Exchange (ETDEWEB)

    Kuriyama, S.N.; Talsness, C.E.; Chahoud, I. [Charite Univ. Medical School Berlin (Germany). Inst. of Clinical Pharmacology and Toxicology, Dept. Toxicology, Campus Benjamin Franklin

    2004-09-15

    Increasing levels of polybrominated diphenyl ethers (PBDEs) in environmental and human samples has resulted in intensive discussion regarding possible hazard identification and risk assessment in the last years. In rodents, exposure to PBDE mixtures or single congeners has resulted in a mixed induction of CYP450- dependent enzymes, showing increased activity of hepatic EROD and PROD. In addition, genotoxicity has been observed in recombination assays, and neurotoxicity has been reported in mice exposed during development. Acute and sub-chronic exposures of mice and rats to a PBDE mixture (DE-71) cause dose-dependent reductions in serum concentrations of thyroxin (T4), and stressinduced elevations in plasma corticosterone. Further, some hydroxylated metabolites of PBDE congeners exhibit a higher potency in vivo than T4 in competitive binding to human transthyretin (TTR), the transport protein mediating transfer of thyroid hormones across the placenta and into the brain. The available information in the literature clearly indicates that PBDEs are potent neurotoxicants, causing effects at doses lower than that able to disrupt thyroid hormone profiles and change CYP 450 activities. Neurobehavior effects, which includes defects in learning and memory, and changes in nicotinic receptors were found at doses starting at 0.45 ppm in mouse (9). The congeners, PBDE 47 and PBDE 99, have also been shown to cause permanent aberrations in spontaneous behavior in mice which was more pronounced with increasing age. PBDE 47 is the most predominant congener found in environmental and human samples, including human breast milk. Its presence in breast milk highlights the importance of evaluating possible effects following early developmental exposure and because this period represents a critical time which an organism is extremely susceptible to minor changes in hormonal milieu. Variances in terms of time point and concentration of exposure to steroids can lead to an organizational

  10. Effects of PBDE-47 on thyroid and steroid hormone status in juvenile turbot (Schophtalamus maximus)

    Energy Technology Data Exchange (ETDEWEB)

    Jenssen, G.; Tyrhaug, I.B.; Sormo, E.G. [Dept. of Biology, Norwegian Univ. of Science and Technology, Trondheim (Norway); Andersen, O.K. [Rogaland Research Akvamiljo, Mekjarvik (Norway)

    2004-09-15

    Many of the brominated flame retardant (BFR) chemicals, and particularly polybrominated diphenyl ethers (PBDEs), has become of increasing concern to scientists over the past decade. Many of the PBDEs are persistent and lipophilic and have been shown to bioaccumulate. The levels of PBDEs in biota seem to be increasing, and several trends, including in humans, indicate that this increase may be rapid1. In general, BFRs have a low acute toxicity, but there is concern about their long-term toxic effects. Exposure studies have revealed a range of subtle biochemical, cellular and physiological effects following low-dose exposure, and many BFRs have been reported to have endocrine disruptive properties. Thus, there is concern about their potential to affect organisms and populations. Thyroid hormones (THs) play an important role in organism's development, metabolism, growth and behavior. Polyhalogenated aromatic hydrocarbons (PHAHs) including BFRs may affect the thyroid system through several mechanisms. They may directly affect the thyroid gland function, the peripheral metabolism of THs and/or the binding of THs to plasma transport proteins. Effects of PHAHs on TH homeostasis have been documented in a number of species, including fish. Du to its persistence against degradation PBDE-47 is among the most abundant PBDE congener in biota, and there is a great concern about its ecotoxicological effects on organisms and populations. The aim of the present study was to examine if PBDE-47 may affect levels of circulating steroid and thyroid hormones in juvenile turbot (Scophtalamus maximus). The turbot is a benthic living flatfish that can be exposed to PHAHs via the sediment living organisms. Thus, plasma levels of T, E, and the thyroid hormones thyroxine (T4) and triiodothyronine (T3) were determined in juvenile turbot that had been continuously exposed to PBDE-47 via water for 3 weeks.

  11. Dietary exposure of juvenile common sole (Solea solea L.) to polybrominated diphenyl ethers (PBDEs): Part 1. Bioaccumulation and elimination kinetics of individual congeners and their debrominated metabolites

    International Nuclear Information System (INIS)

    The uptake and elimination of six PBDE congeners (BDE-28, -47, -99, -100, -153, -209) were studied in juvenile common sole (Solea solea L.) exposed to spiked contaminated food over a three-month period, then depurated over a five-month period. The results show that all of the studied PBDEs accumulate in fish tissues, including the higher brominated congener BDE-209. Several additional PBDE congeners were identified in the tissues of exposed fish, revealing PBDE transformation, mainly via debromination. The identified congeners originating from PBDE debromination include BDE-49 and BDE-202 and a series of unidentified tetra-, penta-, and hepta- BDEs. Contaminant assimilation efficiencies (AEs) were related to their hydrophobicity (log Kow) and influenced by PBDE biotransformation. Metabolism via debromination appears to be a major degradation route of PBDEs in juvenile sole in comparison to biotransformation into hydroxylated metabolites. - Juvenile sole exposed to artificially-contaminated food accumulate PBDEs, including the higher brominated congeners, and have a debromination capacity.

  12. Inhibition of human placental aromatase activity by hydroxylated polybrominated diphenyl ethers (OH-PBDEs)

    International Nuclear Information System (INIS)

    Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in many different polymers, resins and substrates. Due to their widespread production and use, their high binding affinity to particles, and their lipophilic properties, several PBDE congeners can bioaccumulate in the environment. As a result, PBDEs and their hydroxylated metabolites (OH-PBDEs) have been detected in humans and various wildlife samples, such as birds, seals, and whales. Furthermore, certain OH-PBDEs and their methoxylated derivatives (MeO-PBDEs) are natural products in the marine environment. Recently, our laboratory focused on the possible effects on steroidogenesis of PBDEs and OH-PBDEs, e.g. in the human adrenocortical carcinoma (H295R) cell line indicating that some OH-PBDEs can significantly influence steroidogenic enzymes like CYP19 (aromatase) and CYP17. In the present study, human placental microsomes have been used to study the possible interaction of twenty two OH-PBDEs and MeO-PBDEs with aromatase, the enzyme that mediates the conversion of androgens into estrogens. All OH-PBDE derivates showed significant inhibition of placental aromatase activity with IC50 values in the low micromolar range, while the MeO-PBDEs did not have any effect on this enzyme activity. Enzyme kinetics studies indicated that two OH-PBDEs, 5-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (5-OH-BDE47) and 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE47), had a mixed-type inhibition of aromatase activity with apparent Ki/Ki' of 7.68/0,02 μM and 5.01/0.04 μM respectively. For comparison, some structurally related compounds, a dihydroxylated polybrominated biphenyl, which is a natural product (2,2'-dihyroxy-3,3',5,5'-tetrabromobiphenyl (2,2'-diOH-BB80)) and its non-bromo derivative were also included in the study. Again inhibition of aromatase activity could be measured, but their potency was significantly less than those observed for the OH-PBDEs. These results show that a wide range of

  13. Hydroxylated PBDEs induce developmental arrest in zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Usenko, Crystal Y., E-mail: Crystal_usenko@baylor.edu; Hopkins, David C.; Trumble, Stephen J., E-mail: Stephen_trumble@baylor.edu; Bruce, Erica D., E-mail: Erica_bruce@baylor.edu

    2012-07-01

    The ubiquitous spread of polybrominated diphenyl ethers (PBDEs) has led to concerns regarding the metabolites of these congeners, in particular hydroxylated PBDEs. There are limited studies regarding the biological interactions of these chemicals, yet there is some concern they may be more toxic than their parent compounds. In this study three hydroxylated PBDEs were assessed for toxicity in embryonic zebrafish: 3-OH-BDE 47, 5-OH-BDE 47, and 6-OH-BDE 47. All three congeners induced developmental arrest in a concentration-dependent manner; however, 6-OH-BDE 47 induced adverse effects at lower concentrations than the other congeners. Furthermore, all three induced cell death; however apoptosis was not observed. In short-term exposures (24–28 hours post fertilization), all hydroxylated PBDEs generated oxidative stress in the region corresponding to the cell death at 5 and 10 ppm. To further investigate the short-term effects that may be responsible for the developmental arrest observed in this study, gene regulation was assessed for embryos exposed to 0.625 ppm 6-OH-BDE 47 from 24 to 28 hpf. Genes involved in stress response, thyroid hormone regulation, and neurodevelopment were significantly upregulated compared to controls; however, genes related to oxidative stress were either unaffected or downregulated. This study suggests that hydroxylated PBDEs disrupt development, and may induce oxidative stress and potentially disrupt the cholinergic system and thyroid hormone homeostasis. -- Highlights: ► OH-PBDEs induce developmental arrest in a concentration-dependent manner. ► Hydroxyl group location influences biological interaction. ► OH-PBDEs induce oxidative stress. ► Thyroid hormone gene regulation was disrupted following exposure. ► To our knowledge, this is the first whole organism study of OH-PBDE toxicity.

  14. Polybrominated diphenyl ethers and their hydroxylated analogs in plasma of bottlenose dolphins (Tursiops truncatus) from the United States east coast.

    Science.gov (United States)

    Houde, Magali; Pacepavicius, Grazina; Darling, Colin; Fair, Patricia A; Alaee, Mehran; Bossart, Gregory D; Solomon, Keith R; Letcher, Robert J; Bergman, Ake; Marsh, Göran; Muir, Derek C G

    2009-10-01

    Polybrominated diphenyl ethers (PBDEs) and hydroxylated PBDEs (OH-PBDEs) were determined in plasma of free-ranging bottlenose dolphins (Tursiops truncatus) from Charleston (CHS), South Carolina, and the Indian River Lagoon (IRL), Florida, U.S.A. Significantly lower sums (sigma) of PBDE concentrations (sum of 12 congeners) were found in animals from the IRL (arithmetic mean, 5.45 +/- 4.63 ng/g wet wt) compared with those from CHS (30 +/- 40 ng/g wet wt). Brominated diphenyl ether (BDE)-47 was the predominant PBDE in dolphins from the IRL (50% of the sigma PBDEs) and CHS (58%). The sigma PBDE concentrations in plasma of dolphins were negatively correlated with age at both locations. Fifteen and sixteen individual OH-PBDE congeners could be quantified in plasma of dolphins from IRL and CHS, respectively. Similar to sigma PBDE, mean sigma OH-PBDE concentrations were significantly higher in plasma of dolphins at CHS (1150 +/- 708 pg/g wet wt) compared with those at IRL (624 +/- 393 pg/g wet wt). The predominant congener at both locations was 6-OH-PBDE-47 (IRL, 384 +/- 319 pg/g wet wt; CHS, 541 +/- 344 pg/g wet wt), representing 61.5% of total sigma OH-PBDE at IRL and 47.0% at CHS. Concentrations of sigma OH-PBDEs were weakly negatively correlated with age in dolphins from both locations (p dolphins are minor products in plasma relative to sigma PBDEs and a significant proportion may be a consequence of the dietary uptake of naturally produced methoxylated- and OH-PBDEs.

  15. Seasonal Bioaccumulation of Organohalogens in tigerfish, Hydrocynus vittatus Castelnau, from Lake Pongolapoort, South Africa

    OpenAIRE

    Bervoets, L.; Dyke, Sarah; Smit, Nicholas Jacobus; Wepener, V.; Covaci, A.

    2012-01-01

    The study determined current exposure of tigerfish in Lake Pongolaqpoort to organohalogens. Levels of DDT, PCB, HCB, HCH, PBDE and CHLs were measured in tigerfish muscle on a seasonal basis. Historical use of DDT was reflected in the bioaccumulation patterns (5,400–6,000 ng/g lipid) as well as current use of HCBs (7.7–15.7 ng/g lipid) in the agricultural areas. External factors, i.e. increased flow did not play a role in organic pollutant exposure. Levels are a function of the lipid content o...

  16. PBDE levels in human milk: the situation in Germany and potential influencing factors - a controlled study

    Energy Technology Data Exchange (ETDEWEB)

    Vieth, B.; Mielke, H.; Ostermann, B.; Ruediger, T. [Federal Inst. for Risk Assessment, Berlin (Germany); Herrmann, T.; Paepke, O. [ERGO Forschungsgesellschaft mbH, Hamburg (Germany)

    2004-09-15

    An exponential increase of PBDE levels in breast milk from Sweden between 1972 and 1997 has been reported, which is in contrast to the continuous decline of other chlorinated POPs in breast milk. Also in blood samples from Germany, an increasing trend has been observed during the period from 1985 to 1999. The knowledge about human exposure pathways, which contribute to the PBDE body burden, is very limited. Consumption of food of animal origin, inhalation or ingestion of dust and further factors possibly influencing the PBDE levels in human matrices, like age, breast-feeding or smoking are under discussion. Only a few data on PBDE levels in breast milk from Germany have been published. To fill the data gaps, a controlled study was started in 2001 to characterise the PBDE levels in human milk from Germany with special efforts to identify and quantify deca-BDE-209. Furthermore, it was intended to verify potential factors possibly influencing PBDE levels. Two main hypotheses were proposed: (1) Are PBDE levels in breast milk from mothers consuming traditional food (omnivores) higher than those found in breast milk from mothers consuming vegetarian or vegan food? and (2) Are the PBDE levels found in human milk after a three-months period of breast-feeding lower than those detected at the beginning or does breast feeding result in a lower body burden, respectively? This paper summarises preliminary results. Further analytical data and results of data evaluation will be presented at the conference.

  17. Do temporal and geographical patterns of HBCD and PBDE flame retardants in U.S. fish reflect evolving industrial usage?

    Science.gov (United States)

    Chen, Da; La Guardia, Mark J; Luellen, Drew R; Harvey, Ellen; Mainor, T Matteson; Hale, Robert C

    2011-10-01

    Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) are common flame retardants in polymers and textiles. Recognition of the persistent, bioaccumulative, and toxic properties of PBDEs has prompted reductions in their use. In contrast, HBCD has received less scrutiny. The U.S has historically been a dominant BFR consumer. However, the few publications on HBCD in wildlife here suggest modest levels compared to Asian and European studies. In contrast, the HBCD concentrations we detected in U.S. fish are among the highest reported in the world. The temporal trends observed suggest that HBCD use may have risen, and that of Penta-BDE declined, following the 2004 termination of its U.S. manufacture. For example, Hyco River carp collected in 1999-2002 exhibited a mean ∑HBCD (sum of α-, β- and γ-HBCD) concentration of only 13 ng/g (lipid weight basis), but was 4640 ng/g in fish collected in 2006-2007. In contrast, the mean ∑PBDE level in these same fish decreased from 40,700 ng/g in 1999-2002 to 9140 ng/g in 2006-2007. Concentrations of HBCD and PBDEs in several Hyco River fish species exceeded those from rivers less influenced by manufacturing outfalls. Results support the contention that textile-related production, relative to its BFR market share, may release disproportionately large amounts of HBCD to the environment.

  18. Organic anion transporting polypeptides in the hepatic uptake of PBDE congeners in mice

    Energy Technology Data Exchange (ETDEWEB)

    Pacyniak, Erik [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Hagenbuch, Bruno [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); The University of Kansas Cancer Center, Kansas City, KS (United States); Klaassen, Curtis D. [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Lehman-McKeeman, Lois [Bristol Myers Squibb Co., Princeton, NJ (United States); Guo, Grace L., E-mail: lguo@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States)

    2011-11-15

    BDE47, BDE99 and BDE153 are the predominant polybrominated diphenyl ether (PBDE) congeners detected in humans and can induce drug metabolizing enzymes in the liver. We have previously demonstrated that several human liver organic anion transporting polypeptides (humans: OATPs; rodents: Oatps) can transport PBDE congeners. Mice are commonly used to study the toxicity of chemicals like the PBDE congeners. However, the mechanism of the hepatic PBDE uptake in mice is not known. Therefore, the purpose of the current study was to test the hypothesis that BDE47, BDE99, and BDE153 are substrates of mouse hepatic Oatps (Oatp1a1, Oatp1a4, Oatp1b2, and Oatp2b1). We used Human Embryonic Kidney 293 (HEK293) cells transiently expressing individual Oatps and quantified the uptake of BDE47, BDE99, and BDE153. Oatp1a4, Oatp1b2, and Oatp2b1 transported all three PBDE congeners, whereas Oatp1a1 did transport none. Kinetic studies demonstrated that Oatp1a4 and Oatp1b2 transported BDE47 with the greatest affinity, followed by BDE99 and BDE153. In contrast, Oatp2b1 transported all three PBDE congeners with similar affinities. The importance of hepatic Oatps for the liver accumulation of BDE47 was confirmed using Oatp1a4-, and Oatp1b2-null mice. -- Highlights: Black-Right-Pointing-Pointer PBDE congeners are substrates of OATPs expressed in human hepatocytes. Black-Right-Pointing-Pointer Mice are commonly used to study the toxicity of chemicals like the PBDE congeners. Black-Right-Pointing-Pointer Oatp1a4, Oatp1b2, and Oatp2b1 transported all three PBDE congeners in vitro. Black-Right-Pointing-Pointer In vivo Oatp1a4 plays a minor and Oatp1b2 a major role in BDE47 liver accumulation.

  19. A mechanistic view of polybrominated diphenyl ether (PBDE) developmental neurotoxicity.

    Science.gov (United States)

    Costa, Lucio G; de Laat, Rian; Tagliaferri, Sara; Pellacani, Claudia

    2014-10-15

    Polybrominated diphenyl ethers (PBDEs), extensively used in the past few decades as flame retardants in a variety of consumer products, have become world-wide persistent environmental pollutants. Levels in North America are usually higher than those in Europe and Asia, and body burden is 3-to-9-fold higher in infants and toddlers than in adults. The latter has raised concern for potential developmental toxicity and neurotoxicity of PBDEs. Experimental studies in animals and epidemiological observations in humans suggest that PBDEs may be developmental neurotoxicants. Pre- and/or post-natal exposure to PBDEs may cause long-lasting behavioral abnormalities, particularly in the domains of motor activity and cognition. The mechanisms underlying the developmental neurotoxic effects of PBDEs are not known, though several hypotheses have been put forward. One general mode of action relates to the ability of PBDEs to impair thyroid hormone homeostasis, thus indirectly affecting the developing brain. An alternative or additional mode of action involves a direct effect of PBDEs on nervous system cells; PBDEs can cause oxidative stress-related damage (DNA damage, mitochondrial dysfunction, apoptosis), and interfere with signal transduction (particularly calcium signaling), and with neurotransmitter systems. Important issues such as bioavailability and metabolism of PBDEs, extrapolation of results to low level of exposures, and the potential effects of interactions among PBDE congeners and between PBDEs and other contaminants also need to be taken into account. PMID:24270005

  20. Bioaccumulation of emerging organic compounds (perfluoroalkyl substances and halogenated flame retardants) by earthworm in biosolid amended soils.

    Science.gov (United States)

    Navarro, Irene; de la Torre, Adrián; Sanz, Paloma; Pro, Javier; Carbonell, Gregoria; Martínez, María de Los Ángeles

    2016-08-01

    In the present work, the bioaccumulation behavior of 49 target emerging organic compounds (20 perfluoroalkyl substances, PFASs, and 29 halogenated flame retardants, HFRs) was studied in soil invertebrates (Eisenia andrei). Multi species soil systems (MS·3) were used to assess the fate and the effects associated with the application of four biosolids in agricultural soil on terrestrial soil organisms. Biosolid amendment increased concentrations 1.5-14-fold for PFASs, 1.1-2.4-fold for polybrominated diphenyl ethers, PBDEs, and 1.1-3.6-fold for chlorinated flame retardants, CFRs. Perfluorooctanesulfonate, PFOS, (25%) and BDE-209 (60%) were the predominant PFAS and HFR compounds, respectively, in biosolids-amended soils. Total concentrations (ng/g dry weight) in earthworms from biosolid-amended soils ranged from 9.9 to 101 for PFASs, from 45 to 76 for PBDEs and 0.3-32 for CFRs. Bioaccumulation factors (BAFs) were calculated to evaluate the degree of exposure of pollutants in earthworms. The mean BAF ranged from 2.2 to 198 for PFASs, 0.6-17 for PBDEs and 0.5-20 for CFRs. The relationship of PFAS and PBDE BAFs in earthworms and their log Kow were compared: PFAS BAFs increased while PBDE BAFs declined with increasing log Kow values. The effect of the aging (21 days) on the bioavailability of the pollutants in amended soils was also assessed: the residence time affected differently to the compounds studied. PMID:27174781

  1. Seasonal bioaccumulation of organohalogens in tigerfish, Hydrocynus vittatus Castelnau, from Lake Pongolapoort, South Africa.

    Science.gov (United States)

    Wepener, Victor; Smit, Nico; Covaci, Adrian; Dyke, Sarah; Bervoets, Lieven

    2012-02-01

    The study determined current exposure of tigerfish in Lake Pongolaqpoort to organohalogens. Levels of DDT, PCB, HCB, HCH, PBDE and CHLs were measured in tigerfish muscle on a seasonal basis. Historical use of DDT was reflected in the bioaccumulation patterns (5,400-6,000 ng/g lipid) as well as current use of HCBs (7.7-15.7 ng/g lipid) in the agricultural areas. External factors, i.e. increased flow did not play a role in organic pollutant exposure. Levels are a function of the lipid content of the muscle tissue, i.e. 3.8% during low and 9% during high flow, implying that organohalogen exposure remains fairly constant throughout the year. PMID:22033654

  2. Observation-Based Assessment of PBDE Loads in Arctic Ocean Waters.

    Science.gov (United States)

    Salvadó, Joan A; Sobek, Anna; Carrizo, Daniel; Gustafsson, Örjan

    2016-03-01

    Little is known about the distribution of polybrominated diphenyl ethers (PBDE) -also known as flame retardants- in major ocean compartments, with no reports yet for the large deep-water masses of the Arctic Ocean. Here, PBDE concentrations, congener patterns and inventories are presented for the different water masses of the pan-Arctic shelf seas and the interior basin. Seawater samples were collected onboard three cross-basin oceanographic campaigns in 2001, 2005, and 2008 following strict trace-clean protocols. ∑14PBDE concentrations in the Polar Mixed Layer (PML; a surface water mass) range from 0.3 to 11.2 pg·L(-1), with higher concentrations in the pan-Arctic shelf seas and lower levels in the interior basin. BDE-209 is the dominant congener in most of the pan-Arctic areas except for the ones close to North America, where penta-BDE and tetra-BDE congeners predominate. In deep-water masses, ∑14PBDE concentrations are up to 1 order of magnitude higher than in the PML. Whereas BDE-209 decreases with depth, the less-brominated congeners, particularly BDE-47 and BDE-99, increase down through the water column. Likewise, concentrations of BDE-71 -a congener not present in any PBDE commercial mixture- increase with depth, which potentially is the result of debromination of BDE-209. The inventories in the three water masses of the Central Arctic Basin (PML, intermediate Atlantic Water Layer, and the Arctic Deep Water Layer) are 158 ± 77 kg, 6320 ± 235 kg and 30800 ± 3100 kg, respectively. The total load of PBDEs in the entire Arctic Ocean shows that only a minor fraction of PBDEs emissions are transported to the Arctic Ocean. These findings represent the first PBDE data in the deep-water compartments of an ocean. PMID:26840066

  3. Observation-Based Assessment of PBDE Loads in Arctic Ocean Waters.

    Science.gov (United States)

    Salvadó, Joan A; Sobek, Anna; Carrizo, Daniel; Gustafsson, Örjan

    2016-03-01

    Little is known about the distribution of polybrominated diphenyl ethers (PBDE) -also known as flame retardants- in major ocean compartments, with no reports yet for the large deep-water masses of the Arctic Ocean. Here, PBDE concentrations, congener patterns and inventories are presented for the different water masses of the pan-Arctic shelf seas and the interior basin. Seawater samples were collected onboard three cross-basin oceanographic campaigns in 2001, 2005, and 2008 following strict trace-clean protocols. ∑14PBDE concentrations in the Polar Mixed Layer (PML; a surface water mass) range from 0.3 to 11.2 pg·L(-1), with higher concentrations in the pan-Arctic shelf seas and lower levels in the interior basin. BDE-209 is the dominant congener in most of the pan-Arctic areas except for the ones close to North America, where penta-BDE and tetra-BDE congeners predominate. In deep-water masses, ∑14PBDE concentrations are up to 1 order of magnitude higher than in the PML. Whereas BDE-209 decreases with depth, the less-brominated congeners, particularly BDE-47 and BDE-99, increase down through the water column. Likewise, concentrations of BDE-71 -a congener not present in any PBDE commercial mixture- increase with depth, which potentially is the result of debromination of BDE-209. The inventories in the three water masses of the Central Arctic Basin (PML, intermediate Atlantic Water Layer, and the Arctic Deep Water Layer) are 158 ± 77 kg, 6320 ± 235 kg and 30800 ± 3100 kg, respectively. The total load of PBDEs in the entire Arctic Ocean shows that only a minor fraction of PBDEs emissions are transported to the Arctic Ocean. These findings represent the first PBDE data in the deep-water compartments of an ocean.

  4. Acute developmental exposure to polybrominated diphenyl ether 47 (PBDE 47) alters dopamine concentration within the brains of male mice.

    Science.gov (United States)

    Polybrominated diphenyl ethers (PBDEs) are commonly used as commercial flame retardants in a variety of products including plastics and textiles. Previous studies in our laboratory and in the literature have shown that exposure to a specific PBDE congener, PBDE 47, during a criti...

  5. Highest PBDE levels (max 63 ppm) yet found in biota measured in seabird eggs from San Francisco Bay

    Energy Technology Data Exchange (ETDEWEB)

    She, J.; Holden, A.; Tanner, M.; Sharp, M.; Hooper, K. [Department of Toxic Substances Control, Berkeley, CA (United States). Hazardous Materials Lab.; Adelsbach, T. [Environmental Contaminants Division, Sacramento Fish and Wildlife Office, US Fish and Wildlife Service, Sacramento, CA (United States)

    2004-09-15

    High levels of polybrominated diphenylethers (PBDEs) have been found in humans and wildlife from the San Francisco Bay Area, with levels in women among the highest in the world, and levels in piscivorous seabird eggs at the ppm level. Seabirds are useful for monitoring and assessing ecosystem health at various times and places because they occupy a high trophic level in the marine food web, are long-lived, and are generally localized near their breeding and non-breeding sites. In collaboration with the US Fish and Wildlife Services (USFWS), we are carrying out a three-year investigation of dioxin, PCB and PBDE levels in eggs from fish-eating seabirds. Year 1 (2002) PBDE measurements from 73 bird eggs were reported at Dioxin2003. Year 2 (2003) PBDE measurements from 45 samples are presented in this report. The highest PBDE level measured in eggs was 63 ppm, lipid, which is the highest PBDE level, yet reported in biota.

  6. In Vitro Neurotoxicity of PBDE-99: Immediate and Concentration-Dependent Effects on Protein Expression in Cerebral Cortex Cells

    DEFF Research Database (Denmark)

    Alm, Henrik; Scholz, Birger; Kultima, Kim;

    2010-01-01

    effects of low-concentration PBDE-99 exposure are fundamentally different than effects of high-concentration exposure. Low-dose PBDE-99 exposure induced marked effects on cytoskeletal proteins, which was not correlated to cytotoxicity or major morphological effects, suggesting that other more regulatory......Polybrominated diphenyl ethers (PBDEs) are commonly used flame retardants in various consumer products. Pre- and postnatal exposure to congeners of PBDEs disrupts normal brain development in rodents. Two-dimensional difference gel electrophoresis (2D-DIGE) was used to analyze concentration......-dependent differences in protein expression in cultured cortical cells isolated from rat fetuses (GD 21) after 24 h exposure to PBDE-99 (3, 10, or 30 muM). Changes on a post-translational level were studied using a 1 h exposure to 30 muM PBDE-99. The effects of 24 h exposure to 3 and 30 muM PBDE-99 on mRNA levels were...

  7. Serum PBDE levels in exposed rats in relation to effects on thyroxine homeostasis

    Energy Technology Data Exchange (ETDEWEB)

    Darnerud, P.O.; Aune, M.; Larsson, L.; Hallgren, S. [National Food Administration, Uppsala (Sweden)

    2004-09-15

    Brominated flame retardants (BFRs) is a group of environmental chemicals for which lately both interest and knowledge have increased considerably. Among the BFRs, the polybrominated diphenyl ethers (PBDEs) have attained special interest. Much data on environmental and human levels have been presented and several toxicological reviews are now published. Among interesting results is the difference in human PBDE levels that seem to exist between U.S.A. and Europe, results that suggest differences in exposure but without being able to pin-point the exact sources. In experimental studies PBDEs alter serum thyroxin levels, an effect seen both in rats and in mice. The mechanism(s) are still not completely clarified, but are thought to include alterations in serum transport, induced enzymatic degradation and possibly also direct effects on the thyroid gland. As perinatal alterations in thyroid homeostasis could affect brain development, early effects on thyroid hormones may be of special concern. Indeed, PBDEs have been shown to affect behaviour and learning in mice, when given neonatally. The aim of the present study was to relate the serum levels of PBDEs in rats to effects of these compounds on thyroxine homeostasis in these animals. Specifically, the relation between serum PBDE levels and effects on serum thyroxine levels was investigated, after two weeks of daily oral exposure. The result may have consequences for the future risk assessment activities on PBDE and specifically in finding the critical serum PBDE concentration at which the effect on thyroid hormone levels begin to occur.

  8. Bioaccumulation factors for radionuclides in freshwater biota

    International Nuclear Information System (INIS)

    This report analyzes over 200 carefully selected papers to provide concise data sets and methodology for estimation of bioaccumulation factors for tritium and isotopes of strontium, cesium, iodine, manganese, and cobalt in major biotic components of freshwater environments. Bioaccumulation factors of different tissues are distinguished where significant differences occur. Since conditions in the laboratory are often unnatural in terms of chemical and ecological relationships, this review was restricted as far as possible to bioaccumulation factors determined for natural systems. Because bioaccumulation factors were not available for some shorter-lived radionuclides, a methodology for converting bioaccumulation factors of stable isotopes to those of shorter-lived radionuclides was derived and utilized. The bioaccumulation factor for a radionuclide in a given organism or tissue may exhibit wide variations among bodies of water that are related to differences in ambient concentrations of stable-element and carrier-element analogues. To account for these variations, simple models are presented that relate bioaccumulation factors to stable-element and carrier-element concentrations in water. The effects of physicochemical form and other factors in causing deviations from these models are discussed. Bioaccumulation factor data are examined in the context of these models, and bioaccumulation factor relations for the selected radionuclides are presented

  9. Exposure to brominated flame retardant PBDE-99 affects cytoskeletal protein expression in the neonatal mouse cerebral cortex

    DEFF Research Database (Denmark)

    Alm, Henrik; Kultima, Kim; Scholz, Birger;

    2008-01-01

    Polybrominated diphenyl ethers (PBDEs) are environmental contaminants found in human and animal tissues worldwide. Neonatal exposure to the flame retardant 2,2', 4,4',5-pentabromodiphenyl ether (PBDE-99) disrupts normal brain development in mice, and results in disturbed spontaneous behavior in the...... adult. The mechanisms underlying the late effects of early exposure are not clear. To gain insight into the initial neurodevelopmental damage inflicted by PBDE-99, we investigated the short-term effects of PBDE-99 on protein expression in the developing cerebral cortex of neonatal mice, and the......-3 activity. These results indicate that the permanent neurological damage induced by PBDE-99 during the brain growth spurt involve detrimental effects on cytoskeletal regulation and neuronal maturation in the developing cerebral cortex....

  10. Influence of plants on the distribution and composition of PBDEs in soils of an e-waste dismantling area: Evidence of the effect of the rhizosphere and selective bioaccumulation

    International Nuclear Information System (INIS)

    Rhizosphere effects on the distribution of PBDEs in e-waste contaminated soils were investigated. The geometric means of the PBDEs in the rhizosphere and non-rhizosphere soils were 32.6 ng/g and 12.2 ng/g, whereas the geometric means of the PBDEs in vegetable shoots and roots were 2.15 ng/g and 3.02 ng/g, respectively. PBDEs in soil at different distances from the root surface may first rise appreciably and then decrease to a non-rhizosphere level for long-term contaminated soils. Different PBDE compositions in roots and shoots indicated that PBDEs in shoots may be mainly taken up from the air. The ratios of BDE99/100 and BDE153/154 in plants and their corresponding soils were different. The bioaccumulations of BDEs 100 and 154 were much higher than those of BDEs 99 and 153, respectively. This indicated that the bioaccumulation was selective and influenced by the substitution pattern, with ortho-substituted isomers being more prevalent than meta-substituted isomers. -- Highlights: • PBDEs in rhizosphere soils were higher than those in non-rhizosphere soils. • PBDEs in soil may first be accumulated and then reduced towards root surface. • Bioaccumulation of PBDEs is selective and influenced by substituent effect. • Bioaccumulations of BDEs 100 and 154 were much higher than BDEs 99 and 153. -- The bioaccumulation of PBDE isomers was selective and influenced by the substituent effect, with ortho-substitution being favored over meta-substitution

  11. Thyroid hormone levels and hepatic enzyme activity in lactating dams after gestational exposure to low dose PBDE 47

    Energy Technology Data Exchange (ETDEWEB)

    Kuriyama, S.N.; Grande, S.W.; Akkoc, Z.; Souza, C.A.M. de; Chahoud, I. [Charite Univ. Medical School Berlin (Germany). Inst. of Clinical Pharmacology and Toxicology, Dept. Toxicology, Campus Benjamin Franklin; Fidalgo-Neto, A.A. [Oswaldo Cruz Foundation, Rio de Janeiro (Brazil). Lab. of Environmental Toxicology

    2004-09-15

    Polybrominated diphenyl ethers (PBDEs), a class of widely used flame retardants, are found extensively in the environment (shown by several studies on sentinel animal species), as well as in humans. In rodents, technical commercial PBDE mixtures and individual congeners have shown to interfere with thyroid hormone homeostasis, produce a mix-type induction of hepatic microsomal enzymes, disrupt spontaneous behaviour, impair learning and memory and alter the cholinergic transmitter system. In rat and mice, some technical PBDE commercial mixtures such as DE-71 and Bromkal 70 and the congener PBDE 47 have shown to decrease circulating thyroid hormone levels. PBDEs are also able to induce both hepatic phase I and phase II detoxification enzymes, demonstrated by several investigations in laboratory animals. For example, induction of ethoxyresorufin-O-deethylase (EROD), pentoxyresorufin-Odespenthylase (PROD) and uridinediphospho-glucuronosyltransferase (UDPGT) has been shown in rodents and cell lines after exposure to technical mixtures or individual congeners. However, these studies deal with doses much higher than that found in human tissues, highlighting the importance of assessing the adverse effects of doses close to human exposure levels. PBDE 47 is the most predominant congener found in environmental and human samples (including human milk) and, therefore, hazard identification is extremely important for human risk assessment. We administered a single dose to gravid dams on gestation day 6 of either 140 {mu}g/kg BW or 700 {mu}g/kg BW of the congener, 2,2'4,4'-tetrabromo diphenyl ether (PBDE 47). These doses are pertinent to human exposure levels because a study by She et al. found a mean level of 33.3 {mu}g PBDE 47 /kg fat in human breast adipose tissue with a range from 7.01 to 196 {mu}g PBDE 47 /kg fat. In this study, thyroid hormone levels and hepatic enzyme activity were evaluated in lactating dams after in utero administration of low dose PBDE 47.

  12. Temporal Variability of Polybrominated Diphenyl Ether (PBDE) Serum Concentrations over One Year

    OpenAIRE

    Makey, Colleen M.; McClean, Michael D.; Sjödin, Andreas; Weinberg, Janice; Carignan, Courtney C.; Webster, Thomas F

    2014-01-01

    Polybrominated diphenyl ethers (PBDEs) are flame retardant chemicals used in consumer products. They are common contaminants in human serum and associated with adverse health effects. Our objectives were to characterize PBDE serum concentrations in a New England cohort and assess temporal variability of this exposure biomarker over a one-year period. We collected three repeated measurements at six-month intervals from 52 office workers from the greater Boston (MA, United States) area from 201...

  13. Occurrence and fate of PBDE in sewage sludge from municipal waste water treatment plants

    Energy Technology Data Exchange (ETDEWEB)

    Knoth, W.; Mann, W.; Meyer, R.; Nebhuth, J. [Federal Environmental Agency, POP Laboratory, Langen (Germany)

    2004-09-15

    With the rapidly growing use of combustible polymer material, e.g. for IT/TV casings, mattresses, upholstered furniture, the use of flame retardants like polybrominated diphenyl ether (PBDE) has also increased strongly. PBDE are available as three commercial mixtures of BDE congeners named after their principal component: PeBDE, OcBDE and DeBDE. They can release into the environment during their production, use or after disposal and have become ubiquitous. Because of (exponentially) increasing levels of the main congeners of technical Pe- and OcBDE in human blood and milk in Europe and California, the use and the placing on the market of preparations and articles containing these two flame retardants in concentrations >0.1% by mass are prohibited from August 15, 2004 in the European Union4 and in California from the year 2008. The main North American manufacturer of PeBDE flame retardant will voluntarily cease production by the end of 2004. For DeBDE a risk assessment is in progress. Surprising high levels were analysed in blood samples from 155 volunteers in the UK2 and a debromination to more bioavailable Hx- and HpBDE by juvenile carp (cyprinus carpio) following dietary exposure was observed. The objective of this study is to get more information about the actual levels and time trend of PBDE in sewage sludge in Germany and on a possible degradation of DeBDE by photolytic or reductive debromination during waste water treatment process.

  14. Black Carbon Inclusive Multichemical Modeling of PBDE and PCB Biomagnification and -Transformation in Estuarine Food Webs

    NARCIS (Netherlands)

    Paolo, C.; Gandhi, N.; Bhavsar, S.; Heuvel-Greve, van den M.J.; Koelmans, A.A.

    2010-01-01

    Bioavailability and bioaccumulation of polybrominated diphenylethers (PBDEs) are affected by adsorption on black carbon (BC) and metabolism in biota, respectively. Recent studies have addressed these two processes separately, illustrating their importance in assessing contaminant dynamics. In order

  15. Mercury bioaccumulation in the Mediterranean

    Directory of Open Access Journals (Sweden)

    Cinnirella S.

    2013-04-01

    Full Text Available This study details mercury pollution within the food chain of the Mediterranean by analysing the most comprehensive mercury dataset available for biota and water measurements. In this study we computed a bioaccumulation factor (BAF for datasets in the existing mercury-related scientific literature, in on-going programs, and in past measurement campaigns. Preliminary results indicate a major lack of information, making the outcome of any assessment very uncertain. Importantly, not all marine eco-regions are (or have ever been covered by measurement campaigns. Most lacking is information associated with the South-Eastern part of the Mediterranean, and in several eco-regions it is still impossible to reconstruct a trophic net, as the required species were not accounted for when mercury measurements were taken. The datasets also have additional temporal sampling problems, as species were often not sampled systematically (but only sporadically during any given sampling period. Moreover, datasets composed of mercury concentrations in water also suffer from similar geographic limitations, as they are concentrated in the North-Western Mediterranean. Despite these concerns, we found a very clear bioaccumulation trend in 1999, the only year where comprehensive information on both methylmercury concentrations in water and biota was available.

  16. DNA binding hydroxyl radical probes

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Vicky J.; Konigsfeld, Katie M.; Aguilera, Joe A. [Department of Radiology, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0610 (United States); Milligan, Jamie R., E-mail: jmilligan@ucsd.edu [Department of Radiology, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0610 (United States)

    2012-01-15

    The hydroxyl radical is the primary mediator of DNA damage by the indirect effect of ionizing radiation. It is a powerful oxidizing agent produced by the radiolysis of water and is responsible for a significant fraction of the DNA damage associated with ionizing radiation. There is therefore an interest in the development of sensitive assays for its detection. The hydroxylation of aromatic groups to produce fluorescent products has been used for this purpose. We have examined four different chromophores, which produce fluorescent products when hydroxylated. Of these, the coumarin system suffers from the fewest disadvantages. We have therefore examined its behavior when linked to a cationic peptide ligand designed to bind strongly to DNA. - Highlights: > Examined four aromatic groups as a means to detect hydroxyl radicals by fluorescence. > Coumarin system suffers from the fewest disadvantages. > Characterized its reactivity when linked to a hexa-arginine peptide.

  17. Iron bioaccumulation in mycelium of Pleurotus ostreatus

    Directory of Open Access Journals (Sweden)

    Sandra M. Almeida

    2015-03-01

    Full Text Available Pleurotus ostreatus is able to bioaccumulate several metals in its cell structures; however, there are no reports on its capacity to bioaccumulate iron. The objective of this study was to evaluate cultivation variables to increase iron bioaccumulation in P. ostreatusmycelium. A full factorial design and a central composite design were utilized to evaluate the effect of the following variables: nitrogen and carbon sources, pH and iron concentration in the solid culture medium to produce iron bioaccumulated in mycelial biomass. The maximum production of P. ostreatus mycelial biomass was obtained with yeast extract at 2.96 g of nitrogen L−1 and glucose at 28.45 g L−1. The most important variable to bioaccumulation was the iron concentration in the cultivation medium. Iron concentration at 175 mg L−1 or higher in the culture medium strongly inhibits the mycelial growth. The highest iron concentration in the mycelium was 3500 mg kg−1 produced with iron addition of 300 mg L−1. The highest iron bioaccumulation in the mycelium was obtained in culture medium with 150 mg L−1 of iron. Iron bioaccumulation in P. ostreatus mycelium is a potential alternative to produce non-animal food sources of iron.

  18. Potential reference measurement procedures for PBDE in surface water at levels required by the EU Water Frame Directive.

    Science.gov (United States)

    Swart, Claudia; Gantois, Fanny; Petrov, Panayot; Entwisle, John; Goenaga-Infante, Heidi; Nousiainen, Marjaana; Bílsel, Mine; Binici, Burcu; Gonzalez-Gago, Adriana; Pröfrock, Daniel; Gören, Ahmet C

    2016-05-15

    Polybrominated diphenylethers (PBDE), used as flame retardants, are named as priority substances in the Directive 2000/60/EC of the European parliament and of the council establishing a framework for Community action in the field of water policy. An annual average environmental quality standard (EQS) for inland surface waters of 0.0005µg/L (0.0002µg/L for other surface waters) for PBDE congeners involved in the technical penta-PBDE mixtures containing PBDE with five bromine atoms has been established. The directives focus especially on the congeners PBDE 28, 47, 99, 100, 153 and 154 contained in the penta-PBDE mixture. Up to now, no reference measurement procedures have been established reaching the limits of quantification (LOQs) and the associated uncertainties as defined in the directives with results traceable to the SI. Within a recent European project on metrology, different approaches for the traceable quantification of PBDE, based on liquid/liquid or solid phase extraction followed by the detection with gas chromatography coupled to either inductively coupled plasma mass spectrometry or triple quadrupole mass spectrometry, were investigated and the related LOQs and expanded uncertainties of the results were compared. A complete uncertainty budget for each method was estimated according to the Guide to the Expression of Uncertainty in Measurement (GUM). All presented analytical procedures can serve as reference measurement procedures regarding the LOQs and their associated expanded uncertainties for monitoring the six priority PBDEs named above. LOQs as low as 0.026ng/kg with an associated expanded uncertainty of 0.002ng/kg could be achieved. PMID:26992518

  19. Metals Bioaccumulation Mechanism in Neem Bark.

    Science.gov (United States)

    Krishnani, Kishore K; Boddu, Veera M; Moon, Deok Hyun; Ghadge, S V; Sarkar, Biplab; Brahmane, M P; Choudhary, K; Kathiravan, V; Meng, Xiaoguang

    2015-09-01

    The aim of this work was to define the bioaccumulation mechanism of metals onto the non-living biomaterial prepared from an extensively available plant bark biomass of neem (Azadirachta indica). Based on maximum ultimate fixation capacities (mmol/g) of the product, metals ions could be arranged as Hg(2+) Neem bark can be used as bioindicators, bioaccumulators and biomonitors while determining environmental pressures. Metal bioaccumulative properties and structural investigation of plant bark has potential in providing quantitative information on the metal contamination in the surrounding environment.

  20. CDRI-08 Attenuates REST/NRSF-Mediated Expression of NMDAR1 Gene in PBDE-209-Exposed Mice Brain.

    Science.gov (United States)

    Verma, Priya; Gupta, Rajaneesh K; Gandhi, Behrose S; Singh, Poonam

    2015-01-01

    CDRI-08 is a standardized bacoside enriched ethanolic extract of Bacopa monnieri, a nootropic plant. We reported that CDRI-08 attenuated oxidative stress and memory impairment in mice, induced by a flame retardant, PBDE-209. In order to explore the mechanism, present study was designed to examine the role of CDRI-08 on the expression of NMDAR1 (NR1) and the binding of REST/NRSF to NR1 promoter against postnatal exposure of PBDE-209. Male mice pups were orally supplemented with CDRI-08 at the doses of 40, 80, or 120 mg/kg along with PBDE-209 (20 mg/kg) during PND 3-10 and frontal cortex and hippocampus were collected at PND 11 and 60 to study the expression and regulation of NR1 by RT-PCR and electrophoretic mobility shift assay, respectively. The findings showed upregulated expression of NR1 and decreased binding of REST/NRSF to NR1 promoter after postnatal exposure of PBDE-209. Interestingly, supplementation with CDRI-08 significantly restored the expression of NR1 and binding of REST/NRSF to NR1 promoter near to the control value at the dose of 120 mg/kg. In conclusion, the results suggest that CDRI-08 possibly acts on glutamatergic system through expression and regulation of NR1 and may restore memory, impaired by PBDE-209 as reported in our previous study.

  1. CDRI-08 Attenuates REST/NRSF-Mediated Expression of NMDAR1 Gene in PBDE-209-Exposed Mice Brain

    Directory of Open Access Journals (Sweden)

    Priya Verma

    2015-01-01

    Full Text Available CDRI-08 is a standardized bacoside enriched ethanolic extract of Bacopa monnieri, a nootropic plant. We reported that CDRI-08 attenuated oxidative stress and memory impairment in mice, induced by a flame retardant, PBDE-209. In order to explore the mechanism, present study was designed to examine the role of CDRI-08 on the expression of NMDAR1 (NR1 and the binding of REST/NRSF to NR1 promoter against postnatal exposure of PBDE-209. Male mice pups were orally supplemented with CDRI-08 at the doses of 40, 80, or 120 mg/kg along with PBDE-209 (20 mg/kg during PND 3–10 and frontal cortex and hippocampus were collected at PND 11 and 60 to study the expression and regulation of NR1 by RT-PCR and electrophoretic mobility shift assay, respectively. The findings showed upregulated expression of NR1 and decreased binding of REST/NRSF to NR1 promoter after postnatal exposure of PBDE-209. Interestingly, supplementation with CDRI-08 significantly restored the expression of NR1 and binding of REST/NRSF to NR1 promoter near to the control value at the dose of 120 mg/kg. In conclusion, the results suggest that CDRI-08 possibly acts on glutamatergic system through expression and regulation of NR1 and may restore memory, impaired by PBDE-209 as reported in our previous study.

  2. Developmental exposure to a commercial PBDE mixture, DE-71: neurobehavioral, hormonal, and reproductive effects.

    Energy Technology Data Exchange (ETDEWEB)

    Kodavanti, Prasada [U.S. Environmental Protection Agency, Durham, North Carolina; Coburn, Cary [U.S. Environmental Protection Agency, Durham, North Carolina; Moser, Virginia [U.S. Environmental Protection Agency, Durham, North Carolina; MacPhail, Robert [U.S. Environmental Protection Agency, Durham, North Carolina; Fenton, Suzanne [National Institute of Environmental Health Sciences (NIEHS); Stoker, Tammy [U.S. Environmental Protection Agency, Durham, North Carolina; Birnbaum, Linda [National Institute of Environmental Health Sciences (NIEHS)

    2010-06-01

    Developmental effects of polybrominated diphenyl ethers (PBDEs) have been suspected due to their structural similarities to polychlorinated biphenyls (PCBs). This study evaluated neurobehavioral, hormonal, and reproductive effects in rat offspring perinatally exposed to a widely used pentabrominated commercial mixture, DE-71. Pregnant Long-Evans rats were exposed to 0, 1.7, 10.2, or 30.6 mg/kg/day DE-71 in corn oil by oral gavage from gestational day 6 to weaning. DE-71 did not alter maternal or male offspring body weights. However, female offspring were smaller compared with controls from postnatal days (PNDs) 35-60. Although several neurobehavioral endpoints were assessed, the only statistically significant behavioral finding was a dose-by-age interaction in the number of rears in an open-field test. Developmental exposure to DE-71 caused severe hypothyroxinemia in the dams and early postnatal offspring. DE-71 also affected anogenital distance and preputial separation in male pups. Body weight gain over time, reproductive tissue weights, and serum testosterone concentrations at PND 60 were not altered. Mammary gland development of female offspring was significantly affected at PND 21. Congener-specific analysis of PBDEs indicated accumulation in all tissues examined. Highest PBDE concentrations were found in fat including milk, whereas blood had the lowest concentrations on a wet weight basis. PBDE concentrations were comparable among various brain regions. Thus, perinatal exposure to DE-71 leads to accumulation of PBDE congeners in various tissues crossing blood-placenta and blood-brain barriers, causing subtle changes in some parameters of neurobehavior and dramatic changes in circulating thyroid hormone levels, as well as changes in both male and female reproductive endpoints. Some of these effects are similar to those seen with PCBs, and the persistence of these changes requires further investigation.

  3. Bioaccumulation of Triclocarban in Lumbriculus variegatus

    OpenAIRE

    Higgins, Christopher P.; J.Paesani, Zachary; Abbot Chalew, Talia E.; Halden, Rolf U.

    2009-01-01

    The antimicrobial triclocarban (TCC) has been detected in streams and municipal biosolids throughout the United States. In addition, TCC and potential TCC transformation products have been detected at high levels (ppm range) in sediments near major United States cities. Previous work has suggested that TCC is relatively stable in these environments, thereby raising concerns about the potential for bioaccumulation in sediment-dwelling organisms. Bioaccumulation of TCC from sediments was assess...

  4. Oral Exposure of PBDE-47 in Fish: Toxicokinetics and Reproductive Effects in Japanese Medaka (Oryzias latipes) and Fathead Minnows (Pimephales promelas)

    Energy Technology Data Exchange (ETDEWEB)

    Muirhead, Elisabeth K.; Skillman, Ann D.; Hook, Sharon E.; Schultz, Irv R.

    2006-01-15

    The toxicokinetics of 2,2,4,4-tetrabromodipohenyl ether (PBDE-47) was studied in the Japanese Medaka (Oryzias latipes) after a single oral exposure followed by termination at specific time points. The effects of repeated oral exposure to PBDE-47 on reproductive performance was assessed using a pair breeding experimental design with fathead minnows (Pimephales promelas) given daily PBDE-47 exposures for 25 days, during which fecundity was measured as an indicator of reproductive performance. Medaka and fathead minnows were orally exposed to PBDE-47 by bioencapsulation in brine shrimp, Artemia sp. In the medaka studies, measurable levels of PBDE-47 were detected in the carcass within 0.25 hr with peak levels occurring at 8 hrs. The body levels of PBDE-47 slowly declined and were still 25% of peak levels at 624 hrs after dosing. Assimilation of the bioencapsulated dose was at least 80% and may well approach 100 %. The PBDE-47 concentration-time profile was fitted to a one-compartment clearance-volume toxicokinetic model and the model-predicted values for elimination half-life was determined to be 281 hrs and the first order absorption rate constant was (Ka) = 0.26 hr 1. In the fathead minnow study, egg laying in the PBDE-treated breeding pairs stopped after 10 days. The condition factor of PBDE-treated males was significantly reduced (P < 0.011) compared with control males, whereas no significant difference was observed in females. Histological examination revealed a greater than 50% reduction in mature sperm in PBDE-47 exposed minnows compared to controls. Collectively, these results suggest PBDE-47 is selectively toxic to sexually mature male fathead minnows.

  5. Temporal variability of polybrominated diphenyl ether (PBDE) serum concentrations over one year.

    Science.gov (United States)

    Makey, Colleen M; McClean, Michael D; Sjödin, Andreas; Weinberg, Janice; Carignan, Courtney C; Webster, Thomas F

    2014-12-16

    Polybrominated diphenyl ethers (PBDEs) are flame retardant chemicals used in consumer products. They are common contaminants in human serum and associated with adverse health effects. Our objectives were to characterize PBDE serum concentrations in a New England cohort and assess temporal variability of this exposure biomarker over a one-year period. We collected three repeated measurements at six-month intervals from 52 office workers from the greater Boston (MA, United States) area from 2010 to 2011. The intraclass correlation coefficient for BDEs 28, 47, 99, 100, and 153 ranged from 0.87 to 0.99, indicating that a single serum measurement can reliably estimate exposure over a one-year period. This was true for both lipid adjusted and nonlipid adjusted concentrations. The kappa statistics, quantifying the level of agreement of categorical exposure classification, based on medians, tertiles, or quartiles ranged from 0.67 to 0.90. Some congeners showed nonsignificant increases from sampling round 1 (winter) to round 2 (summer) and significant decreases from round 2 to round 3 (winter). This study highlights the high reliability of a single serum PBDE measurement for use in human epidemiologic studies.

  6. PBDE exposure from food in Ireland: optimising data exploitation in probabilistic exposure modelling.

    Science.gov (United States)

    Trudel, David; Tlustos, Christina; Von Goetz, Natalie; Scheringer, Martin; Hungerbühler, Konrad

    2011-01-01

    Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants added to plastics, polyurethane foam, electronics, textiles, and other products. These products release PBDEs into the indoor and outdoor environment, thus causing human exposure through food and dust. This study models PBDE dose distributions from ingestion of food for Irish adults on congener basis by using two probabilistic and one semi-deterministic method. One of the probabilistic methods was newly developed and is based on summary statistics of food consumption combined with a model generating realistic daily energy supply from food. Median (intermediate) doses of total PBDEs are in the range of 0.4-0.6 ng/kg(bw)/day for Irish adults. The 97.5th percentiles of total PBDE doses lie in a range of 1.7-2.2 ng/kg(bw)/day, which is comparable to doses derived for Belgian and Dutch adults. BDE-47 and BDE-99 were identified as the congeners contributing most to estimated intakes, accounting for more than half of the total doses. The most influential food groups contributing to this intake are lean fish and salmon which together account for about 22-25% of the total doses.

  7. Neural defects and cardiac arrhythmia in fish larvae following embryonic exposure to 2,2',4,4'-tetrabromodiphenyl ether (PBDE 47).

    Science.gov (United States)

    Lema, Sean C; Schultz, Irvin R; Scholz, Nathaniel L; Incardona, John P; Swanson, Penny

    2007-05-31

    Polybrominated diphenyl ethers (PBDEs) are added to plastics, polyurethane foam, and textiles as a flame retardant. While PBDEs play a key role in reducing loss of human life and property from fires, these flame retardants have become pervasive organic contaminants in the environment and in the tissues of fish, birds, marine mammals, and humans. Levels of PBDEs in wildlife and humans continue to rise, raising concerns about potential ecological and health risks associated with exposure to these chemicals. Nevertheless, there is little currently known about the toxicological effects of PBDE exposure. Here, we examined the developmental toxicity of the PBDE congener 2,2',4,4'-tetrabromodiphenyl ether (PBDE 47) using the zebrafish (Danio rerio) as an ontogenetic model. Zebrafish embryos were exposed continuously to dissolved phase PBDE 47 (100-5000 microg/l) beginning 3-5 h post-fertilization (hpf). Fish treated with the highest concentrations of PBDE 47 delayed hatching, had reduced growth post-hatching, and displayed an abnormal dorsal curvature of the body with flexion at the hindbrain. By 96h post-fertilization larvae exposed to PBDE 47 had significant tachycardia, which progressed into atrioventricular block arrhythmias. Microinjection of fluorescent dye into the hindbrain ventricle revealed that cerebrospinal fluid in the neural tube and brain ventricles flowed more slowly in fish larvae exposed to PBDE 47, a likely etiology for the dorsal curvature. Similar, though much less pronounced, developmental toxicity also occurred in larvae exposed to PBDE 47 only for a 20h period during early embryogenesis (3-23 hpf), suggesting that PBDEs incorporated in lipid of the egg are bioavailable and cause toxicity later in life. Taken together, this work indicates that exposure to PBDE 47 can cause morphological abnormalities, impair cardiovascular function and cerebrospinal fluid flow, and provides a tractable starting point for using the zebrafish model to explore

  8. Levels of Polybrominated Diphenyl Ether (PBDE) flame retardants in animals representing different trophic levels of the North Sea food web

    NARCIS (Netherlands)

    Boon, J.P.; Lewis, W.E.; Tjoen-A-Choy, M.R.; Allchin, C.R.; Law, R.J.; Boer, de J.

    2002-01-01

    The levels of individual PBDE congeners were investigated in the invertebrate species whelk (Buccinum undatum), seastar (Asterias rubens), and hermit crab (Pagurus bernhardus), the gadoid fish species whiting (Merlangius merlangus) and cod (Gadus morhua), and the marine mammal species harbor seal (P

  9. Time trends of polybrominated diphenyl ethers in East China Seas: Response to the booming of PBDE pollution industry in China.

    Science.gov (United States)

    Li, Yuanyuan; Lin, Tian; Hu, Limin; Feng, Jialiang; Guo, Zhigang

    2016-01-01

    The East China Seas (ECSs) are the receptors of the land-based persistent organic pollutants (POPs), such as polybrominated diphenyl ethers (PBDEs) mainly from China through atmospheric deposition driven by the East Asian winter monsoon and fluvial discharge (e.g., Yangtze River and Yellow River), making the offshore sediments to be a good proxy to reconstruct history of those pollutants in China. In this work, four well-placed sediment cores were extracted from the mud areas in the ECSs, and the (210)Pb-dated cores were analyzed to yield historical concentration profiles of PBDEs in the area. The results showed that there was a persistent increase from 1970s and almost no clear sign in the decline of PBDEs until recently in China. More importantly, there was a faster increase of PBDEs from 1990s in China; while this period was just shown as gradually leveling off or even declining trends in developed countries. The persistently increasing trend of PBDEs in China since 1990s could be largely due to the booming of the manufacturing industry and unexpectedly transfer of PBDE pollution from developed countries to China. Besides, the relative high concentrations and fluxes of PBDEs in the core from coastal ECS located near a well-known electrical/electronic waste (e-waste) recycling area suggests an important contribution of PBDE emissions from recycling centers of e-waste in China. Although efforts in environmental monitoring of PBDE contamination have been substantially increased over the last decade, China is still lagging behind in terms of nationwide regulation of PBDE usage and treatment of disposal PBDE-containing products. PMID:27179303

  10. Bioaccumulation of dioxin-like substances and selected brominated flame retardant congeners in the fat and livers of black pigs farmed within the Nebrodi Regional Park of Sicily.

    Science.gov (United States)

    Brambilla, Gianfranco; De Filippis, Stefania Paola; Iamiceli, Anna Laura; Iacovella, Nicola; Abate, Vittorio; Aronica, Vincenzo; Di Marco, Vincenzo; di Domenico, Alessandro

    2011-02-01

    An observational study was designed to assess the bioaccumulation of polychlorodibenzodioxins (PCDD) and polychlorodibenzofurans (PCDF), dioxin-like polychlorobiphenyls (DL-PCB), and 13 selected polybromodiphenylethers (PBDE) in autochthonous pigs reared in the Nebrodi Park of Sicily (Italy). Perirenal fat and liver samples were drawn from animals representative of three different outdoor farming systems and from wild pigs and then analyzed for the chemicals mentioned previously. The highest concentrations of PCDD + PCDF and DL-PCB were detected in the fat (0.45 and 0.35 pg World Health Organization toxicity equivalents [WHO-TE] per g of fat base [FB], respectively) and livers (12.7 and 3.28 pg WHO-TE per g FB) of the wild group, whereas the free-ranging group showed the lowest levels (0.05 and 0.03 pg WHO-TE per g FB in fat and 0.78 and 0.27 pg WHO-TE per g FB in livers). The sum of PBDE congeners was highest in wild pigs (0.52 ng/g FB in fat and 5.64 ng/g FB in livers) and lowest in the farmed group (0.14 ng/g FB in fat and 0.28 ng/g FB in livers). The contamination levels in fat and livers of outdoor pigs had mean concentration values lower than those levels reported for intensively indoor-farmed animals. In wild pigs, bioaccumulation was associated with their free grazing in areas characterized by bush fires. The results of this study aid to emphasize the quality of the environment as a factor to guarantee food safety in typical processed pig meat products, specifically from outdoor and extensive Nebrodi farming systems. PMID:21333146

  11. Bioaccumulation of Arsenic by Fungi

    Directory of Open Access Journals (Sweden)

    Ademola O. Adeyemi

    2009-01-01

    Full Text Available Problem statement: Arsenic is a known toxic element and its presence and toxicity in nature is a worldwide environmental problem. The use of microorganisms in bioremediation is a potential method to reduce as concentration in contaminated areas. Approach: In order to explore the possible bioremediation of this element, three filamentous fungi-Aspergillus niger, Serpula himantioides and Trametes versicolor were investigated for their potential abilities to accumulate (and possibly solubilize arsenic from an agar environment consisting of non buffered mineral salts media amended with 0.2, 0.4, 0.6 and 0.8% (w/v arsenopyrite (FeAsS. Growth rates, dry weights, arsenic accumulation and oxalate production by the fungi as well as the pH of the growth media were all assessed during this study. Results: There was no visible solubilization of FeAsS particles underneath any of the growing fungal colonies or elsewhere in the respective agar plates. No specific patterns of growth changes were observed from the growth ratios of the fungi on agar amended with different amounts of FeAsS although growth of all fungi was stimulated by the incorporation of varying amounts of FeAsS into the agar with the exception of A. niger on 0.4% (w/v amended agar and T. versicolor on 0.8% (w/v amended agar. The amounts of dry weights obtained for all three fungi also did not follow any specific patterns with different amounts of FeAsS and the quantities obtained were in the order A. niger > S. himantioides > T. versicolor. All fungi accumulated as in their biomasses with all amounts of FeAsS although to varying levels and T. versicolor was the most effective with all amounts of FeAsS while A. niger was the least effective. Conclusion: The accumulation of arsenic in the biomasses of the test fungi as shown in this study may suggested a role for fungi through their bioaccumulating capabilities as agents in the possible bioremediation of arsenic contaminated environments.

  12. Hydroxylated PBDEs and brominated phenolic compounds in particulate matters emitted during recycling of waste printed circuit boards in a typical e-waste workshop of South China

    International Nuclear Information System (INIS)

    The hydroxylated PBDEs (OH-PBDEs) and brominated phenolic compounds in aerosol samples from a printed circuit boards recycling workshop were characterized. The results show that OH-PBDEs, which are naturally occurring compounds or metabolism of PBDEs, could also be emitted from the e-waste recycling. Five OH-PBDEs, several unidentified mono-OH-PBDE and di-OH-PBDE congeners were detected. The concentration of ∑OH-PBDEs was 1.74–4.22 ng m−3 (average of 2.66 ng m−3), with 6-OH-BDE-47 (0.329 ng m−3) as the most abundant identified congener. The total concentration of di- to tri-brominated phenols (BPs) was 18.8–32.0 ng m−3 (average of 26.3 ng m−3) with 2,4,6-triBP as the most abundant congener. These findings suggest that the recycling of printed circuit boards represent a strong source of OH-PBDEs and BPs to the atmosphere. Additionally, some phenolic compounds including brominated bisphenol A, hydroxylated polybrominated biphenyl species and etc. were also identified. -- Highlights: ► OH-PBDEs and BPs were abundant in the PM from printed circuit boards recycling. ► The patterns of OH-PBDEs and BPs were different from that in biotic environment. ► 6-OH-BDE-47 was the most abundant identified OH-PBDE congener. ► 2,4,6-triBP was the most abundant BP congener. ► Possible formation mechanisms of OH-PBDEs and BPs were discussed. -- Recycling of waste printed circuit boards might represent a strong source of OH-PBDEs, BPs and other phenolic compounds

  13. Metals bioaccumulation mechanism in neem bark

    Science.gov (United States)

    The aim of this work was to define the bioaccumulation mechanism of metals onto the non-living biomaterial prepared from an extensively available plant bark biomass of neem (Azadirachta indica). Based on maximum ultimate fixation capacities (mmol/g) of the product, metals ions could be arranged as H...

  14. Polychlorinated biphenyls (PCBs) and their hydroxylated metabolites (OH-PCBs) in harbor seal () livers from San Francisco Bay, California and Gulf of Maine

    OpenAIRE

    Park, June-Soo; Kalantzi, Olga Ioanna; Kopec, Dianne; Petreas, Myrto

    2009-01-01

    Abstract Bioaccumulation of endocrine disruptors in marine mammals positioned at the top of the food chain is of toxicological concern. Stranded four pup and ten adult harbor seal (Phoca vitulina) livers were collected from San Francisco Bay and the Gulf of Maine and analyzed for polychlorinated biphenyls (PCBs) and their hydroxylated metabolites (OH-PCBs). We used GC-ECD and GC-NCI/MS to investigate the presence of 28 PCBs and 8 OH-PCB metabolites, respectively. ?28PCB concentrati...

  15. PCB, PCDD/F and PBDE levels and profiles in crustaceans from the coastal waters of Brittany and Normandy (France)

    OpenAIRE

    Bodin, Nathalie; Abarnou, A.; Fraisse, D.; Defour, S.; Loizeau, V.; Le Guellec, A. M.; Philippon, X.

    2007-01-01

    Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analysed in the muscle of various edible marine crustaceans (spider crab, edible crab, velvet swimming crab and Norway lobster) from the Brittany and Normandy coasts (France). The highest concentrations were measured in species collected from Antifer (Seine Bay). PCB and PBDE patterns in crustacean muscles were similar and independent of the geographi...

  16. Pumping the stellar hydroxyl maser

    Science.gov (United States)

    Dickinson, Dale F.

    1987-01-01

    IRAS far-IR flux data for 163 OH maser stars were analyzed to quantify the contributions 35 and 53 microns inversions make to pumping of the hydroxyl maser. The 35 microns transition is from the 3,3 ground state to the 1,5 rotationally excited level and subsequent decay; the 53 microns transition is a change from the ground state to the 1,3 excited level and relaxation. The stars examined included Mira, short period semi-regular and long-period semi-regular variables. Both transition lines had rough parity in contributing to the approximately 8 percent pumping efficiency at 1612 MHz. However, the individual contributions of the lines could not be determined for the stellar population studied.

  17. Bioaccumulation of radiocaesium in Arctic seals

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, JoLynn; Wolkers, Hans; Andersen, Magnus; Rissanen, Kristina

    2002-12-01

    Seals are high trophic level feeders that bioaccumulate many contaminants to a greater degree than most lower trophic level organisms. Their trophic status in the marine food web and wide-spread distribution make seals useful sentinels of arctic environmental change. The purpose of this investigation is to document the levels and bioaccumulation potential of radiocaesium in high latitude seal species for which data have not previously been available. The study was carried out on harp, ringed, and bearded seals caught north of the island archipelago of Svalbard (82 deg. N) in 1999. The results are then compared with previous studies in order to elucidate factors responsible for bioaccumulation in Arctic seals. Concentrations of {sup 137}Cs were determined in muscle, liver and kidney samples from a total of 10 juvenile and one adult seal. The mean concentration in muscle samples for all animals was 0.23{+-}0.045 Bq/kg f.w. {sup 137}Cs concentrations in both liver and kidney samples were near detection limits ({approx}0.2 Bq/kg f.w.). The results are consistent with previous studies indicating low levels of radiocaesium in Arctic seals in response to a long term trend of decreasing levels of {sup 137}Cs in the Barents Sea region. Bioconcentration factors (BCFs) estimated for seals from NE Svalbard are low, ranging from 34 to 130. Comparing these values with reported BCFs for Greenland seals from other sectors of the European Arctic, we suggest that the combination of physiological and ecological factors on radiocaesium bioaccumulation is comparable among different Arctic seal populations. The application of this work to Arctic monitoring and assessment programs is discussed.

  18. A protocell design for bioaccumulation applications

    OpenAIRE

    von Hegner, Ian

    2015-01-01

    This article provides a specific example of recombinant cell and protocell technology, moving from what is presently known to suggesting how novel application of existing methodologies could be utilized to design a complex synthetic system in form of a self-sufficient light empowered protocell. A practical application of protocells using a primary example of desalination in water treatment is given, followed by a more general approach to bioaccumulation and bio-diagnostics, outlining the poss...

  19. An investigation into ciguatoxin bioaccumulation in sharks.

    Science.gov (United States)

    Meyer, Lauren; Capper, Angela; Carter, Steve; Simpfendorfer, Colin

    2016-09-01

    Ciguatoxins (CTXs) produced by benthic Gambierdiscus dinoflagellates, readily biotransform and bioaccumulate in food chains ultimately bioconcentrating in high-order, carnivorous marine species. Certain shark species, often feeding at, or near the top of the food-chain have the ability to bioaccumulate a suite of toxins, from both anthropogenic and algal sources. As such, these apex predators are likely sinks for CTXs. This assumption, in conjunction with anecdotal knowledge of poisoning incidents, several non-specific feeding trials whereby various terrestrial animals were fed suspect fish flesh, and a single incident in Madagascar in 1994, have resulted in the widespread acceptance that sharks may accumulate CTXs. This prompted a study to investigate original claims within the literature, as well as investigate CTX bioaccumulation in the muscle and liver of 22 individual sharks from nine species, across four locations along the east coast of Australia. Utilizing an updated ciguatoxin extraction method with HPLC-MS/MS, we were unable to detect P-CTX-1, P-CTX-2 or P-CTX-3, the three primary CTX congeners, in muscle or liver samples. We propose four theories to address this finding: (1) to date, methods have been optimized for teleost species and may not be appropriate for elasmobranchs, or the CTXs may be below the limit of detection; (2) CTX may be biotransformed into elasmobranch-specific congeners as a result of unique metabolic properties; (3) 22 individuals may be an inadequate sample size given the rare occurrence of high-order ciguatoxic organisms and potential for CTX depuration; and (4) the ephemeral nature and inconsistent toxin profiles of Gambierdiscus blooms may have undermined our classifications of certain areas as CTX hotspots. These results, in combination with the lack of clarity within the literature, suggest that ciguatoxin bioaccumulation in sharks remains elusive, and warrants further investigation to determine the dynamics of toxin production

  20. PCB and PBDE levels in a highly threatened dolphin species from the Southeastern Brazilian coast.

    Science.gov (United States)

    Lavandier, Ricardo; Arêas, Jennifer; Quinete, Natalia; de Moura, Jailson F; Taniguchi, Satie; Montone, Rosalinda; Siciliano, Salvatore; Moreira, Isabel

    2016-01-01

    In the Northern coast of Rio de Janeiro State is located the major urban centers of the oil and gas industry of Brazil. The intense urbanization in recent decades caused an increase in human use of the coastal areas, which is constantly impacted by agricultural, industrial and wastewater discharges. Franciscana dolphin (Pontoporia blainvillei) is a small cetacean that inhabits coastal regions down to a 30 m depth. This species is considered the most threatened cetacean in the Western South Atlantic Ocean. This study investigated the levels of 52 PCB congeners and 9 PBDE congeners in liver of nine individuals found stranded or accidentally caught between 2011 and 2012 in the Northern coast of Rio de Janeiro. PCB mean levels ranged from 208 to 5543 ng g(-1) lw and PBDEs mean concentrations varied between 13.84 and 36.94 ng g(-1) lw. Contamination patterns suggest the previous use of Aroclor 1254, 1260 and penta-BDE mixtures in Brazil. While still few studies have assessed the organic contamination in cetaceans from the Southern Hemisphere, including Brazil, the levels found in this study could represent a health risk to these endangered species.

  1. PCB and PBDE levels in a highly threatened dolphin species from the Southeastern Brazilian coast.

    Science.gov (United States)

    Lavandier, Ricardo; Arêas, Jennifer; Quinete, Natalia; de Moura, Jailson F; Taniguchi, Satie; Montone, Rosalinda; Siciliano, Salvatore; Moreira, Isabel

    2016-01-01

    In the Northern coast of Rio de Janeiro State is located the major urban centers of the oil and gas industry of Brazil. The intense urbanization in recent decades caused an increase in human use of the coastal areas, which is constantly impacted by agricultural, industrial and wastewater discharges. Franciscana dolphin (Pontoporia blainvillei) is a small cetacean that inhabits coastal regions down to a 30 m depth. This species is considered the most threatened cetacean in the Western South Atlantic Ocean. This study investigated the levels of 52 PCB congeners and 9 PBDE congeners in liver of nine individuals found stranded or accidentally caught between 2011 and 2012 in the Northern coast of Rio de Janeiro. PCB mean levels ranged from 208 to 5543 ng g(-1) lw and PBDEs mean concentrations varied between 13.84 and 36.94 ng g(-1) lw. Contamination patterns suggest the previous use of Aroclor 1254, 1260 and penta-BDE mixtures in Brazil. While still few studies have assessed the organic contamination in cetaceans from the Southern Hemisphere, including Brazil, the levels found in this study could represent a health risk to these endangered species. PMID:26552541

  2. Brominated and phosphorus flame retardants in White-tailed Eagle Haliaeetus albicilla nestlings: Bioaccumulation and associations with dietary proxies (δ{sup 13}C, δ{sup 15}N and δ{sup 34}S)

    Energy Technology Data Exchange (ETDEWEB)

    Eulaers, Igor, E-mail: igor.eulaers@uantwerpen.be [Ethology Group, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Jaspers, Veerle L.B., E-mail: veerle.jaspers@ntnu.no [Ethology Group, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim (Norway); Halley, Duncan J., E-mail: duncan.halley@nina.no [Norwegian Institute for Nature Research, Postboks 5685 Sluppen, 7485 Trondheim (Norway); Lepoint, Gilles, E-mail: G.Lepoint@ulg.ac.be [MARE Centre, Oceanology, University of Liège, Allée de la Chimie 3, 4000 Liège (Belgium); Nygård, Torgeir, E-mail: Torgeir.Nygard@nina.no [Norwegian Institute for Nature Research, Postboks 5685 Sluppen, 7485 Trondheim (Norway); Pinxten, Rianne, E-mail: annie.pinxten@uantwerpen.be [Ethology Group, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Covaci, Adrian, E-mail: adrian.covaci@uantwerpen.be [Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Eens, Marcel, E-mail: marcel.eens@uantwerpen.be [Ethology Group, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium)

    2014-04-01

    Very little is known on the exposure of high trophic level species to current-use brominated (BFRs) and phosphorus flame retardants (PFRs), although observations on their persistence, bioaccumulation potential, and toxicity have been made. We investigated the accumulation of BFRs and PFRs, and their associations with dietary proxies (δ{sup 13}C, δ{sup 15}N and δ{sup 34}S), in plasma and feathers of White-tailed Eagle Haliaeetus albicilla nestlings from Trøndelag, Norway. In addition to accumulation of a wide range of polybrominated diphenyl ether (PBDE) congeners in both plasma and feathers, all non-PBDE BFRs and PFRs could be measured in feathers, while in plasma only two of six PFRs, i.e. tris-(2-chloroisopropyl) phosphate (TCIPP) and tris-(2,3-dichloropropyl) phosphate (TDCPP) were detected. PFR concentrations in feathers (0.95–3000 ng g{sup −1}) were much higher than selected organochlorines (OCs), such as polychlorinated biphenyl 153 (CB 153; 2.3–15 ng g{sup −1}) and dichlorodiphenyldichloroethylene (p,p′-DDE; 2.3–21 ng g{sup −1}), PBDEs (0.03–2.3 ng g{sup −1}) and non-PBDE BFRs (0.03–1.5 ng g{sup −1}). Non-significant associations of PFR concentrations in feathers with those in plasma (P ≥ 0.74), and their similarity to reported atmospheric PFR concentrations, may suggest atmospheric PFR deposition on feathers. Most OCs and PBDEs, as well as tris(chloroethyl) phosphate (TCEP), tris(phenyl) phosphate (TPHP) and tri-(2-butoxyethyl) phosphate (TBOEP) were associated to δ{sup 15}N and/or δ{sup 13}C (all P ≤ 0.02). Besides δ{sup 15}N enrichment, δ{sup 34}S was depleted in nestlings from fjords, inherently close to an urbanised centre. As such, both may have been a spatial proxy for anthropogenic disturbance, possible confounding their use as dietary proxy. - Highlights: • Non-PBDE BFRs and PFRs were highly detected in feathers, but poorly in plasma. • PFR levels in feathers were up to 100-fold those of BFRs and selected OCs.

  3. Effect of polybrominated diphenyl ether (PBDE) treatment on the composition and function of the bacterial community in the sponge Haliclona cymaeformis.

    KAUST Repository

    Tian, Ren-Mao

    2014-01-01

    Marine sponges play important roles in benthic environments and are sensitive to environmental stresses. Polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants since the 1970s and are cytotoxic and genotoxic to organisms. In the present study, we studied the short-period effect of PBDE-47 (2,2\\',4,4\\'-tetrabromodiphenyl ether) treatment on the community structure and functional gene composition of the bacterial community inhabiting the marine sponge Haliclona cymaeformis. Our results showed that the bacterial community shifted from an autotrophic bacteria-dominated community to a heterotrophic bacteria-dominated community in response to PBDE-47 in a time- and concentration-dependent manner. A potentially symbiotic sulfur-oxidizing bacterium (SOB) was dominant (>80% in abundance) in the untreated sponge. However, exposure to a high concentration (1 μg/L) of PBDE-47 caused a substantial decrease in the potential symbiont and an enrichment of heterotrophic bacteria like Clostridium. A metagenomic analysis showed a selective effect of the high concentration treatment on the functional gene composition of the enriched heterotrophic bacteria, revealing an enrichment for the functions responsible for DNA repair, multidrug efflux pumping, and bacterial chemotaxis and motility. This study demonstrated that PBDE-47 induced a shift in the composition of the community and functional genes in the sponge-associated bacterial community, revealing the selective effect of PBDE-47 treatment on the functions of the bacterial community in the microenvironment of the sponge.

  4. Effect of polybrominated diphenyl ether (PBDE treatment on the composition and function of the bacterial community in the sponge Haliclona cymaeformis

    Directory of Open Access Journals (Sweden)

    Renmao eTian

    2015-01-01

    Full Text Available Marine sponges play important roles in benthic environments and are sensitive to environmental stresses. Polybrominated diphenyl ethers (PBDEs have been widely used as flame retardants since the 1970s and are cytotoxic and genotoxic to organisms. In the present study, we studied the short-period effect of PBDE-47 (2,2',4,4'-tetrabromodiphenyl ether treatment on the community structure and functional gene composition of the bacterial community inhabiting the marine sponge Haliclona cymaeformis. Our results showed that the bacterial community shifted from an autotrophic bacteria-dominated community to a heterotrophic bacteria-dominated community in response to PBDE-47 in a time- and concentration-dependent manner. A potentially symbiotic sulfur-oxidizing bacterium (SOB was dominant (>80% in abundance in the untreated sponge. However, exposure to a high concentration (1 µg/L of PBDE-47 caused a substantial decrease in the potential symbiont and an enrichment of heterotrophic bacteria like Clostridium. A metagenomic analysis showed a selective effect of the high concentration treatment on the functional gene composition of the enriched heterotrophic bacteria, revealing an enrichment for the functions responsible for DNA repair, multidrug efflux pumping, and bacterial chemotaxis and motility. This study demonstrated that PBDE-47 induced a shift in the composition of the community and functional genes in the sponge-associated bacterial community, revealing the selective effect of PBDE-47 treatment on the functions of the bacterial community in the microenvironment of the sponge.

  5. Hydroxyl Tagging Velocimetry for Rocket Plumes Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A non-intrusive method for measuring velocities in a rocket exhaust is proposed in a joint effort by MetroLaser and Vanderbilt University. Hydroxyl Tagging...

  6. Cyanotoxins: Bioaccumulation and Effects on Aquatic Animals

    Directory of Open Access Journals (Sweden)

    Betina Kozlowsky-Suzuki

    2011-12-01

    Full Text Available Cyanobacteria are photosynthetic prokaryotes with wide geographic distribution that can produce secondary metabolites named cyanotoxins. These toxins can be classified into three main types according to their mechanism of action in vertebrates: hepatotoxins, dermatotoxins and neurotoxins. Many studies on the effects of cyanobacteria and their toxins over a wide range of aquatic organisms, including invertebrates and vertebrates, have reported acute effects (e.g., reduction in survivorship, feeding inhibition, paralysis, chronic effects (e.g., reduction in growth and fecundity, biochemical alterations (e.g., activity of phosphatases, GST, AChE, proteases, and behavioral alterations. Research has also focused on the potential for bioaccumulation and transferring of these toxins through the food chain. Although the herbivorous zooplankton is hypothesized as the main target of cyanotoxins, there is not unquestionable evidence of the deleterious effects of cyanobacteria and their toxins on these organisms. Also, the low toxin burden in secondary consumers points towards biodilution of microcystins in the food web as the predominant process. In this broad review we discuss important issues on bioaccumulation and the effects of cyanotoxins, with emphasis on microcystins, as well as drawbacks and future needs in this field of research.

  7. Bioaccumulation and biomagnification of classical flame retardants, related halogenated natural compounds and alternative flame retardants in three delphinids from Southern European waters

    International Nuclear Information System (INIS)

    Occurrence and behaviour of classical (PBDEs) and alternative (HNs, HBB, PBEB, DBDPE and HBCD) flame retardants, together with naturally produced MeO-PBDEs, were studied in short-beaked common dolphin (Delphinus delphis), bottlenose dolphin (Tursiops truncatus) and long-finned pilot whale (Globicephala melas) in two sampling locations from Southern European waters. PBDEs, Dec 602, Dec 603, DP, α-HBCD and two MeO-PBDEs were detected in all three species. ∑PBDEs were between 17 and 2680 ng/g lw; ∑HNs were between 1.1 and 59 ng/g lw; α-HBCD levels ranged between 3.2 and 641 ng/g lw; ∑MeO-PBDEs were between 34 and 1966 ng/g lw. Bottlenose dolphins were the most contaminated species and some individuals could present health risk for endocrine disruption since levels found were above the reported threshold (1500 ng/g lw). Stable isotope analysis was used to evaluate the biomagnification capacity of these compounds. PBDEs, MeO-PBDEs and Dec 602 showed a significant positive correlation with trophic position. - Highlights: • Several FRs were detected in three dolphin species from Southern European waters. • Concentrations of classical FRs were higher than concentrations of alternative FRs. • MeO-PBDE concentrations were generally similar to PBDE concentrations. • Evidence of biomagnification capacity of some FRs was observed. • Some individuals were above the threshold level associated to endocrine disruption. - Bioaccumulation and biomagnification of halogenated compounds in dolphins

  8. Elemental bioaccumulators in air pollution studies

    International Nuclear Information System (INIS)

    K0-Based instrumental neutron activation analysis (k0 INAA) was used to determine the concentrations of Cr, Fe, Co, Zn, Se, Sb and Hg in the vascular plants Cistus salvifolius and Inula viscosa and in the lichen Parmelia sulcata. The samples were collected in the neighbourhood of industrial complexes. The elemental accumulation in the vascular plants and the lichen are compared to optimize the choice of the bioaccumulator. It is concluded that P.sulcata seems to be the best accumulator of the three species for the element studied; Cistus salvifolius is sensitive to the contents of Zn, Fe, Cr and Sb in the air; Inula viscosa seems to accumulate Fe, Sb, Co, Cr and Zn. Nevertheless, it is concluded that lichen is a good air pollution indicator, while the vascular plants are not due to the large seasonal variations found in the elemental concentrations. (author) 11 refs.; 7 figs.; 2 tabs

  9. A protocell design for bioaccumulation applications

    CERN Document Server

    von Hegner, Ian

    2015-01-01

    This article provides a specific example of recombinant cell and protocell technology, moving from what is presently known to suggesting how novel application of existing methodologies could be utilized to design a complex synthetic system in form of a self-sufficient light empowered protocell. A practical application of protocells using a primary example of desalination in water treatment is given, followed by a more general approach to bioaccumulation and bio-diagnostics, outlining the possibilities associated with applications of protocells. The key hypothesis is that the inside-negative electrochemical membrane potential generated by chloride pump activity via halorhodopsin could also be utilized to drive the accumulation of cations into a protocell. Thus, the functional expression of halorhodopsin could energize proton-coupled uptake of substances or metals through a selective cotransport channel for a number of applications in biotechnology, molecular medicine, and water biotechnology.

  10. VERIFICATION OF A TOXIC ORGANIC SUBSTANCE TRANSPORT AND BIOACCUMULATION MODEL

    Science.gov (United States)

    A field verification of the Toxic Organic Substance Transport and Bioaccumulation Model (TOXIC) was conducted using the insecticide dieldrin and the herbicides alachlor and atrazine as the test compounds. The test sites were two Iowa reservoirs. The verification procedure include...

  11. Bioaccumulation in aquatic systems: methodological approaches, monitoring and assessment

    DEFF Research Database (Denmark)

    Schäfer, Sabine; Buchmeier, Georgia; Claus, Evelyn;

    2015-01-01

    Bioaccumulation, the accumulation of a chemical in an organism relative to its level in the ambient medium, is of major environmental concern. Thus, monitoring chemical concentrations in biota are widely and increasingly used for assessing the chemical status of aquatic ecosystems. In this paper...... temporal and geographical range. Bioaccumulation is also assessed for regulation of chemicals of environmental concern whereby mainly data from laboratory studies on fish bioaccumulation are used. Field data can, however, provide additional important information for regulators. Strategies......, various scientific and regulatory aspects of bioaccumulation in aquatic systems and the relevant critical issues are discussed. Monitoring chemical concentrations in biota can be used for compliance checking with regulatory directives, for identification of chemical sources or event-related environmental...

  12. BIOACCUMULATION OF HEAVY METALS BY BACILLUS MEGATERIUM FROM PHOSPHOGYPSUM WASTE

    Directory of Open Access Journals (Sweden)

    IOANA ADRIANA STEFANESCU

    2015-05-01

    Full Text Available The aim of present study was to characterize the bioaccumulation capacity of heavy metals by Bacillus megaterium from phosphogypsum waste. The Bacillus megaterium strain (BM30 was isolated from soil near the phosphogypsum (PG dump. For the bioaccumulation quantification produced by BM30 strain were used three experimental treatments respectively with 2, 6 and 10 gL-1 PG. Cellular biomass samples were collected punctually at ages corresponding to the three stages of the development cycle of the microorganism: exponential phase, stationary phase and decline phase and the heavy metals concentrations were measured by atomic absorption spectroscopy. The bioaccumulation yields in cell biomass, relative to the total amount of analyte introduced in the reaction medium were between 20 - 80 %, the lowest value was recorded by Cu and highest by Mn. The study results indicated that the isolated strain near the dump PG, BM30, bioaccumulate heavy metals monitored in cell biomass in the order Cu > Fe > Zn = Mn.

  13. Bioaccumulation dynamics of polychlorinated biphenyls (PCBs) and organochlorine pesticides

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bioaccumulation dynamics of polychlorinated biphenyls (PCBs) and organochlorine pesticides was examined in young-of-the-year bluefish from seven sub-estuaries of...

  14. Hydroxyl induced eclogite fabric and deformation mechanism

    Institute of Scientific and Technical Information of China (English)

    ZHANG Junfeng; JIN Zhenmin; Harry W. Green II

    2005-01-01

    Eclogites from orogens often show strong plastic deformation and high hydroxyl content. We have studied the correlation between crystallographic preferred orientations of garnet and omphacite from natural eclogites with their hydroxyl contents using the electron back-scat- tered diffraction technique. The results show: 1) Omphacite has typical L-type or SL-type crystrallographic preferred orientations, that is, [001] is distributed in a girdle in the foliation plane with a maximum parallel to lineation; (010) is distributed in a girdle normal to the lineation with a maximum parallel to the foliation plane, suggesting a shear dominant deformation regime. Omphacite fabrics do not vary significantly with hydroxyl content, although the hydrous component may cause lower flow strength. 2) Hydroxyl can influence significantly flow properties of garnet in eclogite. Garnets behave as rigid bodies under low temperature and dry conditions. Grain boundary processes will dominate the deformation and lower the flow strength of garnet under high water fugacity conditions. Garnets show no crystallographic preferred orientation in both cases. These results may have important implications for a better understanding of deformation mechanisms and associated fluid activities during deep subduction and exhumation processes.

  15. A Mixture Reflecting Polybrominated Diphenyl Ether (PBDE) Profiles Detected in Human Follicular Fluid Significantly Affects Steroidogenesis and Induces Oxidative Stress in a Female Human Granulosa Cell Line.

    Science.gov (United States)

    Lefevre, Pavine L C; Wade, Mike; Goodyer, Cindy; Hales, Barbara F; Robaire, Bernard

    2016-07-01

    Brominated flame retardants are incorporated into consumer products to prevent flame propagation. These compounds leach into the domestic environment, resulting in chronic exposure. Pregnancy failure is associated with high levels of polybrominated diphenyl ethers (PBDEs), a major class of brominated flame retardants, in human follicular fluid, raising serious questions regarding their impact on female fertility. Our goal was to elucidate the effects of a mixture of PBDEs, similar to the profile found in human follicular fluid, on an immortalized human granulosa cell line, the KGN cell line. We showed that cell viability was altered and oxidative stress was induced as reflected by increased reactive oxygen species formation at 100 μM of the PBDE mixture. Transcriptomic analysis revealed that PBDE treatments of 1, 5, and 20 μM altered the expression of several genes involved in the reactive oxygen species signaling pathway. Significant dose-dependent reductions in progesterone and estradiol levels in the culture medium were measured after PBDE treatment; in parallel, the expression of genes involved in estradiol metabolism, namely CYP1A1, was up-regulated by 5 and 20 μM of the PBDE mixture. Treatment with 20 μM PBDE also increased the expression and secretion of the proinflammatory factor, IL-6, into the KGN cell culture medium. Our results demonstrate that PBDEs can alter human granulosa cell functions by inducing oxidative stress and disrupting steroidogenesis. These results indicate that PBDEs may be detrimental to ovarian functions and thus may adversely affect female reproductive health after chronic exposure. PMID:27219277

  16. Bioaccumulation of trace elements by Avicennia marina

    Directory of Open Access Journals (Sweden)

    Kandasamy Kathiresan

    2014-11-01

    Full Text Available Objective: To analyze the concentrations of 12 micro-nutrients (Al, B, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Zn in different plant parts of Avicennia marina and its rhizosphere soil of the south east coast of India. Methods: The samples were acid digested, then analyzed by using inductively coupled plasma system (ICP-Optical Emission Spectrophotometer. Results: Levels of metals were found in the decreasing order: Cd>Co>Ni>Pb>B >Cr>Zn>Mg>Mn>Cu>Fe>Al. The soil held more levels of metals than plant parts, but within the permissible limits of concentration. Bark and root accumulated higher levels of trace elements in a magnitude of 10-80 folds than other plant parts. The overall bioaccumulation factor in the sampling sites of Vellar, Pichavaram and Cuddalore was 2.88, 1.42 0.47 respectively. Essential elements accumulate high in mature mangroves forest while non-essential elements accumulate high in the industrially polluted mangroves. Conclusions: The ratio between essential and non-essential elements was found higher in young mangrove forest than that in mature mangrove forest and polluted mangrove areas. Thus, the ratio of accumulation can be used as an index of the growth and pollution status of mangroves.

  17. Bioaccumulation of trace elements by Avicennia marina

    Institute of Scientific and Technical Information of China (English)

    Kandasamy Kathiresan; Kandasamy Saravanakumar; Pandiyan Mullai

    2014-01-01

    Objective: To analyze the concentrations of 12 micro-nutrients (Al, B, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Zn) in different plant parts of Avicennia marina and its rhizosphere soil of the south east coast of India. Methods: The samples were acid digested, then analyzed by using inductively coupled plasma system (ICP-Optical Emission Spectrophotometer). Results: Levels of metals were found in the decreasing order: Cd>Co>Ni>Pb>B>Cr>Zn>Mg>Mn>Cu>Fe>Al. The soil held more levels of metals than plant parts, but within the permissible limits of concentration. Bark and root accumulated higher levels of trace elements in a magnitude of 10-80 folds than other plant parts. The overall bioaccumulation factor in the sampling sites of Vellar, Pichavaram and Cuddalore was 2.88, 1.42 0.47 respectively. Essential elements accumulate high in mature mangroves forest while non-essential elements accumulate high in the industrially polluted mangroves. Conclusions:The ratio between essential and non-essential elements was found higher in young mangrove forest than that in mature mangrove forest and polluted mangrove areas. Thus, the ratio of accumulation can be used as an index of the growth and pollution status of mangroves.

  18. Uranium bioaccumulation in a freshwater ecosystem: Impact of feeding ecology

    Energy Technology Data Exchange (ETDEWEB)

    Kraemer, Lisa D., E-mail: lisakraemer@trentu.ca [Trent University, 1600 West Bank Drive, Peterborough, ON, K9J 7B8 (Canada); Evans, Douglas [Trent University, 1600 West Bank Drive, Peterborough, ON, K9J 7B8 (Canada)

    2012-11-15

    Uranium bioaccumulation in a lake that had been historically affected by a U mine and (2) to use a combined approach of gut content examination and stable nitrogen and carbon isotope analysis to determine if U bioaccumulation in fish was linked to foodweb ecology. We collected three species of fish: smallmouth bass (Micropterus dolomieu), yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus), in addition to several invertebrate species including freshwater bivalves (family: Sphaeriidae), dragonfly nymphs (order: Odonata), snails (class: Gastropoda) and zooplankton (family: Daphniidae). Results showed significant U bioaccumulation in the lake impacted by historical mining activities. Uranium accumulation was 2-3 orders of magnitude higher in invertebrates than in the fish species. Within fish, U was measured in operculum (bone), liver and muscle tissue and accumulation followed the order: operculum > liver > muscle. There was a negative relationship between stable nitrogen ratios ({sup 15}N/{sup 14}N) and U bioaccumulation, suggesting U biodilution in the foodweb. Uranium bioaccumulation in all three tissues (bone, liver, muscle) varied among fish species in a consistent manner and followed the order: bluegill > yellow perch > smallmouth bass. Collectively, gut content and stable isotope analysis suggests that invertebrate-consuming fish species (i.e. bluegill) have the highest U levels, while fish species that were mainly piscivores (i.e. smallmouth bass) have the lowest U levels. Our study highlights the importance of understanding the feeding ecology of fish when trying to predict U accumulation.

  19. Uranium bioaccumulation in a freshwater ecosystem: Impact of feeding ecology

    International Nuclear Information System (INIS)

    Uranium bioaccumulation in a lake that had been historically affected by a U mine and (2) to use a combined approach of gut content examination and stable nitrogen and carbon isotope analysis to determine if U bioaccumulation in fish was linked to foodweb ecology. We collected three species of fish: smallmouth bass (Micropterus dolomieu), yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus), in addition to several invertebrate species including freshwater bivalves (family: Sphaeriidae), dragonfly nymphs (order: Odonata), snails (class: Gastropoda) and zooplankton (family: Daphniidae). Results showed significant U bioaccumulation in the lake impacted by historical mining activities. Uranium accumulation was 2–3 orders of magnitude higher in invertebrates than in the fish species. Within fish, U was measured in operculum (bone), liver and muscle tissue and accumulation followed the order: operculum > liver > muscle. There was a negative relationship between stable nitrogen ratios (15N/14N) and U bioaccumulation, suggesting U biodilution in the foodweb. Uranium bioaccumulation in all three tissues (bone, liver, muscle) varied among fish species in a consistent manner and followed the order: bluegill > yellow perch > smallmouth bass. Collectively, gut content and stable isotope analysis suggests that invertebrate-consuming fish species (i.e. bluegill) have the highest U levels, while fish species that were mainly piscivores (i.e. smallmouth bass) have the lowest U levels. Our study highlights the importance of understanding the feeding ecology of fish when trying to predict U accumulation.

  20. Study on Treating Halobios Pollution by Hydroxyl Radical

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The high ratio concentration hydroxyl solution is produced by strong discharge, and applied to the prevention of invasive species in ship ballast water and red tide. This paper introduces the plasma process of hydroxyl radical production, the production process of high ratio hydroxyl solution, and the application to treating ballast water and red tide.

  1. Modeling the role of microplastics in Bioaccumulation of organic chemicals to marine aquatic organisms. Critical Review

    NARCIS (Netherlands)

    Koelmans, A.A.

    2015-01-01

    It has been shown that ingestion of microplastics may increase bioaccumulation of organic chemicals by aquatic organisms. This paper critically reviews the literature on the effects of plastic ingestion on the bioaccumulation of organic chemicals, emphasizing quantitative approaches and mechanistic

  2. Bioaccumulation of dissociating substances; Bioakkumulation dissoziierender Stoffe

    Energy Technology Data Exchange (ETDEWEB)

    Butte, W.; Plegge, V.; Schettgen, C.; Willenborg, R.; Zauke, G.P. [Oldenburg Univ. (Germany). Fachbereich Chemie; Kuhlmann, H. [Oldenburg Univ. (Germany). Fachbereich Chemie]|[Bundesforschungsanstalt fuer Fischerei, Ahrensburg (Germany). Inst. fuer Fischereioekologie

    2000-02-01

    Bioconcentration factors (BCF) are important parameters to assess the environmental fate of chemicals. In this report we describe the determination of BCF for Triclosan, a trichlorophenoxy phenol, for some dissociating herbicides like Dichlorprop, MCPA, Mecoprop, Triclopyr and Picloram as well as for selected pyrethroids like Cyfluthrin, Cypermethrin, Deltamethrin and Permethrin. It was shown that BCF and rate constants for the uptake of Triclosan are decreasing with an increasing pH of the test water. The BCF for the herbicides evaluated are all below 10, confirming data already reported for herbicides of similar structure. Thus, for these compounds there is no tendency to bioaccumulate. Furthermore, there was no correlation between BCF and n-octanol/water partition coefficients or dissociation constants. BCF of pyrethroids were between 860 and 2200. For the analysis of pyrenthroid metabolites a gas chromatographic method using daughter-ion mass spectrometry for detection was established. The detection limit of this method was 1 {mu}g/kg, but metabolites could not be detected in fish during the bioaccumulation experiments. The high toxicity of pyrethroids for fish was approved; LC50-values were between 1 and 5 {mu}g/l. To evaluate physiological effects in fish, produced by pyrethroids, EROD activities in preparations of trout liver were measured. No increase in activity could be detected, but there was a tendency to lower values. We think this to result from the high toxicity of pyrethroids that could have impaired this enzyme system. (orig.) [German] Biokonzentrationsfaktoren (BCF) sind wichtige Parameter, mit Hilfe derer das Umweltverhalten von Chemikalien abgeschaetzt werden kann. Im Rahmen dieses Forschungsvorhabens wurden BCF-Werte fuer Triclosan, ein Trichlorphenoxyphenol, fuer einige dissoziierende Herbizide: Dichlorprop, MCPA, Mecoprop, Triclopyr und Picloram sowie fuer ausgewaehlte Pyrethroide: Cyfluthrin, Cypermethrin, Deltamethrin und Permethrin

  3. Hydroxyl radical induced degradation of ibuprofen

    Energy Technology Data Exchange (ETDEWEB)

    Illés, Erzsébet, E-mail: erzsebet.illes@chem.u-szeged.hu [Institute of Chemistry, Research Group of Environmental Chemistry, University of Szeged, Szeged (Hungary); Institute of Isotopes, Centre for Energy Research, Hungarian Academy of Sciences, Budapest (Hungary); Takács, Erzsébet [Institute of Isotopes, Centre for Energy Research, Hungarian Academy of Sciences, Budapest (Hungary); Dombi, András [Institute of Chemistry, Research Group of Environmental Chemistry, University of Szeged, Szeged (Hungary); Gajda-Schrantz, Krisztina [Institute of Chemistry, Research Group of Environmental Chemistry, University of Szeged, Szeged (Hungary); Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged (Hungary); EMPA, Laboratory for High Performance Ceramics, Duebendorf (Switzerland); Rácz, Gergely; Gonter, Katalin; Wojnárovits, László [Institute of Isotopes, Centre for Energy Research, Hungarian Academy of Sciences, Budapest (Hungary)

    2013-03-01

    Pulse radiolysis experiments were used to characterize the intermediates formed from ibuprofen during electron beam irradiation in a solution of 0.1 mmol dm{sup −3}. For end product characterization {sup 60}Co γ-irradiation was used and the samples were evaluated either by taking their UV–vis spectra or by HPLC with UV or MS detection. The reactions of {sup ·}OH resulted in hydroxycyclohexadienyl type radical intermediates. The intermediates produced in further reactions hydroxylated the derivatives of ibuprofen as final products. The hydrated electron attacked the carboxyl group. Ibuprofen degradation is more efficient under oxidative conditions than under reductive conditions. The ecotoxicity of the solution was monitored by Daphnia magna standard microbiotest and Vibrio fischeri luminescent bacteria test. The toxic effect of the aerated ibuprofen solution first increased upon irradiation indicating a higher toxicity of the first degradation products, then decreased with increasing absorbed dose. Highlights: ► In hydroxyl radical attack on the ring mainly hydroxylated products form ► The hydrated electron attacks the carboxyl group. ► Oxidative conditions are more effective in ibuprofen decomposition than reductive. ► Ecotoxicity of ibuprofen solution first increases then decreases with irradiation.

  4. Bioaccumulation of total mercury in the earthworm Eisenia andrei

    OpenAIRE

    Le Roux, Shirley; Baker, Priscilla; Crouch, Andrew

    2016-01-01

    Earthworms are a major part of the total biomass of soil fauna and play a vital role in soil maintenance. They process large amounts of plant and soil material and can accumulate many pollutants that may be present in the soil. Earthworms have been explored as bioaccumulators for many heavy metal species such as Pb, Cu and Zn but limited information is available for mercury uptake and bioaccumulation in earthworms and very few report on the factors that influence the kinetics of Hg uptake by ...

  5. Neuromodulatory role of Bacopa monnieri on oxidative stress induced by postnatal exposure to decabromodiphenyl ether (PBDE -209 in neonate and young female mice

    Directory of Open Access Journals (Sweden)

    Priya Verma

    2014-04-01

    Full Text Available Objective(s:Bacopa monnieri (BM,a traditional ayurvedic medicine,is a well-known memory enhancer. We have explored the role of BM against decabrominated diphenyl ether (PBDE-209-induced alterations in neonate and young female mice. Materials and Methods: Mice were orally administered with B. monnieri at the doses of 40, 80 or 120 mg/kg body weight along with PBDE-209 (20 mg/kg body weight from postnatal day (PND 3-10. Levels of malondialdehyde, protein carbonyl and activities of superoxide dismutase and glutathione peroxidase were measured at both ages. The correct choices and reference/working memory errors of young mice were evaluated by Morris water and radial arm maze. Results: The results showed that BM at the dose of 120 mg/kg significantly (P

  6. Effect of developmental low dose PBDE 47 exposure on thyroid hormone status and serum concentrations of FSH and inhibin B in male rats

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, A.J.M.; Kuriyama, S.N.; Akkoc, Z.; Talsness, C.E.; Chahoud, I. [Charite Univ. Medical School Berlin (Germany). Inst. of Clinical Pharmacology and Toxicology, Dept. Toxicology, Campus Benjamin Franklin

    2004-09-15

    Several persistent halogenated organic compounds such as PCBs, dioxins and more recently, polybrominated diphenyl ethers (PBDEs) have been shown to disrupt thyroid hormone homeostasis in experimental animals. Particular concern exists regarding exposure to these compounds during critical periods of development when thyroid hormones orchestrate the growth and differentiation of many organs including the brain and the testis. While the contamination levels of PCBs and other persistent organic pollutants have declined in the past years, increasing levels of PBDEs have been detected in environmental and human samples including human breast milk. PBDEs are produced in large quantities and used worldwide as flame retardants in electrical appliances, carpets and furniture upholstery. Similar to other halogenated environmental organic pollutants, PBDEs seem to present a wide range of toxic effects including reproductive, endocrine, neurobehavioral and hepatic toxicity. Recently, it has been demonstrated that in utero and pubertal exposures to DE-71 (a commercial mixture containing mostly tetra- and penta-bromodiphenyl ethers) significantly reduce thyroxine levels (T4) in rats. The present study has focused on the possible effects of the tetra- BDE congener 2,2'4,4'-tetrabromo diphenyl ether (PBDE 47) on thyroid hormone status and associated changes on FSH and inhibin B levels in the developing male rat. We administered a single dose to gravid dams on gestation day 6 of either 140 {mu}g/kg BW or 700 {mu}g/kg BW PBDE 47. These doses are pertinent to human exposure situation because a study by She et al.3 found a mean level of 33.3 {mu}g PBDE 47 /kg fat in human breast adipose tissue with a range from 7.01 to 196 {mu}g PBDE 47 /kg fat.

  7. Developmental exposure to PBDE 99 and PCB affects estrogen sensitivity of target genes in rat brain regions and female sexual behavior

    Energy Technology Data Exchange (ETDEWEB)

    Lichtensteiger, W.; Faass, O.; Ceccatelli, R.; Schlumpf, M. [Zurich Univ. (Switzerland). Inst. of Pharmacology and Toxicology

    2004-09-15

    We recently reported effects of PBDE99 (2,2',4,4'5-pentabromoBDE) on sexual differentiation processes in rat reproductive organs and central nervous system. These studies were prompted by reports on an increase of PBDE levels in human milk, an indicator of the body burden of pregnant women and of potential exposure of the nursing infant, during the last decade. Even higher human adipose tissue and milk levels were reported for North America. PBDE99 is present in human and animal samples and exhibits developmental neurotoxicity in mice. The developing brain is subject to the organizing action of estradiol locally formed from circulating testosterone, and thus represents a target for endocrine active chemicals. One molecular mechanism by which chemicals may interfere with sexual brain differentiation, may be a change in the expression of sex hormone (estrogen)-regulated genes. Such effects may manifest themselves in mRNA expression levels, or in the sensitivity of the genes to estrogen. In order to detect alterations of the latter, more subtle parameter, we have conducted experiments in developmentally chemical-exposed rat offspring that were gonadectomized in adulthood and injected with a challenge dose of estradiol. Effects of PBDE99 were compared with those of a commercial PCB mixture, Aroclor 1254, which had previously been found to influence sexual brain differentiation. We analyzed the expression of estrogen-regulated genes in ventromedial hypothalamus (VMH) and medial preoptic area (MPO), two brain regions that are part of a network involved in the integration of environmental cues, sexual behavior and gonadal function. Since prominent changes were observed in VMH which is particularly important for female sexual behavior, the study was completed by a behavioral analysis.

  8. An assessment of PCB and PBDE contamination in two tropical dolphin species from the Southeastern Brazilian coast.

    Science.gov (United States)

    Lavandier, Ricardo; Arêas, Jennifer; Dias, Patrick S; Taniguchi, Satie; Montone, Rosalinda; de Moura, Jailson Fulgencio; Quinete, Natalia; Siciliano, Salvatore; Moreira, Isabel

    2015-12-30

    PCBs and PBDEs were determined in two dolphin species, Sotalia guianensis and Steno bredanensis, from an upwelling system off the Central-northern coast of Rio de Janeiro, Brazil. PCB levels varied from 0.040 to 0.75 μg g(-1) lw in muscles and from 0.022 to 1.32 μg g(-1)lw in liver samples from S. guianensis. In S. bredanensis, values varied from 0.085 to 11.3 μg g(-1) lw in muscles and from 0.024 to 18.6 μg g(-1) lw in livers. PCB-138, -153 and -180 were the major PCB congeners detected in both species, while BDE-47 was the predominant PBDE congener found in both species. Higher concentrations in S. bredanensis were possibly related to the different feeding habits for both delphinid species. These results contribute to extend the database on organic contamination in cetaceans from the southern hemisphere, understanding their distribution and environmental fate in Southeastern Brazil. PMID:26506024

  9. Trophodynamics of hexabromocyclododecanes and several other non-PBDE brominated flame retardants in a freshwater food web.

    Science.gov (United States)

    Wu, Jiang-Ping; Guan, Yun-Tao; Zhang, Ying; Luo, Xiao-Jun; Zhi, Hui; Chen, She-Jun; Mai, Bi-Xian

    2010-07-15

    Several currently used non-polybrominated diphenyl ether (PBDE) brominated flame retardants (BFRs), including hexabromocyclododecanes (HBCDs), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenyl ethane (DBDPE), hexabromobenzene (HBB), pentabromoethylbenzene (PBEB), and pentabromotoluene (PBT), are examined in the components of a freshwater food web from an electronic waste recycling site, South China. All these BFRs are detectable in the food web, with average concentrations of 13.9-868, 1.71-518, Food web magnification is observed for (+)-alpha-, (-)-alpha-, (+/-)-alpha-, and total HBCDs, and HBB, with trophic magnification factors (TMFs) of 2.22, 2.18, 2.19, 1.82, and 1.46, respectively; whereas there is trophic dilution of BTBPE and PBT through the food web. The TMFs for (+)-alpha-, (-)-alpha-, and (+/-)-alpha-HBCDs are comparable to those of PBDEs detected previously in the same food web. Biota samples show a shift from gamma- toward alpha-HBCD compared with the suspended particles, sediment, and HBCD technical mixtures, with a significant increase of alpha-HBCD on ascending trophic levels. Except for alpha-HBCD in suspended particles and sediment, all the HBCD enantiomers detected are nonracemic in the environmental matrix. In biota, nonracemic residues of alpha-HBCD were observed in mud carp and crucian carp; beta-HBCD in prawn, mud carp, and crucian carp; and gamma-HBCD in water snake, with preferences for (+)-alpha-, (-)-beta-, and (+)-gamma-HBCDs. PMID:20575536

  10. Optimizing fish sampling for fish–mercury bioaccumulation factors

    Science.gov (United States)

    Fish Bioaccumulation Factors (BAFs; ratios of mercury (Hg) in fish (Hgfish) and water (Hgwater)) are used to develop total maximum daily load and water quality criteria for Hg-impaired waters. Both applications require representative Hgfish estimates and, thus, are sensitive to s...

  11. Trait-based modelling of bioaccumulation by freshwater benthic invertebrates.

    Science.gov (United States)

    Sidney, Livia Alvarenga; Diepens, Noël J; Guo, Xiaoying; Koelmans, Albert A

    2016-07-01

    Understanding the role of species traits in chemical exposure is crucial for bioaccumulation and toxicity assessment of chemicals. We measured and modelled bioaccumulation of polychlorinated biphenyls (PCBs) in Chironomus riparius, Hyalella azteca, Lumbriculus variegatus and Sphaerium corneum. We used a battery test procedure with multiple enclosures in one aquarium, which maximized uniformity of exposure for the different species, such that the remaining variability was due mostly to species traits. The relative importance of uptake from either pore water or sediment ingestion was manipulated by using 28 d aged standard OECD sediment with low (1%) and medium (5%) OM content and 13 months aged sediment with medium OM (5%) content. Survival was ≥76% and wet weight increased for all species. Reproduction of H. azteca and weight gain of H. azteca and S. corneum were significantly higher in the medium OM aged sediments than in other sediments, perhaps due to a more developed microbial community (i.e., increase in food resources). Biota-sediment accumulation factors (BSAF) ranged from 3 to 114, depending on species and PCB congener, with C. riparius (3-10)bioaccumulation model with species-specific bioaccumulation parameters fitted well to the experimental data and showed that bioaccumulation parameters were depended on species traits. Enclosure-based battery tests and mechanistic BSAF models are expected to improve the quality of the exposure assessment in whole sediment toxicity tests. PMID:27126443

  12. Uranium bioaccumulation in a freshwater ecosystem: impact of feeding ecology.

    Science.gov (United States)

    Kraemer, Lisa D; Evans, Douglas

    2012-11-15

    The objectives of our study were: (1) to determine if there was significant uranium (U) bioaccumulation in a lake that had been historically affected by a U mine and (2) to use a combined approach of gut content examination and stable nitrogen and carbon isotope analysis to determine if U bioaccumulation in fish was linked to foodweb ecology. We collected three species of fish: smallmouth bass (Micropterus dolomieu), yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus), in addition to several invertebrate species including freshwater bivalves (family: Sphaeriidae), dragonfly nymphs (order: Odonata), snails (class: Gastropoda) and zooplankton (family: Daphniidae). Results showed significant U bioaccumulation in the lake impacted by historical mining activities. Uranium accumulation was 2-3 orders of magnitude higher in invertebrates than in the fish species. Within fish, U was measured in operculum (bone), liver and muscle tissue and accumulation followed the order: operculum>liver>muscle. There was a negative relationship between stable nitrogen ratios ((15)N/(14)N) and U bioaccumulation, suggesting U biodilution in the foodweb. Uranium bioaccumulation in all three tissues (bone, liver, muscle) varied among fish species in a consistent manner and followed the order: bluegill>yellow perch>smallmouth bass. Collectively, gut content and stable isotope analysis suggests that invertebrate-consuming fish species (i.e. bluegill) have the highest U levels, while fish species that were mainly piscivores (i.e. smallmouth bass) have the lowest U levels. Our study highlights the importance of understanding the feeding ecology of fish when trying to predict U accumulation. PMID:22963859

  13. Bioaccumulation factors in aquatic ecosystems. A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Sara; Meili, Markus; Bergstroem, Ulla [Studsvik Eco and Safety AB, Nykoeping (Sweden)

    2002-07-01

    The calculated concentrations of radionuclides in organisms are often obtained by means of bioaccumulation factors (BAF) that describe the internal concentration relative to an external concentration e.g. in the abiotic environments at steady-state conditions. Such factors are often used when modelling the dose to man from radio-nuclides released to the biosphere. Values of bioaccumulation factors vary widely in magnitude among elements, organisms, and environmental conditions which is not always considered. In order to relate the bioaccumulation factors for some radionuclides to environmental conditions as well as to the trophic level of the organism of concern we have compiled an extensive database with bioaccumulation factors (about 5,500 values) together with information on some environmental conditions. The data for nine radionuclides has been extracted and examined. A comparison between the bioaccumulation factors found in this study and values given in literature by IAEA and NCRP shows that the ranges presented in this study are generally somewhat higher with the exception of BAF for molybdenum in freshwater fish which is of the same order of magnitude. This is startling and calls for a thorough research. The amount of readily accessible and reliable values of BAF is limited, often because basic information such as e.g. units and part of organism examined, is not reported. This is surprising and also unfortunate for those who need such data for use in generic or specific models. A major update of recommended values appears to be necessary for many elements to account for the development of analytical methods and experiences from case studies over the past two decades.

  14. Hydroxylated polybrominated diphenyl ethers exhibit different activities on thyroid hormone receptors depending on their degree of bromination

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Xiao-Min, E-mail: rxm200318@gmail.com; Guo, Liang-Hong, E-mail: LHGuo@rcees.ac.cn; Gao, Yu, E-mail: francesscototti@gmail.com; Zhang, Bin-Tian, E-mail: nktianster@gmail.com; Wan, Bin, E-mail: binwan@rcees.ac.cn

    2013-05-01

    Polybrominated diphenyl ethers (PBDEs) have been shown to disrupt thyroid hormone (TH) functions in experimental animals, and one of the proposed disruption mechanisms is direct binding of hydroxylated PBDE (OH-PBDE) to TH receptors (TRs). However, previous data on TH receptor binding and TH activity of OH-PBDEs were very limited and sometimes inconsistent. In the present paper, we examined the binding potency of ten OH-PBDEs with different degrees of bromination to TR using a fluorescence competitive binding assay. The results showed that the ten OH-PBDEs bound to TR with potency that correlated to their bromination level. We further examined their effect on TR using a coactivator binding assay and GH3 cell proliferation assay. Different TR activities of OH-PBDEs were observed depending on their degree of bromination. Four low-brominated OH-PBDEs (2′-OH-BDE-28, 3′-OH-BDE-28, 5-OH-BDE-47, 6-OH-BDE-47) were found to be TR agonists, which recruited the coactivator peptide and enhanced GH3 cell proliferation. However, three high-brominated OH-PBDEs (3-OH-BDE-100, 3′-OH-BDE-154, 4-OH-BDE-188) were tested to be antagonists. Molecular docking was employed to simulate the interactions of OH-PBDEs with TR and identify the structural determinants for TR binding and activity. According to the docking results, low-brominated OH-PBDEs, which are weak binders but TR agonists, bind with TR at the inner side of its binding pocket, whereas high-brominated compounds, which are potent binders but TR antagonists, reside at the outer region. These results indicate that OH-PBDEs have different activities on TR (agonistic or antagonistic), possibly due to their different binding geometries with the receptor. - Highlights: ► Thyroid hormone (TH) activity of OH-PBDEs with different Br number was evaluated. ► Four different experimental approaches were employed to investigate the mechanism. ► Low-brominated OH-PBDEs were agonists, but high-brominated ones were antagonists.

  15. Global tropospheric hydroxyl distribution, budget and reactivity

    Science.gov (United States)

    Lelieveld, Jos; Gromov, Sergey; Pozzer, Andrea; Taraborrelli, Domenico

    2016-10-01

    The self-cleaning or oxidation capacity of the atmosphere is principally controlled by hydroxyl (OH) radicals in the troposphere. Hydroxyl has primary (P) and secondary (S) sources, the former mainly through the photodissociation of ozone, the latter through OH recycling in radical reaction chains. We used the recent Mainz Organics Mechanism (MOM) to advance volatile organic carbon (VOC) chemistry in the general circulation model EMAC (ECHAM/MESSy Atmospheric Chemistry) and show that S is larger than previously assumed. By including emissions of a large number of primary VOC, and accounting for their complete breakdown and intermediate products, MOM is mass-conserving and calculates substantially higher OH reactivity from VOC oxidation compared to predecessor models. Whereas previously P and S were found to be of similar magnitude, the present work indicates that S may be twice as large, mostly due to OH recycling in the free troposphere. Further, we find that nighttime OH formation may be significant in the polluted subtropical boundary layer in summer. With a mean OH recycling probability of about 67 %, global OH is buffered and not sensitive to perturbations by natural or anthropogenic emission changes. Complementary primary and secondary OH formation mechanisms in pristine and polluted environments in the continental and marine troposphere, connected through long-range transport of O3, can maintain stable global OH levels.

  16. PBDE and HBCDD levels in blood from Dutch mothers and infants. Analysis of a Dutch Groningen infant cohort

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, J.; Linderholm, L.; Athanassiadis, I.; Bergman, Aa. [Dept. of Environmental Chemistry, Stockholm Univ. (Sweden); Meijer, L.; Sauer, P. [Dept. of Paediatrics, State Univ. Groningen (Netherlands)

    2004-09-15

    Brominated flame retardants (BFRs) are chemicals with a large industrial production and ubiquitous global use. The three major classes of BFRs produced worldwide are; tetrabromobisphenol A (TBBPA), three commercial mixtures of polybrominated diphenyl ethers (PBDEs), Deca-, Octa- and PentaBDE and hexabromocyclododecane (HBCDD). Several BFRs are, due to their lipophilicity and bioaccumulation properties, both expected and in reality found in wildlife and humans. The aim of this study was to establish a clean up method for HBCDD analysis in human serum, as well as to investigate levels of PBDEs and HBCDD in serum from mothers and infants from a Dutch cohort. A total of 90 human serum samples were analyzed. To the best of our knowledge, HBCDD has not been reported previously in humans, and PBDEs have not been reported in human serum from The Netherlands.

  17. Hydroxyl radical induced degradation of ibuprofen.

    Science.gov (United States)

    Illés, Erzsébet; Takács, Erzsébet; Dombi, András; Gajda-Schrantz, Krisztina; Rácz, Gergely; Gonter, Katalin; Wojnárovits, László

    2013-03-01

    Pulse radiolysis experiments were used to characterize the intermediates formed from ibuprofen during electron beam irradiation in a solution of 0.1mmoldm(-3). For end product characterization (60)Co γ-irradiation was used and the samples were evaluated either by taking their UV-vis spectra or by HPLC with UV or MS detection. The reactions of OH resulted in hydroxycyclohexadienyl type radical intermediates. The intermediates produced in further reactions hydroxylated the derivatives of ibuprofen as final products. The hydrated electron attacked the carboxyl group. Ibuprofen degradation is more efficient under oxidative conditions than under reductive conditions. The ecotoxicity of the solution was monitored by Daphnia magna standard microbiotest and Vibrio fischeri luminescent bacteria test. The toxic effect of the aerated ibuprofen solution first increased upon irradiation indicating a higher toxicity of the first degradation products, then decreased with increasing absorbed dose.

  18. Exchange Reaction Between Selenite and Hydroxyl Ion of Variable Charge Soil Surfaces: Ⅱ. Kinetics of Hydroxyl Release

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shi-Wei; ZHANG Gang-Ya; ZHANG Xiao-Nian

    2003-01-01

    A self-made constant pH automated titration instrument was used to study the kinetics of hydroxyl release during selenite reacting with variable charge soils. The rate of hydroxyl release was very rapid at the first several minutes, then gradually slowed down, and at last did not change any more. The experimental data was well fitted by the Langmuir kinetic equation, and with increasing selenite concentration or decreasing solution pH, the reaction lasted longer, the maximum of hydroxyl release (xm) increased, and the binding constant (k) decreased. The time of hydroxyl release with Xuwen latosol was much longer than that with Jinxian red soil.

  19. Bioaccumulation of Cs-137 and Co-57 by marine phytoplankton

    Energy Technology Data Exchange (ETDEWEB)

    Heldal, H.E. [Inst. of Marine Research, Bergen (Norway); Stupakoff, I.; Fisher, N.S. [State Univ. of New York, Marine Sciences Research Center, Stone Brook, NY (United States)

    1999-11-01

    Under controlled laboratory conditions we have examined the bioaccumulation of Cs-137 and Co-57 in three prymnesiophytes, the coccolithophorid Emiliania huxleyi and the non-calcareous species Isochrysis galbana and Phaeocystis globosa, and two diatoms Skeletonema costatum and Thalassiosira pseudonana. We measured uptake in growing and non-growing cells, and determined concentration factors on both volume and dry weight basis. For Co-57 uptake in non-growing cells, volume concentration factors (VCF) at equilibrium ranged from 0.2{sup *}10{sup 3} for Emiliana huxleyi to 4{sup *}10{sup 3} for the diatom Thalassiosira pseudonana. For Cs-137 uptake in non-growing cells the VCFs were close to zero. The results suggest that, in contrast to Co, the cycling and bioaccumulation in animals of Cs in marine systems is unlikely to be affected by primary producers. (au)

  20. Improving plant bioaccumulation science through consistent reporting of experimental data

    DEFF Research Database (Denmark)

    Fantke, Peter; Arnot, Jon A.; Doucette, William J.

    2016-01-01

    Experimental data and models for plant bioaccumulation of organic contaminants play a crucial role for assessing the potential human and ecological risks associated with chemical use. Plants are receptor organisms and direct or indirect vectors for chemical exposures to all other organisms. As new...... experimental data are generated they are used to improve our understanding of plant-chemical interactions that in turn allows for the development of better scientific knowledge and conceptual and predictive models. The interrelationship between experimental data and model development is an ongoing, never......-ending process needed to advance our ability to provide reliable quality information that can be used in various contexts including regulatory risk assessment. However, relatively few standard experimental protocols for generating plant bioaccumulation data are currently available and because of inconsistent...

  1. Integrated testing strategy (ITS) for bioaccumulation assessment under REACH

    DEFF Research Database (Denmark)

    Lombardo, Anna; Roncaglioni, Alessandra; Benfentati, Emilio;

    2014-01-01

    present an ITS for evaluating the bioaccumulation potential of organic chemicals. The scheme includes the use of all available data (also the non-optimal ones), waiving schemes, analysis of physicochemical properties related to the end point and alternative methods (both in silico and in vitro). In vivo...... in a dossier. REACH promotes the use of alternative methods to replace, refine and reduce the use of animal (eco)toxicity testing. Within the EU OSIRIS project, integrated testing strategies (ITSs) have been developed for the rational use of non-animal testing approaches in chemical hazard assessment. Here we...... methods are used only as last resort. Using the ITS, in vivo testing could be waived for about 67% of the examined compounds, but bioaccumulation potential could be estimated on the basis of non-animal methods. The presented ITS is freely available through a web tool. © 2014 Elsevier Ltd....

  2. Bioaccumulation of heavy metals in two wet retention ponds

    DEFF Research Database (Denmark)

    Søberg, Laila C.; Vollertsen, Jes; Blecken, Godecke-Tobias;

    2016-01-01

    Metal accumulation in stormwater ponds may contaminate the inhabiting fauna, thus jeopardizing their ecosystem servicing function. We evaluated bioaccumulation of metals in natural fauna and caged mussel indicator organisms in two wet retention ponds. Mussel cages were distributed throughout...... the ponds to detect bioaccumulation gradients and obtain a time-integrated measure of metal bioavailability. We further investigated if sediment metal concentrations correlate with those in the fauna and mussels. Metal concentrations in the fauna tended to be higher in the ponds than in a reference lake......, but statistical significance was only shown for Cu. Positive correlations were found for some metals in fauna and sediment. Sediment metal concentrations in one pond decreased from inlet to outlet while no gradients were observed in the mussels in either pond. These findings indicate that metal accumulation...

  3. A facile and efficient method for hydroxylation of azabenzanthrone compounds

    Institute of Scientific and Technical Information of China (English)

    Fang Xian Ning; Xiang Weng; Shi Liang Huang; Li Jun Gu; Zhi Shu Huang; Lian Quan Gu

    2011-01-01

    A novel and facile method of introducing 4-hydroxyl group into the aromatic ring of azabenzanthrone compounds was carded out by reacting azabenzanthrone compounds with hydrazine hydrate or hydroxylamine hydrochloride and sodium hydroxide in diethylene glycol(DEG) solvent.The mechanism of reaction may involve an amino intermediate and follow a hydroxyl substitution process.

  4. Development of predictive models for xenobiotic bioaccumulation in terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Trabalka, J.R.; Garten, C.T. Jr.

    1982-10-01

    We evaluated the suitability of existing, simple empirical models developed for aquatic organisms and the question of extending such models to terrestrial systems. Data sets of other investigators were expanded, and edited showing r/sup 2/ values associated with regressions fell significantly. Expansion of the analysis to include nonruminant mammals and birds produced similar conclusions. A simple sorting model based on hydrophobic tendency was able to successfully separate all but one bioaccumulation hazards from groups of organic compounds (N > 100) when the screening criterion was a specified bioconcentration factor for fish/water (in water-only exposure systems or model ecosystems) or mammal-bird/diet (long-term feeding under laboratory conditions). Approximately one-fourth of the chemicals sorted into the hazardous category did not exhibit significant bioaccumulation and the one hazardous material, which would not have been identified as such, was methylmercury. Results indicate that, although a measure of hydrophobicity is a highly satisfactory first approximation indicator for bioaccumulation potential for most organics in both terrestrial and aquatic vertebrates, this potential is frequently controlled by environmental factors and specific metabolic/steric interactions not adequately represented in existing SARs.

  5. Uptake and bioaccumulation of Cry toxins by an aphidophagous predator.

    Science.gov (United States)

    Paula, Débora P; Andow, David A

    2016-02-01

    Uptake of Cry toxins by insect natural enemies has rarely been considered and bioaccumulation has not yet been demonstrated. Uptake can be demonstrated by the continued presence of Cry toxin after exposure has stopped and gut contents eliminated. Bioaccumulation can be demonstrated by showing uptake and that the concentration of Cry toxin in the natural enemy exceeds that in its food. We exposed larvae of the aphidophagous predator, Harmonia axyridis, to Cry1Ac and Cry1F through uniform and constant tritrophic exposure via an aphid, Myzus persicae, and looked for toxin presence in the pupae. We repeated the experiment using only Cry1F and tested newly emerged adults. Both Cry toxins were detected in pupae, and Cry1F was detected in recently emerged, unfed adults. Cry1Ac was present 2.05 times and Cry1F 3.09 times higher in predator pupae than in the aphid prey. Uptake and bioaccumulation in the third trophic level might increase the persistence of Cry toxins in the food web and mediate new exposure routes to natural enemies. PMID:26686057

  6. Significance of Xenobiotic Metabolism for Bioaccumulation Kinetics of Organic Chemicals in Gammarus pulex

    OpenAIRE

    Ashauer, Roman; Hintermeister, Anita; O’Connor, Isabel; Elumelu, Maline; Hollender, Juliane; Escher, Beate I

    2012-01-01

    Bioaccumulation and biotransformation are key toxicokinetic processes that modify toxicity of chemicals and sensitivity of organisms. Bioaccumulation kinetics vary greatly among organisms and chemicals; thus, we investigated the influence of biotransformation kinetics on bioaccumulation in a model aquatic invertebrate using fifteen 14C-labeled organic xenobiotics from diverse chemical classes and physicochemical properties (1,2,3-trichlorobenzene, imidacloprid, 4,6-dinitro-o-cresol, ethylacry...

  7. Cadmium bioaccumulation factors for terrestrial species: Application of the mechanistic bioaccumulation model OMEGA to explain field data

    Energy Technology Data Exchange (ETDEWEB)

    Veltman, Karin [Department of Environmental Science, Radboud University Nijmegen, P.O. Box 9010, Toernooiveld 1, 6500 GL Nijmegen (Netherlands)], E-mail: K.Veltman@science.ru.nl; Huijbregts, Mark A.J.; Hendriks, A. Jan [Department of Environmental Science, Radboud University Nijmegen, P.O. Box 9010, Toernooiveld 1, 6500 GL Nijmegen (Netherlands)

    2008-12-01

    In environmental risk assessment of metals it is often assumed that the biota-to-soil accumulation factor (BSAF) is generic and constant. However, previous studies have shown that cadmium bioaccumulation factors of earthworms and small mammals are inversely related to total soil concentrations. Here, we provide an overview of cadmium accumulation in terrestrial species belonging to different trophic levels, including plants, snails and moles. Internal metal concentrations of these species are less than linearly related to total soil levels, which is in accordance with previously observed trends. The mechanistic bioaccumulation model OMEGA (Optimal Modeling for Ecotoxicological Applications) is used to provide a quantitative explanation of these trends in cadmium accumulation. Our results indicate that the model accurately predicts cadmium accumulation in earthworms, voles and shrews when accounting for geochemical availability of metals and saturable uptake kinetics.

  8. Searching for a One-Step Bioprocess for the Production of Hydroxyl Fatty Acids and Hydroxyl Oils from Soybean Oil

    Science.gov (United States)

    Soybean oil is produced domestically in large supply, averaging over 20 billion pounds per year with an annual carryover of more than one billion pounds. It is important to find new uses for this surplus soybean oil. Hydroxyl fatty acids and hydroxyl oils are platform materials for specialty chemi...

  9. In vivo and in vitro anti-androgenic effects of DE-71, a commercial polybrominated diphenyl ether (PBDE) mixture

    International Nuclear Information System (INIS)

    PBDEs have been synthesized in large quantities as flame retardants for commercial products, such as electronic equipment and textiles. The rising in levels of PBDEs in tissues in wildlife species and in human milk and plasma samples over the past several years have raised concerns about possible health effects. Recently, we showed that the PBDE mixture, DE-71, delayed puberty and suppressed the growth of androgen-dependent tissues in male Wistar rat following a peri-pubertal exposure. These effects suggested that DE-71 may be either inducing steroid hormone metabolism or acting as an androgen receptor (AR) antagonist. To elucidate the potential anti-androgenic effects of this mixture, we evaluated DE-71 in several in vivo assays, which are responsive to alterations in androgen activity. In a pubertal exposure study designed to further evaluate the delay in preputial separation (PPS), we observed a dose-dependent delay in PPS with 60 and 120 mg/kg/day of DE-71 (4 and 5 days) and a corresponding suppression of ventral prostate (VP) and seminal vesicle growth at both doses. Adult males exposed to 60 mg/kg DE-71 for 3 days resulted in a significant increase in luteinizing hormone and a non-significant increase in testosterone, androstenedione and estrone. DE-71 also tested positive for anti-androgenic activity in an immature rat Hershberger assay, with decreases in mean VP and seminal vesicle weight following doses of 30-240 mg/kg. DE-71 and the individual BDE congeners which comprise the mixture (BDE-47, -99, -100, -153, -154) were also evaluated in vitro. First, AR binding was evaluated in a competitive binding assay using rat VP cytosol. In addition, we evaluated gene activation in a transcriptional activation assay using the MDA-kb2 cell line which contains an endogenous human AR and a transfected luciferase reporter. DE-71 and BDE-100 (2, 4, 6-pentaBDE) both inhibited AR binding, with IC50s of approximately 5 μM. In addition, DE-71 and two of the congeners (BDE

  10. Hydroxyl Emission in the Westbrook Nebula

    Science.gov (United States)

    Strack, Angelica; Araya, Esteban; Ghosh, Tapasi; Arce, Hector G.; Lebron, Mayra E.; Salter, Christopher J.; Minchin, Robert F.; Pihlstrom, Ylva; Kurtz, Stan; Hofner, Peter; Olmi, Luca

    2016-06-01

    CRL 618, also known as the Westbrook Nebula, is a carbon-rich pre-planetary nebula. Hydroxyl (OH) transitions are typically not detected in carbon-rich late-type stellar objects, however observations conducted with the 305m Arecibo Telescope in 2008 resulted in the detection of 4765 MHz OH emission in CRL 618. We present results of observations carried out a few months after the original detection that confirm the line. This is the first detection of 4765 MHz OH emission (most likely a maser) in a pre-planetary nebula. Follow up observations conducted in 2015 resulted in non-detection of the 4765 MHz OH transition. This behavior is consistent with the high level of variability of excited OH lines that have been detected toward a handful of other pre-planetary nebulae. Our work supports that excited OH masers are short-lived during the pre-planetary nebula phase. We also conducted a search for other OH transitions from 1612 MHz to 8611 MHz with the Arecibo Telescope; we report no other detections at rms levels of ~5 mJy.This work has made use of the computational facilities donated by Frank Rodeffer to the WIU Astrophysics Research Laboratory. We also acknowledge support from M. & C. Wong RISE scholarships and a grant from the WIU College of Arts and Sciences.

  11. Vertical Distribution of Vibrationally Excited Hydroxyl

    Science.gov (United States)

    Grygalashvyly, Mykhaylo; Becker, Erich; Sonnemann, Gerd

    2016-04-01

    Knowledge about the vertical distribution of the vibrationally excited states of hydroxyl (OH*) is important for the interpretation of airglow measurements with respect to dynamical processes in the mesopause region. We derive an approximate analytical expression for the distribution of OH* that highlights the dependence on atomic oxygen and temperature. In addition, we use an advanced numerical model for the formation and relaxation of OH* and investigate the distributions of the different vibrationally exited states of OH*. For the production of OH*, the model includes the reaction of atomic hydrogen with ozone, as well as the reaction of atomic oxygen with hydroperoxy radicals. As loss processes we include 1) deactivation by atomic oxygen, molecular oxygen, and molecular nitrogen, 2) spontaneous emission, and 3) loss due to chemical reaction with atomic oxygen. All these processes take the dependence on the vibrational number into account. The quenching by molecular and atomic oxygen is parameterized by a multi-quantum relaxation scheme. This diagnostic model for OH* has been implemented as part of a chemistry-transport model that is driven by the dynamics simulated with the KMCM (Kühlungsborn Mechanistic general Circulation Model). Numerical results confirm that emission from excited states with higher vibrational number is weaker and emanates from higher altitudes. In addition we find that the OH*-peak altitudes depend significantly on season and latitude. This behavior is mainly controlled by the corresponding variations of atomic oxygen and temperature, as is also confirmed by the aforementioned approximate theory.

  12. Functionalization of hydroxyl terminated polybutadiene with biologically active fluorescent molecule

    Indian Academy of Sciences (India)

    R Murali Sankar; Subhadeep Saha; K Seeni Meera; Tushar Jana

    2009-10-01

    A biologically active molecule, 2-chloro-4,6-bis(dimethylamino)-1,3,5-triazine (CBDT), has been covalently attached at the terminal carbon atoms of the hydroxyl terminated polybutadiene (HTPB) backbone. The modification of HTPB backbone by CBDT molecule does not affect the unique physico-chemical properties such as fluidity, hydroxyl value and microstructure of the parent HTPB. The formation of hydrogen bonding between the terminal hydroxyl groups and the nitrogen atoms of triazine moiety is the driving force for the terminal attachment chemistry. The functionalized HTPB (HTPB–CBDT) shows a strong fluorescence emission at 385 nm.

  13. Regioselective alkane hydroxylation with a mutant AlkB enzyme

    Science.gov (United States)

    Koch, Daniel J.; Arnold, Frances H.

    2012-11-13

    AlkB from Pseudomonas putida was engineered using in-vivo directed evolution to hydroxylate small chain alkanes. Mutant AlkB-BMO1 hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. Mutant AlkB-BMO2 similarly hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. These biocatalysts are highly active for small chain alkane substrates and their regioselectivity is retained in whole-cell biotransformations.

  14. Bioaccumulation of Legacy and Emerging Organochlorine Contaminants in Lumbriculus variegatus.

    Science.gov (United States)

    Dang, Viet D; Kroll, Kevin J; Supowit, Samuel D; Halden, Rolf U; Denslow, Nancy D

    2016-07-01

    Freshwater sediment-dwelling Lumbriculus variegatus is known to serve as a vector for the transfer of contaminants from sediments to higher trophic level organisms, but limited data exist on the bioaccumulation of chemicals associated with sediments containing high total organic carbon (TOC). In the current study, sediments from the north shore area of Lake Apopka (Florida, USA), containing very high TOC [39 % (w/w)], were spiked with four chemicals-p,p'-dichlorordiphenyldichloroethylene (p,p'-DDE), dieldrin, fipronil, and triclosan-individually or in a mixture of the four and then used for bioaccumulation studies. Tissue concentrations of chemicals in L. variegatus were measured at 2, 7, 14, 21, and 28 days of exposure, and the bioaccumulation potential was evaluated using biosediment accumulation factors [BSAF (goc/glipid)]. Increase in total body burdens of all four chemicals in L. variegatus was rapid at day 2 and reached a steady-state level after 7 days in both single and mixture experiments. Tissue concentrations of fipronil peaked after 2 days and then decreased by 70 % in sediment experiments suggesting that in addition to the degradation of fipronil that occurred in the sediment, L. variegatus may also be able to metabolize fipronil. The calculated 28-day BSAF values varied among the chemicals and increased in the order fipronil (1.1) < triclosan (1.4) < dieldrin (21.8) < p,p'-DDE (49.8) in correspondence with the increasing degree of their hydrophobicity. The relatively high BSAF values for p,p'-DDE and dieldrin probably resulted from lower-than-expected sorption of chemicals to sediment organic matter either due to the nature of the plant-derived organic matter, as a result of the relatively short equilibration time among the various compartments, or due to ingestion of sediment particles by the worms. PMID:26833202

  15. Arsenic bioaccumulation in a marine juvenile fish Terapon jarbua

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Wei [State Key Laboratory of Oceanography in the Tropics, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China); Huang Liangmin [State Key Laboratory of Oceanography in the Tropics, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301 (China); Wang Wenxiong, E-mail: wwang@ust.hk [Division of Life Science, HKUST, Clear Water Bay, Kowloon (Hong Kong)

    2011-10-15

    Highlights: Radiotracer technique was used to quantify the biokinetics of As(V) in a marine fish. As(V) had a low bioavailability to Terapon jarbua. Dietary assimilation of As was only 3.1-7.4% for fish fed with different preys. Dietary uptake could be the primary route for As bioaccumulation in fish. - Abstract: Arsenic (As) is a ubiquitous toxic metalloid that is causing widespread public concern. Recent measurements have indicated that some marine fish in China might be seriously contaminated with As. Yet the biokinetics and bioaccumulation pathway of As in fish remain little understood. In this study, we employed a radiotracer technique to quantify the dissolved uptake, dietary assimilation and subsequent efflux of As(V) in a marine predatory fish, Terapon jarbua. The dissolved uptake of As showed a linear pattern over a range of dissolved concentrations from 0.5 to 50 {mu}g L{sup -1}, with a corresponding uptake rate constant of 0.0015 L g{sup -1} d{sup -1}. The assimilation efficiencies (AEs) of dietary As were only 3.1-7.4% for fish fed with copepods, clams, prey fish, or artificial diets, and were much lower than the As that entered the trophically available metal fraction in the prey. The dietary AEs were independent of the As(V) concentrations in the artificial diets. The efflux rate constant of As in fish following the dietary exposure was 0.03 d{sup -1}. Modeling calculations showed that dietary uptake could be the primary route for As bioaccumulation in fish, and the corresponding contributions of waterborne and dietary uptakes were related to the bioconcentration factor (BCF) of the prey and the ingestion rate of fish. This study demonstrates that As(V) has a low bioavailability to T. jarbua.

  16. Arsenic bioaccumulation in a marine juvenile fish Terapon jarbua

    International Nuclear Information System (INIS)

    Highlights: Radiotracer technique was used to quantify the biokinetics of As(V) in a marine fish. As(V) had a low bioavailability to Terapon jarbua. Dietary assimilation of As was only 3.1–7.4% for fish fed with different preys. Dietary uptake could be the primary route for As bioaccumulation in fish. - Abstract: Arsenic (As) is a ubiquitous toxic metalloid that is causing widespread public concern. Recent measurements have indicated that some marine fish in China might be seriously contaminated with As. Yet the biokinetics and bioaccumulation pathway of As in fish remain little understood. In this study, we employed a radiotracer technique to quantify the dissolved uptake, dietary assimilation and subsequent efflux of As(V) in a marine predatory fish, Terapon jarbua. The dissolved uptake of As showed a linear pattern over a range of dissolved concentrations from 0.5 to 50 μg L−1, with a corresponding uptake rate constant of 0.0015 L g−1 d−1. The assimilation efficiencies (AEs) of dietary As were only 3.1–7.4% for fish fed with copepods, clams, prey fish, or artificial diets, and were much lower than the As that entered the trophically available metal fraction in the prey. The dietary AEs were independent of the As(V) concentrations in the artificial diets. The efflux rate constant of As in fish following the dietary exposure was 0.03 d−1. Modeling calculations showed that dietary uptake could be the primary route for As bioaccumulation in fish, and the corresponding contributions of waterborne and dietary uptakes were related to the bioconcentration factor (BCF) of the prey and the ingestion rate of fish. This study demonstrates that As(V) has a low bioavailability to T. jarbua.

  17. Effects of sedimentary soot-like materials on bioaccumulation and sorption of polychlorinated biphenyls

    NARCIS (Netherlands)

    Jonker, M.T.O.; Hoenderboom, A.M.; Koelmans, A.A.

    2004-01-01

    Bioaccumulation of hydrophobic organic chemicals from sediments containing soot or sootlike materials has been hypothesized to be limited by strong sorption of the chemicals to the soot matrixes. To test this hypothesis, we quantified bioaccumulation of 11 polychlorinated biphenyls (PCBs) into the a

  18. Modeling bioaccumulation and biomagnification of nonylphenol and its ethoxylates in estuarine-marine food chains

    NARCIS (Netherlands)

    Korsman, J.C.; Schipper, A.M.; Vos, de M.G.; Heuvel-Greve, van den M.J.; Vethaak, A.D.; Voogt, de Pim; Hendriks, A.J.

    2015-01-01

    There are several studies on bioaccumulation and biomagnification of nonylphenol (NP) and its ethoxylates (NPEOs), but their toxico-kinetic mechanisms remain unclear. In the present investigation, we explored the accumulation of NP and NPEOs in estuarine-marine food chains with a bioaccumulation

  19. Modeling bioaccumulation and biomagnification of nonylphenol and its ethoxylates in estuarine-marine food chains

    NARCIS (Netherlands)

    J.C. Korsman; A.M. Schipper; M.G. de Vos; M.J. van den Heuvel-Greve; A.D. Vethaak; P. de Voogt; A.J. Hendriks

    2015-01-01

    There are several studies on bioaccumulation and biomagnification of nonylphenol (NP) and its ethoxylates (NPEOs), but their toxico-kinetic mechanisms remain unclear. In the present investigation, we explored the accumulation of NP and NPEOs in estuarine-marine food chains with a bioaccumulation mod

  20. A closer look at bioaccumulation of petroleum hydrocarbon mixtures in aquatic worms.

    NARCIS (Netherlands)

    Muijs, B.; Jonker, M.T.O.

    2010-01-01

    Petroleum hydrocarbons (oils) are ubiquitous in the aquatic environment, and adequate risk assessment is thus essential. Bioaccumulation plays a key role in risk assessment, but the current knowledge on bioaccumulation of oils is limited. Therefore, this process was studied in detail, using the aqua

  1. Hydroxyl radical production in plasma electrolysis with KOH electrolyte solution

    Energy Technology Data Exchange (ETDEWEB)

    Saksono, Nelson; Febiyanti, Irine Ayu, E-mail: irine.ayu41@ui.ac.id; Utami, Nissa; Ibrahim [Department of Chemical Engineering, Universitas Indonesia, Depok 16424, Indonesia Phone: +62217863516, Fax: +62217863515 (Indonesia)

    2015-12-29

    Plasma electrolysis is an effective technology for producing hydroxyl radical (•OH). This method can be used for waste degradation process. This study was conducted to obtain the influence of applied voltage, electrolyte concentration, and anode depth in the plasma electrolysis system for producing hydroxyl radical. The materials of anode and cathode, respectively, were made from tungsten and stainless steel. KOH solution was used as the solution. Determination of hydroxyl radical production was done by measuring H{sub 2}O{sub 2} amount formed in plasma system using an iodometric titration method, while the electrical energy consumed was obtained by measuring the electrical current throughout the process. The highest hydroxyl radical production was 3.51 mmol reached with 237 kJ energy consumption in the power supply voltage 600 V, 0.02 M KOH, and 0.5 cm depth of anode.

  2. Hydroxyl radical production in plasma electrolysis with KOH electrolyte solution

    Science.gov (United States)

    Saksono, Nelson; Febiyanti, Irine Ayu; Utami, Nissa; Ibrahim

    2015-12-01

    Plasma electrolysis is an effective technology for producing hydroxyl radical (•OH). This method can be used for waste degradation process. This study was conducted to obtain the influence of applied voltage, electrolyte concentration, and anode depth in the plasma electrolysis system for producing hydroxyl radical. The materials of anode and cathode, respectively, were made from tungsten and stainless steel. KOH solution was used as the solution. Determination of hydroxyl radical production was done by measuring H2O2 amount formed in plasma system using an iodometric titration method, while the electrical energy consumed was obtained by measuring the electrical current throughout the process. The highest hydroxyl radical production was 3.51 mmol reached with 237 kJ energy consumption in the power supply voltage 600 V, 0.02 M KOH, and 0.5 cm depth of anode.

  3. Hydroxyl radical production in plasma electrolysis with KOH electrolyte solution

    International Nuclear Information System (INIS)

    Plasma electrolysis is an effective technology for producing hydroxyl radical (•OH). This method can be used for waste degradation process. This study was conducted to obtain the influence of applied voltage, electrolyte concentration, and anode depth in the plasma electrolysis system for producing hydroxyl radical. The materials of anode and cathode, respectively, were made from tungsten and stainless steel. KOH solution was used as the solution. Determination of hydroxyl radical production was done by measuring H2O2 amount formed in plasma system using an iodometric titration method, while the electrical energy consumed was obtained by measuring the electrical current throughout the process. The highest hydroxyl radical production was 3.51 mmol reached with 237 kJ energy consumption in the power supply voltage 600 V, 0.02 M KOH, and 0.5 cm depth of anode

  4. Bioaccumulation of total mercury in the earthworm Eisenia andrei.

    Science.gov (United States)

    Le Roux, Shirley; Baker, Priscilla; Crouch, Andrew

    2016-01-01

    Earthworms are a major part of the total biomass of soil fauna and play a vital role in soil maintenance. They process large amounts of plant and soil material and can accumulate many pollutants that may be present in the soil. Earthworms have been explored as bioaccumulators for many heavy metal species such as Pb, Cu and Zn but limited information is available for mercury uptake and bioaccumulation in earthworms and very few report on the factors that influence the kinetics of Hg uptake by earthworms. It is known however that the uptake of Hg is strongly influenced by the presence of organic matter, hence the influence of ligands are a major factor contributing to the kinetics of mercury uptake in biosystems. In this work we have focused on the uptake of mercury by earthworms (Eisenia andrei) in the presence of humic acid (HA) under varying physical conditions of pH and temperature, done to assess the role of humic acid in the bioaccumulation of mercury by earthworms from soils. The study was conducted over a 5-day uptake period and all earthworm samples were analysed by direct mercury analysis. Mercury distribution profiles as a function of time, bioaccumulation factors (BAFs), first order rate constants and body burden constants for mercury uptake under selected conditions of temperature, pH as well as via the dermal and gut route were evaluated in one comprehensive approach. The results showed that the uptake of Hg was influenced by pH, temperature and the presence of HA. Uptake of Hg(2+) was improved at low pH and temperature when the earthworms in soil were in contact with a saturating aqueous phase. The total amount of Hg(2+) uptake decreased from 75 to 48 % as a function of pH. For earthworms in dry soil, the uptake was strongly influenced by the presence of the ligand. Calculated BAF values ranged from 0.1 to 0.8. Mercury uptake typically followed first order kinetics with rate constants determined as 0.2 to 1 h(-1). PMID:27347466

  5. Bioaccumulation of ergovaline in bovine lateral saphenous veins in vitro.

    Science.gov (United States)

    Klotz, J L; Kirch, B H; Aiken, G E; Bush, L P; Strickland, J R

    2009-07-01

    Ergot alkaloids have been associated with vasoconstriction in grazing livestock affected by the fescue toxicosis syndrome. Previous in vitro investigations studying how ergot alkaloids caused vasoconstriction have shown that ergovaline has a distinct receptor affinity and sustained contractile response. A similar contractile response has not been noted for lysergic acid. The objectives of this study were to determine if repetitive in vitro exposure of bovine lateral saphenous vein to lysergic acid or ergovaline would result in an increasing contractile response and if a measurable bioaccumulation of the alkaloids in the vascular tissue occurs over time. Segments of vein were surgically biopsied from healthy, Angus x Brangus cross-bred, fescue-naïve yearling heifers (n = 16) or collected from healthy mixed breed and sex cattle immediately after slaughter (n = 12) at a local abattoir. Veins were trimmed of excess fat and connective tissue, sliced into cross-sections, and suspended in a myograph chamber containing 5 mL of oxygenated Krebs-Henseleit buffer (95% O(2)/5% CO(2); pH = 7.4; 37 degrees C). Contractile responses to repetitive additions of ergovaline (1 x 10(-9) and 1 x 10(-7) M) and lysergic acid (1 x 10(-5) and 1 x 10(-4) M) were evaluated using the biopsied veins. For the bioaccumulation experiments, veins collected at the abattoir underwent repetitive additions of 1 x 10(-7) M ergovaline and 1 x 10(-5) M lysergic acid and the segments were removed after every 2 additions and media rinses for alkaloid quantification via HPLC/mass spectrometry. Contractile data were normalized as a percentage of contractile response induced by a reference dose of norepinephrine (1 x 10(-4) M). Repetitive additions of 1 x 10(-9) M ergovaline and 1 x 10(-5) and 1 x 10(-4) M lysergic acid resulted in contractile response with a negative slope (P < 0.02). In contrast, repetitive addition of 1 x 10(-7) M ergovaline resulted in a contractile response that increased with each

  6. Anaerobic Dehalogenation of Hydroxylated Polychlorinated Biphenyls by Desulfitobacterium dehalogenans

    OpenAIRE

    Wiegel, Juergen; Zhang, Xiaoming; Wu, Qingzhong

    1999-01-01

    Ten years after reports on the existence of anaerobic dehalogenation of polychlorinated biphenyls (PCBs) in sediment slurries, we report here on the rapid reductive dehalogenation of para-hydroxylated PCBs (HO-PCBs), the excreted main metabolites of PCB in mammals, which can exhibit estrogenic and antiestrogenic activities in humans. The anaerobic bacterium Desulfitobacterium dehalogenans completely dehalogenates all flanking chlorines (chlorines in ortho position to the para-hydroxyl group) ...

  7. Asymmetric Synthesis of β, γ-β-Hydroxyl-γ-butyrolactones

    Institute of Scientific and Technical Information of China (English)

    WANG Jin-Xin; ZHANG Chao-Xin; LI Ying

    2003-01-01

    @@ Chiral β-hydroxyl-γ-butyrolactones have attracted substantial interest in recent years due to their presence inmany strongly active natural products having antitumor, fungicidal, anti-inflammatory activity, and their use as important precursors in natural product synthesis. [1] In the course of the total synthesis of the natural product Tuxpano lide ,[2] we found a concise and efficient strategy on the stereocontrolled synthesis of β-hydroxyl-γ-butyrolactonederivatives from cheap and achiral starting material.

  8. Hydroxyl Radical and Its Scavengers in Health and Disease

    OpenAIRE

    Boguslaw Lipinski

    2011-01-01

    It is generally believed that diseases caused by oxidative stress should be treated with antioxidants. However, clinical trials with such antioxidants as ascorbic acid and vitamin E, failed to produce the expected beneficial results. On the other hand, important biomolecules can be modified by the introduction of oxygen atoms by means of non-oxidative hydroxyl radicals. In addition, hydroxyl radicals can reduce disulfide bonds in proteins, specifically fibrinogen, resulting in their unfoldin...

  9. Species-specific mercury bioaccumulation in a diverse fish community.

    Science.gov (United States)

    Donald, David B; Wissel, Björn; Anas, M U Mohamed

    2015-12-01

    Mercury bioaccumulation models developed for fish provide insight into the sources and transfer of Hg within ecosystems. Mercury concentrations were assessed for 16 fish species of the western reach of Lake Diefenbaker, Saskatchewan, Canada. For top predators (northern pike, Esox Lucius; walleye, Sander vitreum), Hg concentrations were positively correlated to δ(15)N, and δ(15)N to fish age, suggesting that throughout life these fish fed on organisms with increasingly higher trophic values and Hg concentrations. However, fish mass and/or age were the principal parameters related to Hg concentrations for most species. For 9 common species combined, individual variation in Hg concentration was explained in declining order of importance by fish mass, trophic position (δ(15)N), and fish age. Delta (15)N value was not the leading variable related to Hg concentration for the assemblage, probably because of the longevity of lower--trophic-level species (3 species ≥ 20 yr), substantial overlap in Hg concentration and δ(15)N values for large-bodied fish up to 3000 g, and complex relationships between Hg concentration and δ(15)N among species. These results suggest that the quantity of food (and Hg) consumed each year and converted to fish mass, the quantity of Hg bioaccumulated over years and decades, and trophic position were significant determinants of Hg concentration in Lake Diefenbaker fish.

  10. A method for partitioning cadmium bioaccumulated in small aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Siriwardena, S.N.; Rana, K.J.; Baird, D.J. [Univ. of Stirling (United Kingdom). Institute of Aquaculture

    1995-09-01

    A series of laboratory experiments was conducted to evaluate bioaccumulation and surface adsorption of aqueous cadmium (Cd) by sac-fry of the African tilapia Oreochromis niloticus. In the first experiment, the design consisted of two cadmium treatments: 15 {micro}g Cd{center_dot}L{sup {minus}1} in dilution water and a Cd-ethylenediaminetetraacetic acid (Cd-EDTA) complex at 15 {micro}m{center_dot}L{sup {minus}1}, and a water-only control. There were five replicates per treatment and 40 fish per replicate. It was found that EDTA significantly reduced the bioaccumulation of cadmium by tilapia sac-fry by 34%. Based on the results, a second experiment was conducted to evaluate four procedures: a no-rinse control; rinsing in EDTA; rinsing in distilled water; and rinsing in 5% nitric acid, for removing surface-bound Cd from exposed sac-fry. In this experiment, 30 fish in each of five replicates were exposed to 15 {micro}g Cd{center_dot}L{sup {minus}1} for 72 h, processed through the rinse procedures, and analyzed for total Cd. The EDTA rinse treatment significantly reduced (p<0.05) Cd concentrations of the exposed fish relative to those receiving no rinse. It was concluded that the EDTA rinse technique may be useful in studies evaluating the partitioning of surface-bound and accumulated cadmium in small aquatic organisms.

  11. Sediment Bioaccumulation Test with Lumbriculus variegatus: Effects of Organism Loading.

    Science.gov (United States)

    Burkhard, Lawrence P; Hubin-Barrows, Dylan; Billa, Nanditha; Highland, Terry L; Hockett, James R; Mount, David R; Norberg-King, Teresa J

    2016-07-01

    At contaminated sediment sites, the bioavailability of contaminants in sediments is assessed using sediment-bioaccumulation tests with Lumbriculus variegates (Lv). The testing protocols recommend that ratio of total organic carbon (TOC) in sediment to L. variegatus (dry weight) (TOC/Lv) should be no less than 50:1. Occasionally, this recommendation is not followed, especially with sediments having low TOC, e.g., polychlorinated biphenyls (PCBs) in the L. variegatus were measured in six of the seven sediments tested, and differences in PCB residues among loading ratios across all sediments were small, i.e., ±50 %, from those measured at the minimum recommended ratio of 50:1 TOC/Lv. In all sediment, PCB residues increased with increasing loading of the organisms for the mono-, di-, and tri-chloro-PCBs. For tetra-chloro and heavier PCBs, residues increased with increasing loading of organisms for only two of the six sediments. PCB residues were not significantly different between TOC/Lv loadings of 50:1 and mid-20:1 ratios indicating that equivalent results can be obtained with TOC/Lv ratios into the mid-20:1 ratios. Overall, the testing results suggest that when testing recommendation of 50:1 TOC/Lv is not followed, potential biases in the biota-sediment accumulations factors from the sediment-bioaccumulation test will be small. PMID:27165691

  12. Bioaccumulation of animal adenoviruses in the pink shrimp

    Directory of Open Access Journals (Sweden)

    Roger B. Luz

    2015-09-01

    Full Text Available Adenoviruses are among the most promising viral markers of fecal contamination. They are frequently found in the water, sediment and soil of regions impacted by human activity. Studies of the bioaccumulation of enteric viruses in shrimp are scarce. The cities located in the northern coast of the lake systems in Southern Brazil have high urbanization and intensive farming rates, and poor sewage collection and treatment. One hundred (n = 100 Farfantepenaeus paulensis pink-shrimp specimens and 48 water samples were collected from coastal lagoons between June 2012 and May 2013. Water samples were concentrated and the shrimp, mashed. After DNA extraction, samples were analyzed by real time polymerase chain reaction (qPCR in order to detect and quantify viral genomes. Thirty-five percent of shrimp samples were positive for contamination, predominantly by avian adenoviruses. A total of 91.7% of water samples contained adenoviruses DNA, with the human form being the most frequent. Our results provided evidence of significant bioaccumulation of adenoviruses in shrimp, showing the extent of the impact of fecal pollution on aquatic ecosystems.

  13. Arsenic bioaccumulation in a marine juvenile fish Terapon jarbua.

    Science.gov (United States)

    Zhang, Wei; Huang, Liangmin; Wang, Wen-Xiong

    2011-10-01

    Arsenic (As) is a ubiquitous toxic metalloid that is causing widespread public concern. Recent measurements have indicated that some marine fish in China might be seriously contaminated with As. Yet the biokinetics and bioaccumulation pathway of As in fish remain little understood. In this study, we employed a radiotracer technique to quantify the dissolved uptake, dietary assimilation and subsequent efflux of As(V) in a marine predatory fish, Terapon jarbua. The dissolved uptake of As showed a linear pattern over a range of dissolved concentrations from 0.5 to 50 μg L(-1), with a corresponding uptake rate constant of 0.0015 L g(-1)d(-1). The assimilation efficiencies (AEs) of dietary As were only 3.1-7.4% for fish fed with copepods, clams, prey fish, or artificial diets, and were much lower than the As that entered the trophically available metal fraction in the prey. The dietary AEs were independent of the As(V) concentrations in the artificial diets. The efflux rate constant of As in fish following the dietary exposure was 0.03 d(-1). Modeling calculations showed that dietary uptake could be the primary route for As bioaccumulation in fish, and the corresponding contributions of waterborne and dietary uptakes were related to the bioconcentration factor (BCF) of the prey and the ingestion rate of fish. This study demonstrates that As(V) has a low bioavailability to T. jarbua. PMID:21945928

  14. Bioaccumulation of hexachlorobenzene in Eisenia foetida at different aging stages

    Institute of Scientific and Technical Information of China (English)

    GAO Hongjian

    2009-01-01

    The impacts of contact time on the extractability, the availability of hexachlorobenzene (HCB) in different soils (paddy soil, red soil, and fluvo-aquic soil) and bioaccurnulation in earthworm Eisenia foetida were investigated under controlled conditions in laboratory. Results indicated that the aging rate of HCB displaying a biphasic character in different soils: a rapid aging in the first 60 d followed by a slow aging in the next 120 d incubation time. Moreover, most of extractable HCB (about 90%) decline occurred in the first 60 d after HCB was spiked into the soils. The aging rate of HCB in the paddy soil was higher than that in the fluvo-aquic soil or the red soil. The amount of HCB accumulated in the earthworms and its accumulative ability, expressed as a bioaccumulation factor (BAF), declined as the aging time increased from 1 to 180 d. Although the extractable HCB decreased with increasing residence time in soil, much of HCB could still be accumulated by earthworms (457.6-984.3 ng/g) through bioaccumulation, which poses a potential risk to soil ecological safety.

  15. Arsenic and mercury bioaccumulation in the aquatic plant, Vallisneria neotropicalis.

    Science.gov (United States)

    Lafabrie, C; Major, K M; Major, C S; Cebrián, J

    2011-03-01

    Arsenic (As) and mercury (Hg) are among the most toxic metals/metalloids. The overall goal of this study was to investigate the bioaccumulation of these trace elements in Vallisneria neotropicalis, a key trophic species in aquatic environments. For this purpose, As and Hg concentrations were determined in sediments and natural populations of V. neotropicalis in sub-estuaries of Mobile Bay (Alabama, USA), differing with respect to past and present anthropogenic impact. Analyses indicate that the Fish River is the most contaminated among the sub-estuaries investigated; levels of As found in Fish River sediments fall within a range that could potentially cause adverse effects in biota. Sediment As concentrations were only moderately correlated with those in V. neotropicalis; no correlation was found between sediment and plant Hg levels. However, several parameters could have masked such potential relationships (e.g., differences in sediment characteristics and "biological dilution" phenomena). Results presented herein highlight the numerous parameters that can influence metal/metalloids accumulation in aquatic plants as well as species-specific responses to trace element contamination. Finally, this study underscores the need for further investigation into contaminant bioaccumulation in ecologically and economically important coastal environments. PMID:21168896

  16. Bioaccumulation Pattern of Mercury in Bacopa monnieri (L. Pennell

    Directory of Open Access Journals (Sweden)

    Hussain K

    2012-05-01

    Full Text Available Bioaccumulation pattern of mercury was studied in Bacopa monnieri plants cultivated in Hoagland nutrient medium artificially contaminated with 5 and 10μM HgCl2. Mercury content of roots, stem and leaves were analysed using Atomic Absorption Spectrophotometry (AAS. During a period 12 days of growth, more accumulation was noticed in roots followed by stem and leaves. Repeated addition of HgCl2 and enhanced growth period up to 50 days showed only negligible increase in accumulation maintaining a threshold level of mercury in the root. When a comparison was done between the quantities of HgCl2 added to the growth medium and the sum of total accumulation of the plant and content present in the residual medium, a significant quantity of mercury is found to be lost presumably through the process of phytovolatilization from the plant. Studies on the effect of pH on bioaccumulation of mercury showed that acidic pH enhanced accumulation rate and hence for phytoremediation technology ‘chlorination’ is recommended whereas for medicinal purpose, Bacopa monnieri plants can be harvested after ‘liming’ to increase the pH and thereby reducing accumulation rate of mercury.

  17. Hydroxylated polychlorinated biphenyls increase reactive oxygen species formation and induce cell death in cultured cerebellar granule cells

    International Nuclear Information System (INIS)

    Polychlorinated biphenyls (PCBs) are persistent organic pollutants that bioaccumulate in the body, however, they can be metabolized to more water-soluble products. Although they are more readily excreted than the parent compounds, some of the metabolites are still hydrophobic and may be more available to target tissues, such as the brain. They can also cross the placenta and reach a developing foetus. Much less is known about the toxicity of PCB metabolites than about the parent compounds. In the present study, we have investigated the effects of eight hydroxylated (OH) PCB congeners (2'-OH PCB 3, 4-OH PCB 14, 4-OH PCB 34, 4'-OH PCB 35, 4-OH PCB 36, 4'-OH PCB 36, 4-OH PCB 39, and 4'-OH PCB 68) on reactive oxygen species (ROS) formation and cell viability in rat cerebellar granule cells. We found that, similar to their parent compounds, OH-PCBs are potent ROS inducers with potency 4-OH PCB 14 < 4-OH PCB 36 < 4-OH PCB 34 < 4'-OH PCB 36 < 4'-OH PCB 68 < 4-OH PCB 39 < 4'-OH PCB 35. 4-OH PCB 36 was the most potent cell death inducer, and caused apoptotic or necrotic morphology depending on concentration. Inhibition of ERK1/2 kinase with U0126 reduced both cell death and ROS formation, suggesting that ERK1/2 activation is involved in OH-PCB toxicity. The results indicate that the hydroxylation of PCBs may not constitute a detoxification reaction. Since OH-PCBs like their parent compounds are retained in the body and may be more widely distributed to sensitive tissues, it is important that not only the levels of the parent compounds but also the levels of their metabolites are taken into account during risk assessment of PCBs and related compounds.

  18. Role of metal mixtures (Ca, Cu and Pb) on Cd bioaccumulation and phytochelatin production by Chlamydomonas reinhardtii

    International Nuclear Information System (INIS)

    The goal of the study was to determine whether metal uptake and biological effects could be predicted by free ion concentrations when organisms were exposed to Cd and a second metal. Bioaccumulation and algal phytochelatin (PC) concentrations were determined for Chlamydomonas reinhardtii following a 6-h exposure. Bioaccumulation results, after six hours of exposure, showed that Cd uptake decreased in the presence of relatively high concentrations of Ca, Cu and Pb, however, Cd bioaccumulation increased in the presence of ca. equimolar concentrations of Cu. A good correlation was observed between the production of PCs and the amount of metals bioaccumulated for the binary mixtures of Cd–Pb and Cd–Cu, but not the Cd–Ca mixture. Overall, the results suggested that, in the case of mixtures, bioaccumulated metal rather than free ion concentrations would be a better predictor of biological effect. -- Highlights: •Cd bioaccumulation and phytochelatin production were evaluated for metal mixtures. •Bioaccumulated metal rather than free ion was a better predictor of biological effect. •Calcium additions decreased Cd bioaccumulation but increased phytochelatin production. •Copper additions increased Cd bioaccumulation and phytochelatin production. •Lead additions had little effect on either Cd bioaccumulation or phytochelatin production. -- In metal mixtures containing Cd and Ca, Pb or Cu, bioaccumulated metal rather than free ion was a better predictor of biological effect

  19. Use of terrestrial field studies in the derivation of bioaccumulation potential of chemicals

    Science.gov (United States)

    van den Brink, Nico W.; Arblaster, Jennifer A.; Bowman, Sarah R.; Conder, Jason M.; Elliott, John E.; Johnson, Mark S.; Muir, Derek C.G.; Natal-da-Luz, Tiago; Rattner, Barnett A.; Sample, Bradley E.; Shore, Richard F.

    2016-01-01

    Field-based studies are an essential component of research addressing the behavior of organic chemicals, and a unique line of evidence that can be used to assess bioaccumulation potential in chemical registration programs and aid in development of associated laboratory and modeling efforts. To aid scientific and regulatory discourse on the application of terrestrial field data in this manner, this article provides practical recommendations regarding the generation and interpretation of terrestrial field data. Currently, biota-to-soil-accumulation factors (BSAFs), biomagnification factors (BMFs), and bioaccumulation factors (BAFs) are the most suitable bioaccumulation metrics that are applicable to bioaccumulation assessment evaluations and able to be generated from terrestrial field studies with relatively low uncertainty. Biomagnification factors calculated from field-collected samples of terrestrial carnivores and their prey appear to be particularly robust indicators of bioaccumulation potential. The use of stable isotope ratios for quantification of trophic relationships in terrestrial ecosystems needs to be further developed to resolve uncertainties associated with the calculation of terrestrial trophic magnification factors (TMFs). Sampling efforts for terrestrial field studies should strive for efficiency, and advice on optimization of study sample sizes, practical considerations for obtaining samples, selection of tissues for analysis, and data interpretation is provided. Although there is still much to be learned regarding terrestrial bioaccumulation, these recommendations provide some initial guidance to the present application of terrestrial field data as a line of evidence in the assessment of chemical bioaccumulation potential and a resource to inform laboratory and modeling efforts.

  20. Histopathology of fathead minnow (Pimephales promelas) exposed to hydroxylated fullerenes.

    Science.gov (United States)

    Jovanović, Boris; Whitley, Elizabeth M; Palić, Dušan

    2014-11-01

    Hydroxylated fullerenes are reported to be very strong antioxidants, acting to quench reactive oxygen species, thus having strong potential for important and widespread applications in innovative therapies for a variety of disease processes. However, their potential for toxicological side effects is still largely controversial and unknown. Effects of hydroxylated fullerenes C60(OH)24 on the fathead minnow (Pimephales promelas) were investigated microscopically after a 72-hour (acute) exposure by intraperitoneal injection of 20 ppm of hydroxylated fullerenes per gram of body mass. Cumulative, semi-quantitative histopathologic evaluation of brain, liver, anterior kidney, posterior kidney, skin, coelom, gills and the vestibuloauditory system revealed significant differences between control and hydroxylated fullerene-treated fish. Fullerene-treated fish had much higher cumulative histopathology scores. Histopathologic changes included loss of cellularity in the interstitium of the kidney, a primary site of haematopoiesis in fish, and loss of intracytoplasmic glycogen in liver. In the coelom, variable numbers of leukocytes, including many macrophages and fewer heterophils and rodlet cells, were admixed with the nanomaterial. These findings raise concern about in vivo administration of hydroxylated fullerenes in experimental drugs and procedures in human medicine, and should be investigated in more detail.

  1. Ab initio dynamics of the cytochrome P450 hydroxylation reaction

    Energy Technology Data Exchange (ETDEWEB)

    Elenewski, Justin E.; Hackett, John C, E-mail: jchackett@vcu.edu [Department of Physiology and Biophysics and The Massey Cancer Center, School of Medicine, Virginia Commonwealth University, 401 College Street, Richmond, Virginia 23219-1540 (United States)

    2015-02-14

    The iron(IV)-oxo porphyrin π-cation radical known as Compound I is the primary oxidant within the cytochromes P450, allowing these enzymes to affect the substrate hydroxylation. In the course of this reaction, a hydrogen atom is abstracted from the substrate to generate hydroxyiron(IV) porphyrin and a substrate-centered radical. The hydroxy radical then rebounds from the iron to the substrate, yielding the hydroxylated product. While Compound I has succumbed to theoretical and spectroscopic characterization, the associated hydroxyiron species is elusive as a consequence of its very short lifetime, for which there are no quantitative estimates. To ascertain the physical mechanism underlying substrate hydroxylation and probe this timescale, ab initio molecular dynamics simulations and free energy calculations are performed for a model of Compound I catalysis. Semiclassical estimates based on these calculations reveal the hydrogen atom abstraction step to be extremely fast, kinetically comparable to enzymes such as carbonic anhydrase. Using an ensemble of ab initio simulations, the resultant hydroxyiron species is found to have a similarly short lifetime, ranging between 300 fs and 3600 fs, putatively depending on the enzyme active site architecture. The addition of tunneling corrections to these rates suggests a strong contribution from nuclear quantum effects, which should accelerate every step of substrate hydroxylation by an order of magnitude. These observations have strong implications for the detection of individual hydroxylation intermediates during P450 catalysis.

  2. Mercury in mercury(II)-spiked soils is highly susceptible to plant bioaccumulation.

    Science.gov (United States)

    Hlodák, Michal; Urík, Martin; Matúš, Peter; Kořenková, Lucia

    2016-01-01

    Heavy metal phytotoxicity assessments usually use soluble metal compounds in spiked soils to evaluate metal bioaccumulation, growth inhibition and adverse effects on physiological parameters. However, exampling mercury phytotoxicity for barley (Hordeum vulgare) this paper highlights unsuitability of this experimental approach. Mercury(II) in spiked soils is extremely bioavailable, and there experimentally determined bioaccumulation is significantly higher compared to reported mercury bioaccumulation efficiency from soils collected from mercury-polluted areas. Our results indicate this is not affected by soil sorption capacity, thus soil ageing and formation of more stable mercuric complexes with soil fractions is necessary for reasonable metal phytotoxicity assessments.

  3. Hydroxylation Reaction Mechanism for Nitrosodimethylamine by Oxygen Atom

    Institute of Scientific and Technical Information of China (English)

    LI Lan; LIN Xiao-yan; LI Zong-he

    2011-01-01

    The hydroxylation reaction mechanism of nitrosodimethylamine(NDMA)by oxygen atom was theoretically investigated at the B3LYP/6-31G** level.It has been found that the path of the oxydation of the C-H bond is easier than the path involving a Singlet/Triplet crossing.The study of the potential surface shows that both solvent effect at B3LYP/6-31G** level and different method at more credible MP2/6-311G** level in the gas phase have no effect on the hydroxylation reaction mechanism.The oxidation hydroxylation process of NDMA by O is exothermic reaction and easy to occur.

  4. CHROMIUM BIOACCUMULATION FROM COMPOSTS AND VERMICOMPOSTS BASED ON TANNERY SLUDGES

    Directory of Open Access Journals (Sweden)

    Krzysztof GONDEK

    2008-07-01

    Full Text Available Storage of waste substances is not indifferent to ecological equilibrium in the environment therefore should not be the ultimate way to limit waste arduousness. Therefore, the conducted investigations aimed to determine the effect of tannery composts and vermicomposts loaded with chromium on this element bioaccumulation in earthworm bodies and biomass of selected plants. Chromium in composts and vermicomposts based on tannery sludges occurred in small quantities and easily soluble compounds. Chromium concentrations in redworm biomass points to this metal accumulation in Eisenia fetida body tissues. This element content in redworm biomass was signifi cantly positively correlated with its content in composts. Chromium content in plants was diversifi ed and on treatments was generally smaller than on mineral treatment or farmyard manure. Chromium absorbed by plants was stored mainly in the root systems, and over the norm content of this element found in vermicomposts did not cause its excessive accumulation in plant biomass.

  5. Bioaccumulation of heavy metals by fimbrial designer adhesins

    DEFF Research Database (Denmark)

    Schembri, Mark; Kjærgaard, Kristian; Klemm, Per

    1999-01-01

    Naturally occurring adhesins bind to specific molecular targets in a lock-and-key fashion due to the composition of the binding domain of the adhesin. By introduction of random peptide libraries in a suitable surface exposed carrier protein it is possible to create and select designer adhesins wi...... for the bioaccumulation of heavy metals from the environment. (C) 1999 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved........ By serial selection and enrichment procedures specific sequences were identified which conferred the ability on recombinant cells to adhere to various metal oxides (PbO2, CoO, MnO2, Cr2O3 ) The properties inherent in these sequences permitted the distinct recognition of metals to varying degrees, indicating...

  6. Bioaccumulation and transformation of cadmium by Phaeodactylum tricornutum

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper,we report the bioaccumulation and transformation of cadmium (Cd) by Phaeodactylum tricornutum in the presence of ethylenediamine tetra acetic acid (EDTA) and cysteine (Cys). Both EDTA and Cys can alleviate the toxicity of Cd to P. tricornutum. Short term intracellular uptake and extracellular adsorption experiments using ICP-MS indicated that the amounts of Cd accumulated on the cell surface of P. tricornutum and inside the cell decreased along with the increase of EDTA concentration,which conformed to the prediction of the Free Ion Activity Model (FIAM). However,extracellular adsorption of Cd increased at first and then decreased along with the increase in the concentration of Cys,while intracellular uptake increased under Cys concentrations from the blank value to 4.45 μmol/L,and then tended to remain at the same level when the Cys concentration was greater than 4.45 μmol/L,and this deviated remarkably from the FIAM. The interactions of Cd with _Si_OH,_C_OH and NH2(CO) _OH on the cell wall were confirmed using FT-IR and XPS studies. The results obtained using HPLC of the phytochelatins (PCs) produced by P. tricornutum under CdCl2,Cd_EDTA and Cd_Cys stress suggested that the main reason for the different effects of EDTA and Cys on the bioaccumulation and transformation of Cd by P. tricornutum was that Cys is not only a complexing ligand to Cd,as is EDTA,but also it is a precursor of the intracellular synthesizing PCs participating in the cellular defense mechanism against Cd. Furthermore,the discovery of in vivo PCs and oxidized_PCs as well as Cd-PC2 in P. tricornutum using ESI-IT-MS provided the evidence for deactivation of Cd by the PCs,reducing Cd-toxicity to P. tricornutum.

  7. Enantioseletive bioaccumulation of tebuconazole in earthworm Eisenia fetida

    Institute of Scientific and Technical Information of China (English)

    Dingyi Yu; Jianzhong Li; Yanfeng Zhang; Huili Wang; Baoyuan Guo; Lin Zheng

    2012-01-01

    Methods of extraction and determination of tebuconazole enantiomers in earthworm (Eisenia fetida) were developed by capillary electrophoresis (CE) and high performance liquid chromatography (HPLC).Both CE and HPLC have excellent resolution and recovery.The linearity ranges were 2.9-102.4 mg/kg and 3.0-99.6 mg/kg for (+)-R-tebuconazole and (-)-S-tebuconazole respectively in CE,and from 0.56 to 1000 mg/kg for both enantiomers in HPLC.Enantioselective bioaccumulation in earthworms from soil was investigated under laboratory condition at concentrations of 10 and 50 mg/kg dw in soil.The uptake kinetics of (+)-R-tebuconazole fitted the firstorder kinetics well with r2 0.97 and 0.94 under 10 and 50 mg/kg dw exposure condition,respectively,while (-)-S-tebueonazole with r2 0.75 and 0.22 did not show the same.Bioaccumulation of tebuconazole in earthworm tissues was enantioselective with a preferential accumulation of (+)-R-tebuconazole.The (+)-R-tebuconazole might also have biomagnifying effect potential in earthworm food chain with biota-sediment accumulation factor (BSAF) of 1.64 kg OC/kg lip in 10 mg/kg dw exposure group and 2.61 kg OC/kg lip in 50 mg/kg dw exposure group from soil to earthworm after 36 days.Although (-)-S-tebuconazole shares the same physicochemical properties with (+)-R-tebuconazole,it did not biomagnify.BSAFs of (-)-S-tebuconazole were 0.50 kg OC/kg lip (10 mg/kg dw tebuconazole exposure) and 0.28 kg OC/kg lip (50 mg/kg dw tebuconazole exposure) after 36 days,which was possibly owing to biotransformation or metabolism in earthworm tissues.

  8. Bioaccumulation of Aluminium in Hydromacrophytes in Polish Coastal Lakes

    Directory of Open Access Journals (Sweden)

    Senze Magdalena

    2015-03-01

    Full Text Available The research on aluminium content was conducted in water and on aquatic flora of Polish lakes in the central part of the coast. The study included the lakes Sarbsko, Choczewskie, Bia.e, K.odno, D.brze and Salino investigated in the summer of 2013. The examined lakes belong mainly to the direct basin of the Baltic Sea. Samples of aquatic plants and lake waters were collected. In the water samples pH and electrolytic conductivity were measured. The aluminium content was determined both in water and aquatic plants. Submerged hydromacrophyte studies included Myriophyllum alterniflorum L., Potamogeton perfoliatus L. and Ceratophyllum demersum L. Emergent hydromacrophyte studies included Phragmites australis (Cav. Trin. ex Steud., Juncus bulbosus L., Iris pseudacorus L., Eleocharis palustris (L. Roem. % Schult., Phalaris arundinacea L., Carex riparia Curt., Mentha aquatic L., Stratiotes aloides L., Alisma plantago-aquatica L., Glyceria maxima (Hartman Holmb., Sagittaria sagittifolia L., Scirpus lacustris L. and Typha angustifolia L. The purpose of this investigation was the determination of the aluminium content in submerged and emergent hydromacrophytes and also the definition of their bioaccumulative abilities. The average concentration of aluminium in water was 2.68 fęg Al dm.3. The average content of aluminium in plants was 2.8015 mg Al kg.1. The bioaccumulation factor ranged from BCF=19.74 to BCF=16619. On the basis of the analysis of the aluminium content in water and aquatic plants results show that both water and plants were characterized by a moderate level of aluminium. The recorded concentrations indicate a mid-range value and are much lower than those which are quoted for a variety of surface waters in various parts of the world.

  9. Adipose tissue concentrations of PCB, HCB, chlordane, PBDE and P,P'-DDE and the risk for endometrial cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lindstroem, G.; Bavel, B. van; Bjoernfoth, H. [MTM Research Centre, Oerebro Univ., Oerebro (Sweden); Hardell, L. [Dept. of Oncology, Univ. Hospital, Oerebro (Sweden)

    2004-09-15

    Environmental pollutants with hormonal activity, such as xenoestrogens, have for several years been of concern as potential risk factors for hormone dependant tumors. Impacts of increasing levels of xenoestrogens have been observed in aquatic organisms. In humans concern has been focused on ''endocrine disrupting chemicals'' with either estrogenic or antiestrogenic activities. Some persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs), and especially the hydroxylated metabolites, and chlordanes, have been postulated to be endocrine disruptors. PCBs have been shown to reverse gonadal sex in turtle5 and abnormalities of reproductive development has been described in juvenile alligators living in contaminated environment in Florida. Hexachlorobenzene (HCB) has been shown to have endocrine-disrupting properties. Also p,p'-dichlorodiphenyl-dichloroethylene (p,p'-DDE) the most persistent metabolite of p,p'-DDT has been postulated to be an environmental endocrine disruptor. In a case-control study on patients with testicular cancer we found higher concentrations of PCBs, HCB and chlordanes in mothers to cases than in mothers to controls. Similar concentrations were found in cases with testicular cancer as in the population controls. The study gave support to the hypothesis that exposure to endocrine disruptors during the fetal period may be of etiologic importance in the etiology of testicular cancer. Another hormone dependent cancer is endometrial cancer. It accounted for 5.8% of all cancers incidents among Swedish women in 2002. The cumulative probability of developing the disease before 85 years of age was 2.8% in 2002. Estrogen replacement has been suggested as a risk factor among several others. The first cases of endometrial cancer among women using estrogen replacement therapy were reported in early 1960's. Is there a relationship between levels of POPs and incidence rate? The aim is to investigate

  10. Synthesis of Azide-Functionalized Hydroxyl-Terminated Polybutadiene

    Science.gov (United States)

    Shekhar Pant, Chandra; Santosh Mada, S. S. N. M.; Mehilal; Banerjee, Shaibal; Khanna, Pawan K.

    2016-10-01

    This article reports ways to functionalize hydroxyl-terminated polybutadiene (HTPB) by azide groups to impart energetic properties to the polymer. Two different synthetic approaches were explored to synthesize azide-functionalized hydroxyl-terminated polybutadiene (azide-HTPB). The functionalized polymer was analyzed for structural confirmation and determination of important physical and thermal properties. Azide-HTPB obtained by azidation of 10% double bonds of HTPB showed viscosity of 11 Pa.s and a glass transition temperature of -66°C.

  11. Detection of adsorbed water and hydroxyl on the moon

    Science.gov (United States)

    Clark, R.N.

    2009-01-01

    Data from the Visual and Infrared Mapping Spectrometer (VIAAS) on Cassini during its flyby of the AAoon in 1999 show a broad absorption at 3 micrometers due to adsorbed water and near 2.8 micrometers attributed to hydroxyl in the sunlit surface on the AAoon. The amounts of water indicated in the spectra depend on the type of mixing and the grain sizes in the rocks and soils but could be 10 to 1000 parts per million and locally higher. Water in the polar regions may be water that has migrated to the colder environments there. Trace hydroxyl is observed in the anorthositic highlands at lower latitudes.

  12. Optimizing Stream Water Mercury Sampling for Calculation of Fish Bioaccumulation Factors

    Science.gov (United States)

    Mercury (Hg) bioaccumulation factors (BAFs) for game fishes are widely employed for monitoring, assessment, and regulatory purposes. Mercury BAFs are calculated as the fish Hg concentration (Hgfish) divided by the water Hg concentration (Hgwater) and, consequently, are sensitive ...

  13. Optimizing the use of rainbow trout hepatocytes for bioaccumulation assessments with fish

    Science.gov (United States)

    Measured rates of biotransformation by cryopreserved trout hepatocytes can be extrapolated to the whole animal as a means of predicting metabolism impacts on chemical bioaccumulation. Future use of these methods within a regulatory context requires, however, that they be standar...

  14. Molecular effects and bioaccumulation of levonorgestrel in the non-target organism Dreissena polymorpha

    DEFF Research Database (Denmark)

    Contardo-Jara, V.; Lorenz, Claudia; Pflugmacher, S.;

    2011-01-01

    Bioaccumulation and effects of the contraceptive hormone levonorgestrel were examined in the nontarget organism Dreissena polymorpha. Molecular biomarkers of biotransformation, elimination, antioxidant defence and protein damage were analyzed after exposure to increasing concentrations of levonor...

  15. DISTRIBUTION OF TOTAL AND METHYLMERCURY IN DIFFERENT ECOSYSTEM COMPARTMENTS IN THE EVERGLADES: IMPLICATIONS FOR MERCURY BIOACCUMULATION

    Science.gov (United States)

    Mercury (Hg) species distribution patterns among ecosystem compartments in the Everglades were analyzed at the landscape level in order to explore the implications of Hg distribution for Hg bioaccumulation, and to investigate major biogeochemical processes that are pertinent to t...

  16. Bioaccumulation of metals in aquatic insects of streams located in areas with sugar cane cultivation

    OpenAIRE

    Juliano José Corbi; Claudio Gilberto Froehlich; Susana Trivinho Strixino; Ademir dos Santos

    2010-01-01

    Streams located in areas of sugar cane cultivation receive elevated concentrations of metal ions from soils of adjacent areas. The accumulation of metals in the sediments results in environmental problems and leads to bioaccumulation of metal ions by the aquatic organisms. In the present study, bioaccumulation of the metals ions Al, Cd, Cr, Cu, Fe, Mg, Mn and Zn in aquatic insects in streams impacted by the sugar cane was evaluated. The results pointed out that the insects were contaminated b...

  17. Hydroxyl radical reactivity at the air-ice interface

    Directory of Open Access Journals (Sweden)

    T. F. Kahan

    2010-01-01

    Full Text Available Hydroxyl radicals are important oxidants in the atmosphere and in natural waters. They are also expected to be important in snow and ice, but their reactivity has not been widely studied in frozen aqueous solution. We have developed a spectroscopic probe to monitor the formation and reactions of hydroxyl radicals in situ. Hydroxyl radicals are produced in aqueous solution via the photolysis of nitrite, nitrate, and hydrogen peroxide, and react rapidly with benzene to form phenol. Similar phenol formation rates were observed in aqueous solution and bulk ice. However, no reaction was observed at air-ice interfaces, or when bulk ice samples were crushed prior to photolysis to increase their surface area. We also monitored the heterogeneous reaction between benzene present at air-water and air-ice interfaces with gas-phase OH produced from HONO photolysis. Rapid phenol formation was observed on water surfaces, but no reaction was observed at the surface of ice. Under the same conditions, we observed rapid loss of the polycyclic aromatic hydrocarbon (PAH anthracene at air-water interfaces, but no loss was observed at air-ice interfaces. Our results suggest that the reactivity of hydroxyl radicals toward aromatic organics is similar in bulk ice samples and in aqueous solution, but is significantly suppressed in the quasi-liquid layer (QLL that exists at air-ice interfaces.

  18. Sulfur Dioxide Capture by Heterogeneous Oxidation on Hydroxylated Manganese Dioxide.

    Science.gov (United States)

    Wu, Haodong; Cai, Weimin; Long, Mingce; Wang, Hairui; Wang, Zhiping; Chen, Chen; Hu, Xiaofang; Yu, Xiaojuan

    2016-06-01

    Here we demonstrate that sulfur dioxide (SO2) is efficiently captured via heterogeneous oxidation into sulfate on the surface of hydroxylated manganese dioxide (MnO2). Lab-scale activity tests in a fluidized bed reactor showed that the removal efficiency for a simulated flue gas containing 5000 mg·Nm(-3) SO2 could reach nearly 100% with a GHSV (gas hourly space velocity) of 10000 h(-1). The mechanism was investigated using a combination of experimental characterizations and theoretical calculations. It was found that formation of surface bound sulfate proceeds via association of SO2 with terminal hydroxyls. Both H2O and O2 are essential for the generation of reactive terminal hydroxyls, and the indirect role of O2 in heterogeneous SO2 oxidation at low temperature was also revealed. We propose that the high reactivity of terminal hydroxyls is attributed to the proper surface configuration of MnO2 to adsorb water with degenerate energies for associative and dissociative states, and maintain rapid proton dynamics. Viability analyses suggest that the desulfurization method that is based on such a direct oxidation reaction at the gas/solid interface represents a promising approach for SO2 capture. PMID:27123922

  19. Environmental Implications of Hydroxyl Radicals ((•)OH).

    Science.gov (United States)

    Gligorovski, Sasho; Strekowski, Rafal; Barbati, Stephane; Vione, Davide

    2015-12-23

    The hydroxyl radical ((•)OH) is one of the most powerful oxidizing agents, able to react unselectively and instantaneously with the surrounding chemicals, including organic pollutants and inhibitors. The (•)OH radicals are omnipresent in the environment (natural waters, atmosphere, interstellar space, etc.), including biological systems where (•)OH has an important role in immunity metabolism. We provide an extensive view on the role of hydroxyl radical in different environmental compartments and in laboratory systems, with the aim of drawing more attention to this emerging issue. Further research on processes related to the hydroxyl radical chemistry in the environmental compartments is highly demanded. A comprehensive understanding of the sources and sinks of (•)OH radicals including their implications in the natural waters and in the atmosphere is of crucial importance, including the way irradiated chromophoric dissolved organic matter in surface waters yields (•)OH through the H2O2-independent pathway, and the assessment of the relative importance of gas-phase vs aqueous-phase reactions of (•)OH with many atmospheric components. Moreover, considering the fact that people spend so much more time in dwellings than outside, the impact of the reactivity of indoor hydroxyl radicals on health and well-being is another emerging research topic of great concern.

  20. A New 10-Hydroxyl Anthrone Glycoside from Cassia siamea Lam.

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new 10-hydroxyl anthrone glycoside, 1, 8, 10 - trihydroxyl-1-O-β-D-glucopyrano-syl-3-methyl-10- C (S) - β - D- glucopyranosyl-anthrone-9 1 was isolated from the stem of Cassia siamea Lam. The structure was elucidated by spectral evidences, especially by 2 D techniques.

  1. Shrinkage of vitreous body caused by hydroxyl radical

    Energy Technology Data Exchange (ETDEWEB)

    Park, Myoung Joo; Shimada, Takashi; Matuo, Yoichirou; Akiyama, Yoko; Izumi, Yoshinobu; Nishijima, Shigehiro [Osaka University, Osaka (Japan)

    2008-12-15

    In the study, we examined the effect of hydroxyl radical generated by {gamma}-ray and UV irradiation on shrinkage of vitreous body. Change in gel ratio of vitreous body and change in the properties of its components (collagen, sodium hyaluronate) were analyzed. By comparing these results, the amount of hydroxyl radical, which induces the considerable shrinkage of vitreous body, was evaluated from theoretical calculation based on experimental condition and some reported kinetic parameters. It was concluded that the integrated amount of hydroxyl radical required to liquefy half of the vitreous body (vitreous body gel ratio = 50%) was estimated as 140 {mu}molg{sup -1} from {gamma}-ray irradiation experiment. Also, from UV irradiation experiment result, it was confirmed that the effect of hydroxyl radical is larger than that of other reactive species. The causes of shrinkage of vitreous body are supposed as follows, 1) decrease in viscosity by cleavage of glycoside bond in sodium hyaluronate, 2) leaching of collagen from vitreous body and 3) leaching of crosslinked products and scission products of collagen.

  2. Enantioselective Hydroxylation of 4-Alkylphenols by Vanillyl Alcohol Oxidase

    NARCIS (Netherlands)

    Drijfhout, Falko P.; Fraaije, Marco W.; Jongejan, Hugo; Berkel, Willem J.H. van; Franssen, Maurice C.R.

    1998-01-01

    Vanillyl alcohol oxidase (VAO) from Penicillium simplicissimum catalyzes the enantioselective hydroxylation of 4-ethylphenol, 4-propylphenol, and 2-methoxy-4-propylphenol into 1-(4'-hydroxyphenyl)ethanol, 1-(4'-hydroxyphenyl)propanol, and 1-(4'-hydroxy-3'-methoxyphenyl)propanol, respectively, with a

  3. Hydroxyl Radical and Its Scavengers in Health and Disease

    Directory of Open Access Journals (Sweden)

    Boguslaw Lipinski

    2011-01-01

    Full Text Available It is generally believed that diseases caused by oxidative stress should be treated with antioxidants. However, clinical trials with such antioxidants as ascorbic acid and vitamin E, failed to produce the expected beneficial results. On the other hand, important biomolecules can be modified by the introduction of oxygen atoms by means of non-oxidative hydroxyl radicals. In addition, hydroxyl radicals can reduce disulfide bonds in proteins, specifically fibrinogen, resulting in their unfolding and scrambled refolding into abnormal spatial configurations. Consequences of this reaction are observed in many diseases such as atherosclerosis, cancer and neurological disorders, and can be prevented by the action of non-reducing substances. Moreover, many therapeutic substances, traditionally classified as antioxidants, accept electrons and thus are effective oxidants. It is described in this paper that hydroxyl radicals can be generated by ferric ions without any oxidizing agent. In view of the well-known damaging effect of poorly chelated iron in the human body, numerous natural products containing iron binding agents can be essential in the maintenance of human health. However, beneficial effects of the great number of phytochemicals that are endowed with hydroxyl radical scavenging and/or iron chelating activities should not be considered as a proof for oxidative stress.

  4. Effects of storage on sediment toxicity, bioaccumulation potential, and chemistry. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tatem, H.E.; Brandon, D.L.; Lee, C.R.; Jarvis, A.S.; Rhett, R.G.

    1991-01-01

    Current guidance on storage of sediments for bioassay/bioaccumulation tests requires that samples be held at 4 C and used within 2 weeks of collection. The objective of this study was to determine the effects of sediment storage for 40 weeks on sediment toxicity, bioaccumulation potential, and chemical analyses. Toxicity and bioaccumulation tests were conducted five times during 40 weeks of storage. Chemical analyses were performed three times during this period. The data indicate that sediments can be held for longer than 2 to 4 weeks, in many cases, without significant effect on test results. However, results of the study also show that tests performed at different times can produce different results. This study showed that a sediment that was toxic to mysids remained toxic during 16 weeks of sediment storage. Two sediments that were toxic initially continued to show significant toxicity after 8 and 16 weeks of sediment storage. One sediment, not toxic initially or at 4 weeks, changed during storage, becoming significantly toxic compared to the Atlantic Ocean (Ref) sediment. The bioaccumulation results showed that certain sediment contaminants (lead, mercury, polychlorinated biphenyls, and some polycyclic aromatic hydrocarbons, PAHs), generally do not reveal a statistical change in bioaccumulation, relative to Ref animals, during 16 weeks of sediment storage. Other PAHs, including phenanthrene, anthracene, benzo (a) anthracene, and chrysene, did change in bioaccumulation potential during storage.

  5. Bioaccumulation of gasoline in brackish green algae and popular clams

    Directory of Open Access Journals (Sweden)

    Gihan A. El-Shoubaky

    2016-03-01

    Full Text Available The green algae (Ulva lactuca and Enteromorpha clathrata and the clams (Tapes decussates and Venerupis aurea grow together in Timsah Lake, Suez Canal, Egypt. Our ultimate goal is to validate the bioaccumulation of gasoline in the marine organisms and their behavior after exposure to the pollutant, experimentally. These species were treated with a serial treatment of gasoline (1000, 4000, 16,000 and 64,000 μl in aquaria with brackish sea-water for 72 h. The tested green algae and clams were taken for an analysis of total hydrocarbon accumulation daily. The statistical analysis showed significant differences between the four species and also between the duration of exposure. The accumulation of gasoline in U. lactuca and E. clathrata reached their maximum after 48 h at 1000 and 4000 μl. The highest absorption was registered after 24 h only at 16,000 and at 64,000 μl. U. lactuca recorded complete mortality in 64,000 μl at 72 h whereas E. clathrata registered death at 48 h and 72 h in the same treatment. V. aurea was more sensitive than T. decussates. The accumulation of gasoline reached its maximum in V. aurea after only 24 h in the first treatment while it retarded to 48 h in T. decussates with a lesser accumulation. However, both clam species accumulated the highest amount of petroleum hydrocarbons during the first hour of exposure at the first treatment. In the third and fourth treatments, clams did not accumulate gasoline but began to dispose it from their tissues till it became less than that in the control. Mortality gradually increased with time in each treatment except the last one (64,000 μl in which 100% death of the specimens was observed. In general, the bioaccumulation of gasoline level was in a descending order as follows: U. lactuca > E. clathrata > V. aurea > T. decussates. Their behavior changed from accumulation to detoxification with time and with the increase in pollutant concentration. Generally, these

  6. Comparing trace metal bioaccumulation characteristics of three freshwater decapods of the genus Macrobrachium

    Energy Technology Data Exchange (ETDEWEB)

    Cresswell, Tom, E-mail: tom.cresswell@ansto.gov.au [Centre for Environmental Contaminants Research, CSIRO Land and Water, New Illawarra Rd, Lucas Heights, 2234, NSW (Australia); School of Applied Sciences, RMIT University, Plenty Road, Bundoora 3083, VIC (Australia); Smith, Ross E.W. [Hydrobiology, Lang Parade, Auchenflower 4066, QLD (Australia); Nugegoda, Dayanthi [School of Applied Sciences, RMIT University, Plenty Road, Bundoora 3083, VIC (Australia); Simpson, Stuart L. [Centre for Environmental Contaminants Research, CSIRO Land and Water, New Illawarra Rd, Lucas Heights, 2234, NSW (Australia)

    2014-07-01

    Highlights: • Exposed three species of prawns of same genus to solid- and dissolved-phase metals. • Cd bioaccumulated from dissolved phase was significantly different between species. • All three species retained >95% of bioaccumulated Cd during the depuration phase. • Bioaccumulation of As, Pb and Zn from solid phase was different between species. • Results highlight variability among species, even under controlled conditions. - Abstract: Potential sources and kinetics of metal bioaccumulation by the three Macrobrachium prawn species M. australiense, M. rosenbergii and M. latidactylus were assessed in laboratory experiments. The prawns were exposed to two scenarios: cadmium in water only; and exposure to metal-rich mine tailings in the same water. The cadmium accumulation from the dissolved exposure during 7 days, followed by depuration in cadmium-free water for 7 days, was compared with predictions from a biokinetic model that had previously been developed for M. australiense. M. australiense and M. latidactylus accumulated significant tissue cadmium during the exposure phase, albeit with different uptake rates. All three species retained >95% of the bioaccumulated cadmium during the depuration phase, indicating very slow efflux rates. Following exposure to tailings, there were significant (p < 0.05) differences in tissue arsenic, cadmium, lead and zinc concentrations among species. Cadmium and zinc concentrations were increased relative to controls for all three species but were not different between treatments (direct/indirect contact with tailings), suggesting these metals were primarily accumulated via the dissolved phase. All species bioaccumulated significantly greater arsenic and lead when in direct contact with mine tailings, demonstrating the importance of an ingestion pathway for these metals. Copper was not bioaccumulated above control concentrations for any species. The differences between the metal accumulation of the three prawns indicated

  7. Bioaccumulation Studies Associated with the Kingston Fly Ash Spill, Spring 2009 - Fall 2010

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Marshall [ORNL; Brandt, Craig C [ORNL; Fortner, Allison M [ORNL

    2012-05-01

    In December 2008, an ash dike at the Tennessee Valley Authority (TVA) Kingston Fossil Plant ruptured, releasing over one billion gallons of coal fly ash into the Emory and Clinch Rivers. Coal fly ash may contain several contaminants of concern, but of these selenium (Se) and arsenic (As) have been highlighted because of their toxicity and tendency to bioaccumulate in aquatic food chains. To assess the potential impact of the spilled fly ash on humans and the environment, a comprehensive biological and environmental monitoring program was established, for which resident aquatic organisms (among other sample media) are collected to determine contaminant exposure and evaluate the risk to humans and wildlife. Studies on bioaccumulation and fish health are major components of the TVA Biological Monitoring Program for the Kingston fly ash project. These studies were initiated in early Spring 2009 for the purposes of: (1) documenting the levels of fly ash-associated metals in various tissues of representative sentinel fish species in the area of the fly ash spill, (2) determining if exposure to fly ash-associated metals causes short, intermediate, or long-term health effects on these sentinel fish species, (3) assessing if there are causal relationships between exposure (to metals) and effects on fish, (4) evaluating, along with information regarding other ecological and physicochemical studies, the nature and route of contaminant transfer though food chains into higher level consumers, (5) providing important information for the Ecological Risk Assessment (ERA) for the Kingston fly ash project, and (6) serving as an important technology transfer or model study focused on how to best evaluate the environmental effects of fly ash, not only at the Kingston site, but also at sites on other aquatic systems where coal-fired generating stations are located. This report summarizes the bioaccumulation results from the first two years of study after the fly ash spill, including

  8. Fatty acid hydroxylation in rat kidney cortex microsomes.

    Science.gov (United States)

    Ellin, A; Orrenius, S

    1975-08-30

    Rat kidney microsomes have been found to catalyze the hydroxylation of medium-chained fatty acids to the omega- and (omego-1)-hydroxy derivatives. This reaction, which requires NADPH and molecular oxygen, is a function of monooxygenase system present in the kidney microsomes, containing NADPH-cytochrome c reductase and cytochrome P-450K. NADH is about half as effective as an electron donor as NADPH and there is an additive effect in the presence of both nucleotides. Cytochrome P-450K absorbs light maximally at 452-3 nm, when it is reduced and bound to carbon monoxide. The extinction coefficient of this complex is 91 mM(-1) cm(-1). Electrons from NADPH are transferred to cytochrome P-450K via the NADPH-cytochrome c reductase. The reduction rate of cytochrome P-450K is stimulated by added fatty acids and the reduction kinetics reveal the presence of endogenous substrates bound to cytochrome P-450K. Both cytochrome P-450K concentration and fatty acid hydroxylation activity in kidney microsomes are increased by starvation. On the other hand, phenobarbital treatment of the rats has no effect on either the hemoprotein or the overall hydroxylation reaction and 3,4-benzpyrene administration induces a new species of cytochrome P-450K not involved in fatty acid hydroxylation. Cytochrome P-450K shows, in contrast to liver P-450, high substrate specificity. The only substances forming enzyme-substrate complexes with cytochrome P-450K are the medium-chained fatty acids and certain derivatives of these acids. The chemical requirements for substrate binding include a carbon chain of medium length and at the end of the chain a carbonyl group and a free electron pair on a neighbouring atom. The distance between the binding site for the carbonyl group and the active oxygen is suggested to be in the order of 16 A. This distance fixes the ratio of omega- and (omega-1)-hydroxylated products formed from a certain fatty acid by the single species of cytochrome P-450K involved. The

  9. Cadmium tolerance and bioaccumulation of 18 hemp accessions.

    Science.gov (United States)

    Shi, Gangrong; Liu, Caifeng; Cui, Meicheng; Ma, Yuhua; Cai, Qingsheng

    2012-09-01

    Hemp (Cannabis sativa L.) is a fast-growing and high biomass producing plant species, which has been traditionally grown as multiple-use crop and recently considered as an energy crop. In order to screen accessions that can be cultivated in cadmium (Cd)-contaminated soils for biodiesel production, the ability of Cd tolerance and bioaccumulation of 18 hemp cultivars or ecotypes were evaluated in pot experiment under 25 mg Cd kg(-1) (dry weight, DW) soil condition, in terms of plant growth, pigment contents, chlorophyll fluorescence, and Cd accumulation at 45 days after seedling emergence. Results showed that seedlings of all cultivars, except USO-31, Shenyang and Shengmu, could grow quite well under 25 mg Cd kg(-1) (DW) soil condition. Among them, Yunma 1, Yunma 2, Yunma 3, Yunma 4, Qujing, Longxi, Lu'an, Xingtai, and Shuyang showed great biomass (>0.5 g plant(-1)), high tolerance factors (68.6-92.3%), and little reduction of pigment content and chlorophyll fluorescence under 25 mg Cd kg(-1) (DW) soil stress, indicating these cultivars had a strong tolerance to Cd stress and could be cultivated in Cd-contaminated soils. Cultivars Longxi, Lu'an, Xingtai, Yunma 2, Yunma 3, Yunma 4, and Qujing exhibited higher Cd concentrations and total Cd in shoots. These cultivars, therefore, are good candidates for the implementation of the new strategy of cultivating biodiesel crops for phytoremediation of Cd-contaminated soils.

  10. Optimizing fish sampling for fish - mercury bioaccumulation factors

    Science.gov (United States)

    Scudder Eikenberry, Barbara C.; Riva-Murray, Karen; Knightes, Christopher D.; Journey, Celeste A.; Chasar, Lia C.; Brigham, Mark E.; Bradley, Paul M.

    2015-01-01

    Fish Bioaccumulation Factors (BAFs; ratios of mercury (Hg) in fish (Hgfish) and water (Hgwater)) are used to develop Total Maximum Daily Load and water quality criteria for Hg-impaired waters. Both applications require representative Hgfish estimates and, thus, are sensitive to sampling and data-treatment methods. Data collected by fixed protocol from 11 streams in 5 states distributed across the US were used to assess the effects of Hgfish normalization/standardization methods and fish sample numbers on BAF estimates. Fish length, followed by weight, was most correlated to adult top-predator Hgfish. Site-specific BAFs based on length-normalized and standardized Hgfish estimates demonstrated up to 50% less variability than those based on non-normalized Hgfish. Permutation analysis indicated that length-normalized and standardized Hgfish estimates based on at least 8 trout or 5 bass resulted in mean Hgfish coefficients of variation less than 20%. These results are intended to support regulatory mercury monitoring and load-reduction program improvements.

  11. Bioaccumulation and bioavailability of polybrominated diphynel ethers (PBDEs) in soil

    Energy Technology Data Exchange (ETDEWEB)

    Liang Xianwei; Zhu Shuzhen; Chen Peng [College of Environmental Science and Engineering, Nankai University, Weijin Road 94, Tianjin 300071 (China); Key Laboratory of Pollution Processes and Environmental Criteria (Nankai University), Ministry of Education, Tianjin 300071 (China); Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, Nankai University, Tianjin 300071 (China); Zhu Lingyan, E-mail: zhuly@nankai.edu.c [College of Environmental Science and Engineering, Nankai University, Weijin Road 94, Tianjin 300071 (China); Key Laboratory of Pollution Processes and Environmental Criteria (Nankai University), Ministry of Education, Tianjin 300071 (China); Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, Nankai University, Tianjin 300071 (China)

    2010-07-15

    Earthworms were exposed to artificially contaminated soils of DE-71 and DE-79 to investigate the bioaccumulation and bioavailability of PBDEs in soil. All major congeners were bioavailable to earthworms. The uptake and elimination rate coefficients of PBDEs decreased with their logK{sub ow}s. The biota soil accumulation factors of PBDEs also declined with logK{sub ow}. These may be due to the large molecular size and the high affinity of PBDEs to soil particles. The concentrations extracted by Tenax for 6 h correlated very well with those found in earthworms, suggesting that the bioavailability of PBDEs in soil is related to the fraction of rapid desorption from soil. This also indicates that 6 h Tenax extraction is a good proxy for the bioavailability of PBDEs to earthworms in soil. The BSAFs of PBDEs in aged soil decreased 22-84% compared to freshly spiked soil, indicating that aging may diminish the bioavailability of PBDEs in soil significantly. - PBDEs are bioavailable to earthworms in soil and the uptake and elimination rate coefficients and BSAFs declined with their logK{sub ow}s.

  12. Persistence and bioaccumulation of oxyfluorfen residues in onion.

    Science.gov (United States)

    Sondhia, Shobha

    2010-03-01

    A field study was conducted to determine persistence and bioaccumulation of oxyflorfen residues in onion crop at two growth stages. Oxyfluorfen (23.5% EC) was sprayed at 250 and 500 g ai/ha on the crop (variety, N53). Mature onion and soil samples were collected at harvest. Green onion were collected at 55 days from each treated and control plot and analyzed for oxyfluorfen residues by a validated high-performance liquid chromatography method with an accepted recovery of 78-92% at the minimum detectable concentration of 0.003 microg g(-1). Analysis showed 0.015 and 0.005 microg g(-1) residues of oxyfluorfen at 250 g a.i. ha(-1) rate in green and mature onion samples, respectively; however, at 500 g a.i.ha(-1) rates, 0.025 and 0.011 microg g(-1) of oxyfluorfen residues were detected in green and mature onion samples, respectively. Soil samples collected at harvest showed 0.003 and 0.003 microg g(-1) of oxyfluorfen residues at the doses 250 and 500 g a.i. ha(-1), respectively. From the study, a pre-harvest interval of 118 days for onion crop after the herbicide application is suggested. PMID:19238567

  13. Bioaccumulation of Hg in the mushroom Pleurotus ostreatus

    Energy Technology Data Exchange (ETDEWEB)

    Bressa, G.; Cima, L.; Costa, P.

    1988-10-01

    The possibility of utilizing industrial, urban, and other wastes for the growth of a product which is directly edible by humans is fascinating. However, it is possible that many wastes containing toxic substances, for example, heavy metals, could reach the food chain and produce adverse effects on human health. To this end, we studied the possibility of bioaccumulation of Hg by a mushroom, Pleurotus ostreatus, grown on an artificial compost containing this element. Concentrations of 0.05, 0.1, and 0.2 mg/kg of Hg as Hg(NO/sub 3/)/sub 2/.H/sub 2/O were added to three groups of the same compost, successively inoculated with the mycelia of the mushroom. Higher concentrations strongly reduced the growth of the mycelia and therefore were not utilized. The concentrations of Hg in the substrate and in the mushroom were evaluated by AAS. The range of the accumulation factor was found to be 65-140, i.e., very marked. This finding suggests that the cultivation of P. ostreatus on substrates containing Hg from industrial and urban wastes could involve possible risks to human health.

  14. Bioaccumulation and biosorption of chromium by Aspergillus niger MTCC 2594.

    Science.gov (United States)

    Sandana Mala, John Geraldine; Unni Nair, Balachandran; Puvanakrishnan, Rengarajulu

    2006-06-01

    Chromium toxicity is of prime concern due to chrome tanning processes in the leather sector. Chrome tanning results in the discharge of toxic levels of chromium causing pollution hazards. Chromium levels of Cr(III) and Cr(VI) were high above permissible limits in chrome samples after chrome tanning. The potential of Aspergillus niger MTCC 2594 to accumulate chromium as well as its biosorption capacity is investigated in this study. Bioaccumulation of Cr(III) and Cr(VI) in the spent chrome liquor has resulted in a 75-78% reduction of the initial Cr content in 24-36 h. A. niger biomass is found to be very effective in the biosorption of Cr(III) and Cr(VI) in spent chrome liquor. Maximum adsorption of 83% for biosorption of Cr(III) at 48 h and 79% of Cr(VI) at 36 h in spent chrome liquor is observed. The biosorption characteristics fit well with Langmuir and Freundlich isotherms and the adsorption parameters are evaluated. The biosorption of Cr also follows Lagergren kinetics. A. niger biomass is effectively used for the biosorption of chromium with 79-83% Cr removal in 36-48 h.

  15. Heavy metal bioaccumulation by wild edible saprophytic and ectomycorrhizal mushrooms.

    Science.gov (United States)

    Širić, Ivan; Humar, Miha; Kasap, Ante; Kos, Ivica; Mioč, Boro; Pohleven, Franc

    2016-09-01

    Heavy metals cause serious problems in the environment, and they can be accumulated in organisms, especially in the higher fungi. The concentration of Ni, Cr, Pb, Cd, and Hg in 10 species of edible mushrooms in Medvednica Nature Park, Croatia was therefore determined. In addition, the similarity between the studied species was determined by cluster analysis based on concentrations of the aforementioned metals in the fruiting bodies. The contents of nickel, chromium, lead, cadmium, and mercury in the fruiting bodies of mushrooms were obtained by X-ray fluorescence spectrometry. The highest concentrations of Ni (3.62 mg kg(-1)), Cr (3.01 mg kg(-1)), and Cd (2.67 mg kg(-1)) were determined in Agaricus campestris. The highest concentration of Pb (1.67 mg kg(-1)) was determined in Macrolepiota procera, and the highest concentration of Hg (2.39 mg kg(-1)) was determined in Boletus edulis. The concentration of all heavy metals significantly differed (p Cr, and Pb and bioaccumulators of Cd and Hg. Cluster analysis performed on the basis of the accumulation of the studied metals revealed great phenotypic similarity of mushroom species belonging to the same genus and partial similarity of species of the same ecological affiliation. PMID:27272918

  16. Heavy Metal Bioaccumulation and Toxicity with Special Reference to Microalgae

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The bioaccumulation and toxicity of heavy metals were reviewed with special reference to microalgae, the key component of the food web in aquatic ecosystems. Heavy metals enter algal cells either by means of active transport or by endocytosis through chelating proteins and affect various physiological and biochemical processes of the algae. The toxicity primarily results from their binding to the sulphydryl groups in proteins or disrupting protein structure or displacing essential elements. Metals can break the oxidative balance of the algae, inducing antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and ascorbate peroxidase (APX). The amount of oxidized proteins and lipids in the algal cells thus indicates the severity of the stress. Algal tolerance to heavy metal is highly dependent upon the defense response against the probable oxidative damages. Production of binding factors and proteins, exclusion of metals from cells by ion-selective transporters and excretion or compartmentalization have been suggested with regard to reducing heavy metal toxicity. However, a comprehensive description on the mechanisms underlining metal toxicity of microalgae and gaining tolerance is yet to be elaborated.

  17. Triclosan: Current Status, Occurrence, Environmental Risks and Bioaccumulation Potential

    Directory of Open Access Journals (Sweden)

    Gurpreet Singh Dhillon

    2015-05-01

    Full Text Available Triclosan (TCS is a multi-purpose antimicrobial agent used as a common ingredient in everyday household personal care and consumer products. The expanded use of TCS provides a number of pathways for the compound to enter the environment and it has been detected in sewage treatment plant effluents; surface; ground and drinking water. The physico-chemical properties indicate the bioaccumulation and persistence potential of TCS in the environment. Hence, there is an increasing concern about the presence of TCS in the environment and its potential negative effects on human and animal health. Nevertheless, scarce monitoring data could be one reason for not prioritizing TCS as emerging contaminant. Conventional water and wastewater treatment processes are unable to completely remove the TCS and even form toxic intermediates. Considering the worldwide application of personal care products containing TCS and inefficient removal and its toxic effects on aquatic organisms, the compound should be considered on the priority list of emerging contaminants and its utilization in all products should be regulated.

  18. In vitro exposure of DE-71, a penta-PBDE mixture, on immune endpoints in bottlenose dolphins (Tursiops truncatus) and B6C3F1 mice.

    Science.gov (United States)

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

    2015-02-01

    Polybrominated diphenyl ethers (PBDEs) are an emerging contaminant of concern with low level exposures demonstrating toxicity in laboratory animals and wildlife, although immunotoxicity studies have been limited. Bottlenose dolphin peripheral blood leukocytes (PBLs) and mouse splenocytes were exposed to environmentally relevant DE-71 (a penta-PBDE mixture) concentrations (0-50 µg ml(-1) ) in vitro. Natural killer (NK) cell activity and lymphocyte (B and T cell) proliferation were evaluated using the parallelogram approach for risk assessment. This study aimed to substantiate results from field studies with dolphins, assess the sensitivities between the mouse model and dolphins, and to evaluate risk using the parallelogram approach. In mouse cells, NK cell activity increased at in vitro doses 0.05, 0.5 and 25 µg DE-71 ml(-1) , whereas proliferation was not modulated. In dolphin cells, NK cell activity and lymphocyte proliferation was not altered after in vitro exposure. In vitro exposure of dolphin PBLs to DE-71 showed similar results to correlative field studies; NK cell activity in mice was more sensitive to in vitro exposure than dolphins, and the parallelogram approach showed correlation with all three endpoints to predict risk in bottlenose dolphins.

  19. Can PBDE natural formation and degradation processes interfere with the identification of anthropogenic trends and sources? Evidences from sediments of the Nador Lagoon (Morocco).

    Science.gov (United States)

    Piazza, Rossano; Bellucci, Luca Giorgio; Giuliani, Silvia; Romano, Stefania; Frignani, Mauro; Pizzini, Sarah; Polo, Fabio Paolo; Vecchiato, Marco; Zambon, Stefano; El Moumni, Bouchta

    2016-07-15

    This paper presents the first results related to PBDE concentrations in sediments of the Nador Lagoon (N-E Morocco), an area endangered by different pollutant sources. Analyses were performed by HRGC-LRMS and confirmed by HRGC-HRMS on selected samples. Total surficial concentrations were 0.059-8.2ngg(-1). The maxima were found close to Nador City. Along the sedimentary records, the highest total concentrations (11 and 2.2ngg(-1)) were found at depths corresponding to times (1930s-1950s) when these chemicals were not yet produced. Dehydroxylation or demethoxylation of naturally occurring structural analogues of PBDEs under reducing conditions was suggested. BDE-47 dominated the congener compositions, while BDE-209, when present, could be detected only by HRGC-HRMS, proving that analytical degradation modified the original assemblage. Microbial anaerobic degradation could have changed congener compositions in sediments deposited from the 1970s to the 2000s. Current values are not harmful, but increasing trends call for constant monitoring. PMID:27216046

  20. Study on the bioactivity changes of hydroxylated sulfonylureas derivatives: A possible metabolism

    Institute of Scientific and Technical Information of China (English)

    Shu Rong Ban; Cong Wei Niu; Wen Bin Chen; Zhi Hong Yu; Si Wu; Chen Wang; Zhen Xi

    2007-01-01

    Some new sulfonylureas and their hydroxylation products had been synthesized from 2-amino-4-methylpyrimidine. Their bioactivities against E. Coli AHAS Ⅱ in vitro were tested and the results indicated that the hydroxylation decreased the inhibition activities of sulfonylureas significantly. Subsequently herbicidal tests against stem-growth of barnyard grass and root-growth of rape confirmed the above conclusion. The preliminary molecular docking studies were also carried out to investigate the binding modes of non-hydroxylated and hydroxylated sulfonylureas with AHAS.

  1. MODIFICATION OF EPOXY RESINS WITH PHENOLIC HYDROXYL-TERMINATED POLYSILOXANE

    Institute of Scientific and Technical Information of China (English)

    HOU Qingpu; HUANG Ying; YU Yunzhao

    1995-01-01

    Phenolic hydroxyl-terminated polysiloxanes were incorporated into epoxy resins to reduce the internal stress owing to the mismatch in coefficient of thermal expansion (CTE).Polysiloxane-epoxy resin block copolymers were made by a pre-reaction step prior to the curing. In the cured resin, the domain size of the polysiloxane phase depended on the structure of the phenolic hydroxyl-terminated polysiloxane. It was found that the modulus of the cured resin depended largely on the level of the modifier, while the CTE was affected greatly by the structure of the polysiloxane. By means of incorporating a few percent of methylphenylsiloxane unit into the polydimethylsiloxane chain, or by introducing more compatible end-capping groups, the compounds of more effective low stress modifiers were synthesized.

  2. Glow Discharge Induced Hydroxyl Radical Degradation of 2-Naphthylamine

    Science.gov (United States)

    Lu, Quanfang; Yu, Jie; Gao, Jinzhang; Yang, Wu

    2005-06-01

    In an aqueous solution, normal electrolysis at high voltages switches over spontaneously to glow discharge electrolysis and gives rise to hydroxyl radical, hydrogen peroxide, and aqueous electron, as well as several other active species. Hydroxyl radical directly attacks organic contaminants to make them oxidized. In the present paper, 2-naphthylamine is eventually degraded into hydrogen carbonate and carbon dioxide. The degradation process is analyzed by using an Ultraviolet (UV) absorption spectrum, high-performance liquid chromatography (HPLC) and chemical oxygen demand (COD). It is demonstrated that 2-naphthylamine (c0 =30 mg·l-1) is completely converted within 2h at 30°C and 600 V by glow discharge electrolysis, and the degradation is strongly dependent upon the presence of ferrous ions. COD is ascended in the absence of ferrous ions and descended in the presence of them.

  3. Glow Discharge Induced Hydroxyl Radical Degradation of 2-Naphthylamine

    Institute of Scientific and Technical Information of China (English)

    Lu Quanfang; Yu Jie; Gao Jinzhang; Yang Wu

    2005-01-01

    In an aqueous solution, normal electrolysis at high voltages switches over sponta-neously to glow discharge electrolysis and gives rise to hydroxyl radical, hydrogen peroxide, andaqueous electron, as well as several other active species. Hydroxyl radical directly attacks or-ganic contaminants to make them oxidized. In the present paper, 2-naphthylamine is eventuallydegraded into hydrogen carbonate and carbon dioxide. The degradation process is analyzed byusing an Ultraviolet (UV) absorption spectrum, high-performance liquid chromatography (HPLC)and chemical oxygen demand (COD). It is demonstrated that 2-naphthylamine (c0 =30 mg.1-1) iscompletely converted within 2h at 30℃ and 600 V by glow discharge electrolysis, and the degra-dation is strongly dependent upon the presence of ferrous ions. COD is ascended in the absenceof ferrous ions and descended in the presence of them.

  4. Treating ballast water with hydroxyl radical on introduced organisms

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    With physical method of micro-gap gas discharge, a large amount of hydroxyl radical can be produced in 20t/h pilot-scale system using the ionization of O2 and H2O. In this paper, the effect of biochemistry of hydroxyl radicals on introduced organisms in ballast water was experimentally investigated. The results indicate that the contents of chlorophyl-a, chlorophyl-b, chlorophyl-c and carotenoid are decreased by 35%-64% within 8.0s and further to the lowest limit of test 5 minutes. In addition, the main reasons of cell death are the lipid peroxidation, the strong destruction to the monose, amylose, protein, DNA and RNA of cell, and damage in CAT, POD and SOD of antioxidant enzyme system.

  5. UV Photodissociation Dynamics of Nitric Acid: The Hydroxyl Elimination Channel

    Institute of Scientific and Technical Information of China (English)

    Fengyan Wang; Zhichao Chen; Yongwei Zhang; Quan Shuai; Bo Jiang; Dongxu Dai; Xiuyan Wang; Xueming Yang

    2009-01-01

    Sliced velocity mapping ion imaging technique was employed to investigate the dynamics of the hydroxyl elimination channel in the photodissociaiton of nitric acid in the ultraviolet region. The OH product was detected by (2+1) resonance enhanced multiphoton ionization via the D2∑- electronic state. The total kinetic energy spectra of the OH+NO2 channel from the photolysis of HONO2 show that both NO2(X2A1) and NO2 (A2B2) channels are present,suggesting that both 11A" and 21A" excited electronic states of HONO2 are involved in the excitation. The parallel angular distributions suggest that the dissociation of the nitric acid is a fast process in comparison with the rotational period of the HNO3 molecule. The anisotropy parameter β for the hydroxyl elimination channel is found to be dependent on the OH product rotational state as well as the photolysis energy.

  6. Influence of hydroxyl substitution on flavanone antioxidants properties.

    Science.gov (United States)

    Masek, Anna; Chrzescijanska, Ewa; Latos, Malgorzata; Zaborski, Marian

    2017-01-15

    The aim of our study was to determine the effect of the position of the hydroxyl group on the antioxidant properties of flavonoid derivatives. For this purpose, we performed electrochemical analysis and quantum-mechanical calculations to describe the mechanisms of electrochemical oxidation, and we selected the two methods of ABTS (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate), which allowed us to determine the ability to scavenge free radicals. On the basis of the research, we found that the derivatives of flavonoids, which have a hydroxyl group substituted at the R-3 position on the C ring, have outstanding antioxidant activity. Flavone, which had an OH group substituted at the R-6 and R-7 position on the ring A, showed similar antioxidant activity to flavone without -OH groups in the structure and slightly higher activity than the di-substituted flavone on the ring A. PMID:27542504

  7. Production of hydroxylated fatty acids in genetically modified plants

    Energy Technology Data Exchange (ETDEWEB)

    Somerville, Chris (Portola Valley, CA); Broun, Pierre (Burlingame, CA); van de Loo, Frank (Weston, AU); Boddupalli, Sekhar S. (Manchester, MI)

    2011-08-23

    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.

  8. Modelling , of Polyurethanes Based on Hydroxyl- Terminated Polybutadiene

    OpenAIRE

    Manohar Singh; Kanungo, B. K.; T.K. Bansal; M. Rama Rao

    1998-01-01

    Forty formulations based on four different grades ofhydroxyl-terminated polybutadiene, HTPB(hydroxyl value 20- 40 mg KOHlg) at r = [NCO] / [OH] values in the range 0.7 -1.0 with varyingamounts of trimethylol propane and butane diol and containing 86 per cent solid loading wereconsidered to test the applicability of a.-model of Marsh, et al. for prediction of the mechanicalproperties of composite solid propellants. Two network parameters, crosslink density (Ve) andeffective chain length (LX), ...

  9. Structure, electronic properties, and aggregation behavior of hydroxylated carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    López-Oyama, A. B.; Silva-Molina, R. A.; Ruíz-García, J.; Guirado-López, R. A., E-mail: guirado@ifisica.uaslp.mx [Instituto de Física “Manuel Sandoval Vallarta,” Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, 78000 San Luis Potosí, San Luis Potosí (Mexico); Gámez-Corrales, R. [Departamento de Física, Universidad de Sonora, Apartado Postal 5-088, 83190, Hermosillo, Sonora (Mexico)

    2014-11-07

    We present a combined experimental and theoretical study to analyze the structure, electronic properties, and aggregation behavior of hydroxylated multiwalled carbon nanotubes (OH–MWCNT). Our MWCNTs have average diameters of ∼2 nm, lengths of approximately 100–300 nm, and a hydroxyl surface coverage θ∼0.1. When deposited on the air/water interface the OH–MWCNTs are partially soluble and the floating units interact and link with each other forming extended foam-like carbon networks. Surface pressure-area isotherms of the nanotube films are performed using the Langmuir balance method at different equilibration times. The films are transferred into a mica substrate and atomic force microscopy images show that the foam like structure is preserved and reveals fine details of their microstructure. Density functional theory calculations performed on model hydroxylated carbon nanotubes show that low energy atomic configurations are found when the OH groups form molecular islands on the nanotube's surface. This patchy behavior for the OH species is expected to produce nanotubes having reduced wettabilities, in line with experimental observations. OH doping yields nanotubes having small HOMO–LUMO energy gaps and generates a nanotube → OH direction for the charge transfer leading to the existence of more hole carriers in the structures. Our synthesized OH–MWCNTs might have promising applications.

  10. Hydroxyl radical induced degradation of salicylates in aerated aqueous solution

    International Nuclear Information System (INIS)

    Ionizing radiation induced degradation of acetylsalicylic acid, its hydrolysis product salicylic acid and a salicylic acid derivative 5-sulpho-salicylic acid, was investigated in dilute aqueous solutions by UV–vis spectrophotometry, HPLC separation and diode-array or MS/MS detection, chemical oxygen demand, total organic carbon content and by Vibrio fischeri toxicity measurements. Hydroxyl radicals were shown to degrade these molecules readily, and first degradation products were hydroxylated derivatives in all cases. Due to the by-products, among them hydrogen peroxide, the toxicity first increased and then decreased with the absorbed dose. With prolonged irradiation complete mineralization was achieved. - Highlights: • In OH induced reactions of salicylates first products are hydroxylated derivatives. • With prolonged irradiation dihydroxy derivatives also form. • In aerated solutions the one-electron oxidant OH induces 3–4 oxidations. • Toxicity first increases and then decreases with dose mainly due to H2O2 formation. • The toxicity in tap water is smaller than in pure water

  11. Electron stimulated hydroxylation of a metal supported silicate film.

    Science.gov (United States)

    Yu, Xin; Emmez, Emre; Pan, Qiushi; Yang, Bing; Pomp, Sascha; Kaden, William E; Sterrer, Martin; Shaikhutdinov, Shamil; Freund, Hans-Joachim; Goikoetxea, Itziar; Wlodarczyk, Radoslaw; Sauer, Joachim

    2016-02-01

    Water adsorption on a double-layer silicate film was studied by using infrared reflection-absorption spectroscopy, thermal desorption spectroscopy and scanning tunneling microscopy. Under vacuum conditions, small amounts of silanols (Si-OH) could only be formed upon deposition of an ice-like (amorphous solid water, ASW) film and subsequent heating to room temperature. Silanol coverage is considerably enhanced by low-energy electron irradiation of an ASW pre-covered silicate film. The degree of hydroxylation can be tuned by the irradiation parameters (beam energy, exposure) and the ASW film thickness. The results are consistent with a generally accepted picture that hydroxylation occurs through hydrolysis of siloxane (Si-O-Si) bonds in the silica network. Calculations using density functional theory show that this may happen on Si-O-Si bonds, which are either parallel (i.e., in the topmost silicate layer) or vertical to the film surface (i.e., connecting two silicate layers). In the latter case, the mechanism may additionally involve the reaction with a metal support underneath. The observed vibrational spectra are dominated by terminal silanol groups (ν(OD) band at 2763 cm(-1)) formed by hydrolysis of vertical Si-O-Si linkages. Film dehydroxylation fully occurs only upon heating to very high temperatures (∼ 1200 K) and is accompanied by substantial film restructuring, and even film dewetting upon cycling hydroxylation/dehydroxylation treatment.

  12. Effects of Zinc and Lead Toxicity on the Growth and their Bioaccumulation in Fish

    Directory of Open Access Journals (Sweden)

    M. Javed

    2012-06-01

    Full Text Available This study evaluated the impacts of chronic exposure of waterborne zinc (Zn and lead (Pb on the growth and their bioaccumulation in three fish species viz. Catla catla, Labeo rohita and Cirrhina mrigala. Three fish species responded similarly for their feed intakes while weight increments and feed conversion efficiency (FCE varied significantly due to Zn and Pb exposures. Younger fish were significantly more sensitive to metallic ion toxicity. Chronic exposure of both Zn and Pb (at 1/3rd of LC50 to the fish caused significantly lesser gain in weight, feed intakes and FCE than that of control (un-stressed fish. Amongst 9 age groups, 330-day fish exhibited significantly better growth in terms of weight gain and feed intake than the other age groups. Both Zn and Pb bioaccumulations varied significantly among fish organs while the patterns of their bioaccumulation did not vary significantly within three fish species. Fish liver and kidney accumulated significantly higher Zn and Pb during chronic exposures. However, Zn accumulation was significantly more than that of Pb in the fish body. Amongst three fish species, Labeo rohita exhibited significantly higher tendency to accumulate Zn while Catla catla amassed higher Pb in its body. The bioaccumulation of both Zn and Pb was positively dependent upon fish age and exposure concentration of metals. Zn bioaccumulation in fish body followed the order: liver>kidney>skin>gills>scale=muscle while that of Pb was: kidney>liver>gills>skin>muscle=scales.

  13. Bioaccumulation factor of 137Cs in some marine biotas from West Bangka Indonesia

    International Nuclear Information System (INIS)

    Radionuclides may be released from nuclear facilities to the marine environment. Concentrations of radionuclides within marine biotic systems can be influenced by a number of factors, including the type of biota, its source, the radionuclide, and specific characteristics of the sampled specimens and the marine environment (salinity, etc.). The bioconcentration factor for a marine organism is the ratio of the concentration of a radionuclide in that organism to the concentration found in its marine water environment - under conditions of equilibrium. Information on the bioaccumulation of Cs-137 in marine organisms is required to risk assessment evaluates the potential risks to human health. Bioaccumulation of Cs was investigated in marine biota from west Bangka such as Marine cat fish (Arius thalassinus), Baramundi (Lates calcarifer), Mackerel (Scomberomorus commerson), Striped eel catfish (Plotosus lineatus), eel tailed fish (Euristhmus microceps), Yellowtail fusilier (Caesio erythrogaster), Coastal crab (Scylla sp), White shrimp (Penaeus merguiensis) and marine bivalve mollusk (Anadara granosa). Muscle of these marine biota, sediments and water were assayed for Cs-137 by HPGe gamma spectrometer. The bioaccumulation factor for fishes were calculated by ratio of concentration Cs-137 in muscle biota to the its concentration in water. The bioaccumulation factor for mollusks were calculates by ratio of concentration Cs-137 in muscle biota to the its concentration in sediments. The bioaccumulation factor were range 4.99 to 136.34

  14. Organochlorine pollution in tropical rivers (Guadeloupe): Role of ecological factors in food web bioaccumulation

    Energy Technology Data Exchange (ETDEWEB)

    Coat, Sophie, E-mail: coatsophie@gmail.com [EA 926 DYNECAR, Laboratoire de Biologie Marine, UFR Sciences, Universite des Antilles et de la Guyane, BP592, 97159 Pointe-a-Pitre Cedex (France); Monti, Dominique, E-mail: dominique.monti@univ-ag.fr [EA 926 DYNECAR, Laboratoire de Biologie Marine, UFR Sciences, Universite des Antilles et de la Guyane, BP592, 97159 Pointe-a-Pitre Cedex (France); Legendre, Pierre, E-mail: pierre.legendre@umontreal.ca [Departement de Sciences Biologique, Universite de Montreal, C.P. 6128, succursale A, Montreal, Quebec H3C 3J7 (Canada); Bouchon, Claude, E-mail: claude.bouchon@univ-ag.fr [EA 926 DYNECAR, Laboratoire de Biologie Marine, UFR Sciences, Universite des Antilles et de la Guyane, BP592, 97159 Pointe-a-Pitre Cedex (France); Massat, Felix, E-mail: fmassat@ladrome.fr [LDA26, laboratoire Departemental d' Analyses de la Drome, 27 avenue Lautagne, 26000 Valence (France); Lepoint, Gilles, E-mail: g.lepoint@ulg.ac.be [MARE Centre, Laboratoire d' Oceanologie, Universite de Liege, Bat. B6, 4000 Sart Tilman, Belgique (Belgium)

    2011-06-15

    Concentrations of organochlorine pesticides and stable isotope ratios of nitrogen and carbon were measured in a tropical freshwater ecosystem to evaluate the contamination level of biota and examine the bioaccumulation patterns of pollutants through the food web. Chemical analyses showed a general and heavy contamination of the entire food web. They revealed the strong accumulation of pollutants by juveniles of diadromous fishes and shrimps, as they re-enter the river. The role of ecological factors in the bioaccumulation of pesticides was evaluated. Whereas the most persistent pollutants (chlordecone and monohydro-chlordecone) were related to the organisms diet and habitat, bioaccumulation of {beta}-HCH was only influenced by animal lipid content. The biomagnification potential of chlordecone through the food chain has been demonstrated. It highlighted the importance of trophic transfer in this compound bioaccumulation process. In contrast, bioconcentration by passive diffusion from water seemed to be the main exposure route of biota to {beta}-HCH. - Highlights: > We measured OC pesticides and stable isotope ratios in a tropical stream. > Results showed a strong and ubiquitous contamination of the entire food web. > Diadromous juveniles strongly accumulated pollutants when they re-enter the river. > The most persistent pollutant (chlordecone) was related to species diet and habitat. > {beta}-HCH was only influenced by animal lipid content. - This paper determines the bioaccumulation and transfer processes of organochlorine pesticides within the stream food web in Guadeloupe (Caribbean).

  15. Organochlorine pollution in tropical rivers (Guadeloupe): Role of ecological factors in food web bioaccumulation

    International Nuclear Information System (INIS)

    Concentrations of organochlorine pesticides and stable isotope ratios of nitrogen and carbon were measured in a tropical freshwater ecosystem to evaluate the contamination level of biota and examine the bioaccumulation patterns of pollutants through the food web. Chemical analyses showed a general and heavy contamination of the entire food web. They revealed the strong accumulation of pollutants by juveniles of diadromous fishes and shrimps, as they re-enter the river. The role of ecological factors in the bioaccumulation of pesticides was evaluated. Whereas the most persistent pollutants (chlordecone and monohydro-chlordecone) were related to the organisms diet and habitat, bioaccumulation of β-HCH was only influenced by animal lipid content. The biomagnification potential of chlordecone through the food chain has been demonstrated. It highlighted the importance of trophic transfer in this compound bioaccumulation process. In contrast, bioconcentration by passive diffusion from water seemed to be the main exposure route of biota to β-HCH. - Highlights: → We measured OC pesticides and stable isotope ratios in a tropical stream. → Results showed a strong and ubiquitous contamination of the entire food web. → Diadromous juveniles strongly accumulated pollutants when they re-enter the river. → The most persistent pollutant (chlordecone) was related to species diet and habitat. → β-HCH was only influenced by animal lipid content. - This paper determines the bioaccumulation and transfer processes of organochlorine pesticides within the stream food web in Guadeloupe (Caribbean).

  16. Bioaccumulation of 137Cs by culture collection strains of bacteria and fungi

    International Nuclear Information System (INIS)

    Soil decontamination of soil contaminated by low-level activities of radionuclides, mainly by caesium-137, which come from accidental releases by maintenance of nuclear devices and by liquid wastes reprocessing, is long-term and expensive technology. Knowledge of the causations, which control the processes of bioaccumulation of radionuclides, is a necessary condition for critical assessment and successful utilization of processes of bioremediation in situ in practise. The authors present the experimentally gained quantitative values of bioaccumulation of caesium-137 from water solutions by micro organism cultures of Rhodotorula aurantiaca CCY 20-9-1, Sacharomyces cerevisiae, Rhodococcus rhodochrous ATCC 15906, Streptomyces sp. DX-IX, Coriolus versicolor CCWDF-14 and Rhizopus sp. R-18. Intensively growing cultures reach the highest values of bioaccumulation; the cultures in non-growing phase reach several orders lower values. From researched micro organisms the highest values of bioaccumulation of Cs+ 5.1 pmol/g (wet weight) at initial concentration of Cs+ in solution co = 1 nmol/l (without carrier) and 29.2 μmol/g (wet weight) at co = 6 mmol/l Cs+ (adding of carrier CsCl) were found out at growing culture S. cerevisiae as model of eukaryotic cell after an achievement of maximal stationary grow phase. Acquired information refer to the possible role of soil micro organisms at bioaccumulation of 137Cs in contaminated soils and their potential utilization in lowering of radioactive contamination of environment (authors)

  17. The role of exopolymeric substances in the bioaccumulation and toxicity of Ag nanoparticles to algae.

    Science.gov (United States)

    Zhou, Kaijun; Hu, Yi; Zhang, Luqing; Yang, Kun; Lin, Daohui

    2016-01-01

    Exopolymeric substances (EPS) have an important role in bioaccumulation and toxicity of nanoparticles (NPs) to algae, which warrants specific studies. The interaction of EPS with citrate and polyvinyl pyrrolidone (PVP) coated AgNPs (C-AgNPs and P-AgNPs, respectively) and its roles in bioaccumulation and toxicity of the AgNPs to Chlorella pyrenoidosa were investigated. The amino and aromatic carboxylic groups in the EPS were involved in the EPS-AgNP interactions. Compared with Ag(+), C-AgNPs had comparable total bioaccumulation but greater absorption by intact algae with EPS; P-AgNPs had the smallest total bioaccumulation and were mainly adsorbed on algal surfaces. With EPS removed, the total bioaccumulations and surface adsorptions for the three Ag species decreased but the cell internalizations increased; the 96 h half growth inhibition concentrations decreased, indicating EPS alleviated the algal toxicity of Ag. The cell-internalized but not the adsorbed AgNPs could contribute to the nanotoxicity. The EPS could bind both AgNPs and Ag(+), and thus inhibited the cell internalization and the nanotoxicity. However, the EPS-bound Ag on the cell surfaces would migrate along with the algae and be biologically amplified in the aquatic food chains, presenting ecological risks. These results are helpful for understanding the fate and ecological effects of NPs. PMID:27615743

  18. Bioaccumulation factor of {sup 137}Cs in some marine biotas from West Bangka Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Suseno, Heny, E-mail: henis@batan.go.id [Radioactive Waste Technology Center - The Indonesia Nuclear Energy Agency (BATAN) (Indonesia)

    2014-03-24

    Radionuclides may be released from nuclear facilities to the marine environment. Concentrations of radionuclides within marine biotic systems can be influenced by a number of factors, including the type of biota, its source, the radionuclide, and specific characteristics of the sampled specimens and the marine environment (salinity, etc.). The bioconcentration factor for a marine organism is the ratio of the concentration of a radionuclide in that organism to the concentration found in its marine water environment - under conditions of equilibrium. Information on the bioaccumulation of Cs-137 in marine organisms is required to risk assessment evaluates the potential risks to human health. Bioaccumulation of Cs was investigated in marine biota from west Bangka such as Marine cat fish (Arius thalassinus), Baramundi (Lates calcarifer), Mackerel (Scomberomorus commerson), Striped eel catfish (Plotosus lineatus), eel tailed fish (Euristhmus microceps), Yellowtail fusilier (Caesio erythrogaster), Coastal crab (Scylla sp), White shrimp (Penaeus merguiensis) and marine bivalve mollusk (Anadara granosa). Muscle of these marine biota, sediments and water were assayed for Cs-137 by HPGe gamma spectrometer. The bioaccumulation factor for fishes were calculated by ratio of concentration Cs-137 in muscle biota to the its concentration in water. The bioaccumulation factor for mollusks were calculates by ratio of concentration Cs-137 in muscle biota to the its concentration in sediments. The bioaccumulation factor were range 4.99 to 136.34.

  19. Mercury bioaccumulation and biomagnification in a small Arctic polynya ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Clayden, Meredith G., E-mail: meredith.clayden@gmail.com [Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, NB E2L 4L5 (Canada); Arsenault, Lilianne M. [Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, NB E2L 4L5 (Canada); Department of Earth and Environmental Science, Acadia University, Wolfville, NS B4P 2R6 (Canada); Department of Biology, Acadia University, Wolfville, NS B4P 2R6 (Canada); Kidd, Karen A. [Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, NB E2L 4L5 (Canada); O' Driscoll, Nelson J. [Department of Earth and Environmental Science, Acadia University, Wolfville, NS B4P 2R6 (Canada); Mallory, Mark L. [Department of Biology, Acadia University, Wolfville, NS B4P 2R6 (Canada)

    2015-03-15

    Recurring polynyas are important areas of biological productivity and feeding grounds for seabirds and mammals in the Arctic marine environment. In this study, we examined food web structure (using carbon and nitrogen isotopes, δ{sup 13}C and δ{sup 15}N) and mercury (Hg) bioaccumulation and biomagnification in a small recurring polynya ecosystem near Nasaruvaalik Island (Nunavut, Canada). Methyl Hg (MeHg) concentrations increased by more than 50-fold from copepods (Calanus hyperboreus) to Arctic terns (Sterna paradisaea), the abundant predators at this site. The biomagnification of MeHg through members of the food web – using the slope of log MeHg versus δ{sup 15}N – was 0.157 from copepods (C. hyperboreus) to fish. This slope was higher (0.267) when seabird chicks were included in the analyses. Collectively, our results indicate that MeHg biomagnification is occurring in this small polynya and that its trophic transfer is at the lower end of the range of estimates from other Arctic marine ecosystems. In addition, we measured Hg concentrations in some poorly studied members of Arctic marine food webs [e.g. Arctic alligatorfish (Ulcina olrikii) and jellyfish, Medusozoa], and found that MeHg concentrations in jellyfish were lower than expected given their trophic position. Overall, these findings provide fundamental information about food web structure and mercury contamination in a small Arctic polynya, which will inform future research in such ecosystems and provide a baseline against which to assess changes over time resulting from environmental disturbance. - Highlights: • Polynyas are recurring sites of open water in polar marine areas • Mercury (Hg) biomagnification was studied in a small polynya near Nasaruvaalik Island, NU, Canada • Hg biomagnification estimates for invertebrates to fish were low compared to other Arctic systems • Factors underlying this result are unknown but may relate to primary productivity in small polynyas.

  20. UV filters bioaccumulation in fish from Iberian river basins

    Energy Technology Data Exchange (ETDEWEB)

    Gago-Ferrero, Pablo [Dept. of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, E-08034 Barcelona (Spain); Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, 15771 Athens (Greece); Díaz-Cruz, M. Silvia, E-mail: sdcqam@cid.csic.es [Dept. of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, E-08034 Barcelona (Spain); Barceló, Damià [Dept. of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, E-08034 Barcelona (Spain); Catalan Institute for Water Research (ICRA), Parc Científic i Tecnològic de la Universitat de Girona, C/ Emili Grahit, 101 Edifici H2O, E-17003 Girona (Spain)

    2015-06-15

    The occurrence of eight organic UV filters (UV-Fs) was assessed in fish from four Iberian river basins. This group of compounds is extensively used in cosmetic products and other industrial goods to avoid the damaging effects of UV radiation, and has been found to be ubiquitous contaminants in the aquatic ecosystem. In particular, fish are considered by the scientific community to be the most feasible organism for contamination monitoring in aquatic ecosystems. Despite that, studies on the bioaccumulation of UV-F are scarce. In this study fish samples from four Iberian river basins under high anthropogenic pressure were analysed by liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Benzophenone-3 (BP3), ethylhexyl methoxycinnamate (EHMC), 4-methylbenzylidene camphor (4MBC) and octocrylene (OC) were the predominant pollutants in the fish samples, with concentrations in the range of ng/g dry weight (d.w.). The results indicated that most polluted area corresponded to Guadalquivir River basin, where maximum concentrations were found for EHMC (241.7 ng/g d.w.). Sediments from this river basin were also analysed. Lower values were observed in relation to fish for OC and EHMC, ranging from below the limits of detection to 23 ng/g d.w. Accumulation levels of UV-F in the fish were used to calculate biota-sediment accumulation factors (BSAFs). These values were always below 1, in the range of 0.04–0.3, indicating that the target UV-Fs are excreted by fish only to some extent. The fact that the highest concentrations were determined in predators suggests that biomagnification of UV-F may take place along the freshwater food web. - Highlights: • First evidence of UV filters in fish from Iberian rivers • Biota-sediment accumulation factors (BSAFs) were always below 1. • Predator species presented higher UV-F concentrations suggesting trophic magnification.

  1. Bioaccumulation of P-32 in bluegill and catfish

    International Nuclear Information System (INIS)

    Bluegill and catfish were fed P-32 at a constant feeding rate per body weight to determine the bioaccummulation factor (BF/sub r/) for P-32 in muscle relative to water. The fish were maintained in flow-through tanks at two feeding levels. The bluegill accumulated P-32 for 51 days, followed by depuration for 28 days. The catfish study had to be teminated after 11 days. Fish were analyzed in triplicte for P-32 and phosphorus at intervals of 1 to 8 days. Additional aquaria experiments were performed to determine the effects of water temperature, feeding rate, and type of food (worms vs. pellets) on P-32 uptake, and to observe P-32 uptake from water by unfed fish (including fish with blocked esophagus). A simple calculational model was used to determine the phosphorus turnover constant from the specific activity in tissue relative to food. This ratio at steady state approaches the BF/sub r/BF ratio (where BF is the phosphorus bioaccumulation factor) if P-32 transfers rapidly from water to food. The bluegill showed a weight gain of 0.2 %/d, a phosphorous turnover constant in muscle of 0.43 %/d, and a BF/sub r//BF ratio of 0.081 at the higher feeding rate, and 0.05 %/d, 0.34 %/d, and 0.064 at the lower feeding rate. Hence, respective P-32 BF/sub r/ values are 6000 and 4000 at a phosphorus BF of 70,000. The BF/sub r/ values for catfish were approximately twice as high. The aquarium experiments suggest that the higher factors are due to a much higher phosphorus intake, higher water temperature, higher retention from pellets than from worms, and possible higher retention by catfish than bluegill under the same conditions. 36 references, 15 figures, 22 tables

  2. Bioaccumulation and maternal transfer of mercury and selenium in amphibians.

    Science.gov (United States)

    Bergeron, Christine M; Bodinof, Catherine M; Unrine, Jason M; Hopkins, William A

    2010-04-01

    Amphibian population declines have been documented worldwide and environmental contaminants are believed to contribute to some declines. Maternal transfer of bioaccumulated contaminants to offspring may be an important and overlooked mechanism of impaired reproductive success that affects amphibian populations. Mercury (Hg) is of particular concern due to its ubiquity in the environment, known toxicity to other wildlife, and complex relationships with other elements, such as selenium (Se). The objectives of the present study were to describe the relationships between total Hg (THg), methlymercury (MMHg), and Se in three amphibian species (Plethodon cinereus, Eurycea bislineata cirrigera, and Bufo americanus) along a Hg-polluted river and floodplain, and to determine if B. americanus maternally transfers Hg and Se to its eggs in a tissue residue-dependent manner. Total Hg and MMHg concentrations in all species spanned two orders of magnitude between the reference and contaminated areas, while Se concentrations were generally low in all species at both sites. Strong positive relationships between THg and MMHg in tissues of all species were observed throughout. Both Hg and Se were maternally transferred from females to eggs in B. americanus, but the percentage of the females' Hg body burden transferred to eggs was low compared with Se. In addition, Hg concentrations appeared to positively influence the amount of Se transferred from female to eggs. The present study is the first to confirm a correlation between Hg concentrations in female carcass and eggs in amphibians and among the first to describe co-transference of Se and Hg in an anamniotic vertebrate. The results suggest future work is needed to determine whether maternal transfer of Hg has transgenerational implications for amphibian progeny.

  3. UV filters bioaccumulation in fish from Iberian river basins

    International Nuclear Information System (INIS)

    The occurrence of eight organic UV filters (UV-Fs) was assessed in fish from four Iberian river basins. This group of compounds is extensively used in cosmetic products and other industrial goods to avoid the damaging effects of UV radiation, and has been found to be ubiquitous contaminants in the aquatic ecosystem. In particular, fish are considered by the scientific community to be the most feasible organism for contamination monitoring in aquatic ecosystems. Despite that, studies on the bioaccumulation of UV-F are scarce. In this study fish samples from four Iberian river basins under high anthropogenic pressure were analysed by liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Benzophenone-3 (BP3), ethylhexyl methoxycinnamate (EHMC), 4-methylbenzylidene camphor (4MBC) and octocrylene (OC) were the predominant pollutants in the fish samples, with concentrations in the range of ng/g dry weight (d.w.). The results indicated that most polluted area corresponded to Guadalquivir River basin, where maximum concentrations were found for EHMC (241.7 ng/g d.w.). Sediments from this river basin were also analysed. Lower values were observed in relation to fish for OC and EHMC, ranging from below the limits of detection to 23 ng/g d.w. Accumulation levels of UV-F in the fish were used to calculate biota-sediment accumulation factors (BSAFs). These values were always below 1, in the range of 0.04–0.3, indicating that the target UV-Fs are excreted by fish only to some extent. The fact that the highest concentrations were determined in predators suggests that biomagnification of UV-F may take place along the freshwater food web. - Highlights: • First evidence of UV filters in fish from Iberian rivers • Biota-sediment accumulation factors (BSAFs) were always below 1. • Predator species presented higher UV-F concentrations suggesting trophic magnification

  4. Mercury bioaccumulation and biomagnification in a small Arctic polynya ecosystem

    International Nuclear Information System (INIS)

    Recurring polynyas are important areas of biological productivity and feeding grounds for seabirds and mammals in the Arctic marine environment. In this study, we examined food web structure (using carbon and nitrogen isotopes, δ13C and δ15N) and mercury (Hg) bioaccumulation and biomagnification in a small recurring polynya ecosystem near Nasaruvaalik Island (Nunavut, Canada). Methyl Hg (MeHg) concentrations increased by more than 50-fold from copepods (Calanus hyperboreus) to Arctic terns (Sterna paradisaea), the abundant predators at this site. The biomagnification of MeHg through members of the food web – using the slope of log MeHg versus δ15N – was 0.157 from copepods (C. hyperboreus) to fish. This slope was higher (0.267) when seabird chicks were included in the analyses. Collectively, our results indicate that MeHg biomagnification is occurring in this small polynya and that its trophic transfer is at the lower end of the range of estimates from other Arctic marine ecosystems. In addition, we measured Hg concentrations in some poorly studied members of Arctic marine food webs [e.g. Arctic alligatorfish (Ulcina olrikii) and jellyfish, Medusozoa], and found that MeHg concentrations in jellyfish were lower than expected given their trophic position. Overall, these findings provide fundamental information about food web structure and mercury contamination in a small Arctic polynya, which will inform future research in such ecosystems and provide a baseline against which to assess changes over time resulting from environmental disturbance. - Highlights: • Polynyas are recurring sites of open water in polar marine areas • Mercury (Hg) biomagnification was studied in a small polynya near Nasaruvaalik Island, NU, Canada • Hg biomagnification estimates for invertebrates to fish were low compared to other Arctic systems • Factors underlying this result are unknown but may relate to primary productivity in small polynyas

  5. Structural changes in response to bioaccumulation of iron and mercury in Chromolaena odorata (L.) King & Robins.

    Science.gov (United States)

    Swapna, K S; Salim, Nabeesa; Chandra, Ratheesh; Puthur, Jos T

    2015-09-01

    A comparative study was designed to elucidate the effect of iron and mercury on the morphological and anatomical changes as well as bioaccumulation potential in Chromolaena odorata. Plants were grown in half-strength Hoagland nutrient medium artificially contaminated with known quantities of HgCl2 (15 μM) and FeCl3 (1000 μM). Bioaccumulation of Hg and Fe was maximum in the root, and comparatively reduced bioaccumulation was recorded in the stem and leaves. Microscopic studies on morphology and anatomy revealed development of trichomes and lenticels on the stem and modified trichomes on leaves. Localized deposits of stained masses in various internal parts of the root, stem and leaf also were observed. Differential adaptation/strategy of C. odorata to attain tolerance towards Hg and Fe and phytoremediation potential of the plant is discussed. PMID:26239568

  6. Equilibrium Sampling to Determine the Thermodynamic Potential for Bioaccumulation of Persistent Organic Pollutants from Sediment

    DEFF Research Database (Denmark)

    Jahnke, Annika; MacLeod, Matthew; Wickström, Håkan;

    2014-01-01

    Equilibrium partitioning (EqP) theory is currently the most widely used approach for linking sediment pollution by persistent hydrophobic organic chemicals to bioaccumulation. Most applications of the EqP approach assume (I) a generic relationship between organic carbon-normalized chemical...... concentrations in sediments and lipid-normalized concentrations in biota and (II) that bioaccumulation does not induce levels exceeding those expected from equilibrium partitioning. Here, we demonstrate that assumption I can be obviated by equilibrating a silicone sampler with chemicals in sediment, measuring...... chemical concentrations in the silicone, and applying lipid/silicone partition ratios to yield concentrations in lipid at thermodynamic equilibrium with the sediment (CLip⇌Sed). Furthermore, we evaluated the validity of assumption II by comparing CLip⇌Sed of selected persistent, bioaccumulative and toxic...

  7. Bioaccumulation and food chain transfer of corrosion products from radioactive stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Young, J.S.

    1986-07-01

    Two sets of experiments were conducted to determine if corrosion products from radioactive Type 347 stainless steel could be biologically transferred from sediment through a marine food chain, and whether corrosion products dissolved in seawater could be bioaccumulated and then eliminated. Corrosion products containing /sup 60/Co and /sup 63/Ni from the radioactive stainless steel were introduced into marine sediments. Infaunal polychaete worms exposed to these sediments bioaccumulated the radionuclides. The feeding of these worms to shrimp and fish resulted in a trophic transfer of the radioactive products across a one-step food chain. The magnitude of the transfers are described in terms of transfer factors. Dissolved corrosion products as measured by the radionuclides were also bioaccumulated by shrimp and fish concentrating more than fish. Concentration factors were calculated.

  8. Effect of incorporation of uncertainty in PCB bioaccumulation factors on modeled receptor doses

    Energy Technology Data Exchange (ETDEWEB)

    Welsh, C.; Duncan, J.; Purucker, S. [Oak Ridge National Lab., TN (United States). Center for Risk Management; Richardson, N. [ABB Environmental Services, Inc., Wakefield, MA (United States); Redfearn, A. [Automated Sciences Group, Inc., Oak Ridge, TN (United States)

    1995-12-31

    Bioaccumulation factors (BAFs) are regularly employed in ecological risk assessments to model contaminant transfer through ecological food chains. The authors compiled data on bioaccumulation of PCBs in plants, invertebrates, birds, and mammals from published literature and used these data to develop regression equations relating soil or food concentrations to bioaccumulation. They then used Latin Hypercube simulation techniques and simple food chain models to incorporate uncertainty in the BAF regressions into the derivation of exposure dose estimates for selected wildlife receptors. The authors present their preliminary results in this paper. Dose estimates ranged over several orders of magnitude for herbivorous, insectivorous, and carnivorous receptors. These results suggest incorporating the uncertainty in BAF values into food chain exposure models could provide risk assessors and risk managers with information on the probability of a given outcome that can be used in interpreting the potential risks at hazardous waste sites.

  9. Optimal choice of pH for toxicity and bioaccumulation studies of ionizing organic chemicals

    DEFF Research Database (Denmark)

    Rendal, Cecilie; Kusk, Kresten Ole; Trapp, Stefan

    2011-01-01

    at multiple pH levels. Toxicity and bioconcentration factors (BCFs) were higher for acids at lower pH values, whereas the opposite was true for bases. The effect of pH was most pronounced when pH-pKa was in the range of -1 to 3 for acids, and -3 to 1 for bases. The factor by which toxicity and BCF changed......It is recognized that the pH of exposure solutions can influence the toxicity and bioaccumulation of ionizing compounds. The present study investigates whether it can be considered a general rule that an ionizable compound is more toxic and more bioaccumulative when in the neutral state. Three...... processes were identified to explain the behavior of ionizing compounds with changing pH: the change in lipophilicity when a neutral compound becomes ionized, electrical attraction, and the ion trap. The literature was screened for bioaccumulation and toxicity tests of ionizing organic compounds performed...

  10. Bioaccumulation and food chain transfer of corrosion products from radioactive stainless steel

    International Nuclear Information System (INIS)

    Two sets of experiments were conducted to determine if corrosion products from radioactive Type 347 stainless steel could be biologically transferred from sediment through a marine food chain, and whether corrosion products dissolved in seawater could be bioaccumulated and then eliminated. Corrosion products containing 60Co and 63Ni from the radioactive stainless steel were introduced into marine sediments. Infaunal polychaete worms exposed to these sediments bioaccumulated the radionuclides. The feeding of these worms to shrimp and fish resulted in a trophic transfer of the radioactive products across a one-step food chain. The magnitude of the transfers are described in terms of transfer factors. Dissolved corrosion products as measured by the radionuclides were also bioaccumulated by shrimp and fish concentrating more than fish. Concentration factors were calculated

  11. Bioaccumulation of microcystins in two freshwater gastropods from a cyanobacteria-bloom plateau lake, Lake Dianchi

    International Nuclear Information System (INIS)

    To investigate the bioaccumulation patterns of microcystins (MCs) in organs of two gastropods, samples were collected in Lake Dianchi monthly from May to October, 2008, when cyanobacteria typically bloom. The average MCs concentrations for Radix swinhoei (pulmonate) and Margarya melanioides (prosobranch) tended to be similar for the different organs: the highest values in the hepatopancreas (9.33 by 3.74 μg/g DW), followed by digestive tracts (1.66 by 3.03 μg/g DW), gonads (0.45 by 1.34 μg/g DW) and muscles (0.22 by 0.40 μg/g DW). Pulmonate had higher value than prosobranch because of the stronger bioaccumulation ability in hepatopancreas. The levels in organs of R. swinhoei were correlated with environmentally dissolved MCs, but influenced by intracellular MCs for M. melanioides. The estimated MCs concentrations in edible parts of M. melanioides were beyond the WHO’s provisional tolerable daily intake (0.04 μg/kg), suggesting the risk of consumption of M. melanioides from the lake. Highlights: ► We probe bioaccumulated patterns of microcystins in organs of pulmonate and prosobranch. ► The highest microcystins in hepatopancreas for both snails. ► The higher microcystins for pulmonate results from the stronger bioaccumulation ability in hepatopancreas. ► Environmentally dissolved microcystins are the main sources for pulmonate, but intracellular for prosobranch. ► Suggesting the risk of consumption snails in the studying regions. - Higher bioaccumulation MCs level for pulmonate mainly contributed to the stronger bioaccumulation ability in its hepatopancreas.

  12. Assessing element-specific patterns of bioaccumulation across New England lakes

    International Nuclear Information System (INIS)

    Little is known about differences among trace elements in patterns of bioaccumulation in freshwater food webs. Our goal was to identify patterns in bioaccumulation of different elements that are large and consistent enough to discern despite variation across lakes. We measured methylmercury (MeHg) and trace element (As, Cd, Hg, Pb, and Zn) concentrations in food web components of seven New England lakes on 3–5 dates per lake, and contrasted patterns of bioaccumulation across lakes, metals and seasons. In each lake, trace element concentrations were compared across trophic levels, including three size fractions of zooplankton, planktivorous fish, and piscivorous fish. The trophic position of each food web component was estimated from N isotope analysis. Trace element concentrations varied widely among taxa, lakes and sampling dates. Yet, we identified four consistent patterns of bioaccumulation that were consistent across lakes: (1) MeHg concentration increased (i.e., was biomagnified) and Pb concentration decreased (i.e., was biodiminished) with increased trophic position. (2) Zinc concentration (as with MeHg) was higher in fish than in zooplankton, but overall variation in Zn concentration (unlike MeHg) was low. (3) Arsenic and Cd concentrations (as with Pb) were lower in fish than in zooplankton, but (unlike Pb) were not significantly correlated with trophic position within zooplankton or fish groups. (4) Average summer concentrations of As, Pb, Hg, and MeHg in zooplankton significantly predicted their concentrations in either planktivorous or piscivorous fish. Our secondary goal was to review sampling approaches in forty-five published studies to determine the extent to which current sampling programs facilitate cross-lake and cross-study comparisons of bioaccumulation. We found that studies include different components of the food web and sample too infrequently to enable strong cross-lake and cross-study comparisons. We discuss sampling strategies that would

  13. Medium-chain chlorinated paraffins (MCCPs): a review of bioaccumulation potential in the aquatic environment.

    Science.gov (United States)

    Thompson, Roy; Vaughan, Martin

    2014-01-01

    Chlorinated paraffins (CPs) are high molecular weight organochlorine compounds that have been used in a variety of industrial applications for many years. Medium-chain chlorinated paraffins (MCCPs) (CAS 85535-85-9; Alkanes, C14-17 , chloro) are currently under investigation as potential persistent bioaccumulative toxic (PBT) compounds. In this article, the bioaccumulation potential of MCCPs is assessed using a tiered framework proposed after a recent Society of Environmental Toxicology and Chemistry (SETAC) Pellston Workshop in 2008. The framework proposes the use of physicochemical properties and modeling assessment, bioconcentration/bioaccumulation (BCF/BAF) assessment, biomagnification (BMF) assessment, and trophic magnification factor (TMF) assessment. It is hoped that use of this framework could harmonize and improve the efficiency and effectiveness of the chemical substance evaluation screening process for PBT properties. When applied to MCCPs, the following conclusions were made: empirical physiochemical data is available negating the use of models; laboratory BCFs range from 1000 to 15 000 (growth-corrected lipid normalized values) for 2 MCCP structures; field BAFs were an order of magnitude higher than the trigger criterion for "B status possible"; although results may not meet acceptance criteria for field studies, laboratory-derived BMFs for a number of C14-17 chlorinated alkanes were less than the trigger value of 1 (based on whole-body concentrations) whereas field-derived BMFs were less than 1 (based on lipid corrected values [generally used for field data] excluding one measure for sculpin, [Cottus cognatus]-Diporeia that was based on only one detectable sample); and finally, TMFs were less than the trigger criterion value of 1, which are considered the most convincing evidence for bioaccumulative properties of a compound and the "Gold Standard" measure of bioaccumulation. This article also discusses the uncertainties surrounding the published data

  14. Bioaccumulation of heavy metals in fauna from wet detention ponds for stormwater runoff

    DEFF Research Database (Denmark)

    Stephansen, Diana; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild;

    2012-01-01

    Stormwater detention ponds remove pollutants e.g. heavy metals and nutrients from stormwater runoff. These pollutants accumulate in the pond sediment and thereby become available for bioaccumulation in fauna living in the ponds. In this study the bioaccumulation was investigated by fauna samples...... from 5 wet detention ponds for analyses of heavy metal contents. Five rural shallow lakes were included in the study to survey the natural occurrence of heavy metals in water-dwelling fauna. Heavy metal concentrations in water-dwelling fauna were generally found higher in wet detention ponds compared...

  15. Bioaccumulation of metals in aquatic insects of streams located in areas with sugar cane cultivation

    Directory of Open Access Journals (Sweden)

    Juliano José Corbi

    2010-01-01

    Full Text Available Streams located in areas of sugar cane cultivation receive elevated concentrations of metal ions from soils of adjacent areas. The accumulation of metals in the sediments results in environmental problems and leads to bioaccumulation of metal ions by the aquatic organisms. In the present study, bioaccumulation of the metals ions Al, Cd, Cr, Cu, Fe, Mg, Mn and Zn in aquatic insects in streams impacted by the sugar cane was evaluated. The results pointed out that the insects were contaminated by the sediment and that the collector organisms as Chironomus species accumulated higher concentration of metals than the predator organisms.

  16. Assessing element-specific patterns of bioaccumulation across New England lakes

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Darren M.; Mayes, Brandon; Sturup, Stefan; Folt, Carol L.; Chen, Celia Y., E-mail: celia.chen@dartmouth.edu

    2012-04-01

    Little is known about differences among trace elements in patterns of bioaccumulation in freshwater food webs. Our goal was to identify patterns in bioaccumulation of different elements that are large and consistent enough to discern despite variation across lakes. We measured methylmercury (MeHg) and trace element (As, Cd, Hg, Pb, and Zn) concentrations in food web components of seven New England lakes on 3-5 dates per lake, and contrasted patterns of bioaccumulation across lakes, metals and seasons. In each lake, trace element concentrations were compared across trophic levels, including three size fractions of zooplankton, planktivorous fish, and piscivorous fish. The trophic position of each food web component was estimated from N isotope analysis. Trace element concentrations varied widely among taxa, lakes and sampling dates. Yet, we identified four consistent patterns of bioaccumulation that were consistent across lakes: (1) MeHg concentration increased (i.e., was biomagnified) and Pb concentration decreased (i.e., was biodiminished) with increased trophic position. (2) Zinc concentration (as with MeHg) was higher in fish than in zooplankton, but overall variation in Zn concentration (unlike MeHg) was low. (3) Arsenic and Cd concentrations (as with Pb) were lower in fish than in zooplankton, but (unlike Pb) were not significantly correlated with trophic position within zooplankton or fish groups. (4) Average summer concentrations of As, Pb, Hg, and MeHg in zooplankton significantly predicted their concentrations in either planktivorous or piscivorous fish. Our secondary goal was to review sampling approaches in forty-five published studies to determine the extent to which current sampling programs facilitate cross-lake and cross-study comparisons of bioaccumulation. We found that studies include different components of the food web and sample too infrequently to enable strong cross-lake and cross-study comparisons. We discuss sampling strategies that would

  17. Active site dynamics of toluene hydroxylation by cytochrome P-450

    International Nuclear Information System (INIS)

    Rat liver cytochrome P-450 hydroxylates toluene to benzyl alcohol plus o-, m-, and p-cresol. Deuterated toluenes were incubated under saturating conditions with liver microsomes from phenobarbital-pretreated rats, and product yields and ratios were measured. Stepwise deuteration of the methyl leads to stepwise decreases in the alcohol/cresol ratio without changing the cresol isomer ratios. Extensive deuterium retention in the benzyl alcohols from PhCH2D and PhCHD2 suggests there is a large intrinsic isotope effect for benzylic hydroxylation. After replacement of the third benzylic H by D, the drop in the alcohol/cresol ratio was particularly acute, suggsting that metabolic switching from D to H within the methyl group was easier than switching from the methyl to the ring. Comparison of the alcohol/cresol ratio for PhCH3 vs PhCD3 indicated a net isotope effect of 6.9 for benzylic hydroxylation. From product yield data for PhCH3 and PhCD3, DV for benzyl alcohol formation is only 1.92, whereas DV for total product formation is 0.67 (i.e., inverse). From competitive incubations of PhCH3/PhCD3 mixtures D(V/K) isotope effects on benzyl alcohol formation and total product formation (3.6 and 1.23, respectively) are greatly reduced, implying strong commitment to catalysis. In contrast, D(V/K) for the alcohol/cresol ratio is 6.3, indicating that the majority of the intrinsic isotope effect is expressed through metabolic switching. Overall, these data are consistent with reversible formation of a complex between toluene and the active oxygen form of cytochrome P-450, which rearranges internally and reacts to form products faster than it dissociates back to release substrate

  18. Studies of 3-amino-4-hydroxyl benzoic acid phosphate

    International Nuclear Information System (INIS)

    3-amino-4-hydroxyl benzoic acid phosphate was synthesized from 4-chloro benzoic acid through three steps, the whole process was cost-effective in which the materials in each step were reused. More importantly, phosphoric acid medium did no harm to Pd-C catalyst in the hydrogenation and the Pd-C catalyst could be recycled for ten times at least without decrease in catalytic activity. In addition, product could meet the requirement of polymerization reaction of producing poly(2,5-benzoxazole) without dehydrochlorogenation. In this process, good conversion, high overall yield (79.28%) and high purity (99.30% by HPLC) were achieved. (author)

  19. Two new 24-hydroxylated asterosaponins from Culcita novaeguineae

    Institute of Scientific and Technical Information of China (English)

    Xiao Guang Ma; Hai Feng Tang; Chang Hai Zhao; Ning Ma; Min Na Yao; Ai Dong Wen

    2009-01-01

    Two new 24-hydroxylated asterosaponins, sodium (20R,24S)-6α-O-(4-O-sodiumsulfato-β-D-quinovopyranosyl)-5α-cholest-9(11)-en-3β,24-diol 3-sulfate (1) and sodium (20R,24S)-6α-O-[3-O-methyl-β-D-quinovopyranosyl-(1→2)-β-D-xylopyranosyl-(1→3)-β-D-glucopyranosyl]-5α-cholest-9(11)-en-3β,24-diol 3-sulfate (2), were isolated from the starfish Culcita novaeguineae. Their structures were elucidated by extensive spectral analysis and chemical evidences.

  20. Quantum Chemical Study on Reaction of Acetaldehyde with Hydroxyl Radical

    Institute of Scientific and Technical Information of China (English)

    LI,Ming(李明); ZHANG,Jin-Sheng(张金生); SHEN,Wei(申伟); MENG,Qing-Xi(孟庆喜)

    2004-01-01

    The reaction of acetaldehyde with hydroxyl radical was studied by means of quantum chemical methods. The geometries for all the stationary points on the potential energy surfaces were optimized fully, respectively, at the G3MP2, G3, and MP2/6-311++G(d,p) levels. Single-point energies of all the species were calculated at the QCISD/6-311 + +G(d,p) level. The mechanism of the reaction studied was confirmed. The predicted product is acetyl radical that is in agreement with the experiment.

  1. The Haber Process Made Efficient by Hydroxylated Graphene

    CERN Document Server

    Chaban, Vitaly

    2016-01-01

    The Haber-Bosch process is the main industrial method for producing ammonia from diatomic nitrogen and hydrogen. Very demanding energetically, it uses an iron catalyst, and requires high temperature and pressure. Any improvement of the Haber process will have an extreme scientific and economic impact. We report a significant increase of ammonia production using hydroxylated graphene. Exploiting the polarity difference between N2/H2 and NH3, as well as the universal proton acceptor behavior of NH3, we demonstrate a strong shift of the equilibrium of the Haber-Bosch process towards ammonia. Hydroxylated graphene provides the polar environment favoring the forward reaction, and remain stable under the investigated thermodynamic conditions. Ca. 50 kJ mol-1 enthalpy gain and ca. 60-70 kJ mol-1 free energy gain are achieved at 298-1300 K and 1-1000 bar, strongly shifting the reaction equilibrium towards the product. A clear microscopic interpretation of the observed phenomenon is given using electronic structure ca...

  2. Assessment of Mercury Bioaccumulation in Zebra Cichlid (Cichlasoma Nigrofasciatum Exposed to Sublethal Concentrations of Permethrin

    Directory of Open Access Journals (Sweden)

    Mahdi Banaee

    2014-12-01

    Full Text Available Background: Aquatic ecosystems are frequently subjected to contamination by toxic heavy metals and pesticides, yet very little is known about the influence of pesticides on bioaccumulation of heavy metals in aquatic organisms. Mercury is a toxic metal with no known biological benefit to organisms. Bioavailability of mercury in aquatic environments depends on biological and non-biological parameters including other pollutants. Therefore, the objectives of this research were to determine the effects of permethrin on bioaccumulation of mercury in zebra cichlid. Methods: Acute toxicity (LC50 of permethrin and mercury chloride was evaluated by estimating mortality in Probit Model in SPSS (version 19.0 IBM. In sub-lethal toxicity, zebra cichlid (Cichlasoma nigrofasciatum was exposed to various concentrations of permethrin (0.0, 0.40, 0.80, 1.20 and 1.60 µg.L-1 combined with 20 µg.L-1 mercury chloride for 15 days. At the end of the experiment, mercury concentrations were measured using ICP-OES-Perkin elmer (optima 7300-DV. Results: 96 h LC50 values of permethrin and mercury for C. nigrofasciatum were calculated to be 17.55 µg.L-1 and 140.38 µg.L-1, respectively. Our results clearly showed that the bioaccumulation of mercury in the specimens increased with increasing concentrations of permethrin to 1.20 and 1.60 µg.L-1. Conclusion: Increasing the concentration of permethrin had synergistic effects on the bioaccumulation of mercury in fish.

  3. Toxicity and bioaccumulation of sediment-associated silvernanoparticles in the estuarine polychaete, Nereis (Hediste) diversicolor

    DEFF Research Database (Denmark)

    Cong, Yi; Banta, Gary Thomas; Selck, Henriette;

    2014-01-01

    damage (comet assay tail moment and tail DNA intensity %) of Nereis coelomocytes increased in a concentration-dependent manner in all three Ag treatments. Ag NP treatments were more toxic than aqueous Ag for all toxicity endpoints, even though bioaccumulation did not differ significantly among Ag forms...

  4. Bioaccumulation of Polycyclic Aromatic Hydrocarbons and Mercury in Oysters (Crassostrea rhizophorae from Two Brazilian Estuarine Zones

    Directory of Open Access Journals (Sweden)

    Ronaldo J. Torres

    2012-01-01

    Full Text Available Nowadays, organisms are increasingly being used in biomonitoring to assess bioavailability and bioaccumulation of contaminants. This approach can use both native and transplanted organisms in order to accomplish this task. In Brazil, most of the studies related to bioaccumulation of contaminants in oysters deal with metals. The present work employs this kind of test in Brazilian coastal estuaries (Santos and Paranaguá to evaluate total mercury and polycyclic aromatic hydrocarbon contamination in sediments and oysters (native and caged Crassostrea rhizophorae. The methodologies employed were based on known USEPA methods. Results have shown a significant contamination in Santos sediments and consequent bioavailability of organisms. Paranaguá sediments presented lower contamination in sediments, but native oysters were able to accumulate total Hg. The experiments done with caged oysters did not show significant bioaccumulation of Hg and PAHs in the Paranaguá site, but proved to be an excellent tool to assess bioavailability in the Santos estuary since they were able to bioaccumulate up to 1,600% of total PAH in the samples from the inner part of this estuary when compared to control organisms. Multivariate statistical analyses employed to these results have separated the sites evaluated and the most contaminated samples from the least contaminated.

  5. Bioaccumulation and oxidative stress in Daphnia magna exposed to arsenite and arsenate.

    Science.gov (United States)

    Fan, Wenhong; Ren, Jinqian; Li, Xiaomin; Wei, Chaoyang; Xue, Feng; Zhang, Nan

    2015-11-01

    Arsenic pollution and its toxicity to aquatic organisms have attracted worldwide attention. The bioavailability and toxicity of arsenic are highly related to its speciation. The present study investigated the differences in bioaccumulation and oxidative stress responses in an aquatic organism, Daphnia magna, induced by 2 inorganic arsenic species (As(III) and As(V)). The bioaccumulation of arsenic, Na(+) /K(+) -adenosine triphosphatase (ATPase) activity, reactive oxygen species (ROS) content, total superoxide dismutase (SOD) activity, total antioxidative capability, and malondialdehyde content in D. magna were determined after exposure to 500 µg/L of arsenite and arsenate for 48 h. The results showed that the oxidative stress and antioxidative process in D. magna exposed to arsenite and arsenate could be divided into 3 phases, which were antioxidative response, oxidation inhibition, and antioxidative recovery. In addition, differences in bioaccumulation, Na(+) /K(+) -ATPase activity, and total SOD activity were also found in D. magna exposed to As(III) and As(V). These differences might have been the result of the high affinity of As(III) with sulfhydryl groups in enzymes and the structural similarity of As(V) to phosphate. Therefore, arsenate could be taken up by organisms through phosphate transporters, could substitute for phosphate in biochemical reactions, and could lead to a change in the bioaccumulation of arsenic and activity of enzymes. These characteristics were the possible reasons for the different toxicity mechanisms in the oxidative stress process of arsenite and arsenate. PMID:26084717

  6. Forecasting fish biomasses, densities, productions, and bioaccumulation potentials of Mid-Atlantic wadeable streams

    Science.gov (United States)

    Regional fishery conditions of Mid-Atlantic wadeable streams in the eastern United States are estimated using the BASS bioaccumulation and fish community model and data collected by the U.S. Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP)....

  7. Seasonal Trends in Bioaccumulation of Heavy Metals in Fauna of Stormwater Ponds

    DEFF Research Database (Denmark)

    Stephansen, Diana; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild;

    2013-01-01

    Fauna caught in three stormwater ponds, two receiving highway run-off and one receiving runoff from a center for trucks, was analyzed for copper, iron, zinc, cadmium, chromium, and lead. The fauna was monitored from March to October with 1-month intervals to evaluate seasonal trends in bioaccumul...

  8. Bioaccumulation dynamics and exposure routes of Cd and Cu among species of aquatic mayflies

    Science.gov (United States)

    Cain, D.; Croteau, M.-N.; Luoma, S.

    2011-01-01

    Consumption of periphyton is a potentially important route of metal exposure to benthic invertebrate grazers. The present study examined the bioaccumulation kinetics of dissolved and dietary Cd and Cu in five species of mayflies (class Insecta). Artificial stream water and benthic diatoms were separately labeled with enriched stable metal isotopes to determine physiological rate constants used by a biokinetic bioaccumulation model. The model was employed to simulate the effects of metal partitioning between water and food, expressed as the bioconcentration factor (BCF), as well as ingestion rate (IR) and metal assimilation efficiency of food (AE), on the relative importance of water and food to metal bioaccumulation. For all test species, the contribution of dietary uptake of Cd and Cu increased with BCF. For a given BCF, the contribution of food to the body burden increased with kuf, the metal uptake rate constant from food that combined variation in IR and AE. To explore the relative importance of water and diet exposure routes under field conditions, we used estimated site-specific aqueous free-ion concentrations to model Cd and Cu accumulation from aqueous exposure, exclusively. The predicted concentrations accounted for less than 5% of the observed concentrations, implying that most bioaccumulated metal was acquired from food. At least for the taxa considered in this study, we conclude that consumption of metal-contaminated periphyton can result in elevated metal body burdens and potentially increase the risk of metal toxicity. ?? 2011 SETAC.

  9. Bioaccumulation of ionic titanium and titanium dioxide nanoparticles in zebrafish eleutheroembryos.

    Science.gov (United States)

    López-Serrano Oliver, Ana; Muñoz-Olivas, Riansares; Sanz Landaluze, Jon; Rainieri, Sandra; Cámara, Carmen

    2015-01-01

    The production of titanium dioxide nanoparticles (TiO(2) NPs) for commercial applications has greatly increased over the last years and consequently the potential risk for human health. There is a growing awareness of the need to understand the behavior and influence these nanoparticles exert on the environment. Bioaccumulation serves as a good integrator to assess chemical exposure in aquatic systems and is dependent on factors, such as the exposure routes, diet and the aqueous medium. We analyzed the experimental bioaccumulation capability of ionic titanium and TiO(2) NPs by zebrafish (Danio rerio) eleutheroembryos through bioconcentration factors (BCFs), after 48 or 72 h of exposure. The stability of both chemical forms in an aquatic medium was fully characterized for further bioaccumulation studies. Several stabilizing agents (humic acids, soluble starch, polyethylene glycol, Na(4)P(2)O(7) and Na(2)HPO(4)) for anatase and rutile, the two allotrophs of TiO(2) NPs, were evaluated to check the evolution of the aggregation process. Around 60% of TiO(2) NPs remained disaggregated under simulated environmental conditions with the addition of 50 mg L(-1) of humic acids. However, the presence of eleutheroembryos in the exposure medium increased TiO(2) NPs aggregation in the experimental tests. The BCFs values obtained in all cases were <100, which classifies ionic titanium and TiO(2) NPs as non-bioaccumulative substances, under the REACH regulations.

  10. ENHANCED BIOACCUMULATION OF HEAVY METAL BY BACTERIA CELLS DISPLAYING SYNTHETIC PHYTOCHELATINS. (R827227)

    Science.gov (United States)

    A novel strategy using synthetic phytochelatins is described for the purpose of developing microbial agents for enhanced bioaccumulation of toxic metals. Synthetic genes encoding for several metal-chelating phytochelatin analogs (Glu-Cys)nGly (EC8 (n = 8), EC11 (n = 11...

  11. Total mercury bioaccumulation tracking in a fresh water food chain, (Sanandaj Gheshlagh Dam Reservoir, Iran

    Directory of Open Access Journals (Sweden)

    Shahnaz Zare

    2014-05-01

    Conclusion: Due to the high bioaccumulation, biomagnifications factors and mercury concentration recorded in edible parts of SGR fish, local consumers should not eat more than 1182 gram of this fish weekly without accounting for other potential sources of total mercury in their food basket.

  12. Organophosphorus and Organochlorine Pesticides Bioaccumulation by Eichhornia crassipes in Irrigation Canals in an Urban Agricultural System.

    Science.gov (United States)

    Mercado-Borrayo, B M; Heydrich, Silke Cram; Pérez, Irma Rosas; Quiroz, Manuel Hernández; Hill, Claudia Ponce De León

    2015-01-01

    A natural wetland in Mexico City Metropolitan Area is one of the main suppliers of crops and flowers, and in consequence its canals hold a high concentration of organochlorine (OC) and organophosphorus (OP) pesticides. There is also an extensive population of water hyacinth (Eichhornia crassipes), which is considered a plague; but literature suggests water hyacinth may be used as a phytoremediator. This study demonstrates bioaccumulation difference for the OC in vivo suggesting their bioaccumulation is ruled by their log K(ow), while all the OP showed bioaccumulation regardless of their log K(ow). The higher bioaccumulation factors (BAF) of the accumulated OC pesticides cannot be explained by their log K(ow), suggesting that the OC pesticides may also be transported passively into the plant. Translocation ratios showed that water hyacinth is an accumulating plant with phytoremediation potential for all organophosphorus pesticides studied and some organochlorine pesticides. An equation for free water surface wetlands with floating macrophytes, commonly used for the construction of water-cleaning wetlands, showed removal of the pesticides by the wetland with room for improvement with appropriate management. PMID:25976884

  13. Effects of microplastic on fitness and PCB bioaccumulation by the lugworm Arenicola marina

    NARCIS (Netherlands)

    Besseling, E.; Wegner, A.; Foekema, E.M.; Heuvel_Greve, van den M.J.; Koelmans, A.A.

    2013-01-01

    It has been speculated that marine microplastics may cause negative effects on benthic marine organisms and increase bioaccumulation of persistent organic pollutants (POPs). Here, we provide the first controlled study of plastic effects on benthic organisms including transfer of POPs. The effects of

  14. The role of the 4''-hydroxyl on motilin agonist potency in the 9-dihydroerythromycin series.

    Science.gov (United States)

    Liu, Yaoquan; Carreras, Christopher W; Claypool, Mark; Myles, David C; Shaw, Simon J

    2011-06-15

    The role of the erythromycin 4''-hydroxyl group has been explored on the motilin agonist potential in the 9-dihydroerythromycin series of motilides. The compounds show potencies 2- to 4-fold superior to the corresponding hydroxylated compounds. The relationship is maintained when the 9-hydroxyl is alkylated to generate the corresponding 4''-deoxy-9-O-acetamido-9-dihydroerythromycins. However, concomitant with this increase in potency is an increase in hERG inhibition.

  15. Reactivity of electrogenerated free hydroxyl radicals and activation of dioxygen on boron-doped diamond electrodes

    OpenAIRE

    Kapalka, Agnieszka

    2008-01-01

    Synthetic boron-doped diamond (BDD) thin film is an electrode material with high chemical and dimensional stability, low background current and a very wide potential window of water stability. Upon anodic polarization, BDD generates hydroxyl radicals that mediate the oxidation processes in the vicinity of the electrode surface. These hydroxyl radials are assumed to be free, i.e., not adsorbed on the electrode surface. Hydroxyl radicals are formed on BDD during water discharge, which is the ra...

  16. Bioaccumulation of Pb and Cd on Broiler Chicken Fed in Difference Diets

    Directory of Open Access Journals (Sweden)

    Bambang Dwiloka

    2012-10-01

    Full Text Available The study was aimed to compute Pb and Cd bioaccumulation in different organs of broiler. Carcass, heart, liver, gizzard, intestine, and excreta. The data were obtained from broiler reared in the litter cage. Four treatments of feed were given to the broiler chicken, i.e.  T1 = X brand of commercial feed, T2 = Y brand of commercial feed, T3 = self-prepared feed without fish meal addition and T4 = self prepared feed without fish meal but contaminated with cadmium chloride (Cd.Cl2.4H2O. For each treatment, five broiler chicken were grouped each week (from week I up to week VI. Results of the first stage of this study was analyzed descriptively. A polinomial regression equation was used as an empirical model to describe the heavy metal bioaccumulation phenomenon in broiler carcasses. The quadratic equation  turned out to be the most suitable model for describing the bioaccumulation of heavy metal in broiler carcasses. From the simulation, it was found that  quadratic model fit to 61.31% and 54.17%  bioaccumulation data of Pb and Cd respectively. According to the model, initially metal concentrations declined since the first week and started to rebound at the fifth week, both in terms of chronological and physiological age. The patterns of Pb and Cd bioaccumulation in this study can be used as a reference to determine the proper slaughter period. It can be concluded that for reducing the risk of metal contamination the proper slaughter time of the broiler is before the fifth week.

  17. Contrasting PCB bioaccumulation patterns among Lake Huron lake trout reflect basin-specific ecology.

    Science.gov (United States)

    Paterson, Gordon; Ryder, Mark; Drouillard, Ken G; Haffner, G Douglas

    2016-01-01

    This study collected multiple age classes of lake trout from Lake Huron's Main Basin, Georgian Bay, and North Channel regions to compare and contrast top predator polychlorinated biphenyl (PCB) bioaccumulation patterns in separate compartments of the same ecosystem. Sum PCB concentrations were highest for Main Basin (260 ± 24.9 ng g(-1) wet wt) fish, followed by Georgian Bay (74.6 ± 16.2 ng g(-1) ) and North Channel (42.0 ± 3.3 ng g(-1)) fish. Discriminant functions analysis of lake trout PCB profiles and stable carbon (δ(13)C) and nitrogen (δ(15)N) isotope values clearly distinguished fish by location, indicating high degrees of basin fidelity throughout their lifetimes in addition to highly contrasting PCB bioaccumulation profiles. These unique profiles were not attributable to significant differences in lake trout lipid contents (p = 0.856) or trophic position (δ(15)N; p = 0.334), with rainbow smelt representing the primary prey across the basins. Furthermore, significant differences were observed among the basins for the relationships between PCB biomagnification factors and hydrophobicity. An empirical model for predicting PCB biomagnification in Lake Huron lake trout indicated that basin-specific population growth rates and prey abundances were significant for explaining these contrasting patterns of PCB bioaccumulation. The results of the present study are fundamental for understanding the role of ecology in legacy persistent organic pollutant (POP) bioaccumulation. Specifically, ecosystem characteristics such as prey abundances, foraging ecology, and ultimately consumer growth can regulate the variability of legacy POP bioaccumulation as observed within and among a wide range of freshwater ecosystems.

  18. Reaction of hydroxyl radical with phenylpropanoid glycosides from Pedicularis species: a pulse radiolysis study

    Institute of Scientific and Technical Information of China (English)

    王潘奋; 郑荣梁; 高建军; 贾忠建; 王文峰; 姚思德; 张加山; 林念芸

    1996-01-01

    Using pulse radiolysis technique, the reaction between hydroxyl radical and 7 phenylpropanoidglycosides: echinacoside, verbascoside, leucosceptoside A, martynoside, pediculariosides A, M and N which were isolated from Pedicularis were examined. The rate constants of these reactions were determined by transient absorption spectra. All 7 phenylpropanoid glycosides react with hydroxyl radical at high rate constants within (0.97-1.91)×1010L · mol-1 · s-1. suggesting that they are effective hydroxyl radical scavengers. The results demonstrate that the numbers of phenolic hydroxyl groups of phenylpropanoid glycosides are directly related to their scavenging activities. The scavenging activities are likely related to o-dihydroxy group of phenylpropanoid glycosides as well.

  19. The use of microsomal in vitro assay to study phase I biotransformation of chlorobornanes (Toxaphene) in marine mammals and birds. Possible consequences of biotransformation for bioaccumulation and genotoxicity.

    Science.gov (United States)

    Boon, J P; Sleiderink, H M; Helle, M S; Dekker, M; van Schanke, A; Roex, E; Hillebrand, M T; Klamer, H J; Govers, B; Pastor, D; Morse, D; Wester, P G; de Boer, J

    1998-11-01

    The factors determining the bioaccumulation of lipophilic compounds in wildlife are often poorly understood, partly because it is difficult to do in vivo experiments with animals such as marine mammals and birds. To evaluate the role of phase I biotransformation in the bioaccumulation process of chlorobornanes (toxaphene), this was studied in in vitro assays with hepatic microsomes of animals that could be sampled shortly after death. The capacity of microsomes to metabolise a technical toxaphene mixture decreased in the order Phoca vitulina (harbour seal) > Lagenorhynchus albirostris (whitebeaked dolphin) approximately equal to Diomedea immutabilis (Laysan albatross) > Physeter macrocephalus (sperm whale). Harbour seal microsomes metabolised the chlorobornane (CHB) congeners CHB-32 and CHB-62; whitebeaked dolphin and Laysan albatross microsomes only metabolised CHB-32. Metabolism of CHB-26 and CHB-50 was never observed. The negative chemical ionisation (NCI-) mass spectra of some of the hydroxylated metabolites were obtained. The number of peaks in the toxaphene residues of wildlife extracts decreased in the order of increasing in-vitro biotransformation capacity. Thus, the results of the in vitro assays and residue analysis were in accordance, although assays with microsomes of more individuals of the same species are required for a more general conclusion at the species level. Finally, the effect of in vitro biotransformation was evaluated in terms of the genotoxic potential using the Mutatox assay. Only technical toxaphene and CHB-32 were genotoxic in the direct assay, whereas the addition of rat S9 fraction or microsomes of harbour seal and albatross decreased the genotoxic response. Thus, organisms with a low ability to metabolise chlorobornanes, such as whales, may be most affected by the carcinogenic properties of toxaphene. A hypothetical reaction which fits the experimental results is discussed. Based on these results it is concluded that in vitro assays

  20. Crystal structure of tris-(hydroxyl-ammonium) orthophosphate.

    Science.gov (United States)

    Leinemann, Malte; Jess, Inke; Boeckmann, Jan; Näther, Christian

    2015-11-01

    The crystal structure of the title salt, ([H3NOH](+))3·[PO4](3-), consists of discrete hydroxyl-ammonium cations and ortho-phos-phate anions. The atoms of the cation occupy general positions, whereas the anion is located on a threefold rotation axis that runs through the phospho-rus atom and one of the phosphate O atoms. In the crystal structure, cations and anions are linked by inter-molecular O-H⋯O and N-H⋯O hydrogen bonds into a three-dimensional network. Altogether, one very strong O-H⋯O, two N-H⋯O hydrogen bonds of medium strength and two weaker bifurcated N-H⋯O inter-actions are observed. PMID:26594525

  1. Kinetics of the reaction of hydroxyl radicals with nitric acid

    Science.gov (United States)

    Margitan, J. J.; Watson, R. T.

    1982-01-01

    An extensive study was made of the reaction of hydroxyl radicals with nitric acid in a laser photolysis-resonance fluorescence system. A 266 nm laser was used to photolyze HNO3 in the temperature range 225-415 K at pressures of 20-300 torr. A temperature dependence was detected below room temperature, with a leveling off at 298 K and a wide spread in the rate constants. A pressure dependence was observed over the entire range and was more pronounced at lower temperatures. The results are noted to be in agreement with those of previous investigations. However, the wide range of rate constants are suggested to be a problem for stratospheric HO(x) modeling for anthropogenic effects. No explanation could be given of the varying results obtained by other investigators regarding the kinetics of the reactions.

  2. Spectroscopy and reaction dynamics of collision complexes containing hydroxyl radicals

    Energy Technology Data Exchange (ETDEWEB)

    Lester, M.I. [Univ. of Pennsylvania, Philadelphia (United States)

    1993-12-01

    The DOE supported work in this laboratory has focused on the spectroscopic characterization of the interaction potential between an argon atom and a hydroxyl radical in the ground X{sup 2}II and excited A {sup 2}{summation}{sup +} electronic states. The OH-Ar system has proven to be a test case for examining the interaction potential in an open-shell system since it is amenable to experimental investigation and theoretically tractable from first principles. Experimental identification of the bound states supported by the Ar + OH (X {sup 2}II) and Ar + OH(A {sup 2}{summation}{sup +}) potentials makes it feasible to derive realistic potential energy surfaces for these systems. The experimentally derived intermolecular potentials provide a rigorous test of ab initio theory and a basis for understanding the dramatically different collision dynamics taking place on the ground and excited electronic state surfaces.

  3. Exposure assessment of French women and their newborn to brominated flame retardants: Determination of tri- to deca- polybromodiphenylethers (PBDE) in maternal adipose tissue, serum, breast milk and cord serum

    Energy Technology Data Exchange (ETDEWEB)

    Antignac, Jean-Philippe [Laboratoire d' Etude des Residus et Contaminants dans les Aliments (LABERCA), USC INRA 2013, Ecole Nationale Veterinaire de Nantes (ENVN), Route de Gachet, BP 50707, 44307 Nantes Cedex 3 (France)], E-mail: antignac@vet-nantes.fr; Cariou, Ronan [Laboratoire d' Etude des Residus et Contaminants dans les Aliments (LABERCA), USC INRA 2013, Ecole Nationale Veterinaire de Nantes (ENVN), Route de Gachet, BP 50707, 44307 Nantes Cedex 3 (France); Zalko, Daniel [UMR 1089 Xenobiotiques, INRA, 31931 Toulouse (France); Berrebi, Alain [Centre Hospitalier Universitaire de Toulouse, Hopital Paule de Viguier, Service de gynecologie-obstetrique, Toulouse (France); Cravedi, Jean-Pierre [UMR 1089 Xenobiotiques, INRA, 31931 Toulouse (France); Maume, Daniel; Marchand, Philippe; Monteau, Fabrice [Laboratoire d' Etude des Residus et Contaminants dans les Aliments (LABERCA), USC INRA 2013, Ecole Nationale Veterinaire de Nantes (ENVN), Route de Gachet, BP 50707, 44307 Nantes Cedex 3 (France); Riu, Anne [Unite Signalisation Hormonale, Environnement et Cancer, U824 INSERM, 34298 Montpellier Cedex 5 (France); Andre, Francois; Le Bizec, Bruno [Laboratoire d' Etude des Residus et Contaminants dans les Aliments (LABERCA), USC INRA 2013, Ecole Nationale Veterinaire de Nantes (ENVN), Route de Gachet, BP 50707, 44307 Nantes Cedex 3 (France)

    2009-01-15

    In the frame of a French monitoring program, tri- to deca- polybromodiphenylethers (PBDE) have been measured in maternal and cord serum, adipose tissue, and breast milk samples, collected from 93 volunteer women during caesarean deliveries. The seven major tri- to heptaBDE (BDE-28, 47, 99, 100, 153, 154, and 183) were detected in adipose tissue and breast milk with cumulated median values of 2.59 and 2.51 ng g{sup -1} l w. Nine highly brominated octa- to decaBDE (BDE-196, 197, 201, 202, 203, 206, 207, 208 and 209) was performed in the same samples, with cumulated median values of 2.73 and 3.39 ng g{sup -1} l w in adipose tissue and breast milk, respectively. At this opposite, median levels of octa- to decaBDE in maternal and cord serum appeared significantly higher than the levels of tri- to heptaBDE in the same matrices, i.e. 8.85 and 12.34 versus 0.98 and 0.69 ng g{sup -1} l w, respectively. - This study provides the first data at the French level regarding the occurrence of PBDE in human, and demonstrates the exposure of both human foetus at late stage of pregnancy and newborn at early stages of life through breastfeeding with special emphasis on the presence of highly brominated compounds.

  4. Exploring the effects of temperature and resource limitation on mercury bioaccumulation in Fundulus heteroclitus using dynamic energy budget modeling

    Science.gov (United States)

    Dynamic energy budget (DEB) theory provides a generalizable and broadly applicable framework to connect sublethal toxic effects on individuals to changes in population survival and growth. To explore this approach, we conducted growth and bioaccumulation studies that contribute t...

  5. Intra- and inter-laboratory reliability of a cryopreserved trout hepatocyte assay for the prediction of chemical bioaccumulation potential

    Science.gov (United States)

    Cryopreserved trout hepatocytes provide a convenient in vitro system for measuring the intrinsic clearance of xenobiotics. Measured clearance rates can then be extrapolated to the whole animal as a means of improving modeled bioaccumulation predictions. To date, however, the in...

  6. Speciation of bioaccumulated uranium(VI) by Euglena mutabilis cells obtained by laser fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Brockmann, Sina; Bernhard, Gert [Technical Univ. Dresden (Germany). Radiochemistry; Helmholtz-Zentrum Dresden-Rossendorf (HZDR) e.V., Dresden (Germany). Inst. of Resource Ecology; Arnold, Thuro [Helmholtz-Zentrum Dresden-Rossendorf (HZDR) e.V., Dresden (Germany). Inst. of Resource Ecology

    2014-07-01

    The ability of Euglena mutabilis cells - a unicellular protozoan with a flexible pellicle, which is typically found in acid mine drainage (AMD) environments - to bioaccumulate uranium under acid conditions was studied in batch sorption experiments at pH 3 and 4 using Na{sub 2}SO{sub 4} and NaClO{sub 4} as background media. It was found that axenic cultures of Euglena mutabilis Schmitz were able to bioaccumulate in 5 days 94.9 to 99.2% of uranium from a 1 x 10{sup -5} mol/L uranium solution in perchlorate medium and 95.1 to 95.9% in sodium sulfate medium, respectively. The speciation of uranium in solution and uranium bioaccumulated by Euglena mutabilis cells, were studied by laser induced fluorescence spectroscopy (LIFS). The LIFS investigations showed that the uranium speciation in the NaClO{sub 4} systems was dominated by free uranyl(VI) species and that the UO{sub 2}SO{sub 4} species was dominating in the Na{sub 2}SO{sub 4} medium. Fluorescence spectra of the bioaccumulated uranium revealed that aqueous uranium binds to carboxylic and/or (organo)phosphate groups located on the euglenid pellicle or inside the Euglena mutabilis cells. Reduced uranium immobilization rates of 0.93-1.43 mg uranium per g Euglena mutabilis biomass were observed in similar experiments, using sterile filtrated AMD waters containing, 4.4 x 10{sup -5} mol/L uranium. These lower rates were attributed to competition with other cations for available sorption sites. Additional LIFS measurements, however, showed that the speciation of the bioaccumulated uranium by the Euglena mutabilis cells was found to be identical with the uranium speciation found in the bioaccumulation experiments carried out in Na{sub 2}SO{sub 4} and NaClO{sub 4} media. The results indicate that Euglena mutabilis has the potential to immobilize aqueous uranium under acid condition and thus may be used in future as promising agent for immobilizing uranium in low pH waste water environments. (orig.)

  7. Solid-phase Synthesis of a Novel Kind of Hydroxylated Heterocyclic Ketene Aminals

    Institute of Scientific and Technical Information of China (English)

    Tao PENG; Chu Yi YU; Zhi Tang HUANG

    2006-01-01

    An efficient solid-phase synthesis method for novel heterocyclic ketene aminals containing a hydroxyl group has been developed. The loading of the substrate on the resin through the hydroxyl group and the protection of the amine by the Schiff base were the key steps in the synthesis.

  8. Biosorption of Strontium from Simulated Nuclear Wastewater by Scenedesmus spinosus under Culture Conditions: Adsorption and Bioaccumulation Processes and Models

    OpenAIRE

    Mingxue Liu; Faqin Dong; Wu Kang; Shiyong Sun; Hongfu Wei; , Wei Zhang; Xiaoqin Nie; Yuting Guo; Ting Huang; Yuanyuan Liu

    2014-01-01

    Algae biosorption is an ideal wastewater treatment method when coupled with algae growth and biosorption. The adsorption and bioaccumulation of strontium from simulated nuclear wastewater by Scenedesmus spinosus were investigated in this research. One hundred mL of cultured S. spinosus cells with a dry weight of 1.0 mg in simulated nuclear wastewater were used to analyze the effects on S. spinosus cell growth as well as the adsorption and bioaccumulation characters under conditions of 25 ± 1 ...

  9. Age and trophic position dominate bioaccumulation of mercury and organochlorines in the food web of Lake Washington

    International Nuclear Information System (INIS)

    Understanding the mechanisms of bioaccumulation in food webs is critical to predicting which food webs are at risk for higher rates of bioaccumulation that endanger the health of upper-trophic predators, including humans. Mercury and organochlorines were measured concurrently with stable isotopes of nitrogen and carbon in key fishes and invertebrates of Lake Washington to explore important pathways of bioaccumulation in this food web. Across the food web, age and trophic position together were highly significant predictors of bioaccumulation. Trophic position was more important than age for predicting accumulation of mercury, ΣDDT, and Σ-chlordane, whereas age was more important than trophic position for predicting PCB. Excluding age from the analysis inflated the apparent importance of trophic position to bioaccumulation for all contaminants. Benthic and pelagic habitats had similar potential to bioaccumulate contaminants, although higher Σ-chlordane concentrations in organisms were weakly associated with more benthic carbon signals. In individual fish species, contaminant concentrations increased with age, size, and trophic position (δ15N), whereas relationships with carbon source (δ13C) were not consistent. Lipid concentrations were correlated with contaminant concentrations in some but not all fishes, suggesting that lipids were not involved mechanistically in bioaccumulation. Contaminant concentrations in biota did not vary among littoral sites. Collectively, these results suggest that age may be an important determinant of bioaccumulation in many food webs and could help explain a significant amount of the variability in apparent biomagnification rates among food webs. As such, effort should be made when possible to collect information on organism age in addition to stable isotopes when assessing food webs for rates of biomagnification

  10. Metal and metalloid bioaccumulation in the Pacific blue shrimp Litopenaeus stylirostris (Stimpson) from New Caledonia: laboratory and field studies

    OpenAIRE

    Metian, Marc; Eltayeb, Mohamed M.; Hédouin, Laëtitia; Lacoue-Labarthe, Thomas; Teyssié, Jean-Louis; Mugnier, Chantal; Bustamante, Paco; Warnau, Michel

    2010-01-01

    The present work aimed at better understanding metal and metalloid bioaccumulation in the edible Pacific blue shrimp Litopenaeus stylirostris, using both laboratory and field approaches. In the laboratory, the bioaccumulation kinetics of Ag, Cd, Co, Cr, and Zn have been investigated in shrimp exposed via seawater and food, using the corresponding gamma-emitting radiotracers (Ag-110m, Cd-109, Co-57, Cr-51, and Zn-65) and highly sensitive nuclear detection techniques. Results showed that hepato...

  11. Combined effects of sugarcane bagasse extract and Zinc(II ions on the growth and bioaccumulation properties of yeast isolates.

    Directory of Open Access Journals (Sweden)

    Geetanjali Basak

    2011-08-01

    Full Text Available Bioaccumulation of zinc(II ions by yeast isolates viz. Candida rugosa and Cryptococcus laurentii was investigated in different growth media. Both the isolates showed maximum bioaccumulation of zinc(II in the medium prepared from sugarcane bagasse extract. The growth and zinc(II bioaccumulation properties of yeasts in sugar cane bagasse extract were tested as a function of pH, temperature and initial metal concentrations. The combined effects of sugar extracted from bagasse and initial zinc(II ion concentrations on specific growth rate and bioaccumulation efficiencies of yeasts were investigated. At a constant zinc(II concentration, the growthand zinc(II bioaccumulation increased with increasing concentrations of sugar up to 24 g/L. The inhibition effect of zinc(II ions on the specific growth rate of yeasts was studied by non competitive and uncompetitive inhibition models at various concentrations of zinc(II ranging from 0-50 mg/L at constant sugar concentrations (8- 24 g/L. Bioaccumulation of zinc(II by the yeast isolates followed first-order-reaction kinetics.

  12. Bioaccumulation of {sup 137}Cs and {sup 57}Co by five marine phytoplankton species

    Energy Technology Data Exchange (ETDEWEB)

    Heldal, H.E. E-mail: hilde.elise.heldal@imr.no; Stupakoff, I.; Fisher, N.S

    2001-07-01

    Under controlled laboratory conditions, we have examined the bioaccumulation of {sup 137}Cs and {sup 57}Co in three prymnesiophytes, the coccolithophorid Emiliania huxleyi and the non-calcareous species Isochrysis galbana and Phaeocystis globosa, and two diatoms Skeletonema costatum and Thalassiosira pseudonana. We measured the uptake in growing and non-growing cells and determined concentration factors on both volume and dry weight bases. For uptake of {sup 57}Co in non-growing cells, volume concentration factors (VCF) at equilibrium ranged from 0.2x10{sup 3} for E. huxleyi to 4x10{sup 3} for T. pseudonana. For uptake of {sup 137}Cs in non-growing cells, the VCFs were low for all species and the uptake pattern seemed unsystematic. The results suggest that, in contrast to Co, the cycling and bioaccumulation of Cs in marine animals are unlikely to be affected by Cs accumulation in primary producers.

  13. Bioaccumulation of heavy metals in marine organisms and sediments from Admiralty Bay, King George Island, Antarctica.

    Science.gov (United States)

    Trevizani, Tailisi Hoppe; Figueira, Rubens Cesar Lopes; Ribeiro, Andreza Portella; Theophilo, Carolina Yume Sawamura; Majer, Alessandra Pereira; Petti, Monica Angélica Varella; Corbisier, Thais Navajas; Montone, Rosalinda Carmela

    2016-05-15

    The Antarctic continent is considered a low-impact environment; however, there is a tendency to increase the contaminants' levels due to human activities in the research stations. In this study, As, Cd, Cr, Cu, Hg, Ni, Pb and Zn levels in sediment and biota were determined in the environmental samples from Admiralty Bay (King George Island, Antarctica) collected in 2003. The results demonstrated high concentrations of Cu and Zn in the sediments. There was bioaccumulation of As in the biota from Admiralty Bay and bioaccumulation of Zn specifically in the biota from Martel Inlet. In addition, the results were useful in order to understand the heavy metal levels for the pre-accident condition of Comandante Ferraz Antarctic Station, where an accident occurred in 2012, and also for the comparison with current conditions within the monitoring work developed by INCT-APA (National Institute of Science and Technology for Environmental Research Antarctic). PMID:26936119

  14. Use of 65 Zn as radioactive tracer in the bioaccumulation study of zinc by aquatic organisms

    International Nuclear Information System (INIS)

    The present work has as main objective to emphasize the importance of using radioactive tracers as well as to establish a methodology for the utilization of 65 Zn in the bioaccumulation study of zinc by Poecilia reticulata. The exposure time varied from 5 days (short term experiments) to 30 days (long term experiments). The bioaccumulation of zinc from the water as well as the elimination of the metal previously absorbed were determined by measuring the activity of 65 Zn which was added to the water in the beginning of the experiments. The technique chosen is suitable to study the behaviour of the stable zinc since the radionuclide used is an isotope of the same element and therefore presents the same chemical properties. (author)

  15. Heavy Metals Bioaccumulation by Iranian and Australian Earthworms (Eisenia fetida in the Sewage Sludge Vermicomposting

    Directory of Open Access Journals (Sweden)

    MR Shahmansouri, H Pourmoghadas, AR Parvaresh, H Alidadi

    2005-01-01

    Full Text Available Vermicomposting of organic waste has an important part to play in an integrated waste management strategy. In this study, the possibility of heavy metals accumulation with two groups of Iranian and Australian earthworms in sewage sludge vermicompost was investigated. Eisenia fetida was the species of earthworms used in the vermicomposting process. The bioaccumulation of Cr, Cd, Pb, Cu, and Zn as heavy metals by Iranian and Australian earthworms was studied. The results indicated that heavy metals concentration decreased with increasing vermicomposting time. Comparison of the two groups of earthworms showed that the Iranian earthworms consumed higher quantities of micronutrients such as Cu and Zn comparing with the Australian earthworms, while the bioaccumulation of non-essential elements such as Cr, Cd, and Pb by the Australian group was higher. The significant decrease in heavy metal concentrations in the final vermicompost indicated the capability of both Iranian and Australian E.fetida species in accumulating heavy metals in their body tissues.

  16. Influence of feeding and earthworm density on compound bioaccumulation in earthworms Eisenia andrei.

    Science.gov (United States)

    Šmídová, Klára; Šerá, Jana; Bielská, Lucie; Hofman, Jakub

    2015-12-01

    Earthworm density and feeding during exposure to contaminated soil have been used inconsistently in bioaccumulation studies, which may lead to possible errors in risk assessment and modeling. Hydrophobic organic pollutants with a wide range of environmental properties (phenanthrene, pyrene, lindane, p,p'-DDT, and PCB 153) were used to study the effect of different earthworm densities in combination with the presence or absence of feeding on bioaccumulation factors (BAFs). Similar BAFs were found at various soil-to-worm ratios, with the exception of phenanthrene. We recommend using at least 15 gsoil dw per earthworm. The absence of feeding doubled the BAFs and, thus, using no food ration can be considered as "the worst case scenario". Whenever food is to be applied (i.e. to ensure the validity of the test in earthworm mass loss), we suggest feeding depending on the organic carbon content of the studied soil. PMID:26378968

  17. Methylmercury cycling, bioaccumulation, and export from agricultural and non-agricultural wetlands in the Yolo Bypass

    Science.gov (United States)

    Windham-Myers, Lisamarie; Marvin-DiPasquale, Mark; Fleck, Jacob; Alpers, Charles N.; Ackerman, Josh; Eagles-Smith, Collin; Stricker, Craig; Stephenson, Mark; Feliz, David; Gill, Gary; Bachand, Philip; Brice, Ann; Kulakow, Robin

    2010-01-01

    This 18-month field study addresses the seasonal and spatial patterns and processes controlling methylmercury (MeHg) production, bioaccumulation, and export from natural and agricultural wetlands of the Yolo Bypass Wildlife Area (YBWA). The data were collected in conjuntion with a Proposition 40 grant from the State Water Resources Control Board in support of the development of Best Management Practices (BMP's) for reducing MeHg loading from agricultural lands in the wetland-dominated Yolo Bypass to the Sacramento-San Joaquin River Delta. The four managemenr-based questions addressed in this study were: 1. Is there a different among agricultural and managfed wetland types in terms of Me Hg dynamic (production, degradation, bioaccumulation, or export)?

  18. Influence of foraging ecology and body condition on contaminant bioaccumulation in a top marine predator

    OpenAIRE

    Peterson, Sarah Elendil Hardee

    2015-01-01

    Environmental contaminants are a continued threat to marine wildlife because they are globally dispersed, bioaccumulate in top predators, and can disrupt physiological pathways, thus leading to adverse health effects. For adult marine mammals, the main source of contaminants is through their diet, therefore foraging behavior, including geographic location, foraging depth, and prey type, may exacerbate or mitigate contaminant exposure. Fluctuating body condition can also significantly affect c...

  19. Assessment of Mercury Bioaccumulation in Zebra Cichlid (Cichlasoma Nigrofasciatum) Exposed to Sublethal Concentrations of Permethrin

    OpenAIRE

    Mahdi Banaee; Amal Beitsayah; Isar Jorabdoz

    2014-01-01

    Background: Aquatic ecosystems are frequently subjected to contamination by toxic heavy metals and pesticides, yet very little is known about the influence of pesticides on bioaccumulation of heavy metals in aquatic organisms. Mercury is a toxic metal with no known biological benefit to organisms. Bioavailability of mercury in aquatic environments depends on biological and non-biological parameters including other pollutants. Therefore, the objectives of this research were to determine the ef...

  20. Bioaccumulation of Fe2O3(magnetic) nanoparticles in Ceriodaphnia dubia

    International Nuclear Information System (INIS)

    While nano-Fe2O3(magnetic) is generally considered non-toxic, it could serve as a carrier of other toxic chemicals such as As(V) and enhance their toxicity. The bioaccumulation of nano-Fe2O3(m) with different exposure times, NP concentrations, and pH conditions was investigated using Ceriodaphnia dubia (C. dubia) as the model organism. Under natural pH conditions, C. dubia significantly accumulated nano-Fe2O3(m) in the gut, with the maximum accumulation being achieved after 6 h of exposure. The concentration of nano-Fe2O3 also impacted its accumulation, with the maximum uptake occurring at 20 mg/L or more. In addition, the highest bioaccumulation occurred in a pH range of 7–8 where the highest feeding rate was reported, confirming that the ingestion of NPs is the main route of nano-Fe2O3(m) bioaccumulation. In a clean environment without NPs, depuration of nano-Fe2O3(m) occurred, and food addition accelerated the depuration process. - Highlights: ► Nano-Fe2O3(m) enhances the toxicity of As(V). ► C. dubia significantly accumulate nano-Fe2O3(m) through ingestion. ► The bioaccumulation of nano-Fe2O3(m) is affected by time, NP concentration, and pH. ► Food addition accelerates the depuration process of accumulated nano-Fe2O3(m). - Nano-Fe2O3(m) could enhance the toxicity of As(V) due to the significant accumulation of nano-Fe2O3(m) along with sorbed As(V) by C. dubia through ingestion.

  1. Feeding reduces waterborne Cu bioaccumulation in a marine rabbitfish Siganus oramin.

    Science.gov (United States)

    Guo, Zhiqiang; Zhang, Wei; Du, Sen; Zhou, Yanyan; Gao, Na; Zhang, Li; Green, Iain

    2016-01-01

    Waterborne metal uptake has been extensively studied and dietary metal assimilation is increasingly recognized in fish, whilst the interaction between the two uptake routes is largely overlooked. This study compared the waterborne Cu bioaccumulation ((65)Cu as tracer) in a juvenile rabbitfish at different feeding regimes (starvation (SG), feeding normal diet (NDG) or diet supplemented with extra Cu (DCG)) to test the hypothesis that feeding can influence waterborne metal uptake in marine fish. NDG and DCG diet was fed as a single meal and then all fish were exposed to waterborne (65)Cu for 48 h, during which the time course sampling was conducted to determine (65)Cu bioaccumulation, chyme flow and dietary Cu assimilation. The results revealed that SG fish accumulated the highest (65)Cu, followed by NDG (61% of SG), whilst DCG fish accumulated the lowest (65)Cu (34% of SG). These results suggested a protective effect of feeding against waterborne Cu bioaccumulation. This effect was most notable between 10 min and 16 h when there was chyme in gastrointestinal tract (GT). Dietary Cu assimilation mainly occurred before 16 h after feeding. Waterborne (65)Cu influx rate in the GT was positively correlated with (65)Cu contents of chyme in NDG, whereas it was largely negatively correlated with (65)Cu contents of chyme in DCG. The waterborne Cu uptake in the GT was mainly influenced by the chyme flow and dietary Cu assimilation. Overall, our findings suggested that feeding has an important effect on waterborne metal uptake and that both the feeding status of the fish and the relative metal exposure through water and food should be considered in prediction of the metal bioaccumulation and biomonitoring programs.

  2. FRESHWATER ULVA (CHLOROPHYTA) AS A BIOACCUMULATOR OF HEAVY METALS POLLUTION IN NIELBA RIVER (WIELKOPOLSKA REGION)

    OpenAIRE

    Messyasz, Beata; Rybak, Andrzej; Pikosz, Marta

    2012-01-01

    Messyasz B., Rybak A., Pikosz M. (2012). Freshwater Ulva (Chlorophyta) as a bioaccumulator of heavy metals pollution in Nielba river (Wielkopolska region). I Konferencja Młodych Naukowców z okazji Światowego Dnia Wody, Poznań-Morasko, 22-23 marzec 2012, pp. 59-60 (POSTER). Human activities still increase and causes negative impact to environment and consequently lead to ecological degradation. Water pollution, whose source are pesticides and chemical fertilizers from catchment areas, in re...

  3. Selective processes for bioaccumulative up-take of persistent organic pollutants (POPs) in Arctic food webs

    OpenAIRE

    Carlsson, Pernilla Marianne

    2013-01-01

    The overall aim of the present study was to elucidate selective environmental up-take processes in Arctic food webs that lead to the bioaccumulation of persistent organic pollutants (POP) in food items consumed by Arctic indigenous people. In addition, this study aimed to increase the scientific understanding of the principles behind climate change related influences on transport processes of contaminants. Svalbard and Nuuk, Greenland were chosen as study areas since they represent Arctic con...

  4. Quantum dots exhibit less bioaccumulation than free cadmium and selenium in the earthworm Eisenia andrei.

    Science.gov (United States)

    Stewart, David T R; Noguera-Oviedo, Katia; Lee, Vincent; Banerjee, Sarbajit; Watson, David F; Aga, Diana S

    2013-06-01

    The present study addresses the bioaccumulation behavior of cadmium selenide quantum dots by Eisenia andrei earthworms in a terrestrial environment. Earthworms were exposed to quantum dot-treated soil for up to 4 wk and analyzed for cadmium and selenium concentration using inductively coupled plasma mass spectrometry. Results were compared with those from earthworms exposed to cadmium nitrate and selenious acid, as positive controls, and those exposed in untreated soil (negative control). Earthworms exposed to quantum dots showed significant bioaccumulation of cadmium and selenium (5.3- and 1.5-fold higher concentration over negative controls, respectively) after 4 wk. Over the same 4 wk, positive control earthworms accumulated 9.2- and 2.2-fold higher cadmium and selenium, respectively, than negative controls for a much more substantial final body burden of the 2 elements. The concentrations also increased with exposure time; cadmium concentrations increased from 3600 ± 310 ng/g to 8080 ± 660 ng/g, from 1 to 4 wk, suggesting that further bioaccumulation may take place with even longer exposure time. The molar ratio of cadmium to selenium in the quantum dot-exposed worms (6.2) is closer to the ratios seen in positive control worms (7.2) than to the pure quantum dots (1.8), which implies that quantum dots are taken up predominantly in the degraded form. The results suggest that chemical modification of quantum dots to protect them from environmental degradation could potentially reduce bioaccumulation of the nanoparticles by earthworms. PMID:23417745

  5. Microcystin-LR bioaccumulation and depuration kinetics in lettuce and arugula: Human health risk assessment.

    Science.gov (United States)

    Cordeiro-Araújo, Micheline Kézia; Chia, Mathias Ahii; Arruda-Neto, João Dias de Toledo; Tornisielo, Valdemar Luiz; Vilca, Franz Zirena; Bittencourt-Oliveira, Maria do Carmo

    2016-10-01

    Microcystin-LR (MC-LR) is one of the most toxic and common microcystins (MCs) variant found in aquatic ecosystems. Little is known about the possibility of recovering microcystins contaminated agricultural crops. The objectives of this study were to determine the bioaccumulation and depuration kinetics of MC-LR in leaf tissues of lettuce and arugula, and estimate the total daily intake (ToDI) of MC-LR via contaminated vegetables by humans. Arugula and lettuce were irrigated with contaminated water having 5 and 10μgL(-1) of MC-LR for 7days (bioaccumulation), and subsequently, with uncontaminated water for 7days (depuration). Quantification of MC-LR was performed by LC-MS/MS. The one-compartment biokinetic model was employed for MC-LR bioaccumulation and depuration data analysis. MC-LR was only accumulated in lettuce. After 7days of irrigation with uncontaminated water, over 25% of accumulated MC-LR was still retained in leaf tissues of plants treated with 10μgL(-1) MC-LR. Total daily toxin intake by adult consumers (60kg-bw) exceeded the 0.04μgMC-LRkg(-1) limit recommended by WHO. Bioaccumulation was found to be linearly proportional to the exposure concentration of the toxin, increasing over time; and estimated to become saturated after 30days of uninterrupted exposure. On the other hand, MC-LR depuration was less efficient at higher exposure concentrations. This is because biokinetic half-life calculations gave 2.9 and 3.7days for 5 and 10μgL(-1) MC-LR treatments, which means 29-37days are required to eliminate the toxin. For the first time, our results demonstrated the possibility of MC-LR decontamination of lettuce plants.

  6. TOTAL MERCURY (HgT) BIOACCUMULATION AND FISH FOOD HABITS IN NEGRO RIVER BASIN, AMAZON, BRAZIL

    OpenAIRE

    Jean Louchard Ferreira Soares; Ynglea Georgina de Freitas Goch; José Reinaldo Pacheco Peleja; Bruce Rider Forsberg; Edivaldo Júnior de Souza Lemos; Otávio Peleja de Sousa

    2016-01-01

    In the Amazon, the fish is the main nutritional source for the riverine. Thus, fish have been commonly used in environmental monitoring work to be good biomonitors. This study analyzed the total mercury concentration (THg) in fish of different species and feeding habits in order to investigate the existence of bioaccumulation in species in the basin of the Negro river and verify that the THg levels found are in accordance with the stipulated limit for consumption human. Sampling points were d...

  7. Impact of biodegradation on the potential bioaccumulation and toxicity of refinery effluents.

    Science.gov (United States)

    Leonards, Pim E G; Postma, Jaap F; Comber, Mike; Whale, Graham; Stalter, George

    2011-10-01

    Whole effluent assessments (WEA) are being investigated as potential tools for controlling aqueous industrial discharges and minimizing environmental impact. The present study investigated how toxicity and the presence of potentially bioaccumulative substances altered when refinery effluents were subjected to biodegradation tests. Three petrochemical effluents were assessed, two freshwater and one saline, and subjected to two different types of biodegradation tests, resembling either a ready style (dissolved organic carbon (DOC)-die away) or an inherent style (Zahn-Wellens) test and the toxicity and potential to bioaccumulate parameters were re-analysed during and after biodegradation. A high proportion of the potentially bioaccumulative substances (PBS) in these effluents was easily biodegradable. Biodegradation not only lowered the PBS concentration but also toxicity. Appropriate controls are required however, as some increases in toxicity were observed after 4 h. In the present study, six other petrochemical effluents were also assessed for their PBS content and toxicity to increase the understanding of the relationship between PBS and toxicity. The results showed that the PBS concentrations in these samples were lower than the estimated benchmarks of acute toxicity for algae, fish and crustacean, although two samples were above the critical PBS values for chronic narcotic toxicity for Daphnia magna, which support the assumption that narcotic effects are mainly responsible for the observed toxicity in refinery effluents. It can be concluded that for facilities processing petroleum products that the measurement of PBS is a suitable surrogate for toxicity tests at the screening stage. Finally, the combination of persistency, bioaccumulation, and toxicity tests was shown to have additional value compared to an approach using only toxicity tests. PMID:21796668

  8. Feeding reduces waterborne Cu bioaccumulation in a marine rabbitfish Siganus oramin.

    Science.gov (United States)

    Guo, Zhiqiang; Zhang, Wei; Du, Sen; Zhou, Yanyan; Gao, Na; Zhang, Li; Green, Iain

    2016-01-01

    Waterborne metal uptake has been extensively studied and dietary metal assimilation is increasingly recognized in fish, whilst the interaction between the two uptake routes is largely overlooked. This study compared the waterborne Cu bioaccumulation ((65)Cu as tracer) in a juvenile rabbitfish at different feeding regimes (starvation (SG), feeding normal diet (NDG) or diet supplemented with extra Cu (DCG)) to test the hypothesis that feeding can influence waterborne metal uptake in marine fish. NDG and DCG diet was fed as a single meal and then all fish were exposed to waterborne (65)Cu for 48 h, during which the time course sampling was conducted to determine (65)Cu bioaccumulation, chyme flow and dietary Cu assimilation. The results revealed that SG fish accumulated the highest (65)Cu, followed by NDG (61% of SG), whilst DCG fish accumulated the lowest (65)Cu (34% of SG). These results suggested a protective effect of feeding against waterborne Cu bioaccumulation. This effect was most notable between 10 min and 16 h when there was chyme in gastrointestinal tract (GT). Dietary Cu assimilation mainly occurred before 16 h after feeding. Waterborne (65)Cu influx rate in the GT was positively correlated with (65)Cu contents of chyme in NDG, whereas it was largely negatively correlated with (65)Cu contents of chyme in DCG. The waterborne Cu uptake in the GT was mainly influenced by the chyme flow and dietary Cu assimilation. Overall, our findings suggested that feeding has an important effect on waterborne metal uptake and that both the feeding status of the fish and the relative metal exposure through water and food should be considered in prediction of the metal bioaccumulation and biomonitoring programs. PMID:26552536

  9. Microcystin-LR bioaccumulation and depuration kinetics in lettuce and arugula: Human health risk assessment.

    Science.gov (United States)

    Cordeiro-Araújo, Micheline Kézia; Chia, Mathias Ahii; Arruda-Neto, João Dias de Toledo; Tornisielo, Valdemar Luiz; Vilca, Franz Zirena; Bittencourt-Oliveira, Maria do Carmo

    2016-10-01

    Microcystin-LR (MC-LR) is one of the most toxic and common microcystins (MCs) variant found in aquatic ecosystems. Little is known about the possibility of recovering microcystins contaminated agricultural crops. The objectives of this study were to determine the bioaccumulation and depuration kinetics of MC-LR in leaf tissues of lettuce and arugula, and estimate the total daily intake (ToDI) of MC-LR via contaminated vegetables by humans. Arugula and lettuce were irrigated with contaminated water having 5 and 10μgL(-1) of MC-LR for 7days (bioaccumulation), and subsequently, with uncontaminated water for 7days (depuration). Quantification of MC-LR was performed by LC-MS/MS. The one-compartment biokinetic model was employed for MC-LR bioaccumulation and depuration data analysis. MC-LR was only accumulated in lettuce. After 7days of irrigation with uncontaminated water, over 25% of accumulated MC-LR was still retained in leaf tissues of plants treated with 10μgL(-1) MC-LR. Total daily toxin intake by adult consumers (60kg-bw) exceeded the 0.04μgMC-LRkg(-1) limit recommended by WHO. Bioaccumulation was found to be linearly proportional to the exposure concentration of the toxin, increasing over time; and estimated to become saturated after 30days of uninterrupted exposure. On the other hand, MC-LR depuration was less efficient at higher exposure concentrations. This is because biokinetic half-life calculations gave 2.9 and 3.7days for 5 and 10μgL(-1) MC-LR treatments, which means 29-37days are required to eliminate the toxin. For the first time, our results demonstrated the possibility of MC-LR decontamination of lettuce plants. PMID:27267723

  10. Heavy metals toxicity and bioaccumulation in vegetables from potentially polluted area

    OpenAIRE

    Balabanova, Biljana; Stafilov, Trajče; Baceva, Katerina; Vuckovic, Ivana

    2013-01-01

    Food safety and quality are a major public concern worldwide, regarding the risk associated with consumption of food stuffs contaminated with heavy metals as toxins. The levels of 8 elements contents were determined in various vegetables [garlic (Allium sativum), onion (Allium cepa) and parsley (Petroselinum crispum)], cultivated around copper mine environ. Bioaccumulation and mobility of heavy metals were determinate with three soil extraction methods: in 0.1 M HCl; in H2O and in a mixed buf...

  11. The bioaccumulation of persistent organic pollutants in marine species from Irish and surrounding waters

    OpenAIRE

    McHugh, Brendan

    2007-01-01

    The presence of anthropogenic pollutants throughout all compartments of the marine environment have been of international concern for a number of decades. While a great number of datasets documenting “absolute” concentrations of persistent organic pollutants in a variety of marine biota are available, bioaccumulation, biomagnification and the fate of these compounds in the marine food web or marine ecosystem is often not possible. This thesis reports various analytical methodologies employed ...

  12. Mercury bioaccumulation and trophic transfer in sympatric snapper species from the Gulf of Mexico.

    Science.gov (United States)

    Bank, Michael S; Chesney, Edward; Shine, James P; Maage, Amund; Senn, David B

    2007-10-01

    Consumption of marine fish is a major route of toxic methyl mercury (MeHg) exposure to ocean apex predators and human populations. Here we explore the influence of trophic structure on total mercury (Hg) accumulation in red snapper (RS, Lutjanus campechanus) and gray snapper (GS, Lutjanus griseus) from the coastal Louisiana region of the Gulf of Mexico, west of the Mississippi River. The objectives of this investigation were to: (1) determine the effectiveness of the use of offshore recreational fishing charter boats and marinas as sources of fish samples and (2) compare species differences in Hg bioaccumulation, trophic position, and carbon sources. Our data show that length-normalized Hg concentrations (> or = 97% as MeHg in tissue of both species) were 230% greater in GS in comparison to RS collected from the same general area. Stable C and N isotope signatures (delta15N and delta13C) indicate that GS occupy a slightly higher trophic position (approximately 30% of one trophic position higher) on the Gulf food web in comparison to RS and that GS appear to incorporate higher trophic positioned prey, continually and at smaller sizes. Mercury was strongly correlated with combined delta15N and delta13C in pooled species data, arguing that most of the substantial difference in Hg bioaccumulation between RS and GS can be explained by modest differences in their trophic position and, to a lesser degree, carbon sources, which had low variation and high overlap among species. These observations demonstrate that even minor to moderate differences in trophic position and food habits in sympatric species can create relatively large differences in bioaccumulation regimes and underscores the importance of quantitative characterization of trophic structure in marine MeHg bioaccumulation studies. PMID:17974344

  13. Predicting the bioaccumulation of polyaromatic hydrocarbons and polychlorinated biphenyls in benthic animals in sediments.

    Science.gov (United States)

    Tuikka, A I; Leppänen, M T; Akkanen, J; Sormunen, A J; Leonards, P E G; van Hattum, B; van Vliet, L A; Brack, W; Smedes, F; Kukkonen, J V K

    2016-09-01

    There were two main objectives in this study. The first was to compare the accuracy of different prediction methods for the chemical concentrations of polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the organism, based on the measured chemical concentrations existing in sediment dry matter or pore water. The predicted tissue concentrations were compared to the measured ones after 28-day laboratory test using oligochaeta worms (Lumbriculus variegatus). The second objective was to compare the bioaccumulation of PAHs and PCBs in the laboratory test with the in situ bioaccumulation of these compounds. Using the traditional organic carbon-water partitioning model, tissue concentrations were greatly overestimated, based on the concentrations in the sediment dry matter. Use of an additional correction factor for black carbon with a two-carbon model, significantly improved the bioaccumulation predictions, thus confirming that black carbon was important in binding the chemicals and reducing their accumulation. The predicted PAH tissue concentrations were, however, high compared to the observed values. The chemical concentrations were most accurately predicted from their freely dissolved pore water concentrations, determined using equilibrium passive sampling. The patterns of PCB and PAH accumulation in sediments for laboratory-exposed L. variegatus were similar to those in field-collected Lumbriculidae worms. Field-collected benthic invertebrates and L. variegatus accumulated less PAHs than PCBs with similar lipophilicity. The biota to sediment accumulation factors of PAHs tended to decrease with increasing sediment organic carbon normalized concentrations. The presented data yields bioconcentration factors (BCF) describing the chemical water-lipid partition, which were found to be higher than the octanol-water partition coefficients, but on a similar level with BCFs drawn from relevant literature. In conclusion, using the two-carbon model method

  14. Bioaccumulation of gamma emitting radionuclides in red algae from the Baltic Sea under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Tamara Zalewska

    2011-06-01

    Full Text Available The bioaccumulation ability of radionuclides 51Cr, 54Mn, 57Co, 60Co, 65Zn, 85Sr, 109Cd, 110mAg, 113Sn, 137Cs and 241Am in two red algae species from the southern Baltic Sea - Polysiphonia fucoides and Furcellaria lumbricalis - was determined under laboratory conditions. P. fucoides demonstrated better bioaccumulative properties towards most of the investigated radionuclides. As a result, P. fucoides can be recommended as a good bioindicator of radioactive environmental pollution. The bioaccumulation of radionuclides in F. lumbricalis was studied during an extended laboratory experiment. The initial extensive uptake of radioisotopes was followed by the rapid removal of cations; in general, concentrations tended to decrease with time. 137Cs displayed a different behaviour, its concentration in the algae increasing over time mainly due to its large ion radius; this is a factor that could be responsible for the stronger mechanical and chemical bonding of Cs+ and that could hamper the movement of ions in both directions.

  15. Mercury contamination in deposited dust and its bioaccumulation patterns throughout Pakistan.

    Science.gov (United States)

    Eqani, Syed Ali Musstjab Akber Shah; Bhowmik, Avit Kumar; Qamar, Sehrish; Shah, Syed Tahir Abbas; Sohail, Muhammad; Mulla, Sikandar I; Fasola, Mauro; Shen, Heqing

    2016-11-01

    Mercury (Hg) contamination of environment is a major threat to human health in developing countries like Pakistan. Human populations, particularly children, are continuously exposed to Hg contamination via dust particles due to the arid and semi-arid climate. However, a country wide Hg contamination data for dust particles is lacking for Pakistan and hence, human populations potentially at risk is largely unknown. We provide the first baseline data for total mercury (THg) contamination into dust particles and its bioaccumulation trends, using scalp human hair samples as biomarker, at 22 sites across five altitudinal zones of Pakistan. The human health risk of THg exposure via dust particles as well as the proportion of human population that are potentially at risk from Hg contamination were calculated. Our results indicated higher concentration of THg in dust particles and its bioaccumulation in the lower Indus-plain agricultural and industrial areas than the other areas of Pakistan. The highest THg contamination of dust particles (3000ppb) and its bioaccumulation (2480ppb) were observed for the Lahore district, while the highest proportion (>40%) of human population was identified to be potentially at risk from Hg contamination from these areas. In general, children were at higher risk of Hg exposure via dust particles than adults. Regression analysis identified the anthropogenic activities, such as industrial and hospital discharges, as the major source of Hg contamination of dust particles. Our results inform environmental management for Hg control and remediation as well as the disease mitigation on potential hotspots.

  16. Coupled mother-child model for bioaccumulation of POPs in nursing infants

    Energy Technology Data Exchange (ETDEWEB)

    Trapp, Stefan [Technical University of Denmark, Department of Environmental Engineering, Bygningstorvet 115, DK-2800 Kongens Lyngby (Denmark)], E-mail: stt@env.dtu.dk; Ma Bomholtz, Li [Technical University of Denmark, Department of Environmental Engineering, Bygningstorvet 115, DK-2800 Kongens Lyngby (Denmark); Legind, Charlotte N. [Technical University of Denmark, Department of Environmental Engineering, Bygningstorvet 115, DK-2800 Kongens Lyngby (Denmark); Department of Agricultural Sciences, Faculty of Life Sciences, University of Copenhagen, Hojbakkegard Alle 13, DK-2630 Taastrup (Denmark)

    2008-11-15

    Bioaccumulation of persistent organic pollutants (POPs) leads to high levels in human milk and high doses of POPs for nursing infants. This is currently not considered in chemical risk assessment. A coupled model for bioaccumulation of organic chemicals in breast-feeding mother and nursing infant was developed and tested for a series of organic compounds. The bioaccumulation factors (BAFs) in mother, breast milk and child were predicted to vary with log K{sub OW} and, for volatile compounds, with K{sub AW} and concentration in air. The concentrations of POPs in the infant body increase the first half year to about factor 3 above mother and decline thereafter to lower levels. The predicted results are close to empirical data and to an empirical regression. The new mother-child model is compact due to its easy structure and the analytical matrix solution. It could be added to existing exposure and risk assessment systems, such as EUSES. - This paper addresses a model for accumulation of organic compounds by mother and breast-fed infant, applicable for exposure assessment within larger frameworks.

  17. Capability of pentavalent arsenic bioaccumulation and biovolatilization of three fungal strains under laboratory conditions

    Energy Technology Data Exchange (ETDEWEB)

    Su, Shiming; Li, Lianfang; Bai, Lingyu; Zhang, Yanrong [Key Laboratory of Agro-Environment and Climate Change, Chinese Academy of Agricultural Sciences, Beijing (China); Jiang, Xiliang [Key Laboratory for Biological Control, Chinese Academy of Agricultural Sciences, Beijing (China); Zeng, Xibai

    2010-03-15

    In order to control and remediate arsenic (As) contaminated soil, sediment or water, fungi are used to investigate their potential accumulation and volatilization of As. In this study, after cultivation for 2 days, the dry weights of mycelia for Trichoderma asperellum, Fusarium oxysporum and Penicillium janthinellum all show an increased trend when the As(V) concentration ranges from 0-50, 0-50, 0-80 mg/L, respectively. When the culture system is loaded with 2500 {mu}g As(V), which represents 50 mg/L As, and cultivated for 5 days, P. janthinellum presents the highest efficiency of 87.0 {mu}g/g for As bioaccumulation, and the order of the efficiency for As bioaccumulation is P. janthinellum > T. asperellum > F. oxysporum. However, the order of the amount of volatilized As is F. oxysporum > P. janthinellum > T. asperellum, and the highest amount of volatilized As is observed for F. oxysporum at 181.0 {mu}g. Thus, the ability of As bioaccumulation and biovolatilization for T. asperellum and P. janthinellum is reported for the first time in this study. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  18. Bioaccumulation of microcystins in invasive bivalves: A case study from the boreal lagoon ecosystem

    Directory of Open Access Journals (Sweden)

    Aistė Paldavičienė

    2015-01-01

    Full Text Available In the current study we present the first report on the bioaccumulation of microcystins (MC in zebra mussel Dreissena polymorpha from the eutrophic brackish water Curonian Lagoon. The bioaccumulation capacity was related to age structure of mussels and ambient environmental conditions. We also discuss the relevant implications of these findings for biomonitoring of toxic cyanobacteria blooms in the Curonian Lagoon and potential consequences for D. polymorpha cultivation activities considered for the futures as remediation measure. Samples for the analysis were collected twice per year, in June and September, in 2006, 2007 and 2008, from two sites within the littoral zone of the lagoon. The highest microcystin concentrations were measured in mussels larger than 30 mm length and sampled in 2006 (when a severe toxic cyanobacteria bloom occurred. In the following years, a consistent reduction in bioaccumulated MC concentration was noticed. However, certain amount of microcystin was recorded in mussel tissues in 2007 and 2008, when no cyanotoxins were reported in the phytoplankton. Considering high depuration rates and presence of cyanotoxins in the bottom sediments well after the recorded toxic blooms, we assume mechanism of secondary contamination when microcystin residuals could be uptaken by mussels with resuspended sediment particles.

  19. Mercury contamination in deposited dust and its bioaccumulation patterns throughout Pakistan.

    Science.gov (United States)

    Eqani, Syed Ali Musstjab Akber Shah; Bhowmik, Avit Kumar; Qamar, Sehrish; Shah, Syed Tahir Abbas; Sohail, Muhammad; Mulla, Sikandar I; Fasola, Mauro; Shen, Heqing

    2016-11-01

    Mercury (Hg) contamination of environment is a major threat to human health in developing countries like Pakistan. Human populations, particularly children, are continuously exposed to Hg contamination via dust particles due to the arid and semi-arid climate. However, a country wide Hg contamination data for dust particles is lacking for Pakistan and hence, human populations potentially at risk is largely unknown. We provide the first baseline data for total mercury (THg) contamination into dust particles and its bioaccumulation trends, using scalp human hair samples as biomarker, at 22 sites across five altitudinal zones of Pakistan. The human health risk of THg exposure via dust particles as well as the proportion of human population that are potentially at risk from Hg contamination were calculated. Our results indicated higher concentration of THg in dust particles and its bioaccumulation in the lower Indus-plain agricultural and industrial areas than the other areas of Pakistan. The highest THg contamination of dust particles (3000ppb) and its bioaccumulation (2480ppb) were observed for the Lahore district, while the highest proportion (>40%) of human population was identified to be potentially at risk from Hg contamination from these areas. In general, children were at higher risk of Hg exposure via dust particles than adults. Regression analysis identified the anthropogenic activities, such as industrial and hospital discharges, as the major source of Hg contamination of dust particles. Our results inform environmental management for Hg control and remediation as well as the disease mitigation on potential hotspots. PMID:27372253

  20. Distribution of total and methylmercury in different ecosystem compartments in the Everglades: Implications for mercury bioaccumulation

    International Nuclear Information System (INIS)

    We analyzed Hg species distribution patterns among ecosystem compartments in the Everglades at the landscape level in order to explore the implications of Hg distribution for Hg bioaccumulation and to investigate major biogeochemical processes that are pertinent to the observed Hg distribution patterns. At an Everglade-wide scale, THg concentrations were significantly increased in the following order: periphyton < flocculent material (floc) < soil, while relatively high MeHg concentrations were observed in floc and periphyton. Differences in the methylation potential, THg concentration, and MeHg retention capacity could explain the relatively high MeHg concentrations in floc and periphyton. The MeHg/THg ratio was higher for water than for soil, floc, or periphyton probably due to high dissolved organic carbon (DOC) concentrations present in the Everglades. Mosquitofish THg positively correlated with periphyton MeHg and DOC-normalized water MeHg. The relative THg and MeHg distribution patterns among ecosystem compartments favor Hg bioaccumulation in the Everglades. - Mercury bioaccumulation in Florida Everglades is related to the distribution patterns of mercury species among ecosystem compartments

  1. Distribution of total and methylmercury in different ecosystem compartments in the Everglades: Implications for mercury bioaccumulation

    Energy Technology Data Exchange (ETDEWEB)

    Liu Guangliang [Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199 (United States); Southeast Environmental Research Center, Florida International University, Miami, FL 33199 (United States); Cai Yong [Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199 (United States); Southeast Environmental Research Center, Florida International University, Miami, FL 33199 (United States)], E-mail: cai@fiu.edu; Philippi, Thomas [Department of Biological Sciences, Florida International University, Miami, FL 33199 (United States); Kalla, Peter; Scheidt, Daniel [US Environmental Protection Agency, Region 4, Science and Ecosystem Support Division, Athens, GA 30605 (United States); Richards, Jennifer [Department of Biological Sciences, Florida International University, Miami, FL 33199 (United States); Scinto, Leonard [Southeast Environmental Research Center, Florida International University, Miami, FL 33199 (United States); Appleby, Charlie [US Environmental Protection Agency, Region 4, Science and Ecosystem Support Division, Athens, GA 30605 (United States)

    2008-05-15

    We analyzed Hg species distribution patterns among ecosystem compartments in the Everglades at the landscape level in order to explore the implications of Hg distribution for Hg bioaccumulation and to investigate major biogeochemical processes that are pertinent to the observed Hg distribution patterns. At an Everglade-wide scale, THg concentrations were significantly increased in the following order: periphyton < flocculent material (floc) < soil, while relatively high MeHg concentrations were observed in floc and periphyton. Differences in the methylation potential, THg concentration, and MeHg retention capacity could explain the relatively high MeHg concentrations in floc and periphyton. The MeHg/THg ratio was higher for water than for soil, floc, or periphyton probably due to high dissolved organic carbon (DOC) concentrations present in the Everglades. Mosquitofish THg positively correlated with periphyton MeHg and DOC-normalized water MeHg. The relative THg and MeHg distribution patterns among ecosystem compartments favor Hg bioaccumulation in the Everglades. - Mercury bioaccumulation in Florida Everglades is related to the distribution patterns of mercury species among ecosystem compartments.

  2. Comparative toxicity and bioaccumulation of fenvalerate and esfenvalerate to earthworm Eisenia fetida.

    Science.gov (United States)

    Ye, Xiaoqing; Xiong, Kang; Liu, Jing

    2016-06-01

    More attention is being paid to the enantioselective toxicity of chiral pesticides. However, limited investigations have been done to assess the ecological risks of chiral pesticides to soil community. Fenvalerate (FV), an extensively used synthetic pyrethroid, is a typical chiral pesticide. The most insecticidally active enantiomer of FV, esfenvalerate (ESFV), also has been marketed and widely used. In this study, the toxicological sensitivity and bioaccumulation of FV and ESFV in earthworms were assessed. The results showed that FV was less toxic than ESFV, but more accumulated in earthworms. ESFV was at least 4 times more toxic to earthworms than FV according to the filter paper contact toxicity test and the artificial soil test. Enantiospecific induction in oxidative stress was observed in earthworms exposed to FV and ESFV. The bioaccumulation of FV and ESFV in earthworm tissues was also enantioselective, preferentially accumulating FV. The uptake of ESFV by earthworms was lower than that of FV, so that the biota to soil accumulation factor (BSAF) value of ESFV was lower than that of FV. Our findings suggest that the enantioselective toxicity and bioaccumulation of chiral pesticides should be considered for evaluating ecological risks of these compounds to non-target organisms. PMID:26900980

  3. Bioaccumulation and biomagnification potential of pharmaceuticals with a focus to the aquatic environment.

    Science.gov (United States)

    Zenker, Armin; Cicero, Maria Rita; Prestinaci, Francesca; Bottoni, Paola; Carere, Mario

    2014-01-15

    Pharmaceuticals, among the emerging contaminants, are one of the most relevant groups of substances in aquatic ecosystems due to universal use, their chemico-physical properties and known mode of action in aquatic organisms at low concentrations. After administration many drugs and their transformation products are only retained to some extent in wastewater treatment plants therefore entering the aquatic environment in considerable high amounts. The yearly consumption to treat human and animal diseases, also in livestock and aquaculture was estimated to be hundred thousands tons per year leading to high concentrations in surface water of developed countries. Mostly, pharmaceutical residues in effluents of wastewater treatment plants or in the water column of surface waters have been reported, but data about concentrations in the aquatic biota, partitioning of pharmaceuticals to biosolids, soils, and sediments and the bioaccumulation properties are often lacking. Chronic and subtle effects can be expected when aquatic organisms are long term exposed by pseudo-persistent, persistent and accumulative compounds. This review aims to summarize the current state of research about the fate of pharmaceuticals regarding bioconcentration, bioaccumulation and potential biomagnification in aquatic ecosystems. More comprehensive approaches for the evaluation of environmental (ERA) and human health risk assessment (HRA) are included and analytical methods required to detect bioaccumulation of pharmaceuticals are discussed.

  4. Bioaccumulation of human pharmaceuticals in fish across habitats of a tidally influenced urban bayou.

    Science.gov (United States)

    Du, Bowen; Haddad, Samuel P; Luek, Andreas; Scott, W Casan; Saari, Gavin N; Burket, S Rebekah; Breed, Christopher S; Kelly, Martin; Broach, Linda; Rasmussen, Joseph B; Chambliss, C Kevin; Brooks, Bryan W

    2016-04-01

    Though pharmaceuticals and other contaminants of emerging concern are increasingly observed in inland water bodies, the occurrence and bioaccumulation of pharmaceuticals in estuaries and coastal ecosystems are poorly understood. In the present study, bioaccumulation of select pharmaceuticals and other contaminants of emerging concern was examined in fish from Buffalo Bayou, a tidally influenced urban ecosystem that receives effluent from a major (∼200 million gallons per day) municipal wastewater treatment plant in Houston, Texas, USA. Using isotope dilution liquid chromatography-tandem mass spectrometry, various target analytes were observed in effluent, surface water, and multiple fish species. The trophic position of each species was determined using stable isotope analysis. Fish tissue levels of diphenhydramine, which represented the only pharmaceutical detected in all fish species, did not significantly differ between freshwater and marine fish predominantly inhabiting benthic habitats; however, saltwater fish with pelagic habitat preferences significantly accumulated diphenhydramine to the highest levels observed in the present study. Consistent with previous observations from an effluent-dependent freshwater river, diphenhydramine did not display trophic magnification, which suggests site-specific, pH-influenced inhalational uptake to a greater extent than dietary exposure in this tidally influenced urban ecosystem. The findings highlight the importance of understanding differential bioaccumulation and risks of ionizable contaminants of emerging concern in habitats of urbanizing coastal systems. PMID:26587912

  5. Bioaccumulation of Multiwall Carbon Nanotubes in Tetrahymena thermophila by Direct Feeding or Trophic Transfer.

    Science.gov (United States)

    Mortimer, Monika; Petersen, Elijah J; Buchholz, Bruce A; Orias, Eduardo; Holden, Patricia A

    2016-08-16

    Consumer goods contain multiwall carbon nanotubes (MWCNTs) that could be released during product life cycles into the environment, where their effects are uncertain. Here, we assessed MWCNT bioaccumulation in the protozoan Tetrahymena thermophila via trophic transfer from bacterial prey (Pseudomonas aeruginosa) versus direct uptake from growth media. The experiments were conducted using (14)C-labeled MWCNT ((14)C-MWCNT) doses at or below 1 mg/L, which proved subtoxic since there were no adverse effects on the growth of the test organisms. A novel contribution of this study was the demonstration of the ability to quantify MWCNT bioaccumulation at low (sub μg/kg) concentrations accomplished by employing accelerator mass spectrometry (AMS). After the treatments with MWCNTs at nominal concentrations of 0.01 mg/L and 1 mg/L, P. aeruginosa adsorbed considerable amounts of MWCNTs: (0.18 ± 0.04) μg/mg and (21.9 ± 4.2) μg/mg bacterial dry mass, respectively. At the administered MWCNT dose of 0.3 mg/L, T. thermophila accumulated up to (0.86 ± 0.3) μg/mg and (3.4 ± 1.1) μg/mg dry mass by trophic transfer and direct uptake, respectively. Although MWCNTs did not biomagnify in the microbial food chain, MWCNTs bioaccumulated in the protozoan populations regardless of the feeding regime, which could make MWCNTs bioavailable for organisms at higher trophic levels.

  6. Kinetic of benzotriazole oxidation by ozone and hydroxyl radical.

    Science.gov (United States)

    Vel Leitner, Nathalie Karpel; Roshani, Babak

    2010-03-01

    Ozonation experiments were performed in batch reactors in order to determine the rate constants for the reaction of molecular ozone and OH radicals with benzotriazole (BT) at different pHs. The first group of ozonation experiments was carried out for the determination of the rate constant for the direct reactions between ozone and BT. Two different kinetic models were used for the determination of kinetic rate constants: (i) the log-reduction of BT with ozone in excess, (ii) the competition kinetic model. The second-order rate constants for BT with molecular ozone were determined to be 36.4+/-3.8M(-1) s(-1) and 18.4+/-0.8M(-1) s(-1) at pH 2 from the two methods respectively. With the competition method, the value at pH 5 was found to be 22.0+/-2.0M(-1) s(-1). In a following stage, the reaction of BT with OH radicals was investigated at pH values ranging from 2 to 10.2. Using a method involving two probe compounds during the ozonation, the second-order rate constants of the BT reaction with hydroxyl radicals were determined. The rate constants were found to vary from 6.2x10(9)M(-1) s(-1) at pH 10.2 to 1.7x10(10)M(-1) s(-1) at pH 2.

  7. Development of competitive immunoassays to hydroxyl containing fungicide metabolites.

    Science.gov (United States)

    Gough, Kevin C; Jarvis, Shila; Maddison, Ben C

    2011-01-01

    This paper describes the isolation of monoclonal antibodies and the development of competitive immunoassays to pesticide metabolites of the fungicides imazalil, carbendazim and thiabendazole. The metabolite specific hydroxyl residues were used as the reactive group with which to link the metabolite to the carrier proteins Keyhole Limpet Haemocyanin (KLH) and Bovine Serum Albumin (BSA). In each case immune responses in mice were raised and monoclonal antibodies were produced. Antibodies were developed into competitive ELISAs to the appropriate metabolite. The antibody raised to a metabolite of imazalil was optimised into a competitive ELISA format which had an assay IC50 of 7.5 μg/L and a limit of detection (LOD) of 1.1 μg/L. A single antibody isolated against the metabolite of carbendazim had assay IC50s of 3.2 and 2.7 μg/L for the metabolites of carbendazim and thiabendazole respectively with an LOD of 0.38 μg/L for both. These sensitive immunoassays may have application in the monitoring of human exposure to these fungicide residues either by occupational or non-occupational routes.

  8. SERCA overexpression reduces hydroxyl radical injury in murine myocardium.

    Science.gov (United States)

    Hiranandani, Nitisha; Bupha-Intr, Tepmanas; Janssen, Paul M L

    2006-12-01

    Hydroxyl radicals (*OH) are involved in the pathogenesis of ischemia-reperfusion injury and are observed in clinical situations, including acute heart failure, stroke, and myocardial infarction. Acute transient exposure to *OH causes an intracellular Ca(2+) overload and leads to impaired contractility. We investigated whether upregulation of sarcoplasmic reticulum Ca(2+)-ATPase function (SERCA) can attenuate *OH-induced dysfunction. Small, contracting right ventricular papillary muscles from wild-type (WT) SERCA1a-overexpressing (transgenic, TG) and SERCA2a heterogeneous knockout (HET) mice were directly exposed to *OH. This brief 2-min exposure led to a transient elevation of diastolic force (F(dia)) and depression of developed force (F(dev)). In WT mice, F(dia) increased to 485 +/- 49% and F(dev) decreased to 11 +/- 3%. In sharp contrast, in TG mice F(dia) increased only to 241 +/- 17%, whereas F(dev) decreased only to 51 +/- 5% (P group. The results indicate that SERCA overexpression can reduce the *OH-induced contractile dysfunction in murine myocardium, whereas a reduced SR Ca(2+)-ATPase activity aggravates this injury. Loss of pPLB levels at Ser16 likely amplifies the differences observed in injury response.

  9. Hydroxyl radical formation in phagocytic cells of the rat.

    Science.gov (United States)

    Drath, D B; Karnovsky, M L; Huber, G L

    1979-01-01

    Polymorphonuclear leukocytes (PMN) and macrophages, harvested from the peritoneum and lung, release superoxide (O-.2) and hydrogen peroxide (H2O2) during phagocytosis. These two agents are thought to react with each other to produce a highly active oxidative substance known as hydroxyl radical (OH.). We present evidence suggesting that these radicals are generated by phagocytic cells of the rat. Our findings are based upon an assay where ethylene gas is generated from methional by the action of this radical. Ethylene generation was shown to be inhibited by superoxide dismutase, catalase, and scavengers of OH.. Of the cells examined, PMN generated the most ethylene from methional, exhibiting a fourfold increase during phagocytosis. Pulmonary and peritoneal macrophages caused smaller amounts of this gas to be formed. Regardless of cell type, an intact cell was required for ethylene generation. Zymosan appeared to be the most effective particle for all cells in ethylene formation from methional, although opsonization was critical only for PMN. Ethylene generation was dependent on cell concentration to an extent and increased with time. PMID:222719

  10. Single vs multi-level quenching of the hydroxyl airglow

    Science.gov (United States)

    Franzen, Christoph; Espy, Patrick J.; Hibbins, Robert; Djupvik, Anlaug Amanda

    2016-04-01

    The reaction in the upper mesosphere between atomic hydrogen and ozone results in hydroxyl (OH) that is produced in excited vibrational levels 6 through 9. The vibrationally excited OH radiates in a thin (~8 km thick) layer near 87 km, giving rise to the strong near infrared airglow emission that has been used for remote sensing of the mesopause region. The interpretation of the emission relies on accurate knowledge of the population and quenching of the upper states, and open questions remain as to whether the quenching takes place through single- or multi-quantum deactivation. Here we will demonstrate how high quality spectral observations of OH (9,7) and (8,6) airglow emissions are available as background measurements during standard K-band astronomical observations from the Nordic Optical Telescope (18°W, 29°N). These emissions have been analysed to ascertain the quenching of the upper vibrational populations. Together with a steady-state model of these emissions, an estimate of the ratio of single to multi-quantum quenching efficiency and the impact on the populations of the lower vibrational levels will be presented.

  11. Hydroxylated PCBs in abiotic environmental matrices. Precipitation and surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Darling, C.; Alaee, M.; Campbell, L.; Pacepavicius, G.; Ueno, D.; Muir, D. [National Water Research Institute, Burlington, ON (Canada)

    2004-09-15

    Hydroxylated PCBs (OH-PCBs) are of great interest environmentally because of their potential thyroidogenic effects. OH-PCBs can compete with thyroxine for binding sites on transthyretin, one of the three main thyroid hormone transport proteins in mammals1. The chemical structures of some OH-PCBs with a para OH group and adjacent chlorine atoms, particularly 4-OH-CB109, 4- OH-CB146, and 4-OH-CB187, share a similar structure to the thyroid hormones (T3 and T4), which have a para OH with adjacent iodine atoms. A number of OH-PCBs have been identified in the blood of humans and biota during the last 5 to 10 years, however, reports on the identity, presence and levels of OH-PCBs are limited. This presentation describes preliminary studies on the presence of OH-PCBs in abiotic samples and comparisons of congener patterns with biological samples. We have previously shown that OHPCBs were present in lake trout from the Great Lakes and nearby large lakes as well as in nearshore environments. We hypothesized that some of the OH-PCB present in fish might be from abiotic formation in water or the atmosphere, or from microbial oxidation of PCBs and/or deconjugation of PCB metabolites in waste treatment plants.

  12. Modelling , of Polyurethanes Based on Hydroxyl- Terminated Polybutadiene

    Directory of Open Access Journals (Sweden)

    Manohar Singh

    1998-04-01

    Full Text Available Forty formulations based on four different grades ofhydroxyl-terminated polybutadiene, HTPB(hydroxyl value 20- 40 mg KOHlg at r = [NCO] / [OH] values in the range 0.7 -1.0 with varyingamounts of trimethylol propane and butane diol and containing 86 per cent solid loading wereconsidered to test the applicability of a.-model of Marsh, et al. for prediction of the mechanicalproperties of composite solid propellants. Two network parameters, crosslink density (Ve andeffective chain length (LX, were calculated from the model. Tensile strength and modulus werecorrelated to Ve and elongation at break to LX. Using the correlations obtained from experimental dataat r< 0.8, mechanical properties of the various fonnulations were predicted. Good agreement betweenexperimental and predicted properties was obtained for fonnulations with modulus 10 KSC. Probablereasons for deviation observed at stoichiometric ratio r < 0.8 and low modulus values are discussed.Improved correlations between mechanical properties and network parameters, applicable over a widerange of fonnulations, were arrived at. The standard errors of prediction were found to be close to :+- 1 0-value of the measurement.

  13. Hydroxylation of methane through component interactions in soluble methane monooxygenases.

    Science.gov (United States)

    Lee, Seung Jae

    2016-04-01

    Methane hydroxylation through methane monooxygenases (MMOs) is a key aspect due to their control of the carbon cycle in the ecology system and recent applications of methane gas in the field of bioenergy and bioremediation. Methanotropic bacteria perform a specific microbial conversion from methane, one of the most stable carbon compounds, to methanol through elaborate mechanisms. MMOs express particulate methane monooxygenase (pMMO) in most strains and soluble methane monooxygenase (sMMO) under copper-limited conditions. The mechanisms of MMO have been widely studied from sMMO belonging to the bacterial multicomponent monooxygenase (BMM) superfamily. This enzyme has diiron active sites where different types of hydrocarbons are oxidized through orchestrated hydroxylase, regulatory and reductase components for precise control of hydrocarbons, oxygen, protons, and electrons. Recent advances in biophysical studies, including structural and enzymatic achievements for sMMO, have explained component interactions, substrate pathways, and intermediates of sMMO. In this account, oxidation of methane in sMMO is discussed with recent progress that is critical for understanding the microbial applications of C-H activation in one-carbon substrates. PMID:27033202

  14. Coumarin-fused coumarin: antioxidant story from N,N-dimethylamino and hydroxyl groups.

    Science.gov (United States)

    Xi, Gao-Lei; Liu, Zai-Qun

    2015-04-01

    Two coumarin skeletons can form chromeno[3,4-c]chromene-6,7-dione by sharing with the C ═ C in lactone. The aim of the present work was to explore the antioxidant effectiveness of the coumarin-fused coumarin via six synthetic compounds containing hydroxyl and N,N-dimethylamino as the functional groups. The abilities to quench 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS(+•)), 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical revealed that the rate constant for scavenging radicals was related to the amount of hydroxyl group in the scaffold of coumarin-fused coumarin. But coumarin-fused coumarin was able to inhibit DNA oxidations caused by (•)OH, Cu(2+)/glutathione (GSH), and 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH) even in the absence of hydroxyl group. In particular, a hydroxyl and an N,N-dimethylamino group locating at different benzene rings increased the inhibitory effect of coumarin-fused coumarin on AAPH-induced oxidation of DNA about 3 times higher than a single hydroxyl group, whereas N,N-dimethylamino-substituted coumarin-fused coumarin possessed high activity toward (•)OH-induced oxidation of DNA without the hydroxyl group contained. Therefore, the hydroxyl group together with N,N-dimethylamino group may be a novel combination for the design of coumarin-fused heterocyclic antioxidants.

  15. Methylmercury Bioaccumulation in Rice and Wetland Biota: employing integrated indices of processes that drive methylmercury risk

    Science.gov (United States)

    Eagles-Smith, C.; Ackerman, J.; Windham-Myers, L.; Fleck, J.

    2013-12-01

    Wetlands often are associated with elevated methylmercury (MeHg) production and food web bioaccumulation, making them potentially important sources of Hg to surrounding waters and to wetland-dependent fish and wildlife. However, the cycling of MeHg through wetlands can vary markedly with wetland type. Agricultural wetlands such as rice fields can exhibit particularly pronounced MeHg concentrations and bioaccumulation because their biogeochemical, hydrological, and ecological characteristics facilitate the conversion of inorganic mercury (Hg) to MeHg. Rice fields are characterized by a series of seasonal extreme wetting and drying cycles, sulfate-containing fertilizers, and high levels of labile organic carbon, all of which are key processes in the Hg cycle. Rice fields comprise approximately 20% of freshwater habitats and 11% of cultivated land area globally, providing critical wildlife habitat while offering substantial economic, human health, and ecosystem benefits. Thus, there is strong impetus to better understand the drivers of Hg cycling in rice fields and to develop useful management approaches for minimizing Hg risk associated with rice agriculture without compromising rice production. We examined the role of rice wetlands on MeHg bioaccumulation through foodwebs by employing biosentinel caged fish as integrators of MeHg cycling processes. With experimental field studies in California's Central Valley, we placed biosentinel fishes into nine rice wetlands that were subjected to three different harvest strategies, and into nine managed wetlands that encompassed three different hydrological regimes. We simultaneously measured a suite of biogeochemical processes in surface water, sediment, and pore water in order to link the response in fish Hg bioaccumulation with within-field processes that regulate MeHg cycling. Our preliminary results indicate that fish Hg concentrations were 1.6 times higher in rice wetlands than in managed wetlands. Additionally, fish Hg

  16. Hydroxyl radical oxidation of cylindrospermopsin (cyanobacterial toxin) and its role in the photochemical transformation.

    Science.gov (United States)

    Song, Weihua; Yan, Shuwen; Cooper, William J; Dionysiou, Dionysios D; O'Shea, Kevin E

    2012-11-20

    Cylindrospermopsin (CYN), an alkaloid guanidinium sulfated toxin, is produced by a number of cyanobacteria regularly found in lakes, rivers, and reservoirs. Steady-state and time-resolved radiolysis methods were used to determine reaction pathways and kinetic parameters for the reactions of hydroxyl radical with CYN. The absolute bimolecular reaction rate constant for the reaction of hydroxyl radical with CYN is (5.08 ± 0.16) × 10(9) M(-1) s(-1). Comparison of the overall reaction rate of CYN with hydroxyl radical with the individual reaction rate for addition to the uracil ring in CYN indicate the majority of the hydroxyl radicals (84%) react at the uracil functionality of CYN. Product analyses using liquid chromatography-mass spectrometry indicate the major products from the reaction of hydroxyl radical with CYN involve attack of hydroxyl radical at the uracil ring and hydrogen abstraction from the hydroxy-methine bridge linking the uracil ring to the tricyclic guanidine functionality. The role of hydroxyl radical initiated pathways in the natural organic matter (NOM) photosensitized transformation of CYN were evaluated. Scavenger and trapping experiments indicate that hydroxyl radical mediated transformations account for approximately ~70% of CYN destruction in surface waters under solar irradiation in the presence of NOM. The absence of solvent isotope effect indicates singlet oxygen does not play a significant role in the NOM sensitized transformation of CYN. The primary degradation pathways for HO• mediated and NOM photosensitized destruction of CYN involve destruction of the uracil ring. The fundamental kinetic parameters determined from these studies are critical for the accurate evaluation of hydroxyl-radical based technologies for the remediation of this problematic cyanotoxin in drinking water and important in the assessment of the environmental oxidative transformation of uracil based compounds. PMID:23082747

  17. Evaluation of the potential bioaccumulation ability of the blood cockle (Anadara granosa L.) for assessment of environmental matrices of mudflats.

    Science.gov (United States)

    Mirsadeghi, Seiedeh Aghileh; Zakaria, Mohamad Pauzi; Yap, Chee Kong; Gobas, Frank

    2013-06-01

    The spatial distribution of 19 polycyclic aromatic hydrocarbons (tPAHs) was quantified in aquacultures located in intertidal mudflats of the west coast of Peninsular Malaysia in order to investigate bioaccumulation of PAH in blood cockles, Anadara granosa (A. granosa). Fifty-four samples from environmental matrices and A. granosa were collected. The sampling locations were representative of a remote area as well as PAH-polluted areas. The relationship of increased background levels of PAH to anthropogenic PAH sources in the environment and their effects on bioaccumulation levels of A. granosa are investigated in this study. The levels of PAH in the most polluted station were found to be up to ten-fold higher than in remote areas in blood cockle. These high concentrations of PAHs reflected background contamination, which originates from distant airborne and waterborne transportation of contaminated particles. The fraction and source identification of PAHs, based on fate and transport considerations, showed a mix of petrogenic and pyrogenic sources. The relative biota-sediment accumulation factors (RBSAF), relative bioaccumulation factors from filtered water (RBAFw), and from suspended particulate matter (SPM) (RBAFSP) showed higher bioaccumulations of the lower molecular weight of PAHs (LMWs) in all stations, except Kuala Juru, which showed higher bioaccumulation of the higher molecular weight of PAHs (HMWs). Calculations of bioaccumulation factors showed that blood cockle can accumulate PAHs from sediment as well as water samples, based on the physico-chemical characteristics of habitat and behaviour of blood cockles. Correlations among concentrations of PAHs in water, SPM, sediment and A. granosa at the same sites were also found. Identification of PAH levels in different matrices showed that A. granosa can be used as a good biomonitor for LMW of PAHs and tPAHs in mudflats. Considering the toxicity and carcinogenicity of PAHs, the bioaccumulation by blood cockles

  18. Evaluation of the potential bioaccumulation ability of the blood cockle (Anadara granosa L.) for assessment of environmental matrices of mudflats.

    Science.gov (United States)

    Mirsadeghi, Seiedeh Aghileh; Zakaria, Mohamad Pauzi; Yap, Chee Kong; Gobas, Frank

    2013-06-01

    The spatial distribution of 19 polycyclic aromatic hydrocarbons (tPAHs) was quantified in aquacultures located in intertidal mudflats of the west coast of Peninsular Malaysia in order to investigate bioaccumulation of PAH in blood cockles, Anadara granosa (A. granosa). Fifty-four samples from environmental matrices and A. granosa were collected. The sampling locations were representative of a remote area as well as PAH-polluted areas. The relationship of increased background levels of PAH to anthropogenic PAH sources in the environment and their effects on bioaccumulation levels of A. granosa are investigated in this study. The levels of PAH in the most polluted station were found to be up to ten-fold higher than in remote areas in blood cockle. These high concentrations of PAHs reflected background contamination, which originates from distant airborne and waterborne transportation of contaminated particles. The fraction and source identification of PAHs, based on fate and transport considerations, showed a mix of petrogenic and pyrogenic sources. The relative biota-sediment accumulation factors (RBSAF), relative bioaccumulation factors from filtered water (RBAFw), and from suspended particulate matter (SPM) (RBAFSP) showed higher bioaccumulations of the lower molecular weight of PAHs (LMWs) in all stations, except Kuala Juru, which showed higher bioaccumulation of the higher molecular weight of PAHs (HMWs). Calculations of bioaccumulation factors showed that blood cockle can accumulate PAHs from sediment as well as water samples, based on the physico-chemical characteristics of habitat and behaviour of blood cockles. Correlations among concentrations of PAHs in water, SPM, sediment and A. granosa at the same sites were also found. Identification of PAH levels in different matrices showed that A. granosa can be used as a good biomonitor for LMW of PAHs and tPAHs in mudflats. Considering the toxicity and carcinogenicity of PAHs, the bioaccumulation by blood cockles

  19. Hydroxylation of the Herbicide Isoproturon by Fungi Isolated from Agricultural soil

    DEFF Research Database (Denmark)

    Rønhede, S.; Jensen, Bo; Rosendahl, Søren;

    2005-01-01

    )phenyl)-N',N'-dimethylurea. Bacterial metabolism of isoproturon has previously been shown to proceed by an initial demethylation to N-(4-isopropylphenyl)-N'-methylurea. In soils, however, hydroxylated metabolites have also been detected. In this study we identified fungi as organisms that potentially play a major role in the formation...... sp. strain Gr22 hydroxylated the molecule at the second position, yielding N-(4-(1-hydroxy-1-methylethyl)phenyl)-N',N'-dimethylurea. Hydroxylation was the dominant mode of isoproturon transformation in these fungi, although some cultures also produced traces of the N-demethylated metabolite N-(4...

  20. The stability of the hydroxylated (0001) surface of alpha-Al2O3

    DEFF Research Database (Denmark)

    Lodziana, Zbigniew; Nørskov, Jens Kehlet; Stoltze, Per

    2003-01-01

    Self-consistent density functional calculations of the hydroxylated (0001) corundum surfaces are presented. It is demonstrated that the hydroxylated surfaces are the most stable under most, but not all, conditions. Hydroxylation significantly lowers the surface free energy of alpha-alumina. The...... stability of the hydrated surface resolves the discrepancies between the morphology of the alpha-alumina (0001) surface observed under ultra-high vacuum, and at ambient conditions. A method for the calculation of the equilibrium surface stoichiometry is proposed. The proposed approach provides a valuable...

  1. Ginsenoside Rb1 directly scavenges hydroxyl radical and hypochlorous acid.

    Science.gov (United States)

    Lü, Jian-Ming; Weakley, Sarah M; Yang, Zhen; Hu, Ming; Yao, Qizhi; Chen, Changyi

    2012-01-01

    Reactive oxygen species (ROS) have been implicated in a variety of inflammatory diseases including cardiovascular disease (CVD), cancer, diabetes, Alzheimer's disease, autism, cataracts and aging. When endogenous mechanisms for the maintenance of redox homeostasis are overwhelmed, dietary intake of antioxidants contributes substantially to balancing the body's oxidant/antioxidant status. Ginsenosides are thought to be primarily responsible for the pharmacological effect of P. ginseng root extracts on oxidative stress and inflammation. However, little is known about the underlying antioxidant mechanisms of individual ginsenoside; specifically, the reactivity of ginsenoside Rb1 with ROS has not been well studied. We found that Rb1 can significantly and selectively reduce hydroxyl radical (●OH) and hypochlorous acid (HOCl), two of the strongest ROS, with unique molecular mechanisms in a cell-free system. Rb1 directly scavenges the ●OH and protects plasmid DNA from damage induced by ●OH. ●OH likely attacks the double bond on the side chain of Rb1 as well as hydrogen atoms adjacent to the -OH groups, including those of sugar moieties. Rb1 also shows a high reactivity to HOCl and effectively inhibits HOCl-induced tyrosine chlorination in a cell free system. HOCl is added to the double bond of Rb1; the -Cl group and -OH group of HOCl possibly bond at C-24 and C-25 of Rb1 based on the regioselectivity of Markovnikov's Rule. To our knowledge, this is the first demonstration that ginsenoside Rb1 scavenges HOCl and protects tyrosine from HOCl-induced chlorination. Thus, this study reveals unique antioxidant mechanisms of individual ginsenoside Rb1, which may contribute to the pharmacological effect of P. ginseng and to the development of effective strategies for clinical applications of ginsenosides.

  2. Production of Abundant Hydroxyl Radicals from Oxygenation of Subsurface Sediments.

    Science.gov (United States)

    Tong, Man; Yuan, Songhu; Ma, Sicong; Jin, Menggui; Liu, Deng; Cheng, Dong; Liu, Xixiang; Gan, Yiqun; Wang, Yanxin

    2016-01-01

    Hydroxyl radicals (•OH) play a crucial role in the fate of redox-active substances in the environment. Studies of the •OH production in nature has been constrained to surface environments exposed to light irradiation, but is overlooked in the subsurface under dark. Results of this study demonstrate that abundant •OH is produced when subsurface sediments are oxygenated under fluctuating redox conditions at neutral pH values. The cumulative concentrations of •OH produced within 24 h upon oxygenation of 33 sediments sampled from different redox conditions are 2-670 μmol •OH per kg dry sediment or 6.7-2521 μM •OH in sediment pore water. Fe(II)-containing minerals, particularly phyllosilicates, are the predominant contributor to •OH production. This production could be sustainable when sediment Fe(II) is regenerated by the biological reduction of Fe(III) during redox cycles. Production of •OH is further evident in a field injection-extraction test through injecting oxygenated water into a 23-m depth aquifer. The •OH produced can oxidize pollutants such as arsenic and tetracycline and contribute to CO2 emissions at levels that are comparable with soil respiration. These findings indicate that oxygenation of subsurface sediments is an important source of •OH in nature that has not been previously identified, and •OH-mediated oxidation represents an overlooked process for substance transformations at the oxic/anoxic interface. PMID:26641489

  3. Unexpectedly high indoor hydroxyl radical concentrations associated with nitrous acid.

    Science.gov (United States)

    Gómez Alvarez, Elena; Amedro, Damien; Afif, Charbel; Gligorovski, Sasho; Schoemaecker, Coralie; Schoemacker, Coralie; Fittschen, Christa; Doussin, Jean-Francois; Wortham, Henri

    2013-08-13

    The hydroxyl (OH) radical is the most important oxidant in the atmosphere since it controls its self-oxidizing capacity. The main sources of OH radicals are the photolysis of ozone and the photolysis of nitrous acid (HONO). Due to the attenuation of solar radiation in the indoor environment, the possibility of OH formation through photolytic pathways indoors has been ignored up to now. In the indoor air, the ozonolysis of alkenes has been suggested as an alternative route of OH formation. Models and indirect measurements performed up to now according to this hypothesis suggest concentrations of OH radicals on the order of 10(4)-10(5) molecules per cubic centimeter. Here, we present direct measurements of significant amounts of OH radicals of up to 1.8⋅10(6) molecules per cubic centimeter during an experimental campaign carried out in a school classroom in Marseille. This concentration is on the same order of magnitude of outdoor OH levels in the urban scenario. We also show that photolysis of HONO is an important source of OH radicals indoors under certain conditions (i.e., direct solar irradiation inside the room). Additionally, the OH concentrations were found to follow a linear dependence with the product J(HONO)⋅[HONO]. This was also supported by using a simple quasiphotostationary state model on the OH radical budget. These findings force a change in our understanding of indoor air quality because the reactivity linked to OH would involve formation of secondary species through chemical reactions that are potentially more hazardous than the primary pollutants in the indoor air. PMID:23898188

  4. Hydroxyl temperature and intensity measurements during noctilucent cloud displays

    Directory of Open Access Journals (Sweden)

    M. J. Taylor

    Full Text Available Two Fourier transform spectrometers have been used to investigate the properties of the near-infrared hydroxyl (OH nightglow emission under high-latitude summertime conditions and any association with noctilucent clouds (NLCs. The measurements were made from Poker Flat Research Range, Alaska (65.1°N, 147.5°W, during August 1986. Simultaneous photographic observations of the northern twilight sky were made from Gulkana, Alaska (62.2°N, 145.5°W, approximately 340 km to the south to establish the presence of NLCs over the spectrometer site. Data exhibiting significant short-term variations in the relative intensity (as much as 50–100% and rotational temperature (typically 5–15 K were recorded on six occasions when NLCs were observed. Joint measurements were also obtained on several "cloud-free" nights. No obvious relationship was found linking the mean OH intensity or its variation with the occurrence of NLCs. However, a clear tendency was found for the mean OH temperature to be lower on NLC nights than on cloud-free nights. In particular, a significant fraction of the OH(3–1 band spectra recorded by each instrument (16–57% exhibited temperatures below ~154 K on NLC nights compared with <3% on cloud-free nights. This result is qualitatively consistent with current models for ice particle nucleation and growth, but the mean OH temperature on NLC nights (~156 K was significantly higher than would be expected for long-term particle growth in this region. These observations raise questions concerning the expected proximity of the high-latitude, summertime OH layer and the NLC growth region.

  5. Development of Hydroxyl Tagging Velocimetry for Low Velocity Flows

    Science.gov (United States)

    Andre, Matthieu A.; Bardet, Philippe M.; Burns, Ross A.; Danehy, Paul M.

    2016-01-01

    Hydroxyl tagging velocimetry (HTV) is a molecular tagging technique that relies on the photo-dissociation of water vapor into OH radicals and their subsequent tracking using laser induced fluorescence. Velocities are then obtained from time-of-flight calculations. At ambient temperature in air, the OH species lifetime is relatively short (<50 µs), making it suited for high speed flows. Lifetime and radicals formation increases with temperature, which allows HTV to also probe low-velocity, high-temperature flows or reacting flows such as flames. The present work aims at extending the domain of applicability of HTV, particularly towards low-speed (<10 m/s) and moderate (<500 K) temperature flows. Results are compared to particle image velocimetry (PIV) measurements recorded in identical conditions. Single shot and averaged velocity profiles are obtained in an air jet at room temperature. By modestly raising the temperature (100-200 degC) the OH production increases, resulting in an improvement of the signal-to-noise ratio (SNR). Use of nitrogen - a non-reactive gas with minimal collisional quenching - extends the OH species lifetime (to over 500 µs), which allows probing of slower flows or, alternately, increases the measurement precision at the expense of spatial resolution. Instantaneous velocity profiles are resolved in a 100degC nitrogen jet (maximum jet-center velocity of 6.5 m/s) with an uncertainty down to 0.10 m/s (1.5%) at 68% confidence level. MTV measurements are compared with particle image velocimetry and show agreement within 2%.

  6. Tissue-specific bioaccumulation of human and veterinary antibiotics in bile, plasma, liver and muscle tissues of wild fish from a highly urbanized region

    International Nuclear Information System (INIS)

    We investigated the bioaccumulation of antibiotics in bile, plasma, liver and muscle tissues of wild fish from four rivers in the Pearl River Delta region. In total, 12 antibiotics were present in at least one type of fish tissues from nine wild fish species in the four rivers. The mean values of log bioaccumulation factors (log BAFs) for the detected antibiotics in fish bile, plasma, liver, and muscle tissues were at the range of 2.06–4.08, 1.85–3.47, 1.41–3.51, and 0.48–2.70, respectively. As the digestion tissues, fish bile, plasma, and liver showed strong bioaccumulation ability for some antibiotics, indicating a different bioaccumulation pattern from hydrophobic organic contaminants. Human health risk assessment based on potential fish consumption indicates that these antibiotics do not appear to pose an appreciable risk to human health. To the best of our knowledge, this is first report of bioaccumulation patterns of antibiotics in wild fish bile and plasma. - Highlights: • We investigated the bioaccumulation of antibiotics in wild fish from the Pearl River Delta region. • Twelve antibiotics were found in fish bile, plasma, liver and muscle tissues. • High log bioaccumulation factors suggested strong bioaccumulation ability for some antibiotics in wild fish tissues. • The presence of antibiotics in fish bile and plasma tissues indicates a novel bioaccumulation pattern. • Potential adverse effects are possibly caused by the high internal antibiotic concentrations in tissues. - Fish bile and plasma displayed strong bioaccumulation ability for some antibiotics, indicating a novel bioaccumulation pattern for antibiotics in the contaminated environment

  7. A method for improving predictive modeling by taking into account lag time: Example of selenium bioaccumulation in a flowing system.

    Science.gov (United States)

    Beckon, William N

    2016-07-01

    For bioaccumulative substances, efforts to predict concentrations in organisms at upper trophic levels, based on measurements of environmental exposure, have been confounded by the appreciable but hitherto unknown amount of time it may take for bioaccumulation to occur through various pathways and across several trophic transfers. The study summarized here demonstrates an objective method of estimating this lag time by testing a large array of potential lag times for selenium bioaccumulation, selecting the lag that provides the best regression between environmental exposure (concentration in ambient water) and concentration in the tissue of the target organism. Bioaccumulation lag is generally greater for organisms at higher trophic levels, reaching times of more than a year in piscivorous fish. Predictive modeling of bioaccumulation is improved appreciably by taking into account this lag. More generally, the method demonstrated here may improve the accuracy of predictive modeling in a wide variety of other cause-effect relationships in which lag time is substantial but inadequately known, in disciplines as diverse as climatology (e.g., the effect of greenhouse gases on sea levels) and economics (e.g., the effects of fiscal stimulus on employment). PMID:27149556

  8. The effect of hydroxyl group on the electronic structure of carbon nanotubes with different diameters

    Science.gov (United States)

    Kheirmand, M.

    2016-09-01

    A single hydroxyl group is functionalized on both sides of one ring of several carbon nanotubes (CNT) as CNT-OH. The electronic structure and chemical bonding parameters are studied with the help of quantum theory of atoms in molecules (QTAIM). Anionic states of the CNT-O as deprotonated hydroxyl are studied in order to get insight into the nature of CNT-OH species, considering frozen and relaxed geometries of CNT-O compounds. The results show a significant difference between inside or outside substituted hydroxyl groups; and also complicated behavior of the CNT's diameter, and it can be concluded that hydroxyl group can be used to tune the CNT's properties, effectively, in interesting application of these nanostructures.

  9. Observation of temperature dependence of the IR hydroxyl absorption bands in silica optical fiber

    Science.gov (United States)

    Yu, Li; Bonnell, Elizabeth; Homa, Daniel; Pickrell, Gary; Wang, Anbo; Ohodnicki, P. R.; Woodruff, Steven; Chorpening, Benjamin; Buric, Michael

    2016-07-01

    This study reports on the temperature dependent behavior of silica based optical fibers upon exposure to high temperatures in hydrogen and ambient air. The hydroxyl absorption bands in the wavelength range of 1000-2500 nm of commercially available multimode fibers with pure silica and germanium doped cores were examined in the temperature range of 20-800 °C. Two hydroxyl-related infrared absorption bands were observed: ∼2200 nm assigned to the combination of the vibration mode of Si-OH bending and the fundamental hydroxyl stretching mode, and ∼1390 nm assigned to the first overtone of the hydroxyl stretching. The absorption in the 2200 nm band decreased in intensity, while the 1390 nm absorption band shifted to longer wavelengths with an increase in temperature. The observed phenomena were reversible with temperature and suspected to be due, in part, to the conversion of the OH spectral components into each other and structural relaxation.

  10. Atmospheric hydroxyl radical production from electronically excited NO2 and H2O.

    Science.gov (United States)

    Li, Shuping; Matthews, Jamie; Sinha, Amitabha

    2008-03-21

    Hydroxyl radicals are often called the "detergent" of the atmosphere because they control the atmosphere's capacity to cleanse itself of pollutants. Here, we show that the reaction of electronically excited nitrogen dioxide with water can be an important source of tropospheric hydroxyl radicals. Using measured rate data, along with available solar flux and atmospheric mixing ratios, we demonstrate that the tropospheric hydroxyl contribution from this source can be a substantial fraction (50%) of that from the traditional O(1D) + H2O reaction in the boundary-layer region for high solar zenith angles. Inclusion of this chemistry is expected to affect modeling of urban air quality, where the interactions of sunlight with emitted NOx species, volatile organic compounds, and hydroxyl radicals are central in determining the rate of ozone formation.

  11. Atmospheric hydroxyl radical production from electronically excited NO2 and H2O.

    Science.gov (United States)

    Li, Shuping; Matthews, Jamie; Sinha, Amitabha

    2008-03-21

    Hydroxyl radicals are often called the "detergent" of the atmosphere because they control the atmosphere's capacity to cleanse itself of pollutants. Here, we show that the reaction of electronically excited nitrogen dioxide with water can be an important source of tropospheric hydroxyl radicals. Using measured rate data, along with available solar flux and atmospheric mixing ratios, we demonstrate that the tropospheric hydroxyl contribution from this source can be a substantial fraction (50%) of that from the traditional O(1D) + H2O reaction in the boundary-layer region for high solar zenith angles. Inclusion of this chemistry is expected to affect modeling of urban air quality, where the interactions of sunlight with emitted NOx species, volatile organic compounds, and hydroxyl radicals are central in determining the rate of ozone formation. PMID:18356524

  12. Synthesis of Two Naturally Occurring 4-Hydroxylated Butenolides with PTPIB Inhibitory Activity

    Institute of Scientific and Technical Information of China (English)

    赵亚; 蒋晟; 郭跃伟; 姚祝军

    2005-01-01

    Two new naturally 4-hydroxylated butenolides were concisely synthesized in excellent enantiomeric purities. An aldol condensation and a Suzuki reaction served successfully as the key steps in the synthesis.

  13. Creation of localized spins in graphene by ring-opening of epoxy derived hydroxyl.

    Science.gov (United States)

    Chen, Jie; Zhang, Weili; Sun, Yuanyuan; Zheng, Yongping; Tang, Nujiang; Du, Youwei

    2016-05-26

    Creation of high-density localized spins in the basal plane of graphene sheet by introduction of sp(3)-type defects is considered to be a potential route for the realization of high-magnetization graphene. Theoretical and experimental studies confirmed that hydroxyl can be an effective sp(3)-type candidate for inducing robust magnetic moment. However, the artificial generation of hydroxyl groups for creating high-density spins on the basal plane of graphene sheet is very scarce. Here we demonstrate that high-content hydroxyl groups can be generated on the basal plane of graphene oxide (GO) sheet by ring opening of epoxy groups. We show that by introduction of 10.74 at.% hydroxyl groups, the density of localized spins of GO can be significantly increased from 0.4 to 5.17 μB/1000 C. Thus, this study provided an effective method to obtain graphene with high-density localized spins.

  14. Creation of localized spins in graphene by ring-opening of epoxy derived hydroxyl

    Science.gov (United States)

    Chen, Jie; Zhang, Weili; Sun, Yuanyuan; Zheng, Yongping; Tang, Nujiang; Du, Youwei

    2016-05-01

    Creation of high-density localized spins in the basal plane of graphene sheet by introduction of sp3-type defects is considered to be a potential route for the realization of high-magnetization graphene. Theoretical and experimental studies confirmed that hydroxyl can be an effective sp3-type candidate for inducing robust magnetic moment. However, the artificial generation of hydroxyl groups for creating high-density spins on the basal plane of graphene sheet is very scarce. Here we demonstrate that high-content hydroxyl groups can be generated on the basal plane of graphene oxide (GO) sheet by ring opening of epoxy groups. We show that by introduction of 10.74 at.% hydroxyl groups, the density of localized spins of GO can be significantly increased from 0.4 to 5.17 μB/1000 C. Thus, this study provided an effective method to obtain graphene with high-density localized spins.

  15. Monitoring of hydroxyl groups in wood during heat treatment using NIR spectroscopy.

    Science.gov (United States)

    Mitsui, Katsuya; Inagaki, Tetsuya; Tsuchikawa, Satoru

    2008-01-01

    This paper deals with the evaluation of thermally treated wood by near-infrared (NIR) spectroscopy. In the NIR second derivative spectrum, the absorption band at 6913 cm(-1) appeared with the procession of heat treatment, which conclusively assigned to the phenolic hydroxyl groups due to the lignin in comparison with the spectrum of acetylated spruce wood. As a result of the changes in the ratio of the areal integral calculated from spectral separation in the region of hydroxyl groups (7200-6100 cm(-1)) by the Gauss-Newton method, it was clear that the degradation of hydroxyl group in the cellulose started predominantly from the amorphous region and followed to semicrystalline and crystalline region. There was an obvious correlation between the weight decrement of wood and the decrement of hydroxyl groups in the cellulose by heat treatment.

  16. Tuning magnetic splitting of zigzag graphene nanoribbons by edge functionalization with hydroxyl groups

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Huizhen; Yang, Haifang; Li, Lin; Fu, Huixia; Ma, Wei; Niu, Chunyao; Sun, Jiatao, E-mail: jtsun@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing 100190 (China); Meng, Sheng; Gu, Changzhi, E-mail: czgu@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing 100190 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China)

    2015-03-21

    The electronic properties and relative stability of zigzag graphene nanoribbons are studied by varying the percentage of hydroxyl radicals for edge saturation using first principle calculations. The passivated structures of zigzag graphene nanoribbon have spin-polarized ground state with antiferromagnetic exchange coupling across the edge and ferromagnetic coupling along the edges. When the edges are specially passivated by hydroxyl, the potentials of spin exchange interaction across the two edges shift accordingly, resulting into a spin-semiconductor. Varying the concentration of hydroxyl groups can alter the maximum magnetization splitting. When the percentage of asymmetrically adsorbed hydroxyl reaches 50%, the magnetization splitting can reach a value as high as 275 meV due to the asymmetrical potential across the nanoribbon edges. These results would favor spintronic device applications based on zigzag graphene nanoribbons.

  17. Synthesis of multi-hydroxyl and sulfonyl dual-functionalized room temperature ionic liquids

    Institute of Scientific and Technical Information of China (English)

    Guo Yang Zhu; Rong Wang; Guo Hua Liu; Li Qun Xu; Bei Zhang; Xia Qin Wu

    2007-01-01

    Starting from the hydroxylamine (dimethyl amino ethanol, triethanolamine) and 1,3-propane sultone, a series of hydroxyl and sulfonyl dual-functionalized zwitterionic salts and corresponding acidic room temperature ionic liquids have been synthesized.The hydroxyl groups of the synthesized substances were confirmed by the 1H NMR measurement.These zwitterionic salts and ionic liquids may be used for synthesizing other functionalized ionic liquids or ionic liquid-polymer (polyelectrolyte).

  18. Determination of surface-accessible acidic hydroxyls and surface area of lignin by cationic dye adsorption

    OpenAIRE

    Sipponen, Mika Henrikki; Pihlajaniemi, Ville; Littunen, Kuisma; Pastinen, Ossi; Laakso, Simo

    2014-01-01

    A new colorimetric method for determining the surface-accessible acidic lignin hydroxyl groups in lignocellulose solid fractions was developed. The method is based on selective adsorption of Azure B, a basic dye, onto acidic hydroxyl groups of lignin. Selectivity of adsorption of Azure B on lignin was demonstrated using lignin and cellulose materials as adsorbents. Adsorption isotherms of Azure B on wheat straw (WS), sugarcane bagasse (SGB), oat husk, and isolated lignin materials were determ...

  19. Rate constants of reactions of {kappa}-carrageenan with hydrated electron and hydroxyl radical

    Energy Technology Data Exchange (ETDEWEB)

    Abad, L.V. [Nuclear Professional School, School of Engineering Laboratory, University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan); Philippine Nuclear Research Institute, Commonwealth Avenue, Diliman, Quezon City (Philippines)], E-mail: lvabad@pnri.dost.gov.ph; Saiki, S.; Kudo, H.; Muroya, Y.; Katsumura, Y. [Nuclear Professional School, School of Engineering Laboratory, University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan); Rosa, A.M. de la [Philippine Nuclear Research Institute, Commonwealth Avenue, Diliman, Quezon City (Philippines)

    2007-12-15

    The rate constants for the reactions of {kappa}-carrageenan with hydrated electron and hydroxyl radical was investigated by pulse radiolysis and laser photolysis. The kinetics of the reaction of hydrated electron indicates no seeming reaction with {kappa}-carrageenan. On the other hand, hydroxyl radical reacts very rapidly with {kappa}-carrageenan at a rate constant of approximately 1.2 x 10{sup 9} M{sup -1} s{sup -1}. This rate constant varies with pH.

  20. The thermal stability of the framework, hydroxyl groups, and active sites of faujasites

    Energy Technology Data Exchange (ETDEWEB)

    Mishin, I.V.; Kalinin, V.P.; Nissenbaum, V.D. [Zelinskii Institute of Organic Chemistry, Moscow (Russian Federation); Beyer, H.K. [Hungarian Academy of Sciences, Budapest (Hungary); Karge, H.G. [Fritz Haber Institute of the Max Planck Soceity, Berlin (Germany)

    1994-07-01

    The effect of the framework composition on the crystallinity and {open_quotes}density{close_quotes} of hydroxyl groups and the concentration of active sites is reported for hydrogen forms of Y zeolites preheated at 400 - 1000{degrees}C. The increase in the Si/Al ratios results in improved resistance of the framework atoms and hydroxyl groups to high temperatures and in enhanced thermal stability of the sites that are active in the cracking of isooctane and disproportionation of ethylbenzene.

  1. Bioaccumulation factor for 32P measured in bluegill, Lepomis macrochirus, and catfish, Ictalurus punctatus

    International Nuclear Information System (INIS)

    The ratio of the bioaccumulation factors for 32P and phosphorus was determined for edible tissue in two species of freshwater fish by measuring the specific activity (32P activity per milligram phosphorus) in muscle relative to feed. The 32P tracer was added to the feed at a uniform level throughout the study. Feeding was at two levels: ad libitum and at a lower but constant intake per body weight. In the main experiment, bluegill were maintained in a large flow-through tank and sacrificed at approximately weekly intervals for 51 d of 32P accumulation and 28 d of depuration to compare the specific activity with values predicted with a calculational model. In experiments performed in smaller aquaria, the specific activity in bluegill and catfish muscle was compared at two feeding levels and two temperatures. In addition, unfed fish were exposed to 32P in water at a known specific activity to determine the extent of phosphorus uptake directly from water. The pattern of specific activity increase and decrease in fish muscle during the accumulation/depuration experiment was consistent with a one-compartment model, so that specific activity ratios at steady state could be predicted from measurements during relatively brief exposures. On this basis, the ratio of the bioaccumulation factors of 32P and phosphorus in fish feeding ad libitum was 0.081 for bluegill and 0.17 for catfish. Hence, at a mean phosphorus bioaccumulation factor of 70,000, the factors for 32P are 6000 and 12,000, respectively. The ratios were less at lower phosphorus intakes associated with lower feeding rates; moreover, the lesser value for bluegill occurred at a much lower phosphorus intake than by catfish

  2. Bioaccumulation of Cadmium by Pseudomonas Sp. Isolated From Metal Polluted Industrial Region

    Directory of Open Access Journals (Sweden)

    Rinoy Varghese

    2012-10-01

    Full Text Available In the present study, bacterial strains were isolated from soil, sediment and water samples of metal contaminated industrial area and investigated the heavy metal resistance and bioaccumulation potential of the isolates. Cadmium analysis of the samples revealed that Cd concentration varying from 2.31µg L-1 to 8.96 µg L-1 in water, 0.55µg g-1 to 25.44µg g-1 in soil and 0.45µg g-1 to 22.90µg g-1 in sediment. Cadmium resistance studies of the bacterial isolates showed that out of 164 isolates collected most of them showed  low resistance (<500µg/ml and many isolates showed high resistance of  >1500µg/ml. Ten bacterial genera were represented in soil and 11 from water, while only 5 bacterial genera were recorded from sediment samples.  Bacillus, pseudomonas and Enterobacter were found in soil, sediment and water samples. Results of cadmium removal study revealed that with increase in time, the biomass of the selected Pseudomonas sp. increased. Correspondingly, with increase in biomass, the cadmium bioaccumulation was also increased. Relatively an Increased removal of cadmium was observed in the first day of the experiment. About 40% of the cadmium in the experimental flask was reduced while only 5% reduction occurs in the control flasks till the end of the experiment (74hours. Comparatively cadmium showed higher reduction at pH 7. From the results, it could be concluded that the selected bacterial isolates possessed potential in respect of bioaccumulation activity and thus, appeared to be an appropriate nominee in bioremediation processes.DOI: http://dx.doi.org/10.5755/j01.erem.61.3.1268

  3. Forest floor decomposition, metal exchangeability, and metal bioaccumulation by exotic earthworms: Amynthas agrestis and Lumbricus rubellus.

    Science.gov (United States)

    Richardson, J B; Görres, J H; Friedland, A J

    2016-09-01

    Earthworms have the potential to reduce the retention of pollutant and plant essential metals in the forest floor (organic horizons) by decomposing organic matter and increasing exchangeability of metals. We conducted a laboratory experiment to investigate the effects of two exotic earthworms, Amynthas agrestis and Lumbricus rubellus, on forest floor decomposition, metal exchangeability, and metal bioaccumulation. Eighty-one pots containing homogenized forest floor material were incubated for 20, 40, or 80 days under three treatments: no earthworms, A. agrestis added, or L. rubellus added. For earthworm treatments, A. agrestis and L. rubellus were stocked at densities observed in previous field studies. Pots containing either A. agrestis or L. rubellus had lost more forest floor mass than the control plots after 40 and 80 days of incubation. Forest floor pots containing A. agrestis had significantly lower % C (16 ± 1.5 %) than control pots (21 ± 1.2 %) after 80 days. However, L. rubellus consumed more forest floor and C mass than A. agrestis, when evaluated on a per earthworm biomass basis. Exchangeable (0.1 M KCl + 0.01 M AcOH extractable) and stable (15 M HNO3+ 10 M HCl extractable) concentrations of Al, Ca, Cd, Cu, Mg, Mn, Pb, and Zn in forest floor material were measured. Stable concentrations and % exchangeable metals in forest floor material were similar among treatments. Although exchangeable metal concentrations varied significantly for most metals among treatments (except Mg and Zn), we conclude that earthworms did not increase or decrease the exchangeability of metals. However, earthworms bioaccumulated Cu, Cd, Zn, and Mg and had potentially hazardous tissue concentrations of Al and Pb. This was best illustrated by calculating bioaccumulation factors using exchangeable concentrations rather than total concentrations. Future research is needed to understand the effect of earthworms on metals in other soil types. PMID:27272919

  4. Bioaccumulation trends of arsenic and antimony in a freshwater ecosystem affected by mine drainage

    Science.gov (United States)

    Dovick, Meghan A.; Kulp, Thomas R.; Arkle, Robert .; Pilliod, David

    2016-01-01

    We compared As and Sb bioaccumulation and biomagnification when these metalloids co-occurred at varying environmental concentrations in a stream and wetlands near a contaminated mine site in Idaho (USA). We measured As and Sb concentrations in water and substrate samples, and in tissues of organisms representing several trophic levels. Bioaccumulation of both As and Sb was observed in stream organisms with the following trend of bio-diminution with increasing trophic level: primary producers>tadpoles>macroinvertebrates>trout. We also note reductions in metalloid concentrations in one of two stream remediation reaches engineered within the past 17 years to ameliorate metalloid contamination in the stream. Several wetlands contained thick microbial mats and were highly populated with boreal toad tadpoles that fed on them. The mats were extremely contaminated (up to 76 564 mg kg-1 As and 675 mg kg-1 Sb) with amorphous As- and Sb-bearing minerals that we interpret as biogenic precipitates from geomicrobiological As- and Sb-cycling. Ingested mat material provided a direct source of metalloids to tadpoles, and concentrations of 3867 mg kg-1 (As) and 375 mg kg-1 (Sb) reported here represent the highest whole body As and Sb levels ever reported in living tadpoles. The bulk of tadpole metalloid burden remained in the gut despite attempts to purge the tadpoles prior to analysis. This study adds to a number of recent investigations reporting bioaccumulation, but not biomagnification, of As and Sb in food webs. Moreover, our results suggest that tadpoles, in particular, may be more resistant to metalloid contamination than previously assumed.

  5. Toxicity and bioaccumulation of biosolids-borne triclocarban (TCC) in terrestrial organisms.

    Science.gov (United States)

    Snyder, Elizabeth Hodges; O'Connor, George A; McAvoy, Drew C

    2011-01-01

    Triclocarban (TCC) toxicity and bioaccumulation data are primarily limited to direct human and animal dermal exposures, animal ingestion exposures to neat and feed-spiked TCC, and/or aquatic organism exposures. Three non-human, terrestrial organism groups anticipated to be the most highly exposed to land-applied, biosolids-borne TCC are soil microbes, earthworms, and plants. The three ecological receptors are expected to be at particular risk due to unique modes of exposure (e.g. constant, direct contact with soil; uptake of amended soil and pore water), inherently greater sensitivity to environmental contaminants (e.g. increased body burdens, permeable membranes), and susceptibility to minute changes in the soil environment. The toxicities of biosolids-borne TCC to Eisenia fetida earthworms and soil microbial communities were characterized using adaptations of the USEPA Office of Prevention, Pesticides, and Toxic Substances (OPPTS) Guidelines 850.6200 (Earthworm Subchronic Toxicity Test) and 850.5100 (Soil Microbial Community Toxicity Test), respectively. The resultant calculated TCC LC50 value for E. fetida was 40 mg TCC kg amended fine sand(-1). Biosolids-borne TCC in an amended fine sand had no significant effect on soil microbial community respiration, ammonification, or nitrification. Bioaccumulation of biosolids-borne TCC by E. fetida and Paspulum notatum was measured to characterize potential biosolids-borne TCC movement through the food chain. Dry-weight TCC bioaccumulation factor (BAF) values in E. fetida and P. notatum ranged from 5.2-18 and 0.00041-0.007 (gsoil gtissue(-1)), respectively.

  6. Literature review on the use of bioaccumulation for heavy metal removal and recovery. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Benemann, J.R. [Benemann (J.R.), Pinole, CA (United States); Wilde, E.W. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1991-02-01

    Bioaccumulation of metals by microbes -- `` bioremoval`` -- is a powerful new technology for the concentration, recovery, and removal of toxic heavy metals and radionuclides from waste streams and contaminated environments. Algae are particularly well suited for metal bioremoval. A recent commercial application of bioremoval utilizes inert (dead) immobilized microalgae biomass as ion exchange materials for the removal of heavy metals from industrial waste waters. Also, living microalgal cultures have been used to remove metals from mine effluents. Microbial cells and biomass can bioaccumulate metals and radionuclides by a large variety of mechanisms, both dependent and independent of cell metabolism. Microbial cell walls can act as ion exchange and metal complexation agents. Heavy metals can precipitate and even crystallize on cell surfaces. Metabolically produced hydrogen sulfide or other metabolic products can bioprecipitate heavy metals. Many microbes produce both intra- and extracellular metal complexing agents which could be considered in practical metal removal processes. Bioremoval processes are greatly affected by the microbial species and even strain used, pH, redox potential, temperature, and other conditions under which the microbes are grown. Development of practical applications of bioremoval requires applies research using the particular waste solutions to be treated, or close simulations thereof. From a practical perspective, the selection of the microbial biomass and the process for contacting the microbial biomass with the metal containing solutions are the key issues. Much of the recent commercial R&D has emphasized commercially available, inert, microbial biomass sources as these can be acquired in sufficient quantities at affordable costs. The fundamental research and practical applications of bioaccumulation by microalgae suggests these organisms warrant a high priority in the development of advanced bioremoval processes.

  7. Literature review on the use of bioaccumulation for heavy metal removal and recovery

    Energy Technology Data Exchange (ETDEWEB)

    Benemann, J.R. (Benemann (J.R.), Pinole, CA (United States)); Wilde, E.W. (Westinghouse Savannah River Co., Aiken, SC (United States))

    1991-02-01

    Bioaccumulation of metals by microbes -- bioremoval'' -- is a powerful new technology for the concentration, recovery, and removal of toxic heavy metals and radionuclides from waste streams and contaminated environments. Algae are particularly well suited for metal bioremoval. A recent commercial application of bioremoval utilizes inert (dead) immobilized microalgae biomass as ion exchange materials for the removal of heavy metals from industrial waste waters. Also, living microalgal cultures have been used to remove metals from mine effluents. Microbial cells and biomass can bioaccumulate metals and radionuclides by a large variety of mechanisms, both dependent and independent of cell metabolism. Microbial cell walls can act as ion exchange and metal complexation agents. Heavy metals can precipitate and even crystallize on cell surfaces. Metabolically produced hydrogen sulfide or other metabolic products can bioprecipitate heavy metals. Many microbes produce both intra- and extracellular metal complexing agents which could be considered in practical metal removal processes. Bioremoval processes are greatly affected by the microbial species and even strain used, pH, redox potential, temperature, and other conditions under which the microbes are grown. Development of practical applications of bioremoval requires applies research using the particular waste solutions to be treated, or close simulations thereof. From a practical perspective, the selection of the microbial biomass and the process for contacting the microbial biomass with the metal containing solutions are the key issues. Much of the recent commercial R D has emphasized commercially available, inert, microbial biomass sources as these can be acquired in sufficient quantities at affordable costs. The fundamental research and practical applications of bioaccumulation by microalgae suggests these organisms warrant a high priority in the development of advanced bioremoval processes.

  8. Hot Spots of Mercury Bioaccumulation in Amphibian Populations From the Conterminous United States

    Science.gov (United States)

    Bank, M. S.

    2008-12-01

    Mercury (Hg) contamination in the United States (U.S.) is well-documented and continues to be a public- health issue of great concern. Fish consumption advisories have been issued throughout much of the U.S. due to elevated levels of methylmercury (MeHg). Methylmercury contamination in the developing fetus and in young children is a major public health issue for certain sectors of the global human population. Moreover, identifying MeHg hot spots and the effects of MeHg pollution on environmental health and biodiversity are also considered a high priority for land managers, risk assessors, and conservation scientists. Despite their overall biomass and importance to aquatic and terrestrial ecosystems, Hg and MeHg bioaccumulation dynamics and toxicity in amphibians are not well studied, especially when compared to other vertebrate taxa such as birds, mammals, and fish species. Population declines in amphibians are well documented and likely caused by synergistic and interacting, multiple stressors such as climate change, exposure to toxic pollutants, fungal pathogens, and habitat loss and ecosystem degradation. Protecting quality of terrestrial ecosystems in the U.S. has enormous ramifications for economic and public health of the nation's residents and is fundamental to maintaining the biotic integrity of surface waters, riparian zones, and environmental health of forested landscapes nationwide. Determining Hg concentration levels for terrestrial and surface water ecosystems also has important implications for protecting the nation's fauna. Here I present an overview of the National Amphibian Mercury Program and evaluate variation in MeHg hotspots, Hg bioaccumulation and distribution in freshwater and terrestrial habitats across a broad gradient of physical, climatic, biotic, and ecosystem settings to identify the environmental conditions and ecosystem types that are most sensitive to Hg pollution. The role of geography, disturbance mechanisms, and abiotic and biotic

  9. Mercury in Pacific bluefin tuna (Thunnus orientalis):bioaccumulation and trans-Pacific Ocean migration

    Science.gov (United States)

    Colman, John A.; Nogueira, Jacob I.; Pancorbo, Oscar C.; Batdorf, Carol A.; Block, Barbara A.

    2015-01-01

    Pacific bluefin tuna (Thunnus orientalis) have the largest home range of any tuna species and are well known for the capacity to make transoceanic migrations. We report the measurement of mercury (Hg) concentrations in wild Pacific bluefin tuna (PBFT), the first reported with known size-of-fish and capture location. The results indicate juvenile PBFT that are recently arrived in the California Current from the western Pacific Ocean have significantly higher Hg concentrations in white muscle (0.51 ug/g wet mass, wm) than PBFT of longer California Current residency (0.41 ug/g wm). These new arrivals are also higher in Hg concentration than PBFT in farm pens (0.43 ug/g wm) that were captured on arrival in the California Current and raised in pens on locally derived feed. Analysis by direct Hg analyzer and attention to Hg by tissue type and location on the fish allowed precise comparisons of mercury among wild and captive fish populations. Analysis of migration and nearshore residency, determined through extensive archival tagging, bioaccumulation models, trophic investigations, and potential coastal sources of methylmercury, indicates Hg bioaccumulation is likely greater for PBFT juvenile habitats in the western Pacific Ocean (East China Sea, Yellow Sea) than in the eastern Pacific Ocean (California Current). Differential bioaccumulation may be a trophic effect or reflect methylmercury availability, with potential sources for coastal China (large hypoxic continental shelf receiving discharge of three large rivers, and island-arc volcanism) different from those for coastal Baja California (small continental shelf, no large rivers, spreading-center volcanism).

  10. Literature review on the use of bioaccumulation for heavy metal removal and recovery

    International Nuclear Information System (INIS)

    Bioaccumulation of metals by microbes -- '' bioremoval'' -- is a powerful new technology for the concentration, recovery, and removal of toxic heavy metals and radionuclides from waste streams and contaminated environments. Algae are particularly well suited for metal bioremoval. A recent commercial application of bioremoval utilizes inert (dead) immobilized microalgae biomass as ion exchange materials for the removal of heavy metals from industrial waste waters. Also, living microalgal cultures have been used to remove metals from mine effluents. Microbial cells and biomass can bioaccumulate metals and radionuclides by a large variety of mechanisms, both dependent and independent of cell metabolism. Microbial cell walls can act as ion exchange and metal complexation agents. Heavy metals can precipitate and even crystallize on cell surfaces. Metabolically produced hydrogen sulfide or other metabolic products can bioprecipitate heavy metals. Many microbes produce both intra- and extracellular metal complexing agents which could be considered in practical metal removal processes. Bioremoval processes are greatly affected by the microbial species and even strain used, pH, redox potential, temperature, and other conditions under which the microbes are grown. Development of practical applications of bioremoval requires applies research using the particular waste solutions to be treated, or close simulations thereof. From a practical perspective, the selection of the microbial biomass and the process for contacting the microbial biomass with the metal containing solutions are the key issues. Much of the recent commercial R ampersand D has emphasized commercially available, inert, microbial biomass sources as these can be acquired in sufficient quantities at affordable costs. The fundamental research and practical applications of bioaccumulation by microalgae suggests these organisms warrant a high priority in the development of advanced bioremoval processes

  11. Modeling bioaccumulation in humans using poly-parameter linear free energy relationships (PPLFERS)

    International Nuclear Information System (INIS)

    Chemical partition coefficients between environmental media and biological tissues are a key component of bioaccumulation models. The single-parameter linear free energy relationships (spLFERs) commonly used for predicting partitioning are often derived using apolar chemicals and may not accurately capture polar chemicals. In this study, a poly-parameter LFER (ppLFER) based model of organic chemical bioaccumulation in humans is presented. Chemical partitioning was described by an air-body partition coefficient that was a volume weighted average of ppLFER based partition coefficients for the major organs and tissues constituting the human body. This model was compared to a spLFER model treating the body as a mixture of lipid (∼ octanol) and water. Although model agreement was good for hydrophobic chemicals (average difference 15% for log KOW > 4 and log KOA > 8), the ppLFER model predicted ∼ 90% lower body burdens for hydrophilic chemicals (log KOW < 0). This was mainly due to lower predictions of muscle and adipose tissue sorption capacity for these chemicals. A comparison of the predicted muscle and adipose tissue sorption capacities of hydrophilic chemicals with measurements indicated that the ppLFER and spLFER models' uncertainties were similar. Consequently, little benefit from the implementation of ppLFERs in this model was identified. - Research Highlights: →Implementation of ppLFERs resulted in on average 90% lower predicted body burdens. →Uncertainties in spLFER and ppLFER predictions were similar. →The benefit from implementation of ppLFERs in bioaccumulation models was limited.

  12. Interactions between zooplankton and crude oil: toxic effects and bioaccumulation of polycyclic aromatic hydrocarbons.

    Directory of Open Access Journals (Sweden)

    Rodrigo Almeda

    Full Text Available We conducted ship-, shore- and laboratory-based crude oil exposure experiments to investigate (1 the effects of crude oil (Louisiana light sweet oil on survival and bioaccumulation of polycyclic aromatic hydrocarbons (PAHs in mesozooplankton communities, (2 the lethal effects of dispersant (Corexit 9500A and dispersant-treated oil on mesozooplankton, (3 the influence of UVB radiation/sunlight exposure on the toxicity of dispersed crude oil to mesozooplankton, and (4 the role of marine protozoans on the sublethal effects of crude oil and in the bioaccumulation of PAHs in the copepod Acartia tonsa. Mortality of mesozooplankton increased with increasing oil concentration following a sigmoid model with a median lethal concentration of 32.4 µl L(-1 in 16 h. At the ratio of dispersant to oil commonly used in the treatment of oil spills (i.e. 1∶20, dispersant (0.25 µl L(-1 and dispersant-treated oil were 2.3 and 3.4 times more toxic, respectively, than crude oil alone (5 µl L(-1 to mesozooplankton. UVB radiation increased the lethal effects of dispersed crude oil in mesozooplankton communities by 35%. We observed selective bioaccumulation of five PAHs, fluoranthene, phenanthrene, pyrene, chrysene and benzo[b]fluoranthene in both mesozooplankton communities and in the copepod A. tonsa. The presence of the protozoan Oxyrrhis marina reduced sublethal effects of oil on A. tonsa and was related to lower accumulations of PAHs in tissues and fecal pellets, suggesting that protozoa may be important in mitigating the harmful effects of crude oil exposure in copepods and the transfer of PAHs to higher trophic levels. Overall, our results indicate that the negative impact of oil spills on mesozooplankton may be increased by the use of chemical dispersant and UV radiation, but attenuated by crude oil-microbial food webs interactions, and that both mesozooplankton and protozoans may play an important role in fate of PAHs in marine environments.

  13. Structure-activity relationships for hydroxylated polychlorinated biphenyls as inhibitors of the sulfation of dehydroepiandrosterone catalyzed by human hydroxysteroid sulfotransferase SULT2A1.

    Science.gov (United States)

    Ekuase, Edugie J; Liu, Yungang; Lehmler, Hans-Joachim; Robertson, Larry W; Duffel, Michael W

    2011-10-17

    Polychlorinated biphenyls (PCBs) are persistent worldwide pollutants that are of concern due to their bioaccumulation and health effects. Metabolic oxidation of PCBs results in the formation of hydroxylated metabolites (OHPCBs). Among their biological effects, OHPCBs have been shown to alter the metabolism of endocrine hormones, including inhibition of mammalian cytosolic sulfotransferases (SULTs) that are responsible for the inactivation of thyroid hormones and phenolic steroids (i.e., hSULT1A1, hSULT1B1, and hSULT1E1). OHPCBs also interact with a human hydroxysteroid sulfotransferase that plays a role in the sulfation of endogenous alcohol-containing steroid hormones and bile acids (i.e., hSULT2A1). The objectives of our current study were to examine the effects of a series of OHPCB congeners on the activity of hSULT2A1 and to develop a three-dimensional quantitative structure-activity relationship (3D-QSAR) model for OHPCBs as inhibitors of the enzyme. A total of 15 OHPCBs were examined, and the sulfation of 1 μM [(3)H] dehydroepiandrosterone (DHEA) was utilized as a model reaction catalyzed by the enzyme. All 15 OHPCBs inhibited the sulfation of DHEA, with IC(50) values ranging from 0.6 μM to 96 μM, and eight of these OHPCBs were also substrates for the enzyme. Comparative molecular field analysis (CoMFA) provided a predictive 3D-QSAR model with a q(2) value of 0.697 and an r(2) value of 0.949. The OHPCBs that had the highest potency as inhibitors of DHEA sulfation were those with a 3, 5-dichloro-4-hydroxy substitution pattern on the biphenyl ring system, and these congeners were also substrates for sulfation catalyzed by hSULT2A1.

  14. Optical Emission Spectroscopic Measurement of Hydroxyl Radicals in Air Discharge with Atomized Water%Optical Emission Spectroscopic Measurement of Hydroxyl Radicals in Air Discharge with Atomized Water

    Institute of Scientific and Technical Information of China (English)

    孙明; 陈维刚; 张颖

    2011-01-01

    Effects of discharge mode, voltage applied, size of the nozzle discharge electrode and flow rate of water on the generation of hydroxyl radical were investigated in air discharge with atomized water, by using optical emission spectroscopy (OES). Water was injected into the discharge region through the discharge nozzle electrode, and a large amount of fine water drops, formed and distributed in the discharge region, corona discharge was more effective to generate were observed. It was found that negative DC the hydroxyl radicals in comparison to positive DC corona discharge or negative pulsed discharge. A larger outer diameter of the nozzle electrode or a stronger electric field is beneficial for hydroxyl-radical generation. Moreover, there is a critical value in the flow rate of atomized water against the discharge voltage. Below this critical value, hydroxyl-radical generation increases with the increase in flow rate of the water, while above this value, it decreases. In addition, it is observed that OES from the discharge is mainly in the ultraviolet domain. The results are helpful in the study of the mechanism and application of plasma in pollution-control in either air or water.

  15. Habitat type-based bioaccumulation and risk assessment of metal and As contamination in earthworms, beetles and woodlice.

    Science.gov (United States)

    Vermeulen, Frouke; Van den Brink, Nico W; D'Havé, Helga; Mubiana, Valentine K; Blust, Ronny; Bervoets, Lieven; De Coen, Wim

    2009-11-01

    The present study investigated the contribution of environmental factors to the accumulation of As, Cd, Cu, Pb and Zn in earthworms, beetles and woodlice, and framed within an exposure assessment of the European hedgehog. Soil and invertebrate samples were collected in three distinct habitat types. Results showed habitat-specific differences in soil and invertebrate metal concentrations and bioaccumulation factors when normalized to soil metal concentration. Further multiple regression analysis showed residual variability (habitat differences) in bioaccumulation that could not be fully explained by differences in soil metal contamination, pH or organic carbon (OC). Therefore, the study demonstrated that in bioaccumulation studies involving terrestrial invertebrates or in risk assessment of metals, it is not sufficient to differentiate habitat types on general soil characteristics such as pH and/or OC alone. Furthermore, simple generic soil risk assessments for Cd and Cu showed that risk characterization was more accurate when performed in a habitat-specific way.

  16. Assessment of concentration, bioaccumulation and sources of polycyclic aromatic hydrocarbons in zooplankton of Chabahar Bay.

    Science.gov (United States)

    Ziyaadini, Morteza; Mehdinia, Ali; Khaleghi, Leila; Nassiri, Mahmoud

    2016-06-15

    The amounts and sources of polycyclic aromatic hydrocarbons (PAHs) and their bioaccumulation factors (BAFs) in the zooplankton community of Chabahar Bay were investigated. The highest amounts of total PAHs (tPAHs) in the water and zooplankton samples were 62.2ngL(-1) and 1478.6ngg(-1) dry weights, in near the Shahid Beheshti Port and desalination, respectively. The greatest amount of BAF (51,780) was obtained in the entry of Bay, and it was related to the phenanthrene accumulation. Using molecular ratio, the results showed that the major input source of PAH compounds in zooplankton of Chabahar Bay was pyrolytic (fuel) source. PMID:26944700

  17. Bioaccumulation of silver nanoparticles in rainbow trout (Oncorhynchus mykiss): Influence of concentration and salinity

    Energy Technology Data Exchange (ETDEWEB)

    Salari Joo, Hamid, E-mail: h.salary1365@gmail.com [Department of Aquaculture, Marine Science Faculty, Tarbiat Modares University, Mazandaran, Noor (Iran, Islamic Republic of); Kalbassi, Mohammad Reza, E-mail: kalbassi_m@modares.ac.ir [Department of Aquaculture, Marine Science Faculty, Tarbiat Modares University, Mazandaran, Noor (Iran, Islamic Republic of); Yu, Il Je, E-mail: u1670916@chol.com [Institute of Nano-product Safety Research, Hoseo University, 165 Sechul-ri, Baebang-myun, Asan 336-795 (Korea, Republic of); Lee, Ji Hyun, E-mail: toxin@dreamwiz.com [Institute of Nano-product Safety Research, Hoseo University, Asan (Korea, Republic of); Johari, Seyed Ali, E-mail: a.johari@uok.ac.ir [Aquaculture Department, Natural Resources Faculty, University of Kurdistan, Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2013-09-15

    Highlights: •We studied influence of concentration and salinity on bioaccumulation of silver nanoparticles in rainbow trout (Oncorhynchus mykiss). •The Ag-NPs were characterized using standard methods. •The organisms were exposed to Ag-NPs in three different salinity concentrations, for 14 days in static renewal systems. •The bioaccumulation of Ag in the studied tissues was concentration-dependent in all the salinities and its order were liver > kidneys ≈ gills > white muscles respectively. -- Abstract: With the increasing use of silver nanoparticles (Ag-NPs), their entrance into aquatic ecosystems is inevitable. Thus, the present study simulated the potential fate, toxicity, and bioaccumulation of Ag-NPs released into aquatic systems with different salinities. The Ag-NPs were characterized using inductively coupled plasma-atomic emission spectroscopy (ICP-AES), dynamic light scattering (DLS), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDX), and UV–vis spectroscopy. Juvenile rainbow trout were exposed to Ag-NPs in three different salinity concentrations, including low (0.4 ppt), moderate (6 ± 0.3 ppt), and high (12 ± 0.2 ppt) salinity, for 14 days in static renewal systems. The nominal Ag-NP concentrations in the low salinity were 0.032, 0.1, 0.32, and 1 ppm, while the Ag-NP concentrations in the moderate and high salinity were 3.2, 10, 32, and 100 ppm. UV–vis spectroscopy was used during 48 h (re-dosing time) to evaluate the stability and possible changes in size of the Ag-NPs in the water. The results revealed that the λ{sub max} of the Ag-NPs remained stable (415–420 nm) at all concentrations in the low salinity with a reduction of absorbance between 380 and 550 nm. In contrast, the λ{sub max} quickly shifted to a longer wavelength and reduced absorbance in the moderate and higher salinity. The bioaccumulation of Ag in the studied tissues was concentration-dependent in all the salinities based on the following

  18. PILLARED ZEOLITES AMENDMENTS INFLUENCE FROM POLLUTED SOIL ON HEAVY METALS BIOACCUMULATION IN TOMATOES

    OpenAIRE

    SMARANDA MASU; B. LIXANDRU; I. DEMETROVICI; ANCA PRICOP

    2013-01-01

    Due to anthropic activities, the presence of metals in polluted soils has effects on plants development and metals bioaccumulation into trophic levels. In this paper, were followed experiments regarding the tomatoes development into polluted soils with 43.4 – 58.4 mg Cd/kg d.s. and 500- 633 mg Pb/kg d.s. Nickel, zinc and copper content in soils are in the range of diffuse pollution values. Comparatively, an experiment was realized with polluted soils and amended with pillared zeolites. Pillar...

  19. [Dissolution, absorption and bioaccumulation in gastrointestinal tract of mercury in HgS-containing traditional medicines Cinnabar and Zuotai].

    Science.gov (United States)

    Zheng, Zhi-yuan; Li, Cen; Zhang, Ming; Yang, Hong-xia; Geng, Lu-jing; Li, Lin-shuai; Du, Yu-zhi; Wei, Li-xin

    2015-06-01

    α-HgS is the main component of traditional Chinese medicine cinnabar, while β-HgS is the main component of Tibetan medicine Zuotai. However, there was no comparative study on the dissolution and absorption in gastrointestinal tract and bioaccumulation in organs of mercury in Cinnabar, Zuotai, α-HgS and β-HgS. In this study, the dissolution process of the four compounds in the human gastrointestinal tract was simulated to determine the mercury dissolutions and compare the mercury dissolution of different medicines and the dissolution-promoting capacity of different solutions. To explore the absorption and bioaccumulation of cinnabar and Zuotai in organisms, mice were orally administered with clinical equivalent doses cinnabar and Zuotai. Meanwhile, a group of mice was given α-HgS and β-HgS with the equivalent mercury with cinnabar, while another group was given β-HgS and HgCl2 with the equivalent mercury with Zuotai. The mercury absorption and bioaccumulation capacities of different medicines in mice and their mercury bioaccumulation in different tissues and organs were compared. The experimental results showed a high mercury dissolutions of Zuotai in artificial gastrointestinal fluid, which was followed by β-HgS, cinnabar and α-HgS. As for the mercury absorption and bioaccumulation in mice, HgCl2 was the highest, β-HgS was the next, and a-HgS was slightly higher than cinnabar. The organs with the mercury bioaccumulation from high to low were kidney, liver and brain. This study is close to clinical practices and can provide reference for the clinical safe medication as well as a study model for the safety evaluation on heavy metal-containing medicines by observing the mercury dissolution, absorption, distribution and accumulation of mercury-containing medicines cinnabar and zuotai. PMID:26591542

  20. Inhibition of hydroxyl radical reaction with aromatics by dissolved natural organic matter

    Science.gov (United States)

    Lindsey, M.E.; Tarr, M.A.

    2000-01-01

    Reaction of aromatic compounds with hydroxyl radical is inhibited by dissolved natural organic matter (NOM). The degree of inhibition is significantly greater than that expected based on a simple model in which aromatic compound molecules bound to NOM are considered to be unreactive. In this study, hydroxyl radical was produced at steady-state concentrations using Fenton chemistry (H2O2 + Fe2+ ??? Fe3+ + HO- + HO??). Suwannee River fulvic acid and humic acid were used as NOM. The most likely mechanism for the observed inhibition is that hydroxyl radical formation occurs in microenvironmental sites remote from the aromatic compounds. In addition to changes in kinetics, pyrene hydroxyl radical reaction also exhibited a mechanistic change in the presence of fulvic acid. The mechanism changed from a reaction that was apparently firstorder in pyrene to one that was apparently secondorder in pyrene, indicating that pyrene self-reaction may have become the dominant mechanism in the presence of fulvic acid. Dissolved NOM causes significant changes in the rate and mechanism of hydroxyl radical degradation of aromatic compounds. Consequently, literature rate constants measured in pure water will not be useful for predicting the degradation of pollutants in environmental systems. The kinetic and mechanistic information in this study will be useful for developing improved degradation methods involving Fenton chemistry.Reaction of aromatic compounds with hydroxyl radical is inhibited by dissolved natural organic matter (NOM). The degree of inhibition is significantly greater than that expected based on a simple model in which aromatic compounds molecules bounds to NOM are considered to be unreactive. In this study, hydroxyl radical was produced at steady-state concentrations using Fenton chemistry (H2O2 + Fe2+ ??? Fe3+ + HO- + HO??). Suwannee River fulvic acid and humic acid were used as NOM. The most likely mechanisms for the observed inhibition is that hydroxyl radical

  1. Explaining differences between bioaccumulation measurements in laboratory and field data through use of a probabilistic modeling approach

    Science.gov (United States)

    Selck, Henriette; Drouillard, Ken; Eisenreich, Karen; Koelmans, Albert A.; Palmqvist, Annemette; Ruus, Anders; Salvito, Daniel; Schultz, Irv; Stewart, Robin; Weisbrod, Annie; van den Brink, Nico W.; van den Heuvel-Greve, Martine

    2012-01-01

    In the regulatory context, bioaccumulation assessment is often hampered by substantial data uncertainty as well as by the poorly understood differences often observed between results from laboratory and field bioaccumulation studies. Bioaccumulation is a complex, multifaceted process, which calls for accurate error analysis. Yet, attempts to quantify and compare propagation of error in bioaccumulation metrics across species and chemicals are rare. Here, we quantitatively assessed the combined influence of physicochemical, physiological, ecological, and environmental parameters known to affect bioaccumulation for 4 species and 2 chemicals, to assess whether uncertainty in these factors can explain the observed differences among laboratory and field studies. The organisms evaluated in simulations including mayfly larvae, deposit-feeding polychaetes, yellow perch, and little owl represented a range of ecological conditions and biotransformation capacity. The chemicals, pyrene and the polychlorinated biphenyl congener PCB-153, represented medium and highly hydrophobic chemicals with different susceptibilities to biotransformation. An existing state of the art probabilistic bioaccumulation model was improved by accounting for bioavailability and absorption efficiency limitations, due to the presence of black carbon in sediment, and was used for probabilistic modeling of variability and propagation of error. Results showed that at lower trophic levels (mayfly and polychaete), variability in bioaccumulation was mainly driven by sediment exposure, sediment composition and chemical partitioning to sediment components, which was in turn dominated by the influence of black carbon. At higher trophic levels (yellow perch and the little owl), food web structure (i.e., diet composition and abundance) and chemical concentration in the diet became more important particularly for the most persistent compound, PCB-153. These results suggest that variation in bioaccumulation

  2. Persistent organic pollutants in the Antarctic coastal environment and their bioaccumulation in penguins.

    Science.gov (United States)

    Mwangi, John Kennedy; Lee, Wen-Jhy; Wang, Lin-Chi; Sung, Ping-Jyun; Fang, Lee-Shing; Lee, Yen-Yi; Chang-Chien, Guo-Ping

    2016-09-01

    Persistent organic pollutants (POPs), including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), polybrominated biphenyls (PBBs), and polybrominated diphenyl ethers (PBDEs), have been identified in penguins, lichens, soils, and ornithogenic soils in the Antarctic coastal environment in this study. To the best of our knowledge, no previous study has reported PBDD/F and PBB data from Antarctica. The POP mass contents in penguins were in the following order: PCBs > PBDEs > PCDD/Fs; PCBs were the dominant pollutants (6310-144,000 pg/g-lipid), with World Health Organization toxic equivalency values being 2-14 times higher than those of PCDD/Fs. Long-range atmospheric transport is the most primary route by which POPs travel to Antarctica; however, local sources, such as research activities and penguin colonies, also influence POP distribution in the local Antarctic environment. In penguins, the biomagnification factor (BMF) of PCBs was 61.3-3760, considerably higher than that for other POPs. According to BMF data in Adélie penguins, hydrophobic PBDE congeners were more biomagnified at log Kow > 6, and levels decreased at log Kow > 7.5 because larger molecular sizes inhibited transfer across cell membranes.

  3. Post-translational hydroxylation by 2OG/Fe(II-dependent oxygenases as a novel regulatory mechanism in bacteria

    Directory of Open Access Journals (Sweden)

    Laura M van Staalduinen

    2015-01-01

    Full Text Available Protein hydroxylation has been well-studied in eukaryotic systems. The structural importance of hydroxylation of specific proline and lysine residues during collagen biosynthesis is well established while, recently, key roles for post-translational hydroxylation in signalling and degradation pathways have been discovered. The function of hydroxylation in signalling is highlighted by its role in the hypoxic response of eukaryotic cells, where oxygen dependent hydroxylation of the hypoxia inducible transcription factor both targets it for degradation and blocks its activation. In contrast, the role of protein hydroxylation has been largely understudied in prokaryotes. Recently, an evolutionarily conserved class of ribosomal oxygenases (ROX that catalyze the hydroxylation of specific residues in the ribosome has been identified in bacteria. ROX activity has been linked to cell growth, and has been found to have a direct impact on bulk protein translation. This discovery of ribosomal protein hydroxylation in bacteria could lead to new therapeutic targets for regulating bacterial growth, as well as, shed light on new prokaryotic hydroxylation signalling pathways. In this review, recent structural and functional studies will be highlighted and discussed, underscoring the regulatory potential of post-translational hydroxylation in bacteria.

  4. Review of OPFRs in animals and humans: Absorption, bioaccumulation, metabolism, and internal exposure research.

    Science.gov (United States)

    Hou, Rui; Xu, Yiping; Wang, Zijian

    2016-06-01

    Due to their widespread use, organophosphate flame retardants (OPFRs) are commonly detected in various environmental matrices and have been identified as emerging contaminants. Considering the adverse effects of OPFRs, many researchers have paid their attention on the absorption, bioaccumulation, metabolism and internal exposure processes of OPFRs in animals and humans. In this article, we first review the diverse absorption routes of OPFRs by animals and humans (e.g., inhalation, ingestion, dermal absorption and gill absorption). Bioaccumulation and biomagnification potentials of OPFRs in different types of organisms and food webs are also summarized, based on quite limited available data and results. For metabolism, we review the Phase-I and Phase-II metabolic processes for each type of OPFRs (chlorinated OPFRs, alkyl-OPFRs and aryl-OPFRs) in the animals and humans, as well as toxicokinetic information and putative exposure biomarkers on OPFRs. Finally, we highlight gaps in our knowledge and critical directions for future internal exposure studies of OPFRs in animals and humans. PMID:27010170

  5. Mercury bioaccumulation in an estuarine predator: Biotic factors, abiotic factors, and assessments of fish health.

    Science.gov (United States)

    Smylie, Meredith S; McDonough, Christopher J; Reed, Lou Ann; Shervette, Virginia R

    2016-07-01

    Estuarine wetlands are major contributors to mercury (Hg) transformation into its more toxic form, methylmercury (MeHg). Although these complex habitats are important, estuarine Hg bioaccumulation is not well understood. The longnose gar Lepisosteus osseus (L. 1758), an estuarine predator in the eastern United States, was selected to examine Hg processes due to its abundance, estuarine residence, and top predator status. This study examined variability in Hg concentrations within longnose gar muscle tissue spatially and temporally, the influence of biological factors, potential maternal transfer, and potential negative health effects on these fish. Smaller, immature fish had the highest Hg concentrations and were predominantly located in low salinity waters. Sex and diet were also important factors and Hg levels peaked in the spring. Although maternal transfer occurred in small amounts, the potential negative health effects to young gar remain unknown. Fish health as measured by fecundity and growth rate appeared to be relatively unaffected by Hg at concentrations in the present study (less than 1.3 ppm wet weight). The analysis of biotic and abiotic factors relative to tissue Hg concentrations in a single estuarine fish species provided valuable insight in Hg bioaccumulation, biomagnification, and elimination. Insights such as these can improve public health policy and environmental management decisions related to Hg pollution. PMID:27086072

  6. Uranium bioaccumulation and biological disorders induced in zebrafish (Danio rerio) after a depleted uranium waterborne exposure

    Energy Technology Data Exchange (ETDEWEB)

    Barillet, Sabrina, E-mail: sabrina.barillet@free.f [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Adam-Guillermin, Christelle, E-mail: christelle.adam-guillermin@irsn.f [Laboratory of Radioecology and Ecotoxicology, IRSN (Institute for Radiological protection and Nuclear Safety), DEI/SECRE/LRE, Cadarache, Bat 186, BP 3, 13115 St-Paul-Lez-Durance cedex (France); Palluel, Olivier, E-mail: olivier.palluel@ineris.f [Ecotoxicological Risk Assessment Unit, INERIS (National Institute for Industrial Environment and Risks), Parc technologique ALATA, 60 550 Verneuil-en-Halatte (France); Porcher, Jean-Marc, E-mail: jean-marc.porcher@ineris.f [Ecotoxicological Risk Assessment Unit, INERIS (National Institute for Industrial Environment and Risks), Parc technologique ALATA, 60 550 Verneuil-en-Halatte (France); Devaux, Alain, E-mail: alain.devaux@entpe.f [Universite de Lyon, INRA, EFPA-SA, Environmental Science Laboratory (LSE), ENTPE, 69518 Vaulx en Velin cedex (France)

    2011-02-15

    Because of its toxicity and its ubiquity within aquatic compartments, uranium (U) represents a significant hazard to aquatic species such as fish. In a previous study, we investigated some biological responses in zebrafish either exposed to depleted or to enriched U (i.e., to different radiological activities). However, results required further experiments to better understand biological responses. Moreover, we failed to clearly demonstrate a significant relationship between biological effects and U radiological activity. We therefore chose to herein examine U bioaccumulation and induced effects in zebrafish according to a chemical dose-response approach. Results showed that U is highly bioconcentrated in fish, according to a time- and concentration-dependent model. Additionally, hepatic antioxidant defenses, red blood cells DNA integrity and brain acetylcholinesterase activity were found to be significantly altered. Generally, the higher the U concentration, the sooner and/or the greater the effect, suggesting a close relationship between accumulation and effect. - Research highlights: Depleted U bioconcentration factor is of about 1000 in zebrafish exposed to 20 {mu}g/L. Hepatic antioxidant disorders are noticed as soon as the first hours of exposure. DNA damage is induced in red blood cells after 20 d of exposure to 500 {mu}g DU/L. The brain cholinergic system (AChE activity) is impacted. - This study demonstrates that U is highly bioaccumulated in fish, resulting in biological disorders such as hepatic oxidative stress as well as genotoxic and neurotoxic events.

  7. Fluoride bioaccumulation by hydroponic cultures of camellia (Camellia japonica spp.) and sugar cane (Saccharum officinarum spp.).

    Science.gov (United States)

    Camarena-Rangel, Nancy; Rojas Velázquez, Angel Natanael; Santos-Díaz, María del Socorro

    2015-10-01

    The ability of hydroponic cultures of camellia and sugar cane adult plants to remove fluoride was investigated. Plants were grown in a 50% Steiner nutrient solution. After an adaptation period to hydroponic conditions, plants were exposed to different fluoride concentrations (0, 2.5, 5 and 10 mg L(-1)). Fluoride concentration in the culture medium and in tissues was measured. In sugar cane, fluoride was mainly located in roots, with 86% of it absorbed and 14% adsorbed. Sugar cane plants removed 1000-1200 mg fluoride kg(-1) dry weight. In camellia plants the highest fluoride concentration was found in leaf. Roots accumulated fluoride mainly through absorption, which was 2-5 times higher than adsorption. At the end of the experiment, fluoride accumulation in camellia plants was 1000-1400 mgk g(-1) dry weight. Estimated concentration factors revealed that fluoride bioaccumulation is 74-221-fold in camellia plants and 100-500-fold in sugar cane plants. Thus, the latter appear as a suitable candidate for removing fluoride from water due to their bioaccumulation capacity and vigorous growth rate; therefore, sugar cane might be used for phytoremediation. PMID:25930125

  8. Bioaccumulation of metals in sediments, fish and plant from Tisza river (Serbia)

    Science.gov (United States)

    Štrbac, Snežana; Gajica, Gordana; Kašanin-Grubin, Milica; Šajnović, Aleksandra; Vasić, Nebojša; Jovančićević, Branimir; Simonović, Predrag

    2014-05-01

    In the aquatic environments metals originate from various natural and anthropogenic sources. The purpose of the study was to assess the bioaccumulation level of metals in sediments fish and common reed at four different localities of the Tisza River stretch in Serbia. For purpose of this study concentrations of Al, As, B, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sr and Zn were determined in sediment, common reed (Phragmites australis (Cav.) Trin. ex Steud. 1841) and four ecologically different fish species (piscivorous northern pike (Esox lucius L.), benthivorous sterlet (Acipenser ruthenus L.) silver bream (Brama brama L.), omnivorous common carp (Cyprinus carpio L.)). Analysis of metals was carried out for liver, gills, brain, testicles and ovaries in fish and in the rhizome, stem and leaves of the common reed and sediment fraction leaves>stems. Obtained results indicate that the location does not have impact to the level of bioaccumulation. On the basis of this research the under-ground organ (rhizome) of common reed, liver and gills and omnivorous fish species could be recommended as environmental indicators for the presence of metals during environmental monitoring.

  9. Bioaccumulation of heavy metals in Mbaa River and the impact on aquatic ecosystem.

    Science.gov (United States)

    Ajima, M N O; Nnodi, P C; Ogo, O A; Adaka, G S; Osuigwe, D I; Njoku, D C

    2015-12-01

    The bioaccumulation and toxic effects of heavy metals have caused ecological damage to aquatic ecosystem. In this study, concentration of heavy metals including zinc, lead, cadmium, iron, and copper were determined in the sediment and water as well as in the muscle, gill, and intestine of two fish species (Pelmatochromis guentheri and Pelmatochromis pulcher) of Mbaa River in Southeastern Nigeria. Samples were collected at three different spots from the river, and the level of heavy metals specified above were determined by atomic absorption spectroscopy (AAS) after a modified wet digestion process. The results indicated that sediment had the highest concentration of the heavy metals investigated while water had the lowest concentration. Fish tissues showed appreciable bioaccumulation of these metals as evidenced by a higher concentration profile when compared with that of water. Furthermore, the concentration of these heavy metals in water and their bioconcentration factor in the fish were above the recommended limit by WHO and FEPA, indicating that Mbaa River along Inyishi may not be suitable for drinking nor the fish safe for human consumption. The study also reveals the use of fish as bioindicator of aquatic environment. PMID:26597816

  10. Uranium bioaccumulation and biological disorders induced in zebrafish (Danio rerio) after a depleted uranium waterborne exposure

    International Nuclear Information System (INIS)

    Because of its toxicity and its ubiquity within aquatic compartments, uranium (U) represents a significant hazard to aquatic species such as fish. In a previous study, we investigated some biological responses in zebrafish either exposed to depleted or to enriched U (i.e., to different radiological activities). However, results required further experiments to better understand biological responses. Moreover, we failed to clearly demonstrate a significant relationship between biological effects and U radiological activity. We therefore chose to herein examine U bioaccumulation and induced effects in zebrafish according to a chemical dose-response approach. Results showed that U is highly bioconcentrated in fish, according to a time- and concentration-dependent model. Additionally, hepatic antioxidant defenses, red blood cells DNA integrity and brain acetylcholinesterase activity were found to be significantly altered. Generally, the higher the U concentration, the sooner and/or the greater the effect, suggesting a close relationship between accumulation and effect. - Research highlights: → Depleted U bioconcentration factor is of about 1000 in zebrafish exposed to 20 μg/L. → Hepatic antioxidant disorders are noticed as soon as the first hours of exposure. → DNA damage is induced in red blood cells after 20 d of exposure to 500 μg DU/L. → The brain cholinergic system (AChE activity) is impacted. - This study demonstrates that U is highly bioaccumulated in fish, resulting in biological disorders such as hepatic oxidative stress as well as genotoxic and neurotoxic events.

  11. Zinc and copper bioaccumulation in fish from Laizhou Bay, the Bohai Sea

    Science.gov (United States)

    Liu, Jinhu; Cao, Liang; Huang, Wei; Zhang, Chuantao; Dou, Shuozeng

    2014-05-01

    Zinc (Zn) and copper (Cu) concentrations were determined in the tissues (muscle, stomach, liver, gills, skin, and gonads) of five commercial fish species (mullet Liza haematocheilus, flathead Platycephalus indicus, mackerel Scomberomorus niphonius, silver pomfret Pampus argenteus, and sea bass Lateolabrax japonicus) from Laizhou Bay in the Bohai Sea. Metal bioaccumulation was highest in the metabolically active tissues of the gonads and liver. Bioconcentration factors for Zn were higher in all tissues (gonads 44.35, stomach 7.73, gills 7.72, liver 5.61, skin 4.88, and muscle 1.63) than the corresponding values for Cu (gonads 3.50, stomach 3.00, gills 1.60, liver 5.43, skin 1.50, and muscle 0.93). Mackerel tissues accumulated metal to higher concentrations than did other fish species, but bioaccumulation levels were not significantly correlated with the trophic levels of the fish. Zn and Cu concentrations in the tissues were generally negatively correlated with fish length, except for a few tissues of sea bass. Risk assessment based on national and international permissible limits and provisional tolerances for weekly intake of Zn and Cu revealed that the concentrations of these two metals in muscle were relatively low and would not pose hazards to human health.

  12. Delonix regia and Casuarina equisetifolia as passive biomonitors and as bioaccumulators of atmospheric trace metals.

    Science.gov (United States)

    Ukpebor, Emmanuel Ehiabhi; Ukpebor, Justina Ebehirieme; Aigbokhan, Emmanuel; Goji, Idris; Onojeghuo, Alex Okiemute; Okonkwo, Anthony Chinedum

    2010-01-01

    The suitability of two common and ubiquitously distributed and exotic ornamental plant species in Nigeria-Delonix regia and Casuarina equisetifolia as biomonitors and as effective bioaccumulators of atmospheric trace metals (Cd, Pb, Zn and Cu) has been evaluated. Bark and leaf samples from these plant species were collected in June and July 2006 at five locations in Benin City. Four of the sampling sites were in areas of high traffic density and commercial activities, the fifth site is a remote site, selected to act as a control and also to provide background information for the metals. The plant samples were collected and processed using standard procedures and trace metals were determined using atomic absorption spectrometer. The bark of the plants was able to bioaccumulate the trace metals, especially Pb which originates from anthropogenic contributions in the city. The Pb range of 20.00-70.00 microg/g measured for the bark samples of D. regia, exceeded the normal plant Pb concentration of 0.2-20.0 microg/g and most Pb data available in literature. The bark of the plants was observed to accumulate more metals compared to the leave, while D. regia was found to be slightly better than C. equisetifolia in trace metal uptake efficiency. Spatial variations in the distributions of Pb and Zn were significant (p < 0.05), and the continuous use of leaded fuel in Nigeria was identified as the predominant source of Pb in the atmosphere.

  13. Fluoride bioaccumulation by hydroponic cultures of camellia (Camellia japonica spp.) and sugar cane (Saccharum officinarum spp.).

    Science.gov (United States)

    Camarena-Rangel, Nancy; Rojas Velázquez, Angel Natanael; Santos-Díaz, María del Socorro

    2015-10-01

    The ability of hydroponic cultures of camellia and sugar cane adult plants to remove fluoride was investigated. Plants were grown in a 50% Steiner nutrient solution. After an adaptation period to hydroponic conditions, plants were exposed to different fluoride concentrations (0, 2.5, 5 and 10 mg L(-1)). Fluoride concentration in the culture medium and in tissues was measured. In sugar cane, fluoride was mainly located in roots, with 86% of it absorbed and 14% adsorbed. Sugar cane plants removed 1000-1200 mg fluoride kg(-1) dry weight. In camellia plants the highest fluoride concentration was found in leaf. Roots accumulated fluoride mainly through absorption, which was 2-5 times higher than adsorption. At the end of the experiment, fluoride accumulation in camellia plants was 1000-1400 mgk g(-1) dry weight. Estimated concentration factors revealed that fluoride bioaccumulation is 74-221-fold in camellia plants and 100-500-fold in sugar cane plants. Thus, the latter appear as a suitable candidate for removing fluoride from water due to their bioaccumulation capacity and vigorous growth rate; therefore, sugar cane might be used for phytoremediation.

  14. Bioaccumulation and Elimination of the Herbicide Clomazone in the Earthworms Eisenia fetida.

    Science.gov (United States)

    Cao, Jia; Li, Ping; Li, Qing X; Zheng, Pengfei; Diao, Xiaoping

    2015-11-01

    Acute toxicity, bioaccumulation, and elimination of herbicide clomazone in the earthworm Eisenia fetida were investigated in the different exposure systems. The LC50 values of clomazone on earthworms were 5.6 μg cm(-2) in the contact filter paper test (48 h), 174.9 mg kg(-1) (7 days) and 123.4 mg kg(-1) (14 days) in artificial soil test, respectively. Clomazone could rapidly bioaccumulate in earthworms and reached the highest concentration after 3 days exposure, with the maximum concentrations of 9.0, 35.3 and 142.3 mg kg(-1) at 10.0, 40.0 and 160.0 mg kg(-1) of clomazone, respectively. Clomazone uptake showed a good correlation with exposure concentration. After the 14th day, clomazone declined to minimum value. About 74%-80% of accumulated clomazone was eliminated within 1 day after exposed to clomazone-free soil. However, a trace amount of clomazone persisted for a relatively long time in earthworms.

  15. TOTAL MERCURY (HgT BIOACCUMULATION AND FISH FOOD HABITS IN NEGRO RIVER BASIN, AMAZON, BRAZIL

    Directory of Open Access Journals (Sweden)

    Jean Louchard Ferreira Soares

    2016-03-01

    Full Text Available In the Amazon, the fish is the main nutritional source for the riverine. Thus, fish have been commonly used in environmental monitoring work to be good biomonitors. This study analyzed the total mercury concentration (THg in fish of different species and feeding habits in order to investigate the existence of bioaccumulation in species in the basin of the Negro river and verify that the THg levels found are in accordance with the stipulated limit for consumption human. Sampling points were distributed in the basin of the Negro river during the period of high water. After the fisheries specimens were identified, measured and weighed. Then muscle samples were taken and subjected to acid digestion and analyzed by Cold Vapor Atomic Fluorescence Spectrophotometer - CVAFS. To research data was used analysis of variance and linear regression. A total of 264 specimens distributed into 10 species were analyzed, and the THg of the concentrations ranged from 0.030 for 1,670 mg.kg-1. The species Hoplias malabaricus, Serrasalmus rhombeus, Hemiodus immaculatus and Cichla temensis showed bioaccumulation. High concentrations of THg were found in carnivorous, piscivorous, planctívos and omnivores fish. No specimen showed mean concentrations of THg in violation to ANVISA, but this occurred in relation to FAO and WHO. keywords: Brazilian Amazon; biomonitoring; high waters; Hg.

  16. Modeling bioaccumulation and biomagnification of nonylphenol and its ethoxylates in estuarine-marine food chains.

    Science.gov (United States)

    Korsman, John C; Schipper, Aafke M; de Vos, Martine G; van den Heuvel-Greve, Martine J; Vethaak, A Dick; de Voogt, Pim; Hendriks, A Jan

    2015-11-01

    There are several studies on bioaccumulation and biomagnification of nonylphenol (NP) and its ethoxylates (NPEOs), but their toxico-kinetic mechanisms remain unclear. In the present investigation, we explored the accumulation of NP and NPEOs in estuarine-marine food chains with a bioaccumulation model comprising five trophic levels. Using this model, we estimated uptake and elimination rate constants for NPEOs based on the organisms' weight and lipid content and the chemicals' Kow. Further, we calculated accumulation factors for NP and NPEOs, including biota-sediment accumulation factors (BSAF) and biomagnification factors (BMF), and compared these to independent field measurements collected in the Western Scheldt estuary in The Netherlands and field data reported in the literature. The estimated BSAF values for NP and total NPEOs were below 1 for all trophic levels. The estimated BMF values were around 1 for all trophic levels except for the highest level (carnivorous mammals and birds). For this trophic level, the estimated BMF value varied between 0.1 and 2.4, depending on the biotransformation capacity. For all trophic levels, except primary producers, the accumulation estimates that accounted for biotransformation of NPEOs into NP were closer to the field data than model estimates that did not include biotransformation, indicating that NP formation by biotransformation of NPEOs might occur in organisms. PMID:26026901

  17. The Bioaccumulation of Some Heavy Metals in the Fruiting Body of Wild Growing Mushrooms

    Directory of Open Access Journals (Sweden)

    Carmen Cristina ELEKES

    2010-09-01

    Full Text Available Due to their effective mechanism of accumulation of heavy metals from soil, the macrofungi show high concentrations of metals in their fruiting body. According with this ability, the mushrooms can be used to evaluate and control the level of environmental pollution, but also represent danger for human ingestion. We analyzed some macrofungi species from a wooded area to establish the heavy metal concentrations and ability of bioaccumulation and translocation for Zn, Cu and Sn in fruiting body. The metallic content was established by the Inductively Coupled Plasma-Atomic Emission Spectrometry method (ICP-AES. The minimal detection limits of method is 0.4 mg/kg for Zn and Cu and 0.6 mg/kg for Sn. Heavy metals concentrations in the fruiting body ranged between 6.98-20.10 mg/kg for Zn (the higher value was for Tapinella atrotomentosa; 16.13-144.94 mg/kg for Cu (the higher value was for Hypholoma fasciculare; and 24.36-150.85 mg/kg for Sn (the higher value was for Paxillus involutus. The bioaccumulation factor has important values (higher than 1 only for copper in all the analyzed species (between 1.30 and 8.86 and for tin in Paxillus involutus species (1.19. The translocation factor shows that zinc and tin were accumulated in higher concentrations in cap of mushrooms and the copper had higher concentrations in stipe.

  18. Heavy metals bioaccumulation in Berseem (Trifolium alexandrinum) cultivated in areas under intensive agriculture, Punjab, India.

    Science.gov (United States)

    Bhatti, Sandip Singh; Sambyal, Vasudha; Nagpal, Avinash Kaur

    2016-01-01

    Berseem (Trifolium alexandrinum) is one of the main fodder crops of Punjab, India. But due to the heavy metal contamination of agricultural soils by anthropogenic activities, there is rise in metal bioaccumulation in crops like Berseem. In addition to human influence, heavy metal contents in soil are highly dependent on soil characteristics also. Therefore a study was conducted in areas having intensive agricultural practices to analyze physico-chemical characteristics of soils under Berseem cultivation and heavy metal bioaccumulation in Berseem. The studied soils were alkaline, sandy in texture and low in soil organic matter. Among the studied heavy metals (Cr, Cu, Cd, Co and Pb) in soil and Berseem, Cr content in Berseem was found to be above maximum permissible limits. Soil to Berseem metal bioaccmulation factor (BAF) was above 1 for Cr, Cu, Cd and Co in many samples and highest BAF was found for Co (4.625). Hence it can be concluded that Berseem from studied areas was unsafe for animal consumption. PMID:27026870

  19. Marine foraging ecology influences mercury bioaccumulation in deep-diving northern elephant seals

    Science.gov (United States)

    Peterson, Sarah H.; Ackerman, Joshua T.; Costa, Daniel P.

    2015-01-01

    Mercury contamination of oceans is prevalent worldwide and methylmercury concentrations in the mesopelagic zone (200–1000 m) are increasing more rapidly than in surface waters. Yet mercury bioaccumulation in mesopelagic predators has been understudied. Northern elephant seals (Mirounga angustirostris) biannually travel thousands of kilometres to forage within coastal and open-ocean regions of the northeast Pacific Ocean. We coupled satellite telemetry, diving behaviour and stable isotopes (carbon and nitrogen) from 77 adult females, and showed that variability among individuals in foraging location, diving depth and δ13C values were correlated with mercury concentrations in blood and muscle. We identified three clusters of foraging strategies, and these resulted in substantially different mercury concentrations: (i) deeper-diving and offshore-foraging seals had the greatest mercury concentrations, (ii) shallower-diving and offshore-foraging seals had intermediate levels, and (iii) coastal and more northerly foraging seals had the lowest mercury concentrations. Additionally, mercury concentrations were lower at the end of the seven-month-long foraging trip (n = 31) than after the two-month- long post-breeding trip (n = 46). Our results indicate that foraging behaviour influences mercury exposure and mesopelagic predators foraging in the northeast Pacific Ocean may be at high risk for mercury bioaccumulation.

  20. Bioaccumulation of PCBs in the cuttlefish Sepia officinalis from seawater, sediment and food pathways

    Energy Technology Data Exchange (ETDEWEB)

    Danis, B. [Laboratoire de Biologie Marine (CP 160-15), Universite Libre de Bruxelles, 50 Av. F.D. Roosevelt, B-1050 Brussels (Belgium)]. E-mail: bdanis@ulb.ac.be; Bustamante, P. [Laboratoire de Biologie et Environnement Marins, UPRES-EA 3168, Universite de La Rochelle, 22 Av. Michel Crepeau, F-17042 La Rochelle Cedex (France); Cotret, O. [Marine Environment Laboratory - International Atomic Energy Agency, 4 Quai Antoine Ier, Monaco, MC-98000 Monaco (Monaco); Teyssie, J.L. [Marine Environment Laboratory - International Atomic Energy Agency, 4 Quai Antoine Ier, Monaco, MC-98000 Monaco (Monaco); Fowler, S.W. [Marine Environment Laboratory - International Atomic Energy Agency, 4 Quai Antoine Ier, Monaco, MC-98000 Monaco (Monaco); Warnau, M. [Marine Environment Laboratory - International Atomic Energy Agency, 4 Quai Antoine Ier, Monaco, MC-98000 Monaco (Monaco)

    2005-03-01

    The cuttlefish Sepia officinalis was selected as a model cephalopod to study PCB bioaccumulation via seawater, sediments and food. Newly hatched, juvenile cuttlefish were exposed for 17 days to environmentally realistic concentrations of {sup 14}C-labeled 2,2',4,4',5,5'-hexachlorobiphenyl (PCB no. 153) (18 ng PCB l{sup -1} seawater; 30 ng PCB g{sup -1} dry wt sediments; Artemia salina exposed to 18 ng PCB l{sup -1} seawater). Accumulation of PCB no. 153 was followed in three body compartments: digestive gland, cuttlebone and the combined remaining tissues. Results showed that (1) uptake kinetics were source- and body compartment-dependent, (2) for each body compartment, the accumulation was far greater when S. officinalis was exposed via seawater, (3) the cuttlebone accumulated little of the contaminant regardless of the source, and (4) the PCB congener showed a similar distribution pattern among the different body compartments following exposure to contaminated seawater, sediment or food with the lowest concentrations in the cuttlebone and the highest in the remaining tissues. The use of radiotracer techniques allowed delineating PCB kinetics in small whole organisms as well as in their separate tissues. The results underscore the enhanced ability of cephalopods to concentrate organic pollutants such as PCBs, and raise the question of potential risk to their predators in contaminated areas. - Bioaccumulation of PCBs by cuttlefish is studied, via seawater, sediments and their food.

  1. Bioaccumulation of selenium from coal fly ash and associated environmental hazards in a freshwater fish community

    International Nuclear Information System (INIS)

    Bioaccumulation of Se by fish from Pigeon River and Pigeon Lake, Michigan, which receive inputs of Se from a coal fly-ash disposal facility, was studied to assess potential hazards of Se toxicity to fish and wildlife. Se concentrations in fish from sites receiving Se inputs from fly ash disposal ponds were significantly greater than concentrations in fish from upstream sites, which were near normal background concentrations. Se bioaccumulation differed substantially among fish species, especially in the most contaminated site, where whole-body Se concentrations for the five species analyzed ranged from 1.4 to 3.8 microg/g (wet wt.). The top predator in the community, northern pike (Esox lucius), had Se concentrations less than those in likely prey species. Among lower-order consumers, Se concentrations were greater in limnetic species (spottail shiner, Notropis hudsonius, and yellow perch, Perca flavescens), than in benthic species (white sucker, Catostomus commersoni, and rock bass, Ambloplites rupestris). Se concentrations in tissues of fish from the lower Pigeon River and Pigeon Lake approached, but did not exceed lowest observable effect concentrations (LOAECs) for Se in tissues of sensitive fish species. However, Se concentrations in several fish species exceeded LOAECs for dietary Se exposure of sensitive species of birds and mammals, suggesting that consumption of fish in these areas may pose a hazard to piscivorous wildlife

  2. Bioaccumulation and analytics of pharmaceutical residues in the environment: A review.

    Science.gov (United States)

    Puckowski, Alan; Mioduszewska, Katarzyna; Łukaszewicz, Paulina; Borecka, Marta; Caban, Magda; Maszkowska, Joanna; Stepnowski, Piotr

    2016-08-01

    The presence of pharmaceutical residues in various environmental compartments is an issue of increasing concern. The widespread occurrence of these compounds in water and soil samples has been demonstrated in a number of analytical studies. However, the data about their concentrations in biota samples is scarce. Moreover, the trophic transfer of pharmaceuticals remains largely unexplored, despite increasing evidence of the potential bioaccumulation of those compounds. Therefore, the main aim of this review is to present an overview of the current state of data about the bioaccumulation and analytical methodologies used for the determination of pharmaceutical residues in biota samples. This work focuses on the most commonly found pharmaceuticals in the environment: antibiotics, analgesic and anti-inflammatory drugs, steroid hormones, antihypertensives and antidepressants. We do hope that the collected data will allow a better understanding of pharmaceutical pollution and the exposure of non-target organisms. However, although impressive progress has undoubtedly been made, in order to fully understand the behavior of these chemicals in the environment, there are still numerous gaps to be filled in our overall knowledge in this field. PMID:26968887

  3. Antioxidative responses and bioaccumulation in Japanese flounder larvae and juveniles under chronic mercury exposure.

    Science.gov (United States)

    Huang, Wei; Cao, Liang; Ye, Zhenjiang; Yin, Xuebo; Dou, Shuozeng

    2010-06-01

    This study investigated the sub-lethal effects of waterborne mercury on growth, bioaccumulation and antioxidative responses of larvae and juveniles of Japanese flounder (Paralichthys olivaceus). Fish were exposed to 0-10 microg Hg(2)(+)L(-1) solutions from embryonic to the juvenile stages for 80 days. Antioxidative responses to mercury exposure were studied in metamorphosing larvae (18 days post hatching, dph), settling larvae (33 dph) and juveniles (78 dph). Results showed that increasing mercury concentration led to increased mercury bioaccumulation and reduced flounder growth. Of the antioxidants investigated, superoxide dismutase (SOD) and catalase (CAT) activities at the three developmental stages were sensitive to mercury exposure and increased with increasing mercury concentration. Glutathione (GSH) content was elevated in metamorphosing larvae, but decreased in juveniles as mercury concentration increased. Glutathione-S-transferase (GST) activity did not significantly vary with mercury concentration in either larvae or juveniles. Mercury exposure did not affect malondialdehyde (MDA) content of larvae, but significantly increased MDA content of juveniles. Results suggest that flounder larvae and juveniles have the potential to manipulate the levels of antioxidants such as SOD, CAT and GSH, which protect flounder from oxidative stress induced by mercury exposure. These antioxidants could serve as biomarkers of mercury contamination in the aquatic environment.

  4. Clustering of Oxygen Vacancies at CeO2(111): Critical Role of Hydroxyls.

    Science.gov (United States)

    Wu, Xin-Ping; Gong, Xue-Qing

    2016-02-26

    By performing density functional theory calculations corrected by an on site Coulomb interaction, we find that the defects at the CeO_{2}(111) surface observed by the scanning tunneling microscopy (STM) measurements of Esch et al. [Science 309, 752 (2005)] are not mere oxygen vacancies or fluorine impurities as suggested by Kullgren et al. [Phys. Rev. Lett. 112, 156102 (2014)], but actually the hydroxyl-vacancy combined species. Specifically, we show that hydroxyls play a critical role in the formation and propagation of oxygen vacancy clusters (VCs). In the presence of neighboring hydroxyls, the thermodynamically unstable VCs can be significantly stabilized, and the behaviors of oxygen vacancies become largely consistent with the STM observations. In addition to the clarification of the long term controversy on the surface defect structures of CeO_{2}(111), the "hydroxyl-vacancy model" proposed in this work emphasizes the coexistence of hydroxyls and oxygen vacancies, especially VCs, which is important for understanding the catalytic and other physicochemical properties of reducible metal oxides. PMID:26967428

  5. Developmental Stage-dependent Regulation of Prolyl 3-Hydroxylation in Tendon Type I Collagen.

    Science.gov (United States)

    Taga, Yuki; Kusubata, Masashi; Ogawa-Goto, Kiyoko; Hattori, Shunji

    2016-01-01

    3-Hydroxyproline (3-Hyp), which is unique to collagen, is a fairly rare post-translational modification. Recent studies have suggested a function of prolyl 3-hydroxylation in fibril assembly and its relationships with certain disorders, including recessive osteogenesis imperfecta and high myopia. However, no direct evidence for the physiological and pathological roles of 3-Hyp has been presented. In this study, we first estimated the overall alterations in prolyl hydroxylation in collagens purified from skin, bone, and tail tendon of 0.5-18-month-old rats by LC-MS analysis with stable isotope-labeled collagen, which was recently developed as an internal standard for highly accurate collagen analyses. 3-Hyp was found to significantly increase in tendon collagen until 3 months after birth and then remain constant, whereas increased prolyl 3-hydroxylation was not observed in skin and bone collagen. Site-specific analysis further revealed that 3-Hyp was increased in tendon type I collagen in a specific sequence region, including a previously known modification site at Pro(707) and newly identified sites at Pro(716) and Pro(719), at the early ages. The site-specific alterations in prolyl 3-hydroxylation with aging were also observed in bovine Achilles tendon. We postulate that significant increases in 3-Hyp at the consecutive modification sites are correlated with tissue development in tendon. The present findings suggest that prolyl 3-hydroxylation incrementally regulates collagen fibril diameter in tendon.

  6. Determination of surface-accessible acidic hydroxyls and surface area of lignin by cationic dye adsorption.

    Science.gov (United States)

    Sipponen, Mika Henrikki; Pihlajaniemi, Ville; Littunen, Kuisma; Pastinen, Ossi; Laakso, Simo

    2014-10-01

    A new colorimetric method for determining the surface-accessible acidic lignin hydroxyl groups in lignocellulose solid fractions was developed. The method is based on selective adsorption of Azure B, a basic dye, onto acidic hydroxyl groups of lignin. Selectivity of adsorption of Azure B on lignin was demonstrated using lignin and cellulose materials as adsorbents. Adsorption isotherms of Azure B on wheat straw (WS), sugarcane bagasse (SGB), oat husk, and isolated lignin materials were determined. The maximum adsorption capacities predicted by the Langmuir isotherms were used to calculate the amounts of surface-accessible acidic hydroxyl groups. WS contained 1.7-times more acidic hydroxyls (0.21 mmol/g) and higher surface area of lignin (84 m(2)/g) than SGB or oat husk materials. Equations for determining the amount of surface-accessible acidic hydroxyls in solid fractions of the three plant materials by a single point measurement were developed. A method for high-throughput characterization of lignocellulosic materials is now available. PMID:25033327

  7. Human Insulin Resistance Is Associated With Increased Plasma Levels of 12α-Hydroxylated Bile Acids

    Science.gov (United States)

    Haeusler, Rebecca A.; Astiarraga, Brenno; Camastra, Stefania; Accili, Domenico; Ferrannini, Ele

    2013-01-01

    Bile acids (BAs) exert pleiotropic metabolic effects, and physicochemical properties of different BAs affect their function. In rodents, insulin regulates BA composition, in part by regulating the BA 12α-hydroxylase CYP8B1. However, it is unclear whether a similar effect occurs in humans. To address this question, we examined the relationship between clamp-measured insulin sensitivity and plasma BA composition in a cohort of 200 healthy subjects and 35 type 2 diabetic (T2D) patients. In healthy subjects, insulin resistance (IR) was associated with increased 12α-hydroxylated BAs (cholic acid, deoxycholic acid, and their conjugated forms). Furthermore, ratios of 12α-hydroxylated/non–12α-hydroxylated BAs were associated with key features of IR, including higher insulin, proinsulin, glucose, glucagon, and triglyceride (TG) levels and lower HDL cholesterol. In T2D patients, BAs were nearly twofold elevated, and more hydrophobic, compared with healthy subjects, although we did not observe disproportionate increases in 12α-hydroxylated BAs. In multivariate analysis of the whole dataset, controlling for sex, age, BMI, and glucose tolerance status, higher 12α-hydroxy/non–12α-hydroxy BA ratios were associated with lower insulin sensitivity and higher plasma TGs. These findings suggest a role for 12α-hydroxylated BAs in metabolic abnormalities in the natural history of T2D and raise the possibility of developing insulin-sensitizing therapeutics based on manipulations of BA composition. PMID:23884887

  8. Structure-guided unravelling: Phenolic hydroxyls contribute to reduction of acrylamide using multiplex quantitative structure-activity relationship modelling.

    Science.gov (United States)

    Zhang, Yu; Huang, Mengmeng; Wang, Qiao; Cheng, Jun

    2016-05-15

    We reported a structure-activity relationship study on unravelling phenolic hydroxyls instead of alcoholic hydroxyls contribute to the reduction of acrylamide formation by flavonoids. The dose-dependent study shows a close correlation between the number of phenolic hydroxyls of flavonoids and their reduction effects. In view of positions of hydroxyls, the 3',4'(ortho)-dihydroxyls in B cycle, 3-hydroxyl or hydroxyls of 3-gallate in C cycle, and 5,7(meta)-dihydroxyls in A cycle of flavonoid structures play an important role in the reduction of acrylamide. Flavone C-glycosides are more effective at reducing the formation of acrylamide than flavone O-glycosides when sharing the same aglycone. The current multiplex quantitative structure-activity relationship (QSAR) equations effectively predict the inhibitory rates of acrylamide using selected chemometric parameters (R(2): 0.835-0.938). This pioneer study opens a broad understanding on the chemoprevention of acrylamide contaminants on a structural basis.

  9. Combined effects of sugarcane bagasse extract and synthetic dyes on the growth and bioaccumulation properties of Pichia fermentans MTCC 189.

    Science.gov (United States)

    Das, Devlina; Charumathi, D; Das, Nilanjana

    2010-11-15

    Bioaccumulation of synthetic dyes viz. Acid Blue 93, Direct Red 28 and Basic Violet 3 by growing cells of yeast, Pichia fermentans MTCC 189 was investigated in growth media prepared from sugarcane bagasse extract. The maximum dye bioaccumulation was determined at pH 5.0 for all the dyes tested. Two kinetic models viz. Noncompetitive and Uncompetitive models were tested in order to determine the toxic effects of dyes on the specific growth rate of P. fermentans MTCC 189. Basic Violet 3 was found to be more toxic than the other two dyes. The combined effects of sugarcane bagasse extract and initial Basic Violet 3 dye concentrations on the specific growth rate and dye bioaccumulation efficiency of P. fermentans MTCC 189 was investigated and optimized using Response Surface Methodology (RSM). A 2(2) full factorial central composite design was successfully used for analysis of results. The optimum combination predicted via RSM confirmed that P. fermentans MTCC 189 was capable of bioaccumulating Basic Violet 3 dye upto 69.8% in the medium containing 10 mg/L of dye and 24 g/L sugar extracted from sugarcane bagasse.

  10. Biosorption of Strontium from Simulated Nuclear Wastewater by Scenedesmus spinosus under Culture Conditions: Adsorption and Bioaccumulation Processes and Models

    Directory of Open Access Journals (Sweden)

    Mingxue Liu

    2014-06-01

    Full Text Available Algae biosorption is an ideal wastewater treatment method when coupled with algae growth and biosorption. The adsorption and bioaccumulation of strontium from simulated nuclear wastewater by Scenedesmus spinosus were investigated in this research. One hundred mL of cultured S. spinosus cells with a dry weight of 1.0 mg in simulated nuclear wastewater were used to analyze the effects on S. spinosus cell growth as well as the adsorption and bioaccumulation characters under conditions of 25 ± 1 °C with approximately 3,000 lux illumination. The results showed that S. spinosus had a highly selective biosorption capacity for strontium, with a maximum bioremoval ratio of 76%. The adsorbed strontium ion on cell walls was approximately 90% of the total adsorbed amount; the bioaccumulation in the cytoplasm varied by approximately10%. The adsorption quantity could be described with an equilibrium isotherm. The pseudo-second-order kinetic model suggested that adsorption was the rate-limiting step of the biosorption process. A new bioaccumulation model with three parameters was proposed and could give a good fit with the experiment data. The results suggested that S. spinosus may be a potential biosorbent for the treatment of nuclear wastewater in culture conditions.

  11. Toxic effects and bioaccumulation of nano-, micron-, and ionic-Ag on the polychaete, Nereis diversicolor

    DEFF Research Database (Denmark)

    Cong, Yi; Banta, Gary Thomas; Selck, Henriette;

    2011-01-01

    ionic (AgNO3)- Ag on the sediment-dwelling polychaete, Nereis diversicolor, were compared after 10 days of sediment exposure, using survival, DNA damage (comet assay) and bioaccumulation as endpoints. The nominal concentrations used in all exposure scenarios were 0, 1, 5, 10, 25, and 50 g Ag/g dry...

  12. Bioavailability of PAHs in aluminum smelter affected sediments: evaluation through assessment of pore water concentrations and in vivo bioaccumulation.

    Science.gov (United States)

    Ruus, Anders; Bøyum, Olav; Grung, Merete; Næs, Kristoffer

    2010-12-15

    Bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) from coal tar pitch polluted sediments was predicted by (1) a generic approach based on organic carbon-water partitioning and Gibbs linear free energy relationship (between K(OW) and K(OC)), and (2) measurements of freely dissolved concentrations of PAHs in the sediment pore water, using passive samplers and solid phase extraction. Results from these predictions were compared with those from in vivo bioaccumulation experiments using Nereis diversicolor (Polychaeta), Hinia reticulata (Gastropoda), and Nuculoma tenuis (Bivalvia). Measured sediment/water partition coefficients were higher than predicted by the generic approach. Furthermore, predicted biota-to-sediment accumulation factors (BSAFs) derived from measured pore water concentrations were more in agreement with the bioaccumulation observed for two of the three species. Discrepancies associated with the third species (N. tenuis) were likely a result of particles remaining in the intestine (as shown by microscopic evaluation). These results indicate the importance of conducting site-specific evaluations of pore water concentrations and/or bioaccumulation studies by direct measurements to accurately provide a basis for risk assessment and remediation plans. The importance of knowledge regarding specific characteristics of model organisms is emphasized.

  13. Habitat type-based bioaccumulation and risk assessment of metal and As contamination in earthworms, beetles and woodlice

    International Nuclear Information System (INIS)

    The present study investigated the contribution of environmental factors to the accumulation of As, Cd, Cu, Pb and Zn in earthworms, beetles and woodlice, and framed within an exposure assessment of the European hedgehog. Soil and invertebrate samples were collected in three distinct habitat types. Results showed habitat-specific differences in soil and invertebrate metal concentrations and bioaccumulation factors when normalized to soil metal concentration. Further multiple regression analysis showed residual variability (habitat differences) in bioaccumulation that could not be fully explained by differences in soil metal contamination, pH or organic carbon (OC). Therefore, the study demonstrated that in bioaccumulation studies involving terrestrial invertebrates or in risk assessment of metals, it is not sufficient to differentiate habitat types on general soil characteristics such as pH and/or OC alone. Furthermore, simple generic soil risk assessments for Cd and Cu showed that risk characterization was more accurate when performed in a habitat-specific way. - Our study provided essential insights into habitat-specific accumulation patterns with respect to factors influencing metal bioaccumulation, BAFs, and site-specific risk assessment.

  14. Sterilization affects soil organic matter chemistry and bioaccumulation of spiked p,p'-DDE and anthracene by earthworms

    Energy Technology Data Exchange (ETDEWEB)

    Kelsey, Jason W., E-mail: kelsey@muhlenberg.ed [Program in Environmental Science and Department of Chemistry, Muhlenberg College, 2400 Chew Street, Allentown, PA 18104 (United States); Slizovskiy, Ilya B.; Peters, Richard D.; Melnick, Adam M. [Program in Environmental Science and Department of Chemistry, Muhlenberg College, 2400 Chew Street, Allentown, PA 18104 (United States)

    2010-06-15

    Laboratory experiments were conducted to assess the effects of soil sterilization on the bioavailability of spiked p,p'-DDE and anthracene to the earthworms Eisenia fetida and Lumbricus terrestris. Physical and chemical changes to soil organic matter (SOM) induced by sterilization were also studied. Uptake of both compounds added after soil was autoclaved or gamma irradiated increased for E. fetida. Sterilization had no effect on bioaccumulation of p,p'-DDE by L. terrestris, and anthracene uptake increased only in gamma-irradiated soils. Analyses by FT-IR and DSC indicate sterilization alters SOM chemistry and may reduce pollutant sorption. Chemical changes to SOM were tentatively linked to changes in bioaccumulation, although the effects were compound and species specific. Artifacts produced by sterilization could lead to inaccurate risk assessments of contaminated sites if assumptions derived from studies carried out in sterilized soil are used. Ultimately, knowledge of SOM chemistry could aid predictions of bioaccumulation of organic pollutants. - Soil sterilization affects soil organic matter chemistry and pollutant bioaccumulation.

  15. Habitat type-based bioaccumulation and risk assessment of metal and As contamination in earthworms, beetles and woodlice

    Energy Technology Data Exchange (ETDEWEB)

    Vermeulen, Frouke, E-mail: frouke.vermeulen@ua.ac.b [Ecophysiology, Biochemistry and Toxicology Group (U7), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Van den Brink, Nico W., E-mail: nico.vandenbrink@wur.n [Alterra, Wageningen UR, Box 47, NL6700AA Wageningen (Netherlands); D' Have, Helga [Ecophysiology, Biochemistry and Toxicology Group (U7), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Mubiana, Valentine K., E-mail: kayawe.mubiana@ua.ac.b [Ecophysiology, Biochemistry and Toxicology Group (U7), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Blust, Ronny, E-mail: ronny.blust@ua.ac.b [Ecophysiology, Biochemistry and Toxicology Group (U7), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Bervoets, Lieven, E-mail: lieven.bervoets@ua.ac.b [Ecophysiology, Biochemistry and Toxicology Group (U7), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); De Coen, Wim, E-mail: wim.decoen@ua.ac.b [Ecophysiology, Biochemistry and Toxicology Group (U7), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2009-11-15

    The present study investigated the contribution of environmental factors to the accumulation of As, Cd, Cu, Pb and Zn in earthworms, beetles and woodlice, and framed within an exposure assessment of the European hedgehog. Soil and invertebrate samples were collected in three distinct habitat types. Results showed habitat-specific differences in soil and invertebrate metal concentrations and bioaccumulation factors when normalized to soil metal concentration. Further multiple regression analysis showed residual variability (habitat differences) in bioaccumulation that could not be fully explained by differences in soil metal contamination, pH or organic carbon (OC). Therefore, the study demonstrated that in bioaccumulation studies involving terrestrial invertebrates or in risk assessment of metals, it is not sufficient to differentiate habitat types on general soil characteristics such as pH and/or OC alone. Furthermore, simple generic soil risk assessments for Cd and Cu showed that risk characterization was more accurate when performed in a habitat-specific way. - Our study provided essential insights into habitat-specific accumulation patterns with respect to factors influencing metal bioaccumulation, BAFs, and site-specific risk assessment.

  16. Toxicity and bioaccumulation of copper in Limnodrilus hoffmeisteri under different pH values: Impacts of perfluorooctane sulfonate.

    Science.gov (United States)

    Meng, Lingjun; Yang, Shaogui; Feng, Mingbao; Qu, Ruijuan; Li, Yong; Liu, Jiaoqin; Wang, Zunyao; Sun, Cheng

    2016-03-15

    Aquatic oligochaete Limnodrilus hoffmeisteri (L. hoffmeisteri) has been commonly used as a lethal and/or sub-lethal toxicological model organism in ecological risk assessments in contaminated water environments. In this study, experiments were conducted to investigate the potential toxic effects of copper (Cu(II)) with or without perfluorooctane sulfonate (PFOS) under different pH values (6.0, 7.0 and 8.0) on LC50, bioaccumulation, and oxidative stress biomarkers in L. hoffmeisteri after 3 and 7 days. The LC50 values of Cu(II) decreased with the increasing pH and the addition of PFOS. After each exposure, increasing bioaccumulation of Cu(II) in L. hoffmeisteri was observed in the combined exposure treatments, whereas the bioaccumulation of PFOS decreased. Moreover, the activity of superoxide dismutase, the level of glutathione, and the content of malondialdehyde were significantly altered after these exposures, possibly indicating that the bioaccumulation of Cu(II) and PFOS caused adverse effects on antioxidant defenses of L. hoffmeisteri. The integrated biomarker response index, indicates that the combined effect was proposed as synergism, which is coincided with the results of toxic unit. Moreover, this work showed that aquatic environment may become more livable when water conditions changed from acidic to near-neutral or alkaline.

  17. Characterisation of bioaccumulation dynamics of three differently coated silver nanoparticles and aqueous silver in a simple freshwater food chain

    DEFF Research Database (Denmark)

    Kalman, Judit; Paul, Kai B.; Khan, Farhan R.;

    2015-01-01

    This study investigated the bioaccumulation dynamics of silver nanoparticles (Ag NPs) with different coatings (polyvinyl pyrrolidone, polyethylene glycol and citrate), in comparison with aqueous Ag (added as AgNO3), in a simplified freshwater food chain comprising the green alga Chlorella vulgaris...

  18. Habitat-specific bioaccumulation of methylmercury in invertebrates of small mid-latitude lakes in North America

    Energy Technology Data Exchange (ETDEWEB)

    Chetelat, John, E-mail: john.chetelat@ec.gc.c [Groupe de recherche interuniversitaire en limnologie, Departement de sciences biologiques, Universite de Montreal, Montreal, Quebec H3C 3J7 (Canada); Amyot, Marc; Garcia, Edenise [Groupe de recherche interuniversitaire en limnologie, Departement de sciences biologiques, Universite de Montreal, Montreal, Quebec H3C 3J7 (Canada)

    2011-01-15

    We examined habitat-specific bioaccumulation of methylmercury (MeHg) in aquatic food webs by comparing concentrations in pelagic zooplankton to those in littoral macroinvertebrates from 52 mid-latitude lakes in North America. Invertebrate MeHg concentrations were primarily correlated with water pH, and after controlling for this influence, pelagic zooplankton had significantly higher MeHg concentrations than littoral primary consumers but lower MeHg than littoral secondary consumers. Littoral primary consumers and pelagic zooplankton are two dominant prey for fish, and greater MeHg in zooplankton is likely sufficient to increase bioaccumulation in pelagic feeders. Intensive sampling of 8 lakes indicated that habitat-specific bioaccumulation in invertebrates (of similar trophic level) may result from spatial variation in aqueous MeHg concentration or from more efficient uptake of aqueous MeHg into the pelagic food web. Our findings demonstrate that littoral-pelagic differences in MeHg bioaccumulation are widespread in small mid-latitude lakes. - Methylmercury levels in dominant invertebrate prey for fish differ between littoral and pelagic habitats within a lake.

  19. Habitat-specific bioaccumulation of methylmercury in invertebrates of small mid-latitude lakes in North America

    International Nuclear Information System (INIS)

    We examined habitat-specific bioaccumulation of methylmercury (MeHg) in aquatic food webs by comparing concentrations in pelagic zooplankton to those in littoral macroinvertebrates from 52 mid-latitude lakes in North America. Invertebrate MeHg concentrations were primarily correlated with water pH, and after controlling for this influence, pelagic zooplankton had significantly higher MeHg concentrations than littoral primary consumers but lower MeHg than littoral secondary consumers. Littoral primary consumers and pelagic zooplankton are two dominant prey for fish, and greater MeHg in zooplankton is likely sufficient to increase bioaccumulation in pelagic feeders. Intensive sampling of 8 lakes indicated that habitat-specific bioaccumulation in invertebrates (of similar trophic level) may result from spatial variation in aqueous MeHg concentration or from more efficient uptake of aqueous MeHg into the pelagic food web. Our findings demonstrate that littoral-pelagic differences in MeHg bioaccumulation are widespread in small mid-latitude lakes. - Methylmercury levels in dominant invertebrate prey for fish differ between littoral and pelagic habitats within a lake.

  20. Sensing dissolved sediment porewater concentrations of persistent and bioaccumulative poolutants using disposable solid-phase microextraction fibers

    NARCIS (Netherlands)

    Mayer, P.; Vaes, W.H.J.; Wijnker, F.; Legierse, K.C.H.M.; Kraaij, R.H.; Tolls, J.; Hermens, J.L.M.

    2000-01-01

    Polymer coated glass fibers were applied as disposable samplers to measure dissolved concentrations of persistent and bioaccumulative pollutants (PBPs) in sediment porewater. The method is called matrix solid-phase microextraction (matrix-SPME), because it utilizes the entire sediment matrix as a re

  1. Influence of hydroxyl contents on photocatalytic activities of polymorphic titania nanoparticles

    International Nuclear Information System (INIS)

    Polymorphic titania nanoparticles, prepared by a Water-based Ambient Condition Sol (WACS) process, were post-treated by a Solvent-based Ambient Condition Sol (SACS) process in sec-butanol. All samples were characterized for phase composition, surface area, lattice hydroxyl contamination, and particle morphology by X-ray diffraction, N2 physisorption, FT-IR, solid state Magic Angle Spinning (MAS) 1H NMR and scanning electron microscopy. The results were compared to a commercial titania, Degussa P25. Evaluation of methyl orange degradation under UV irradiation results showed that the lower lattice hydroxyl content in SACS titania nanoparticles enhances photocatalytic activity. As-prepared titania and post-treated SACS samples, which have similar surface areas and crystallinity, were compared in order to prove that the superior photocatalytic activity came from a reduction in lattice hydroxyl content

  2. Deep-ocean foraging northern elephant seals bioaccumulate persistent organic pollutants

    International Nuclear Information System (INIS)

    As top predators in the northeast Pacific Ocean, northern elephant seals (Mirounga angustirostris) are vulnerable to bioaccumulation of persistent organic pollutants (POPs). Our study examined a suite of POPs in blubber (inner and outer) and blood (serum) of free-ranging northern elephant seals. For adult females (N = 24), we satellite tracked and sampled the same seals before and after their approximately seven month long foraging trip. For males, we sampled different adults and sub-adults before (N = 14) and after (N = 15) the same foraging trip. For females, we calculated blubber burdens for all compounds. The highest POP concentrations in males and females were found for ∑ DDTs and ∑ PCBs. In blubber and serum, males had significantly greater concentrations than females for almost all compounds. For males and females, ∑ DDT and ∑ PBDEs were highly correlated in blubber and serum. While ∑ PCBs were highly correlated with ∑ DDTs and ∑ PBDEs in blubber and serum for males, ∑ PCBs showed weaker correlations with both compounds in females. As females gained mass while foraging, concentrations of nearly all POPs in inner and outer blubber significantly decreased; however, the absolute burden in blubber significantly increased, indicating ingestion of contaminants while foraging. Additionally, we identified three clusters of seal foraging behavior, based on geography, diving behavior, and stable carbon and nitrogen isotopes, which corresponded with differences in ∑ DDTs, ∑ PBDEs, MeO-BDE 47, as well as the ratio of ∑ DDTs to ∑ PCBs, indicating the potential for behavior to heighten or mitigate contaminant exposure. The greatest concentrations of ∑ DDTs and ∑ PBDEs were observed in the cluster that foraged closer to the coast and had blood samples more enriched in 13C. Bioaccumulation of POPs by elephant seals supports mesopelagic food webs as a sink for POPs and highlights elephant seals as a potential sentinel of contamination in deep

  3. Deep-ocean foraging northern elephant seals bioaccumulate persistent organic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Sarah H., E-mail: sarahpeterson23@gmail.com [Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, 100 Shaffer Road, Santa Cruz, CA 95060 (United States); Peterson, Michael G. [Department of Environmental Science, Policy and Management, University of California, Berkeley, 130 Mulford Hall, Berkeley, CA 94720 (United States); Debier, Cathy [Institut des Sciences de la Vie, Université catholique de Louvain, Croix du Sud 2/L7.05.08, 1348 Louvain-la-Neuve (Belgium); Covaci, Adrian [Toxicological Center, Campus Drie Eiken, Universiteit Antwerpen, Universiteitsplein 1, 2610 Wilrijk (Belgium); Dirtu, Alin C. [Toxicological Center, Campus Drie Eiken, Universiteit Antwerpen, Universiteitsplein 1, 2610 Wilrijk (Belgium); Department of Chemistry, “Al. I. Cuza” University of Iasi, 700506 Iasi (Romania); Malarvannan, Govindan [Toxicological Center, Campus Drie Eiken, Universiteit Antwerpen, Universiteitsplein 1, 2610 Wilrijk (Belgium); Crocker, Daniel E. [Department of Biology, Sonoma State University, 1801 East Cotati Ave, Rohnert Park, CA 94928 (United States); Schwarz, Lisa K. [Institute of Marine Sciences, University of California, Santa Cruz, 100 Shaffer Road, Santa Cruz, CA 95060 (United States); Costa, Daniel P. [Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, 100 Shaffer Road, Santa Cruz, CA 95060 (United States)

    2015-11-15

    As top predators in the northeast Pacific Ocean, northern elephant seals (Mirounga angustirostris) are vulnerable to bioaccumulation of persistent organic pollutants (POPs). Our study examined a suite of POPs in blubber (inner and outer) and blood (serum) of free-ranging northern elephant seals. For adult females (N = 24), we satellite tracked and sampled the same seals before and after their approximately seven month long foraging trip. For males, we sampled different adults and sub-adults before (N = 14) and after (N = 15) the same foraging trip. For females, we calculated blubber burdens for all compounds. The highest POP concentrations in males and females were found for ∑ DDTs and ∑ PCBs. In blubber and serum, males had significantly greater concentrations than females for almost all compounds. For males and females, ∑ DDT and ∑ PBDEs were highly correlated in blubber and serum. While ∑ PCBs were highly correlated with ∑ DDTs and ∑ PBDEs in blubber and serum for males, ∑ PCBs showed weaker correlations with both compounds in females. As females gained mass while foraging, concentrations of nearly all POPs in inner and outer blubber significantly decreased; however, the absolute burden in blubber significantly increased, indicating ingestion of contaminants while foraging. Additionally, we identified three clusters of seal foraging behavior, based on geography, diving behavior, and stable carbon and nitrogen isotopes, which corresponded with differences in ∑ DDTs, ∑ PBDEs, MeO-BDE 47, as well as the ratio of ∑ DDTs to ∑ PCBs, indicating the potential for behavior to heighten or mitigate contaminant exposure. The greatest concentrations of ∑ DDTs and ∑ PBDEs were observed in the cluster that foraged closer to the coast and had blood samples more enriched in {sup 13}C. Bioaccumulation of POPs by elephant seals supports mesopelagic food webs as a sink for POPs and highlights elephant seals as a potential sentinel of contamination in

  4. Bioaccumulation of trace elements in fish as an early detection of impact from uranium mining

    International Nuclear Information System (INIS)

    The open-cut Ranger uranium mine is located in the Alligator Rivers Region about 250 km east of Darwin, northern Australia. In this paper we evaluate a two-decade time series of monitoring data to assess bioaccumulation of contaminants in fish collected from the first permanent water body downstream of the mine (Mudginberri Billabong) and from a control site (Sandy Billabong). Due to the potential for enrichment of some contaminants in fish tissues, the bioaccumulation monitoring can provide early warning of levels of metals that could impact on human health. A review of long-term monitoring data, ranging from 1980 (pre-mining) to 2003, of selected metals (cadmium, copper, lead, manganese, uranium and zinc) revealed that none of these contaminants have significantly increased over time, and that fish tissue concentrations are similar for Mudginberri Billabong and Sandy Billabong. Most copper and zinc tissue concentrations are above the generally expected levels for fish flesh at both the 'impact' and control site (i.e. the 90th percentile of the Australian National Residue Survey Results, 2003) reflecting the naturally higher metal and radionuclide concentrations in the Alligator Rivers Region. Lead concentrations in all fish flesh studied are below the maximum level of 0.5 mg/kg wet weight (Australian and New Zealand food standards). Concentrations of the selected metals are higher in viscera than in flesh. This indicates their potential to bioaccumulate in fish, which is also consistent with the published literature. In all fish analysed in this study, concentrations of uranium and manganese are lower than for copper, lead and zinc. In recent years (2000, 2002 and 2003) fish tissues were analysed more comprehensively for a suite of over 20 contaminants in flesh, liver, gill and bone tissues. Interestingly, the metals appeared to accumulate in specific fish organs: aluminium was highest in gill; barium, lead, manganese and uranium were highest in bones; and

  5. Mercury Speciation and Bioaccumulation In Riparian and Upland Food Webs of the White Mountains Region, New Hampshire, USA

    Science.gov (United States)

    Rodenhouse, N.; Gebauer, R.; Lowe, W.; McFarland, K.; Bank, M. S.

    2015-12-01

    The soils and foods webs associated with mid to high elevation, forested, headwater streams are potential hotspots for mercury methylation and bioaccumulation but are not well studied. We tested the hypothesis that spatial variation in mercury bioaccumulation in upland taxa associated with headwater streams can be explained by variation in soil conditions promoting Hg methylation such as soil moisture, pH, and sulfur and organic matter content. We sampled at high (c. 700m) and mid elevation (c. 500m) in northern hardwood forest adjacent to and away from (75m) replicate headwater streams in the Hubbard Brook and Jeffers Brook watersheds of the White Mountains region, New Hampshire, USA. These forested watersheds differed primarily in soil calcium content and pH. We measured and assessed spatial variation in total Hg (THg) and methyl Hg (MeHg) concentrations in soils, insects, spiders, salamanders and birds. We also tested whether trophic position, as determined by nitrogen stable isotopes, was a major predictor of Hg bioaccumulation across these riparian and upland forest taxa. We found elevated levels of THg in all measured components of the food web, and conditions for methylation were better in the upland forest sites compared to the riparian sites located adjacent to headwater streams. Both THg and MeHg in biota were positively correlated with trophic position as indicated by 15N enrichment. In fact, trophic position was a better predictor of THg and MeHg content than spatial location, but the spatial patterning of bioaccumulation differed among taxa. Our data show that that significant Hg bioaccumulation and biomagnification can occur in soils and food webs of mid to high elevation temperate deciduous forests of the Northeast. They also suggest that mercury methylation in forested watersheds is a widespread phenomenon and not limited to areas with high soil moisture, such as lotic environments.

  6. The mismatch between bioaccumulation in field and laboratory environments: Interpreting the differences for metals in benthic bivalves

    International Nuclear Information System (INIS)

    Laboratory-based bioaccumulation and toxicity bioassays are frequently used to predict the ecological risk of contaminated sediments in the field. This study investigates the bioassay conditions most relevant to achieving environmentally relevant field exposures. An identical series of metal-contaminated marine sediments were deployed in the field and laboratory over 31 days. Changes in metal concentrations and partitioning in both sediments and waters were used to interpret differences in metal exposure and bioaccumulation to the benthic bivalve Tellina deltoidalis. Loss of resuspended sediments and deposition of suspended particulate matter from the overlying water resulted in the concentrations of Cu, Pb and Zn (major contaminants) becoming lower in the 1-cm surface layer of field-deployed sediments. Lower exchange rates of overlying waters in the laboratory resulted in higher dissolved metal exposures. The prediction of metal bioaccumulation by the bivalves in field and laboratory was improved by considering the metal partitioning within the surface sediments. - Highlights: • Particulate metals are the dominant metal exposure route in laboratory and field tests (87). • There is an over-representation of the dissolved metal exposure in the laboratory (81). • Laboratory bioassays result in higher bioaccumulation of major metals, Cu, Pb, Zn (82). • Differences in exposure must be considered for a proper sediment quality evaluation (83). • Traditional measurements are not sufficient to explain bioaccumulation results (79). - To improve the value of field- and laboratory-based sediment bioassays in ecological risk assessments, it is necessary to create exposure conditions that resemble those in the field

  7. Microanalyses of the hydroxyl-poly-calcium sodium phosphate coatings produced by ion beam assisted deposition

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Thin calcium phosphate coatings on titanium alloy substrates wereprepared by Ar+ ion beam assisted deposition (IBAD) from hydroxyl-poly-calciumsodium phosphate (HPPA) target. The coatings were analyzed by XRD, FTIR, XPS.These analyses revealed that the as-deposited films were amorphous or no apparentcrystallinity. No distinct absorption band of the hydroxyl group was observed in FTIRspectra of the coatings but new absorption bands were presented for CO3-2. Thecalcium to phosphorous ratio of these coatings in different IBAD conditions variedfrom 0.46 to 3.36.

  8. The selection reaction of homogeneous catalyst in soy-epoxide hydroxylation

    Science.gov (United States)

    Elvistia Firdaus, Flora

    2014-04-01

    Hydroxylation reaction of soy-epoxide has resulted soy-polyol; a prepolymeric material for polyurethane. The conversion and selectivity of soy-epoxide butanol based to hydroxylation was found higher than soy-ethylene glycol (EG) based. These reactions were performed by sulfur acid which commonly known as homogeneous catalyst. Conversion and selectivity of homogeneous catalyst compared to bentonite; a heteregeneous catalyst was lower as in fact the mixtures were more viscous. The catalysis were significantly effected to cell morphology. Foams were conducted by heterogeneous catalyst resulted an irregular form of windows while homogeneous catalyst are more ordered.

  9. Dioxygen reactivity of meso-hydroxylated hemes: intermediates in heme degradation process catalyzed by heme oxygenase

    Indian Academy of Sciences (India)

    Sankar Prasad Rath

    2006-11-01

    Heme oxygenase (HO) is the only enzyme in mammals known to catalyse the physiological degradation of unwanted heme into biliverdin, Fe ion and CO. The process involves introduction of the hydroxyl group at one of its meso-positions as the first fundamental step of the heme cleavage process. It was also found that meso-amino heme undergoes similar ring-cleavage process while reacting with dioxygen in presence of pyridine as an axial ligand. The present paper briefly reviews the reactions of model meso-hydroxylated heme and its analogues with dioxygen, and their relevance in the heme degradation process.

  10. Advances in Study on Catalysts for Phenol Synthesis via Catalytic Hydroxylation of Benzene in China

    Institute of Scientific and Technical Information of China (English)

    Zheng Zhaohui

    2004-01-01

    Synthesis of phenol via direct hydroxylation of benzene as a typical reaction of atomic economy has attracted extensive attention worldwide and has also become an actively investigated domain in China. This article refers to the recent domestic advances in study on phenol synthesis via hydroxylation of benzene from the viewpoint of catalysts, and considers the TS-1/H2O2 and FeZSM-5/N2O catalytic systems to be promising ones with good prospects for commercialization along with some suggestions on future research work.

  11. Effect of indole-3-acetic acid on pea root growth, peroxidase profiles and hydroxyl radical formation

    Directory of Open Access Journals (Sweden)

    Kukavica Biljana

    2007-01-01

    Full Text Available Changes in growth, peroxidase profiles, and hydroxyl radical formation were examined in IAA (0.5-10 mg/l treated pea plants grown hydroponically and in isolated roots in liquid in vitro culture. IAA inhibited root elongation, both in hydroponically grown pea plants and in isolated roots in vitro. A remarkable increase in the number of POD iso­forms was noticed in isolated roots grown in vitro, compared to the roots from plants grown hydroponically. IAA induced both disappearance of several root POD isoforms and hydroxyl radical formation in the root and the root cell wall.

  12. CATALYSIS OF POLYSTYRENE N-HYDROXYL SULFONAMIDE FOR ESTERIFICATION OF BUTANOL WITH ACETIC ANHYDRIDE

    Institute of Scientific and Technical Information of China (English)

    LI Shufeng; LI Qian; YANG Xinlin; HUANG Wenqiang

    2004-01-01

    Polystyrene N-hydroxyl sulfonamide resin 1 was prepared and used to catalyze the esterification of n-butanol and acetic anhydride. The mechanism of catalytic esterification proved by IR spectra of the resins was found that O-H and N-H of the N-hydroxyl sulfonamide resin reacted with the acetic anhydride respectively to form the active intermediate polystyrene N,O-diacetyl sulfonamate which was cleaved by n-butanol to produce butyl acetate. The catalytic esterification by resin 1 was in good agreement with the kinetic model of "bi-bi-ping-pong" mechanism.

  13. Hydroxylation-Dependent Interaction of Substrates to the Von Hippel-Lindau Tumor Suppressor Protein (VHL).

    Science.gov (United States)

    Heir, Pardeep; Ohh, Michael

    2016-01-01

    Oxygen-dependent hydroxylation of critical proline residues, catalyzed by prolyl hydroxylase (PHD1-3) enzymes, is a crucial posttranslational modification (PTM) within the canonical hypoxia-inducible factor (HIF)-centric cellular oxygen-sensing pathway. Alteration of substrates in this way often leads to proteasomal degradation mediated by the von Hippel-Lindau Tumor Suppressor protein (VHL) containing E3-ubiquitin ligase complex known as ECV (Elongins B/C, CUL2, VHL). Here, we outline in vitro protocols to demonstrate the ability of VHL to bind to a prolyl-hydroxylated substrate. PMID:27581016

  14. Kinetics and reaction mechanism of hydroxyl radical reaction with methyl formate

    Energy Technology Data Exchange (ETDEWEB)

    Good, D.A.; Hanson, J.; Francisco, J.S.; Li, Z.; Jeong, G.R.

    1999-12-16

    Ab initio molecular orbital theory has been used to examine the kinetics and mechanism for the reaction of hydroxyl radical with methyl formate. From the ab initio parameters the room temperature rate constant is calculated and found to be in good agreement with the experimental determination. It is found that 86% of the reaction proceeds via abstraction of the carbonyl hydrogen from methyl formate by hydroxyl radical, resulting in the formation of CH{sub 3}OCO radical. CH{sub 3}OCO is expected to oxidize to formaldehyde and carbon dioxide under tropospheric conditions.

  15. Regioselective alkane hydroxylation with a mutant CYP153A6 enzyme

    Science.gov (United States)

    Koch, Daniel J.; Arnold, Frances H.

    2013-01-29

    Cytochrome P450 CYP153A6 from Myobacterium sp. strain HXN1500 was engineered using in-vivo directed evolution to hydroxylate small-chain alkanes regioselectively. Mutant CYP153A6-BMO1 selectively hydroxylates butane and pentane at the terminal carbon to form 1-butanol and 1-pentanol, respectively, at rates greater than wild-type CYP153A6 enzymes. This biocatalyst is highly active for small-chain alkane substrates and the regioselectivity is retained in whole-cell biotransformations.

  16. Mild Detritylation of Nucleic Acid Hydroxyl Groups by Warming-up

    OpenAIRE

    Salon, Jozef; Zhang, Bo; Huang, Zhen

    2011-01-01

    It is challenging to effectively deprotect hydroxyl groups of acid-or-base sensitive bio-macromolecules without causing even minor defects and compromising high quality of final products. We report here a mild detritylation strategy in mildly acidic buffers to remove the DMTr protection from the 5’-hydroxyl groups of synthetic nucleic acids. The DMTr-groups can be easily and effectively removed at pH 4.5 or 5.0 with slight warming-up (40 °C), offering virtually quantitative deprotection. This...

  17. Species-specific bioaccumulation of halogenated organic pollutants and their metabolites in fish serum from an e-waste site, South China.

    Science.gov (United States)

    Zeng, Yan-Hong; Luo, Xiao-Jun; Zheng, Xiao-Bo; Tang, Bin; Wu, Jiang-Ping; Mai, Bi-Xian

    2014-10-01

    Halogenated organic pollutants (HOPs)-including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenylethers (PBDEs), polybromobiphenyls (PBBs), dechlorane plus (DP), tetrabromobisphenol A (TBBPA), and hexabromocyclododecanes (HBCDs) as well as PCB metabolites (methylsulfone [MeSO2-]) and hydroxylated (OH-) PCBs and OH-PBDEs-were determined in the serum of mud carp and northern snakehead from an electronic-waste (e-waste) site in South China. The average concentrations (mean ± SD) of ΣPCBs, ΣPBDEs, ΣOCPs, ΣPBBs, ΣTBBPA, ΣHBCDs, and ΣDP were 1410 ± 324, 70 ± 20, 3.0 ± 0.4, 2.8 ± 0.8, 1.6 ± 0.4, 1.0 ± 0.2, and 0.3 ± 0.03 ng/g wet weight (ww) in mud carp and 6430 ± 781, 468 ± 49, 22.4 ± 1.1, 7.0 ± 0.6, 2.9 ± 2.3, 5.5 ± 1.1, and 4.6 ± 0.6 ng/g ww in northern snakehead, respectively. MeSO2-PCBs, OH-PCBs, and OH-PBDEs were detected at a total concentration of 0.44 ± 0.03 and 9.7 ± 0.3 ng/g ww in mud carp and northern snakehead, respectively. The congener profiles of PCBs, PBDEs, OH/MeSO2-PCBs, and OH-PBDEs were found to be significantly different between the two fish species, possibly as a result of species-specific bioaccumulation and/or metabolism of the HOPs. Chirality of ten PCB congeners and α-HBCD, as well as the f anti values of DP in the serum samples, supported the species-specific biotransformation of HOPs. Furthermore, the presence of covaried and counter-varied enantiomeric fractions of PCBs between the two fish species indicated species- and congener-specific enantiomer enrichment of PCBs.

  18. Lead bioaccumulation and toxicity in tissues of economically fish species from river and marine water.

    Science.gov (United States)

    Askary Sary, Abolfazl; Mohammadi, Maryam

    2012-07-01

    Bioaccumulation of lead was determined in muscle and liver of Barbus xanthopterus, Liza abu, Barbus grypus, Acanthopagrus latus, Platycephalus indicus, Otolithes ruber exposed to lead contaminated river and marine in Khouzestan. Significant variations in metal values were evaluated using student's t test at p fish, liver was polluted in comparison with muscle and high level was in B. xanthopterus (2.80 mg kg(-1) wet weight) except for B. grypus in Karkhe River (1.73 mg kg(-1)wet weight). In marine fish, muscle was contaminated than liver and high level was in O. ruber (47.18 mg kg(-1)wet weight) except for O. ruber in Mahshahr seaport (17.85 mg kg(-1) wet weight).

  19. Bioaccumulation of organochlorine pesticides (OCPs) in the northern fulmar (Fulmarus glacialis) from the Sea of Okhotsk.

    Science.gov (United States)

    Tsygankov, Vasiliy Yu; Boyarova, Margarita D; Lukyanova, Olga N

    2016-09-15

    Hexachlorocyclohexane (HCH) isomers (α-, β-, and γ-), DDT and its metabolites (DDD and DDE) were detected in five individuals of Northern fulmar Fulmarus glacialis Linnaeus, 1761 from the Sea of Okhotsk. The average amount of HCHs in the organs of fulmars ranged from 608±177ng/g lipids in the total homogenate of the organs to 2093±264ng/g lipids in the feathers with skin. The average range of the amounts of DDTs was from 3606±333ng/g lipids in the feathers with skin to 4076±1624ng/g lipids in the feathers. The bioaccumulation of DDTs by seabirds of the Sea of Okhotsk is approximately equal to that of birds from other regions of the world's oceans, while the HCHs concentration is significantly higher. PMID:27357915

  20. Toxicant Exposure and Bioaccumulation: A Common and Potentially Reversible Cause of Cognitive Dysfunction and Dementia

    Directory of Open Access Journals (Sweden)

    Stephen J. Genuis

    2015-01-01

    Full Text Available Juxtaposed alongside the ongoing rise in the incidence and prevalence of dementia, is the surge of recent research confirming widespread exposure and bioaccumulation of chemical toxicants. Evidence from sources such as the Centers for Disease Control reveals that most people have accrued varying degrees of assorted toxic pollutants including heavy metals, flame retardants, and pesticide residues within their bodies. It has been well established that many of these toxicants have neurodegenerative as well as neurodevelopmental impact as a result of various pathophysiologic mechanisms including neuronal mitochondrial toxicity and disruption of neurotransmitter regulation. Elimination of stockpiled toxicants from the body may diminish adverse toxicant impact on human biology and allow restoration of normal physiological function. Incorporating a review of medical literature on toxicant exposure and dementia with a case history of a lead-exposed individual diagnosed with dementia, this paper will discuss a much overlooked and potentially widespread cause of declining brain function and dementia.

  1. PILLARED ZEOLITES AMENDMENTS INFLUENCE FROM POLLUTED SOIL ON HEAVY METALS BIOACCUMULATION IN TOMATOES

    Directory of Open Access Journals (Sweden)

    SMARANDA MASU

    2013-12-01

    Full Text Available Due to anthropic activities, the presence of metals in polluted soils has effects on plants development and metals bioaccumulation into trophic levels. In this paper, were followed experiments regarding the tomatoes development into polluted soils with 43.4 – 58.4 mg Cd/kg d.s. and 500- 633 mg Pb/kg d.s. Nickel, zinc and copper content in soils are in the range of diffuse pollution values. Comparatively, an experiment was realized with polluted soils and amended with pillared zeolites. Pillared zeolites change metals distribution in soil fractions and their solubility. Tomato plants grew onto polluted soils, but did not present fruits. Tomatoes from polluted and amended soils presented fruits and metals in tissues (Zn  Cu  Ni. Zinc concentration was five times greater then Ni. Fruits do not accumulate cadmium and lead.

  2. Biomarkers and heavy metal bioaccumulation in mussels transplanted to coastal waters of the Beagle Channel.

    Science.gov (United States)

    Giarratano, Erica; Duarte, Claudia A; Amin, Oscar A

    2010-03-01

    Mussels coming from a mussel farm at Brown Bay (Beagle Channel) were transplanted to four sites inside Ushuaia Bay for 2 and 4 weeks. The objective of this study was to assess the quality of coastal waters of Ushuaia Bay by measuring catalase activity, lipid peroxidation, total lipid content, bioaccumulation of heavy metals and condition index in transplanted mussel Mytilus edulis chilensis. Biomarkers except condition index showed significant differences among exposure times as well as among tissues. Digestive gland presented the highest catalase activity, malondialdehyde level and total lipid content. Digestive gland also was the main target tissue of accumulation of iron and copper, while gill accumulated the highest levels of zinc. A principal component analyzes with the whole set of data allowed to separate stations based on physicochemical conditions and biochemical responses of each studied area. PMID:19913913

  3. Bioaccumulation of arsenic and other heavy metals in the oyster crassostrea virginica: a radiotracer study

    International Nuclear Information System (INIS)

    Cienfuegos Bay, situated in the Southern part of Cuba, is a semi enclosed bay of important as natural resource for the country, due to industrial and artesian fishing activities, maritime transport, tourism industry and natural parks. During the last decade important economic and social development, around the bay has resulted in a significant increase in inputs of industrial and domestic wastes to its waters. Regarding arsenic, direct input occurred through the Nitrogen Fertilizer Factory, which was operating until 1989 and where two important accidental spills took place, in 1979 and 2001. Therefore, understanding the behaviour and fate of As in this region is of prime importance in order to be able to develop coastal zone monitoring programs and improve local marine resource protection and management. The objective of this work was to investigate the bioaccumulation behaviour of As and other co occurring metals in the edible oyster Crassostrea virginica, a specie that is abundant, widely distributed in the bay, and frequently eaten by local populations. Seven different metals (As, Ag, Cr, Co, Cd, Mn and Zn) were considered and their bioconcentration was studied using γ emitting radiotracers (73As, 110mAg, 51Cr, 57Co, 109Cd, 54Mn and 65Zn). The organisms were exposed for 14 d to background concentrations of the seven metals via seawater and then held for 21 d under non contaminated conditions. During these periods, uptake and loss kinetics of the metal radiotracers were determined in whole body individuals. In addition, tissue distribution of the metals was determined at the end of both exposure and depuration periods. In another experiment, C. virginica was exposed to four increasing concentrations of As dissolved in seawater in order to determine possible differences in As bioaccumulation according to ambient contamination level. Uptake kinetics were expressed as the variation of the concentration factor (CF, ratio between radioactivity in the organism and in

  4. Assessment of metal bioaccumulation in Clarias batrachus and exposure evaluation in human

    Directory of Open Access Journals (Sweden)

    Mayank Pandey

    2014-12-01

    Full Text Available The present work was conducted for heavy metal (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb quantification in the river Ganga water and their bioaccumulation in vital organ tissues of Clarias batrachus. Heavy metal characterization in vital organ tissues (gills, liver and muscle and comparison with FAO permissible guidelines revealed that Cd and Pb were hyper-accumulated which may lead to metal toxicity in fish and its consumers. High metal pollution index (MPI was recorded for organ tissues of exposed samples (liver 6.05; gills 22.95; muscle 44.48 as compared to unexposed samples (liver 4.5; gills 18.8; muscle 36.76. Effective ingestive dose (EID was calculated to assess the exposure threat to the human which may occur through dietary inputs. Results revealed that EID for Cr, Co, Cd and Pb was found significantly higher than the dose concentration prescribed by USEPA.

  5. BIO-ACCUMULATION AND RELEASE OF MERCURY IN VIGNA MUNGO (L. HEPPER SEEDLINGS

    Directory of Open Access Journals (Sweden)

    Hussain. K

    2010-09-01

    Full Text Available Effect of mercury on the seedling of Vigna mungo seedlings was studied by culturing the seedlings in Hoagland medium artificially contaminated with 5 and 10mM Mercuric Chloride. Histochemical localization of the mercury in shoot and root tissues was done by staining with dithizone and quantitative analyses of mercury content accumulated in root, stem and leaf tissues were done using mercury analyser. Localization of mercury was observed as coloured masses in the cells of root and stem. Stem tissues of seedlings showed anatomical modification in the epidermal cells as trichomes. Patterns of bioaccumulation of mercury was root> stem> leaves revealing feeble translocation to the shoot system. A comparison of residual mercury content retained in the growth medium after sample harvesting and quantity accumulated in the plant body reveals that some quantity of mercury is lost presumably through the trichomes developed on the stem and/ or through stomata of the leaves.

  6. Heavy metal bioaccumulation and health hazard assessment for three fish species from Nansi Lake, China.

    Science.gov (United States)

    Li, Pengfei; Zhang, Jian; Xie, Huijun; Liu, Cui; Liang, Shuang; Ren, Yangang; Wang, Wenxing

    2015-04-01

    Metal accumulation in fish is a global public health concern, because the consumption of contaminated fish accounts for the primary exposure of humans to toxic metals. In this study, the concentrations of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) in Crucian carp (Carassius auratus),Yellow catfish (Pelteobagrus fulvidraco), and Bighead carp (Hypophthalmichthys nobilis) from Nansi Lake of China were evaluated, and compared with the corresponding historical values in 2001 when the government started to govern water environment effectively. Bioaccumulation of heavy metal was highest in P.fulvidraco, followed by C.auratus and H.nobilis. The concentrations of Pb, As, Cd were much lower than the historical values, but Hg concentration was higher, suggesting that heavy metal pollution problem in fish from Nansi Lake still exists. Health hazard assessment showed no health risk from exposure to Pb, As, Cd, and Hg by consuming fish from this lake. PMID:25636438

  7. Reviewing the serotonin reuptake inhibitors (SSRIs) footprint in the aquatic biota: uptake, bioaccumulation and ecotoxicology.

    Science.gov (United States)

    Silva, Liliana J G; Pereira, André M P T; Meisel, Leonor M; Lino, Celeste M; Pena, Angelina

    2015-02-01

    Selective serotonin re-uptake inhibitors (SSRIs) antidepressants are amongst the most prescribed pharmaceutical active substances throughout the world. Their presence, already described in different environmental compartments such as wastewaters, surface, ground and drinking waters, and sediments, and their remarkable effects on non-target organisms justify the growing concern about these emerging environmental pollutants. A comprehensive review of the literature data with focus on their footprint in the aquatic biota, namely their uptake, bioaccumulation and both acute and chronic ecotoxicology is presented. Long-term multigenerational exposure studies, at environmental relevant concentrations and in mixtures of related compounds, such as oestrogenic endocrine disruptors, continue to be sparse and are imperative to better know their environmental impact.

  8. The pH dependent toxicity and bioaccumulation of chloroquine tested on S. viminalis (basket willow)

    DEFF Research Database (Denmark)

    Rendal, Cecilie; Trapp, Stefan; Legind, Charlotte Nielsen

    2010-01-01

    divalent weak base) on S. viminalis (basket willow). The transpiration of sprouted S. viminalis cuttings was monitored under the exposure of increasing concentrations (1, 10, 20, and 40 mg/L) of chloroquine at pH levels of 6, 7, 8, and 9. Solutions were buffered with phosphate (pH 6 and 7) and TRIS...... (hydroxymethyl) – aminomethane (pH 8 and 9). Concentrations were determined with spectrophotometer. Toxicity was derived from calculations of normalized transpiration over time, and RCF (root concentration factor) values were calculated. Increasing BCF values were found for increasing pH levels, and the toxicity......It is known that the uptake and accumulation of electrolytes is very sensitive to pH owing to the slower diffusion of charged compounds across membranes, and other factors such as the Nernst effect and the ion trap effect. However, the significance of pH to the bioaccumulation of electrolytes has...

  9. Bioaccumulation of heavy metals by Phragmites australis cultivated in synthesized substrates

    Institute of Scientific and Technical Information of China (English)

    WANG He; JIA Yongfeng

    2009-01-01

    Accumulation of heavy metals from various oxides with adsorbed cadmium by wetland plant Phragmites australis was studied to evaluate the fate of heavy metals in the sediment of constructed wetlands.Hoagland solution Was used as nutrition supply,and single metal oxide with adsorbed cadmium was applied as contaminant to study the accumulation characteristics of cadmium and the substrate metals by P. australis.After 45-d treatment,the bioaccumulation degree in root followed the order:Al(OH)3>Al2O3>Fe3O4>MnO2 >FeOOH.Heavy metals absorbed by P. australis were largely immobilized by the roots with little translocation to aboveground Darts.

  10. Bioaccumulation of arsenic and silver by the caddisfly larvae Hydropsyche siltalai and H. pellucidula

    DEFF Research Database (Denmark)

    Awrahman, Zmnako; Rainbow, Philip S; Smith, Brian D;

    2015-01-01

    , respectively, for H. pellucidula in moderately hard synthetic water at 10 °C. The assimilation efficiencies (±SE) of As and Ag from radiolabeled ingested food were 46.0 ± 7.7% and 75.7 ± 3.6%, respectively, for H. siltalai, and 61.0 ± 4.2% and 52.6 ± 8.6%, respectively, for H. pellucidula. Ag, but not As, AEs......Biodynamic modeling was used to investigate the uptake and bioaccumulation of arsenic and silver from water and food by two Hydropsychid caddisfly larvae: Hydropsyche siltalai and Hydropsyche pellucidula. Radiotracer techniques determined the uptake rate constants of arsenic and silver from water...... and silver concentrations in environmental water and food (suspended particles) samples were measured. Biodynamic models successfully predicted accumulated As and Ag concentrations in resident H. siltalai and H. pellucidula at each site. The models also showed that more than 95% of accumulated As and almost...

  11. Potential of Melastoma malabathricum as bio-accumulator for uranium and thorium from soil

    Science.gov (United States)

    Saat, Ahmad; Kamsani, Ain Shaqina; Kamri, Wan Nur Aina Nadzira; Talib, Nur Hasyimah Mat; Wood, Ab Khalik; Hamzah, Zaini

    2015-04-01

    Uranium and Thorium are naturally occuring radionuclides. However, due to anthropogenic activities in some locations their concentrations in the soils could be elevated. This study explores the potential of Melastoma malabathricum (locally known as `pokok senduduk') as bio-accumulator of uranium and thorium from soils of three different study areas, namely former tin mining, industrial and residential/commercial areas in Peninsular Malaysia. The study found elevated concentrations of uranium and thorium in former tin mining soils as compared to natural abundance. However in industral and residential/commercial areas the concentrations are within the range of natural abundance. In terms of transfer factor (TF), in ex-mining areas TF > 1 for uranium in the leaf, stem and roots, indicating accumulation of uranium from soil. However for thorium TF uranium and thorium were observed. The results indicated the potential of Melastoma malabathricum to be used as bio-accumulatior of uranium, especially in areas of elevated concentration.

  12. Recovery of high-value metals from geothermal sites by biosorption and bioaccumulation.

    Science.gov (United States)

    Lo, Yung-Chung; Cheng, Chieh-Lun; Han, Yin-Lung; Chen, Bor-Yann; Chang, Jo-Shu

    2014-05-01

    Generation of geothermal energy is associated with a significant amount of geothermal fluids, which may be abundant in high-value metals, such as lithium, cesium, rubidium, and other precious and rare earth metals. The recovery of high-value metals from geothermal fluids would thus have both economic and environmental benefits. The conventional technologies applied to achieve this are mostly physicochemical, which may be energy intensive, pose the risk of secondary pollution whilst being inefficient in recovering metals from dilute solutions. Biological methods, based on biosorption or bioaccumulation, have recently emerged as alternative approaches, as they are more environmentally friendly, cost effective, and suitable for treating wastewater with dilute metal contents. This article provides a comprehensive review of the related biological technologies used to recover the high-value metals present in geothermal fluids as well as critical discussion on the key issues that are often used to evaluate the effectiveness of those methods.

  13. Pesticide bioaccumulation and plasma sex steroids in fishes during breeding phase from north India.

    Science.gov (United States)

    Singh, Pratap B; Singh, Vandana

    2008-05-01

    The investigation was done to monitor the total hexachlorocyclohexane (∑HCH) and total dichlorodiphenyltrichloroethane (∑DDT), aldrin, endosulfan and chlorpyrifos in liver, brain and ovary, gonadosomatic index (GSI) and plasma levels of testosterone (T) and estradiol-17β (E2) during breeding season of captured catfishes and carps from the unpolluted ponds of Gujartal, Jaunpur (reference site) and polluted rivers Gomti, Jaunpur and Ganga, Varanasi. Results have indicated that catfishes have higher bioaccumulation of pesticides than the carps, which was beyond the permissible limits for ∑HCH whereas ∑DDT only by catfishes of polluted rivers. The GSI and plasma levels of T and E2 were lowered in the fishes captured from the polluted rivers. In conclusion, the fishes from river Gomti and Ganga showed a high degree of contamination and disrupted reproductive axis when compared to those from the reference site reflecting the degree of pesticide pollution present in those water bodies. PMID:21783872

  14. Inter- and intraspecific variation in mercury bioaccumulation by snakes inhabiting a contaminated river floodplain.

    Science.gov (United States)

    Drewett, David V V; Willson, John D; Cristol, Daniel A; Chin, Stephanie Y; Hopkins, William A

    2013-04-01

    Although mercury (Hg) is a well-studied contaminant, knowledge about Hg accumulation in snakes is limited. The authors evaluated Hg bioaccumulation within and among four snake species (northern watersnakes, Nerodia sipedon; queen snakes, Regina septemvittata; common garter snakes, Thamnophis sirtalis; and rat snakes, Elaphe obsoleta [Pantherophis alleghaniensis]) from a contaminated site on the South River (Waynesboro, VA, USA) and two nearby reference sites. Total Hg (THg) concentrations in northern watersnake tail tissue at the contaminated site ranged from 2.25 to 13.84 mg/kg dry weight (mean: 4.85 ± 0.29), or 11 to 19 times higher than reference sites. Blood THg concentrations (0.03-7.04 mg/kg wet wt; mean: 2.24 ± 0.42) were strongly correlated with tail concentrations and were the highest yet reported in a snake species. Within watersnakes, nitrogen stable isotope values indicated ontogenetic trophic shifts that correlated with THg bioaccumulation, suggesting that diet plays a substantial role in Hg exposure. Female watersnakes had higher mean THg concentrations (5.67 ± 0.46 mg/kg) than males (4.93 ± 0.49 mg/kg), but no significant differences between sexes were observed after correcting for body size. Interspecific comparisons identified differences in THg concentrations among snake species, with more aquatic species (watersnakes and queen snakes) accumulating higher mean concentrations (5.60 ± 0.40 and 4.59 ± 0.38 mg/kg in tail tissue, respectively) than the more terrestrial species, garter snakes and rat snakes (1.28 ± 0.32 and 0.26 ± 0.09 mg/kg, respectively). The results of the present study warrant further investigation of potential adverse effects and will aid in prioritizing conservation efforts.

  15. Phylogenetic consistencies among chondrichthyan and teleost fishes in their bioaccumulation of multiple trace elements from seawater

    Energy Technology Data Exchange (ETDEWEB)

    Jeffree, Ross A., E-mail: R.Jeffree@iaea.org [IAEA Marine Environment Laboratories, 4, Quai Antoine 1er, MC 98000 (Monaco); Oberhansli, Francois; Teyssie, Jean-Louis [IAEA Marine Environment Laboratories, 4, Quai Antoine 1er, MC 98000 (Monaco)

    2010-07-15

    Multi-tracer experiments determined the accumulation from seawater of selected radioactive trace elements (Mn-54, Co-60, Zn-65, Cs-134, Am-241, Cd-109, Ag-110m, Se-75 and Cr-51) by three teleost and three chondrichthyan fish species to test the hypothesis that these phylogenetic groups have different bioaccumulation characteristics, based on previously established contrasts between the carcharhiniform chondrichthyan Scyliorhinus canicula (dogfish) and the pleuronectiform teleost Psetta maxima (turbot). Discriminant function analysis on whole body: water concentration factors (CFs) separated dogfish and turbot in two independent experiments. Classification functions grouped the perciform teleosts, seabream (Sparus aurata) and seabass (Dicentrarchus labrax), with turbot and grouped the chondrichthyans, undulate ray (Raja undulata; Rajiformes) and spotted torpedo (Torpedo marmorata; Torpediniformes), with dogfish, thus supporting our hypothesis. Hierarchical classificatory, multi-dimensional scaling and similarity analyses based on the CFs for the nine radiotracers, also separated all three teleosts (that aggregated lower in the hierarchy) from the three chondrichthyan species. The three chondrichthyans were also more diverse amongst themselves compared to the three teleosts. Particular trace elements that were more important in separating teleosts and chondrichthyans were Cs-134 that was elevated in teleosts and Zn-65 that was elevated in chondrichthyans, these differences being due to their differential rates of uptake rather than loss. Chondrichthyans were also higher in Cr-51, Co-60, Ag-110m and Am-241, whereas teleosts were higher only in Mn-54. These contrasts in bioaccumulation patterns between teleosts and chondrichthyans are interpreted in the context of both proximate causes of underlying differences in physiology and anatomy, as well as the ultimate cause of their evolutionary divergence over more than 500 million years before present (MyBP). Our results

  16. Benthic and pelagic pathways of methylmercury bioaccumulation in estuarine food webs of the northeast United States.

    Science.gov (United States)

    Chen, Celia Y; Borsuk, Mark E; Bugge, Deenie M; Hollweg, Terill; Balcom, Prentiss H; Ward, Darren M; Williams, Jason; Mason, Robert P

    2014-01-01

    Methylmercury (MeHg) is a contaminant of global concern that bioaccumulates and bioamagnifies in marine food webs. Lower trophic level fauna are important conduits of MeHg from sediment and water to estuarine and coastal fish harvested for human consumption. However, the sources and pathways of MeHg to these coastal fisheries are poorly known particularly the potential for transfer of MeHg from the sediment to biotic compartments. Across a broad gradient of human land impacts, we analyzed MeHg concentrations in food webs at ten estuarine sites in the Northeast US (from the Hackensack Meadowlands, NJ to the Gulf of Maine). MeHg concentrations in water column particulate material, but not in sediments, were predictive of MeHg concentrations in fish (killifish and Atlantic silversides). Moreover, MeHg concentrations were higher in pelagic fauna than in benthic-feeding fauna suggesting that MeHg delivery to the water column from methylation sites from within or outside of the estuary may be an important driver of MeHg bioaccumulation in estuarine pelagic food webs. In contrast, bulk sediment MeHg concentrations were only predictive of concentrations of MeHg in the infaunal worms. Our results across a broad gradient of sites demonstrate that the pathways of MeHg to lower trophic level estuarine organisms are distinctly different between benthic deposit feeders and forage fish. Thus, even in systems with contaminated sediments, transfer of MeHg into estuarine food webs maybe driven more by the efficiency of processes that determine MeHg input and bioavailability in the water column.

  17. Benthic and pelagic pathways of methylmercury bioaccumulation in estuarine food webs of the northeast United States.

    Directory of Open Access Journals (Sweden)

    Celia Y Chen

    Full Text Available Methylmercury (MeHg is a contaminant of global concern that bioaccumulates and bioamagnifies in marine food webs. Lower trophic level fauna are important conduits of MeHg from sediment and water to estuarine and coastal fish harvested for human consumption. However, the sources and pathways of MeHg to these coastal fisheries are poorly known particularly the potential for transfer of MeHg from the sediment to biotic compartments. Across a broad gradient of human land impacts, we analyzed MeHg concentrations in food webs at ten estuarine sites in the Northeast US (from the Hackensack Meadowlands, NJ to the Gulf of Maine. MeHg concentrations in water column particulate material, but not in sediments, were predictive of MeHg concentrations in fish (killifish and Atlantic silversides. Moreover, MeHg concentrations were higher in pelagic fauna than in benthic-feeding fauna suggesting that MeHg delivery to the water column from methylation sites from within or outside of the estuary may be an important driver of MeHg bioaccumulation in estuarine pelagic food webs. In contrast, bulk sediment MeHg concentrations were only predictive of concentrations of MeHg in the infaunal worms. Our results across a broad gradient of sites demonstrate that the pathways of MeHg to lower trophic level estuarine organisms are distinctly different between benthic deposit feeders and forage fish. Thus, even in systems with contaminated sediments, transfer of MeHg into estuarine food webs maybe driven more by the efficiency of processes that determine MeHg input and bioavailability in the water column.

  18. Bioaccumulation and trophic magnification of pharmaceuticals and endocrine disruptors in a Mediterranean river food web.

    Science.gov (United States)

    Ruhí, Albert; Acuña, Vicenç; Barceló, Damià; Huerta, Belinda; Mor, Jordi-Rene; Rodríguez-Mozaz, Sara; Sabater, Sergi

    2016-01-01

    Increasing evidence exists that emerging pollutants such as pharmaceuticals (PhACs) and endocrine-disrupting compounds (EDCs) can be bioaccumulated by aquatic organisms. However, the relative role of trophic transfers in the acquisition of emerging pollutants by aquatic organisms remains largely unexplored. In freshwater ecosystems, wastewater treatment plants are a major source of PhACs and EDCs. Here we studied the entrance of emerging pollutants and their flow through riverine food webs in an effluent-influenced river. To this end we assembled a data set on the composition and concentrations of a broad spectrum of PhACs (25 compounds) and EDCs (12 compounds) in water, biofilm, and three aquatic macroinvertebrate taxa with different trophic positions and feeding strategies (Ancylus fluviatilis, Hydropsyche sp., Phagocata vitta). We tested for similarities in pollutant levels among these compartments, and we compared observed bioaccumulation factors (BAFs) to those predicted by a previously-developed empirical model based on octanol-water distribution coefficients (Dow). Despite a high variation in composition and levels of emerging pollutants across food web compartments, observed BAFs in Hydropsyche and Phagocata matched, on average, those already predicted. Three compounds (the anti-inflammatory drug diclofenac, the lipid regulator gemfibrozil, and the flame retardant TBEP) were detected in water, biofilm and (at least) one macroinvertebrate taxa. TBEP was the only compound present in all taxa and showed magnification across trophic levels. This suggests that prey consumption may be, in some cases, a significant exposure route. This study advances the notion that both waterborne exposure and trophic interactions need to be taken into account when assessing the potential ecological risks of emerging pollutants in aquatic ecosystems. PMID:26170111

  19. Bioaccumulation and trophic transfer of perfluorinated compounds in a eutrophic freshwater food web

    International Nuclear Information System (INIS)

    In this study, the bioaccumulation of perfluorinated compounds from a food web in Taihu Lake in China was investigated. The organisms included egret bird species, carnivorous fish, omnivorous fish, herbivorous fish, zooplankton, phytoplankton, zoobenthos and white shrimp. Isotope analysis by δ13C and δ15N indicated that the carnivorous fish and egret were the top predators in the studied web, occupying trophic levels intermediate between 3.66 and 4.61, while plankton was at the lowest trophic level. Perfluorinated carboxylates (PFCAs) with 9–12 carbons were significantly biomagnified, with trophic magnification factors (TMFs) ranging from 2.1 to 3.7. The TMF of perfluorooctane sulfonate (PFOS) (2.9) was generally comparable to or lower than those of the PFCAs in the same food web. All hazard ratio (HR) values reported for PFOS and perfluorooctanoate (PFOA) were less than unity, suggesting that the detected levels would not cause any immediate health effects to the people in Taihu Lake region through the consumption of shrimps and fish. -- Highlights: • Biomagnification of PFCs in the food web of a eutrophic freshwater lake was studied. • Carnivorous fish and egret were the top predators while plankton was at the lowest trophic level. • PFCAs with 9–12 carbons were significantly biomagnified. • TMF of PFOS was comparable to or lower than those of the PFCAs in the same food web. • PFOS and PFOA would not cause health effects to the people via diet consumption. -- PFCs were found to be bioaccumulated and biomagnified in a food web from a eutrophic freshwater lake in subtropical area

  20. Bioaccumulation and Depuration of Copper in the Kidney and Liver of a Freshwater Fish, Capoeta fusca

    Directory of Open Access Journals (Sweden)

    Borhan Mansouri

    2016-07-01

    Full Text Available Background: This study aims to investigate the patterns of bioaccumulation and depuration of copper in the selected kidney and liver of Capoeta fusca. Methods: The fish were collected between September and November 2010 from a qanat in Birjand. They were exposed to two types treatments with copper (0.25 and 0.75 mg/L for a period of 41 days. The fish under study were exposed to the above-mentioned sub-lethal concentrations separately for 14 and 21 days (accumulation period. At the end of this period, the remaining fish were kept in tap water (elimination period for 31 and 41 days. Results: The findings showed that the accumulation of copper in lower and higher sub-lethal concentrations was higher in kidney as the mean accumulation of copper on day 21 was 1.9±0.1 μg/g and 2.93±0.47 μg/g respectively, in 0.25 μg/g and 0.75 μg/g concentrations. On the other hand, the results also showed that the depuration level of copper in the given concentrations was higher in liver than kidney. The bioaccumulation and depuration of copper significantly increased in the kidney and liver of C. fusca (P<0.01. Conclusion: Based on the present work, it is concluded that C. fusca has a potential for the rapid accumulation and depuration of copper in freshwater. Also, the results indicate that the fish C. fusca, as representative fish species in the East of Iran, can be a useful bioindicator organism of water contamination with copper.

  1. Molecular effects and bioaccumulation of levonorgestrel in the non-target organism Dreissena polymorpha

    Energy Technology Data Exchange (ETDEWEB)

    Contardo-Jara, Valeska, E-mail: contardo@igb-berlin.d [Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Mueggelseedamm 301, 12587 Berlin (Germany); Lorenz, Claudia, E-mail: claudia.lorenz@igb-berlin.d [Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Mueggelseedamm 301, 12587 Berlin (Germany); Pflugmacher, Stephan, E-mail: pflugmacher@igb-berlin.d [Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Mueggelseedamm 301, 12587 Berlin (Germany); Nuetzmann, Gunnar, E-mail: nuetzmann@igb-berlin.d [Department of Ecohydrology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Mueggelseedamm 301, 12587 Berlin (Germany); Kloas, Werner, E-mail: werner.kloas@igb-berlin.d [Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Mueggelseedamm 301, 12587 Berlin (Germany); Wiegand, Claudia, E-mail: wiegand@biology.sdu.d [University of Southern Denmark, Institute of Biology, Campusvej 55, 5230 Odense M (Denmark)

    2011-01-15

    Bioaccumulation and effects of the contraceptive hormone levonorgestrel were examined in the non-target organism Dreissena polymorpha. Molecular biomarkers of biotransformation, elimination, antioxidant defence and protein damage were analyzed after exposure to increasing concentrations of levonorgestrel in a flow-through system. The lowest concentration (0.312 {mu}g L{sup -1}) was 100-fold bioconcentrated within four days. A decrease of the bioconcentration factor was observed within one week for the highest test concentrations (3.12 and 6.24 {mu}g L{sup -1}) suggesting enhanced excretory processes. The immediate mRNA up-regulation of pi class glutathione S-transferase proved that phase II biotransformation processes were induced. Disturbance of fundamental cell functions was assumed since the aryl hydrocarbon receptor has been permanently down-regulated. mRNA up-regulation of P-glycoprotein, superoxide dismutase and metallothioneine suggested enhanced elimination processes and ongoing oxidative stress. mRNA up-regulation of heat shock protein 70 in mussels exposed to the two highest concentrations clearly indicated impacts on protein damage. - Fundamental cell processes as biotransformation, elimination and prevention from oxidative stress are influenced by exposure of the contraceptive levonorgestrel in non-target organisms. - Research highlights: Bioaccumulation of levonorgestrel in mussels is higher than expected based on its lipophilicity. Exposure to levonorgestrel causes oxidative stress and enhanced elimination processes. Glutathione S-transferase (pi class) mRNA induction after one day hint on phase II biotransformation. mRNA induction of heat shock protein 70 after one week prove protein damage.

  2. Bioaccumulation and retention of lead in the mussel Mytilus galloprovincialis following uptake from seawater

    Energy Technology Data Exchange (ETDEWEB)

    Boisson, Florence; Cotret, Olivier; Fowler, Scott W. [International Atomic Energy Agency, Marine Environment Laboratory, 4 Quai Antoine Ier, BP 800, MC-98012 Monaco (France)

    1998-10-15

    Bioaccumulation of lead in the mussel Mytilus galloprovincialis from {sup 210}Pb-labeled bulk seawater (dissolved and particulate pathways combined) was examined over 21 days. The lead bioaccumulation factor (BAF) at equilibrium was estimated to be 211{+-}10 ml g{sup -1}. This value was two orders of magnitude lower than BAFs reported in the literature for other trace metals in this bivalve indicating that lead is not efficiently accumulated by mussels from bulk seawater. The resultant lead distribution in mussels was 49{+-}10% in soft tissues and 46{+-}16% in the shell suggesting similar uptake rates (Bq day{sup -1}) in both compartments throughout the exposure. Total elimination for lead in mussels was adequately described by a short-term compartment with a biological half-life for loss of 1.4{+-}0.3 days and a long-term compartment which released lead only very slowly (T{sub b1/2}=2.5{+-}0.7 months). No difference was noted for lead elimination rates in shell and in soft parts. When experimentally exposed to lead under conditions representative of natural environmental lead levels in water, including both that in the dissolved phase and in the food, the shell compartment was shown to contain the major fraction of the total lead accumulated by mussels. Therefore mussels may be considered as good bioindicators of lead contamination accumulated from the dissolved rather than from the particulate source. Furthermore, the relatively slow uptake and the long depuration half-life of lead will limit the ability of mussels to accurately record short-term variations in lead concentrations in the surrounding waters, a fact that should be taken into consideration in order to define the appropriate sampling frequency for mussels used in biomonitoring programs involving lead

  3. Implications of Dynamic Loading and Changing Climate on Mercury Bioaccumulation in a Planktivorous Fish (Orthodon microlepidotus)

    Science.gov (United States)

    Carroll, R. W. H.; Flickinger, A.; Warwick, J. J.; Schumer, R.

    2015-12-01

    A bioenergetic and mercury (Hg) mass balance (BioHg) model is developed for the Sacramento blackfish (Orthodon microlepidotus), a filter feeding cyprinid found in northern California and Nevada. Attention focuses on the Lahontan Reservoir in northern Nevada, which receives a strong temporally varying load of dissolved methylmercury (DMeHg) from the Carson River. Hg loads are the result of contaminated bank erosion during high flows and diffusion from bottom sediments during low flows. Coupling of dynamic reservoir loading with periods of maximum plankton growth and maximum fish consumption rates are required to explain the largest body burdens observed in the planktivore. In contrast, the large body burdens cannot be achieved using average water column concentrations. The United States Bureau of Reclamation has produced future streamflow estimates for 2000-2099 using 112 CMIP3 climate projections and the Variable Infiltration Capacity (VIC) model. These are used to drive a fully dynamic Hg transport model to assess changes in contaminant loading to the reservoir and implications on planktivorous bioaccumulation. Model results suggest the future loads of DMeHg entering the Lahontan Reservoir will decrease most significantly in the spring and summer due to channel width increases and depth decreases in the Carson River which reduce bank erosion over the century. The modeled concentrations of DMeHg in the reservoir are expected to increase during the summer due to a decrease in reservoir volume affecting the concentrations more than the decrease in loads, and the model results show that bioaccumulation levels may increase in the upstream sections of the reservoir while maintaining contamination levels above the federal action limit for human consumption in the lower reservoir.

  4. Elemental analysis of lichen bioaccumulators before exposure as transplants in air pollution monitoring

    International Nuclear Information System (INIS)

    Lichen transplants from relatively unpolluted sites are successfully used as heavy metal bioaccumulators for long-term air pollution monitoring. Significant element accumulations are generally revealed after 6 to 12 months of exposure. The main objective of this interdisciplinary research is to get a low-price survey of the air pollution level in some critical areas of Romania by nuclear and atomic analytical methods, based on the element accumulating property of transplanted lichens. The lichen species Evernia prunastri and Pseudevernia furfuracea collected from the Prealps, northeast Italy, have been selected for this study. Experimental setup for standardized lichen exposure needs special plastic frames ('little traps': 15 · 15 · 1.5 cm, with 1cm2 mesh) which are fixed horizontally on stainless steel posts at about 1.5 m above the ground. Prior to exposure, the lichen material is cleansed of some vegetal impurities and then shortly washed using de-ionised water. The initial (zero-level) contents of lichens were determined by Instrumental Neutron Activation Analysis (INAA) and Energy Dispersive X-Ray Fluorescence Analysis (EDXRFA) methods. INAA was carried out at the Institute of Physics and Nuclear Engineering in Bucharest (IFIN) and while EDXRFA at the University of Hohenheim in Stuttgart. The investigated elements were: As, Br, Ca, Cd, Co, Cr, Cu, Fe, K, Mn, Ni, Pb, S, Sb, Se, V and Zn. From among them, Cd, Co and Sb can be determined only by INAA and ICP-MS, Pb only by EDXRFA and PIXE, and S only by EDXRFA. A statistical intercomparison of the results allowed a good quality control of the used analytical methods for these specific matrices. This work was supported in part by European Commission Center of Excellence Project ICA1-CT-2000-70023: IDRANAP (Inter-Disciplinary Research and Applications based on Nuclear and Atomic Physics), Work Package 2 (Air pollution monitoring by sampling airborne particulate matter combined with lichen bioaccumulator exposure

  5. Assessment on Biocides Bioaccumulation in Mullet Liza klunzingeri in Kuwaiti Waters, off the Arabian Gulf

    Directory of Open Access Journals (Sweden)

    A. H. BU-Olayan

    2006-01-01

    Full Text Available Biocides, such as formaldehyde (HCHO, sodium hypochlorite (NaOCl and glutaraldehyde (C5H8O2 that are commonly used in thermal, desalination and power plants and industries were tested on the commercially important mullet fish, Liza klunzingeri to determine the environmental contamination in the stressed ecosystem of Kuwait Bay sites. Multi-factor Probit analysis toxicity tests (96 h on L. klunzingeri showed the lowest observed effective concentration (LOEC and median lethal concentration (LC50 with NaOCl (0.019 and 0.027 µg Lˉ1 followed by HCHO (0.058 and 0.157 µg Lˉ1 and C5H8O2 (0.056 and 0.072 µg Lˉ1. Site-wise analysis in the absence of feed showed high biocides toxicity in L. klunzingeri reared in seawater from Site I when compared to Sites II-III. Experiments were conducted (2-9 months by rearing fish separately in seawater collected from three Kuwait Bay sites to test the bio-accumulated toxicity levels at LOEC of biocides fed fish using Feed Conversion Ratio (FCR calculation. The lowest FCR was observed in fish fed with biocides in the sequence of NaOCl (0.40-1.1 followed by C5H8O2 (0.91-1.2 and HCHO (0.92-1.3 as well as with fish reared in seawater from Site I followed by Site II and Site III. High FCR was recorded in control (1.2-1.6 without the addition of biocides. These results exemplify the use of L. klunzingeri as an indicator species and may characterize a better quantification of biocides bioaccumulation using FCR calculation in mullet fish.

  6. Synthesis and Electrochemical Studies on BEDT-TTF Derivatives with Hydroxyl Groups

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    New electron donors with hydroxyl groups were synthesized and characterized spectroscopically.Their redox potentials were determined with cyclic voltammetry, and the comparison with BEDT-TTF [Bis(ethylenedithio)tetrathiafulvalene] in this aspect was made.These results indicated that the new electron donors had similar electron-donating capabilities as BEDT-TTF.

  7. Glutathione conjugation of busulfan produces a hydroxyl radical-trapping dehydroalanine metabolite.

    Science.gov (United States)

    Peer, Cody J; Younis, Islam R; Leonard, Stephen S; Gannett, Peter M; Minarchick, Valerie C; Kenyon, Allison J; Rojanasakul, Yon; Callery, Patrick S

    2012-12-01

    The Phase 2 drug metabolism of busulfan yields a glutathione conjugate that undergoes a β-elimination reaction. The elimination product is an electrophilic metabolite that is a dehydroalanine-containing tripeptide, γ-glutamyldehydroalanylglycine (EdAG). In the process, glutathione lacks thiol-related redox properties and gains a radical scavenging dehydroalanine group. EdAG scavenged hydroxyl radical generated in the Fenton reaction in a concentration-dependent manner was monitored by electron paramagnetic resonance (EPR) spectroscopy. The apparent rate of hydroxyl radical scavenging was in the same range as published values for known antioxidants, including N-acyl dehydroalanines. A captodatively stabilized carbon-centered radical intermediate was spin trapped in the reaction of EdAG with hydroxyl radical. The proposed structure of a stable product in the Fenton reaction with EdAG was consistent with that of a γ-glutamylserylglycyl dimer. Observation of the hydroxyl trapping properties of EdAG suggests that the busulfan metabolite EdAG may contribute to or mitigate redox-related cytotoxicity associated with the therapeutic use of busulfan, and reaffirms indicators that support a role in free radical biology for dehydroalanine-containing peptides and proteins.

  8. Equilibrium of hydroxyl complex ions in Pb2+-H2O system

    Institute of Scientific and Technical Information of China (English)

    WANG Yun-yan; CHAI Li-yuan; CHANG Hao; PENG Xiao-yu; SHU Yu-de

    2009-01-01

    The thermodynamics equilibrium principle was used to construct the diagrams for the concentration of complex ions (pc) vs pH, the distribution ratio of lead hydroxyl complex ions (αn) vs pH, and the conditional solubility product of Pb(OH)2 vs pH in the Pb2+-H2O system. The relationship between the equilibrium concentration of each kind of lead hydroxyl complex ions in equilibrium with Pb(OH)2(s) and pH value was shown in the system. The minimum solubility of lead is at the pH value of 10.096-10.997. The distribution ratio of each kind of the lead hydroxyl complex ions is determined as a function of the pH value and the total lead concentration ([Pb]T). The diagram for the conditional solubility product, pKSP vs pH, shows that each kind of lead hydroxyl complex ions existing in the system is dependent upon an optimized pH value at the established concentration of [Pb]T, and that pKSP reaches the minimum at the pH value of 10.3-11.2. The results can provide a theoretical basis for removing lead ions from wastewater by the neutralization and hydrolyzation technology.

  9. DFT STUDY OF ALPHA-MALTOSE: INFLUENCE OF HYDROXYL ORIENTATIONS ON THE GLYCOSIDIC BOND

    Science.gov (United States)

    The result of DFT geometry optimization of 68 unique alpha-maltose conformers at the B3LYP/6-311++G** level of theory is described. Particular attention is paid to the hydroxyl group rotational positions and their influence on the glycosidic bond dihedral angles. The orientation of lone pair elect...

  10. Advances in the synthesis mulitmetallic systems: hydroxyl group protection in aryldiamine platinum species

    NARCIS (Netherlands)

    Koten, G. van; Davies, P.J.; Grove, D.M.

    1997-01-01

    A multimetallic system containing three platinum atoms has been synthesized through use of an (aryldiamine)platinum complex with a protected hydroxyl group which, after deprotection, is coupled with the trisubstituted aryl molecule 1,3,5-tris(chlorocarbonyl)benzene that provides the core moiety. The

  11. ESR ST study of hydroxyl radical generation in wet peroxide system catalyzed by heterogeneous ruthenium

    NARCIS (Netherlands)

    Rokhina, E.V.; Golovina, E.A.; As, van H.; Virkutyte, J.

    2009-01-01

    Ru-based catalysts gained popularity because of their applicability for a variety of processes, including carbon monoxide oxidation, wet air catalytic oxidation and wastewater treatment. The focus of a current study was generation of hydroxyl radicals in the wet peroxide system catalyzed by heteroge

  12. Glutathione--hydroxyl radical interaction: a theoretical study on radical recognition process.

    Directory of Open Access Journals (Sweden)

    Béla Fiser

    Full Text Available Non-reactive, comparative (2 × 1.2 μs molecular dynamics simulations were carried out to characterize the interactions between glutathione (GSH, host molecule and hydroxyl radical (OH(•, guest molecule. From this analysis, two distinct steps were identified in the recognition process of hydroxyl radical by glutathione: catching and steering, based on the interactions between the host-guest molecules. Over 78% of all interactions are related to the catching mechanism via complex formation between anionic carboxyl groups and the OH radical, hence both terminal residues of GSH serve as recognition sites. The glycine residue has an additional role in the recognition of OH radical, namely the steering. The flexibility of the Gly residue enables the formation of further interactions of other parts of glutathione (e.g. thiol, α- and β-carbons with the lone electron pair of the hydroxyl radical. Moreover, quantum chemical calculations were carried out on selected GSH/OH(• complexes and on appropriate GSH conformers to describe the energy profile of the recognition process. The relative enthalpy and the free energy changes of the radical recognition of the strongest complexes varied from -42.4 to -27.8 kJ/mol and from -21.3 to 9.8 kJ/mol, respectively. These complexes, containing two or more intermolecular interactions, would be the starting configurations for the hydrogen atom migration to quench the hydroxyl radical via different reaction channels.

  13. Protective Effect against Hydroxyl-induced DNA Damage and Antioxidant Activity of Radix Codonopsis

    Directory of Open Access Journals (Sweden)

    Xican Li

    2013-02-01

    Conclusion: Radix Codonopsis can effectively protect against hydroxyl-induced DNA damage. One mechanism of protective effect may be radical-scavenging which is via donating hydrogen atom (H and middot;, donating electron (e. Its antioxidant ability can be mainly attributed to the existences of flavonoids or phenolic acids. [J Intercult Ethnopharmacol 2013; 2(1.000: 1-8

  14. Omega-hydroxylation of phytanic acid in rat liver microsomes: implications for Refsum disease.

    Science.gov (United States)

    Komen, J C; Duran, M; Wanders, R J A

    2004-07-01

    The 3-methyl-branched fatty acid phytanic acid is degraded by the peroxisomal alpha-oxidation route because the 3-methyl group blocks beta-oxidation. In adult Refsum disease (ARD), peroxisomal alpha-oxidation is defective, which is caused by mutations in the gene coding for phytanoyl-CoA hydroxylase in the majority of ARD patients. As a consequence, phytanic acid accumulates in tissues and body fluids. This study focuses on an alternative route of phytanic acid degradation, omega-oxidation. The first step in omega-oxidation is hydroxylation at the omega-end of the fatty acid, catalyzed by a member of the cytochrome P450 multienzyme family. To study this first step, the formation of hydroxylated intermediates was studied in rat liver microsomes incubated with phytanic acid and NADPH. Two hydroxylated metabolites of phytanic acid were formed, omega- and (omega-1)-hydroxyphytanic acid (ratio of formation, 5:1). The formation of omega-hydroxyphytanic acid was NADPH dependent and inhibited by imidazole derivatives. These results indicate that phytanic acid undergoes omega-hydroxylation in rat liver microsomes and that an isoform of cytochrome P450 catalyzes the first step of phytanic acid omega-oxidation.

  15. Microbial formation of hydroxylated aromatic compounds from 4-chloro- and 4-nitrobenzoate.

    NARCIS (Netherlands)

    Groenewegen, P.E.J.

    1993-01-01

    In the introduction of this thesis several aspects of the production of hydroxylated aromatic compounds are described. These compounds are applied in the production of pharmaceuticals, polymers, flavors and dyes, but their chemical synthesis is rather difficult in preparative organic chemistry. Ther

  16. Excited-state hydroxyl maser catalogue from the methanol multibeam survey -- I. Positions and Variability

    CERN Document Server

    Avison, A; Fuller, G A; Caswell, J L; Green, J A; Breen, S L; Ellingsen, S P; Gray, M D; Pestalozzi, M; Thompson, M A; Voronkov, M A

    2016-01-01

    We present the results of the first complete unbaised survey of the Galactic Plane for 6035-MHz excited-state hydroxyl masers undertaken as part of the Methanol Multibeam Survey. These observations cover the Galactic longitude ranges $186^{\\circ}< l < 60^{\\circ}$ including the Galactic Centre. We report the detection of 127 excited-state hydroxyl masers within the survey region, 47 being new sources. The positions of new detections were determined from interferometric observations with the Australia Telescope Compact Array. We discuss the association of 6035-MHz masers in our survey with the 6668-MHz masers from the MMB Survey, finding 37 likely methanol-excited-state hydroxyl masers maser pairs with physical separations of <=0.03pc and 55 pairings separated by <=0.1pc. Using these we calculate for the first time an excited-state hydroxyl maser life time of between 3.3x10^3 and 8.3x10^3 years. We also discuss the variability of the 6035-MHz masers and detection rates of counterpart 6030-MHz excite...

  17. Comparison of chemiluminescence methods for analysis of hydrogen peroxide and hydroxyl radicals

    Energy Technology Data Exchange (ETDEWEB)

    Pehrman, R.; Amme, M. (European Commission, Joint Research Centre, Institute for Transuranium Elements, Karlsruhe, (Germany)); Cachoir, C. (SCK.CEN, Waste and Disposal Unit., Mol (Belgium))

    2010-03-15

    Full text: Disposal of spent nuclear fuel in underground repositories is being considered in many countries and for this purpose understanding of behaviour of radiolysis products is required. To study the effects of alpha radiolysis products of water on oxidation and dissolution of actinides, a method to analyse those products is needed. Chemiluminescence is generally considered a simple, sensitive and reasonably selective method to detect reactive oxygen species on low concentrations. Concentrations of interest for both hydrogen peroxide and hydroxyl radicals are 10-6 to 10-9 M. The aim of this study is to compare various chemiluminescence methods for detecting hydrogen peroxide and hydroxyl radicals. Four methods to analyse hydrogen peroxide were chosen based on the estimated suitability for radiolysis experiments. Two of these use luminol, catalyzed by either mu-peroxidase or hemin, one uses 10-methyl-9-(p-formylphenyl) acridinium carboxylate trifluoromethanesulfonate and one potassium periodate. All methods were tested as batch systems in basic conditions. For hydroxyl radical detection luminophores tested were 3-hydroxyphthalic hydrazide (product of phthalic hydrazide and hydroxyl radical) and rutin. Both methods were tested as batch systems. The results are compared and the applicability of the methods for near-field dissolution studies is discussed. (author)

  18. Decarboxylation of [1-(13)C]leucine by hydroxyl radicals.

    Science.gov (United States)

    Guitton, J; Tinardon, F; Lamrini, R; Lacan, P; Desage, M; Francina, A

    1998-08-01

    The decarboxylation of [1-13C]leucine by hydroxyl radicals was studied by using gas chromatography-isotope ratio mass spectrometry (GC-IRMS) to follow the production of 13CO2. A Fenton reaction between a (Fe2+)-porphyrin and hydrogen peroxide under aerobic conditions yielded hydroxyl radicals. The decarboxylation rates (VLeu) measured by GC-IRMS were dependent on [1-13C]leucine, porphyrin and hydrogen peroxide concentrations. The 13CO2 production was also dependent on bicarbonate or carbon dioxide added in the reaction medium. Bicarbonate facilitated 13CO2 production, whereas carbon dioxide decreased 13CO2 production. Proton effects on some decarboxylation intermediates could explain bicarbonate or carbon dioxide effects. No effect on the decarboxylation rates was observed in the presence of the classical hydroxyl radicals scavengers dimethyl sulfoxide, mannitol, and uric acid. By contrast, a competitive effect with a strong decrease of the decarboxylation rates was observed in the presence of various amino acids: unlabeled leucine, valine, phenylalanine, cysteine, lysine, and histidine. Two reaction products, methyl-4 oxo-2 pentanoate and methyl-3 butanoate were identified by gas chromatography-mass spectrometry in comparison with standards. The present results suggest that [1-13C]leucine can participate to the coordination sphere of (Fe2+)-porphyrin, with a caged process of the hydroxyl radicals which cannot get out of the coordination sphere. PMID:9680180

  19. Cytotoxic Effects of Hydroxylated Fullerenes in Three Types of Liver Cells

    Directory of Open Access Journals (Sweden)

    Yoshiaki Ikarashi

    2013-07-01

    Full Text Available Fullerenes C60 have attracted considerable attention in the biomedical field due to their interesting properties. Although there has been a concern that C60 could be metabolized to hydroxylated fullerenes (C60(OHx in vivo, there is little information on the effect of hydroxylated C60 on liver cells. In the present study, we evaluated the cytotoxic effects of fullerene C60 and various hydroxylated C60 derivatives, C60(OH2, C60(OH6–12, C60(OH12 and C60(OH36, with three different types of liver cells, dRLh-84, HepG2 and primary cultured rat hepatocytes. C60, C60(OH2 and C60(OH36 exhibited little or no cytotoxicity in all of the cell types, while C60(OH6–12 and C60(OH12 induced cytotoxic effects in dRLh-84 cells, accompanied by the appearance of numerous vacuoles around the nucleus. Moreover, mitochondrial activity in liver cells was significantly inhibited by C60(OH6–12 and C60(OH12. These results indicate that the number of hydroxyl groups on C60(OHx contribute to the difference of their cytotoxic potential and mitochondrial damage in liver cells.

  20. Evidence against hydroxyl radical mechanism in photo-Fenton degradation of p-chlorophenol

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper provides evidence for the degradation of organic pollutant by the photo-Fenton complex mechanism. Both the tum yield. The hydroxyl radical involved in the photo-Fenton process can also be generated from the decomposition of H2O2,photolysis of Fe3+ and degradation of hydrated Fe(Ⅵ)-complex, excepting the traditional Fenton reaction.

  1. QSPR prediction of the hydroxyl radical rate constant of water contaminants.

    Science.gov (United States)

    Borhani, Tohid Nejad Ghaffar; Saniedanesh, Mohammadhossein; Bagheri, Mehdi; Lim, Jeng Shiun

    2016-07-01

    In advanced oxidation processes (AOPs), the aqueous hydroxyl radical (HO) acts as a strong oxidant to react with organic contaminants. The hydroxyl radical rate constant (kHO) is important for evaluating and modelling of the AOPs. In this study, quantitative structure-property relationship (QSPR) method is applied to model the hydroxyl radical rate constant for a diverse dataset of 457 water contaminants from 27 various chemical classes. The constricted binary particle swarm optimization and multiple-linear regression (BPSO-MLR) are used to obtain the best model with eight theoretical descriptors. An optimized feed forward neural network (FFNN) is developed to investigate the complex performance of the selected molecular parameters with kHO. Although the FFNN prediction results are more accurate than those obtained using BPSO-MLR, the application of the latter is much more convenient. Various internal and external validation techniques indicate that the obtained models could predict the logarithmic hydroxyl radical rate constants of a large number of water contaminants with less than 4% absolute relative error. Finally, the above-mentioned proposed models are compared to those reported earlier and the structural factors contributing to the AOP degradation efficiency are discussed. PMID:27124124

  2. The endothelium-dependent relaxation of rabbit aorta: effects of antioxidants and hydroxylated eicosatetraenoic acids.

    OpenAIRE

    Förstermann, U.; Neufang, B.

    1984-01-01

    Acetylcholine (ACh) induced concentration-dependent relaxations of rabbit aortic strips precontracted with noradrenaline. The relaxations were abolished if the endothelium of the strips was disrupted. Three different antioxidants (butylated hydroxytoluene, dithiothreitol and alpha-tocopherol) reversed the endothelium-dependent vasodilation in a concentration-dependent manner. However, the antioxidant ascorbic acid did not alter the vasodilatation. The hydroxylated eicosatetraenoic acids 5-HET...

  3. Hydroxylated sterols : matabolism and effects on steroid production and steroid uptake

    NARCIS (Netherlands)

    J.G.M. Huijmans (Jan)

    1989-01-01

    textabstractThe isolated rat adrenal cell was used as a model system. The isolation technique for rat adrenal cells has been extensively studied : in our laboratory (Falke et al., 1975a,b, 1976a,b) . Starting with these cells we looked at the properties of hydroxylated sterols as a precursor for ste

  4. Characterization of the reaction rate coefficient of DNA with the hydroxyl radical

    Energy Technology Data Exchange (ETDEWEB)

    Milligan, J.R.; Ward, J.F.; Aguilera, J.A. [Univ. of California, La Jolla, CA (United States)] [and others

    1996-11-01

    Using agarose gel electrophoresis, we have measured the yield of single-strand breaks (SSBs) induced by {sup 137}Cs {gamma} irradiation in a variety of plasmid DNA substrates ranging in size from 2.7 kb to 38 kb irradiated in aerobic aqueous solution in the presence of the hydroxyl radical scavenger dimethyl sulfoxide (DMSO). Under these conditions DNA SSBs are caused mainly by the hydroxyl radical. Using the competition between DMSO and DNA for the hydroxyl radical, we have estimated the rate coefficient for the reaction of the hydroxyl radical with DNA. The results cannot be characterized by conventional steady-state competition kinetics. However, it is possible to describe the second-order rate constant for the reaction as a function of the scavenging capacity of the solution. The second-order rate constant increases with increasing scavenging capacity, rising from about 5x10{sup 8} dm{sup 3} mol{sup -1} s{sup -1} at 10{sup 5} s{sup -1} to about 10{sup 10} dm{sup 3} mol{sup -1} s{sup -1} at 10{sup 10} s{sup -1}. This dependence of the second-order rate constant on the scavenging capacity appears to be more pronounced for larger plasmids. 17 refs., 4 figs.

  5. Quenching of excited hydroxyl (2Σ+, υ′ = 0) radicals in flames

    NARCIS (Netherlands)

    Hooymayers, H.P.; Alkemade, C.T.J.

    1967-01-01

    An alternating current photoelectric device (compare the work of Boers et al.,(1)Alkemade,(2) Hooymayers et al.(3,4) and Hooymayers(5)) has been used for determining the yield factor p of resonance fluorescence for some specific rotational transitions of the (0,0) band of the hydroxyl 2Σ+ → 2Π-band

  6. Progress modelling of aqueous electrons and hydroxyl radicals in RAIM code

    Energy Technology Data Exchange (ETDEWEB)

    Kim, A Yeong; Kim, Han-Chul; Lee, Jongseong [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-10-15

    In this paper, the RAIM code was revised minutely with regards to aqueous electrons and hydroxyl radicals, and simulated the P10T2 test. The recent study indicated that the RAIM had the potential for improvement of simulating the iodine behavior influenced by water radiolysis products such as aqueous electrons and hydroxyl radicals. In the existing RAIM modelling, it was considered that aqueous electrons only interacted with oxygen as a consumption reaction, but the reaction with hydrogen peroxide also could be major contributor to the iodine behavior as well as the consumption reaction of aqueous electrons. In case of hydroxyl radicals, RAIM took no notice of the pH impact. In other words, it dealt with the consumption reaction constants but not as a variable of pH. In this communication, the procedures to develop the model related to aqueous electrons and hydroxyl radicals in RAIM will be addressed. And the upgraded RAIM (RAIM-1, 2, 3) codes were applied to OECD-BIP P10T2 test which showed the effect of pH on the iodine behavior and compared with the existing RAIM1.8.3 code. Comparing with the existing RAIM, the improvement reduced the difference about 10%. However, the absolute difference values that is about one order at pH 10 could not be reduced by this approach.

  7. Toxicity of hydroxylated polychlorinated biphenyls (HO-PCBs) using the bioluminescent assay Microtox(®).

    Science.gov (United States)

    Bhalla, Renu; Tehrani, Rouzbeh; Van Aken, Benoit

    2016-09-01

    Hydroxylated polychlorinated biphenyls (HO-PCBs) are toxic contaminants which are produced in the environment by biological or abiotic oxidation of PCBs. The toxicity of a suite of 23 mono-hydroxylated derivatives of PCBs and 12 parent PCBs was determined using the bacterial bioluminescent assay Microtox(®). All HO-PCBs tested exhibited higher toxicity than the corresponding parent PCB, with effect concentration 50 % (EC50) ranging from 0.07 to 133 mg L(-1). The highest toxicities were recorded with 4-hydroxylated derivatives of di-chlorinated biphenyls (EC50 = 0.07-0.36 mg L(-1)) and 2-hydroxylated derivatives of tri-chlorinated biphenyls carrying a chlorine substituent on the phenolic ring (EC50 = 0.34-0.48 mg L(-1)). The toxicity of HO-PCBs generally decreased when the degree of chlorination increased. Consistently with this observation, a significant positive correlation was measured between toxicity (measured by EC50) and octanol-water partition coefficient (pK ow) for the HO-PCBs under study (Pearson's correlation coefficient, r = 0.74), which may be explained by the lower solubility and bioavailability generally associated with higher hydrophobicity. This study is the first one which assessed the toxicity of a suite of PCBs and HO-PCBs using the bioluminescent assay Microtox(®), showing an inverse correlation between toxicity and hydrophobicity. PMID:27411941

  8. A new mechanism for hydroxyl radical production in irradiated nanoparticle solutions.

    Science.gov (United States)

    Sicard-Roselli, Cécile; Brun, Emilie; Gilles, Manon; Baldacchino, Gérard; Kelsey, Colin; McQuaid, Harold; Polin, Chris; Wardlow, Nathan; Currell, Frederick

    2014-08-27

    The absolute yield of hydroxyl radicals per unit of deposited X-ray energy is determined for the first time for irradiated aqueous solutions containing metal nanoparticles based on a "reference" protocol. Measurements are made as a function of dose rate and nanoparticle concentration. Possible mechanisms for hydroxyl radical production are considered in turn: energy deposition in the nanoparticles followed by its transport into the surrounding environment is unable to account for observed yield whereas energy deposition in the water followed by a catalytic-like reaction at the water-nanoparticle interface can account for the total yield and its dependence on dose rate and nanoparticle concentration. This finding is important because current models used to account for nanoparticle enhancement to radiobiological damage only consider the primary interaction with the nanoparticle, not with the surrounding media. Nothing about the new mechanism appears to be specific to gold, the main requirements being the formation of a structured water layer in the vicinity of the nanoparticle possibly through the interaction of its charge and the water dipoles. The massive hydroxyl radical production is relevant to a number of application fields, particularly nanomedicine since the hydroxyl radical is responsible for the majority of radiation-induced DNA damage. PMID:24863679

  9. Radiation-induced destruction of hydroxyl-containing amino acids and dipeptides

    Science.gov (United States)

    Sladkova, А. А.; Sosnovskaya, А. А.; Edimecheva, I. P.; Shadyro, О. I.

    2012-12-01

    The yields of molecular products resulting from radiolysis of hydroxyl-containing amino acids and dipeptides under various conditions were determined. The possibility of a new radiation-induced destruction pathway has been shown for serine and threonine, as well as for the dipeptides having residues of these amino acids at the N-terminal part of the respective molecule. This process includes formation of N-centered radicals from the starting molecules followed by their decomposition with elimination of side substituents. On radiolysis, serine and threonine were also shown to undergo free-radical destruction to form acetaldehyde and acetone, respectively. A mechanism has been proposed including consecutive stages of fragmentation of α-hydroxyl-containing carbon-centered radicals with elimination of ammonia and decomposition of the secondary radicals with elimination of CO2. The yields of CO2 obtained on radiolysis of serine and threonine were significantly higher (except for solutions at pH 12) than those for alanine and valine, which have no hydroxyl groups in their structures. The obtained data indicate that the hydroxyl-containing amino acids occupy a special place among other amino acids as regards the variety of radiation-induced reactions which they may undergo due to their structural features.

  10. Evidence for formation of hydroxyl radicals during reperfusion after global cerebral ischaemia in rats using salicylate trapping and microdialysis

    DEFF Research Database (Denmark)

    Christensen, Thomas; Bruhn, T; Balchen, T;

    1994-01-01

    Systemic administration of salicylate (SA) to rats (100 mg kg-1 i.p. ) was used as an in vivo trap of hydroxyl radicals (.OH). In the brain SA reacts with hydroxyl radicals to form the stable adducts 2, 3- and 2,5 dihydroxybenzoic acid (DHBAs) which can thus be taken as an index of .OH formation...

  11. Development of a dynamic energy budget modeling approach to investigate the effects of temperature and resource limitation on mercury bioaccumulation in Fundulus heteroclitus.

    Science.gov (United States)

    Dynamic energy budget (DEB) theory provides a generalizable and broadly applicable framework to connect sublethal toxic effects on individuals to changes in population survival and growth. To explore this approach, we are developing growth and bioaccumulation studies that contrib...

  12. Development of a dynamic energy budget modeling approach to investigate the effects of temperature and resource limitation on mercury bioaccumulation in Fundulus heteroclitus-presentation

    Science.gov (United States)

    Dynamic energy budget (DEB) theory provides a generalizable and broadly applicable framework to connect sublethal toxic effects on individuals to changes in population survival and growth. To explore this approach, we are conducting growth and bioaccumulation studies that contrib...

  13. Cadmium accumulation in herbivorous and carnivorous small mammals: meta-analysis of field data and validation of the bioaccumulation model optomal modeling for ecotoxicological applications

    NARCIS (Netherlands)

    Veltman, K.; Huijbregts, M.A.J.; Hamers, T.; Wijnhoven, S.; Hendriks, A.J.

    2007-01-01

    Environmental risk assessment procedures often use bioaccumulation as a criterion for hazard identification of a polluted location. Field studies regarding metal concentrations in food chains, however, have provided widely different information, because accumulation is shown to vary between the extr

  14. Impact of humic substances on the aqueous solubility, uptake and bioaccumulation of platinum, palladium and rhodium in exposure studies with Dreissena polymorpha.

    Science.gov (United States)

    Sures, Bernd; Zimmermann, Sonja

    2007-03-01

    Zebra mussels (Dreissena polymorpha) were exposed to different types of water containing PGE salts (PtCl4, PdSO4, RhCl3) to investigate the influence of humic substances on the aqueous solubility, uptake and bioaccumulation of noble metals. The results showed a time dependent decrease of the aqueous PGE concentrations in tank water for all groups. This could mainly be related to non-biological processes. The aqueous solubility of Pd and Rh was higher in humic water compared with non-chlorinated tap water, whereas Pt showed opposing results. Highest metal uptake rates and highest bioaccumulation plateaus were found for Pd, followed by Pt and Rh. Pd uptake and bioaccumulation was significantly hampered by humic substances, whose presence appear to increase Pt uptake and bioaccumulation. No clear trend emerged for Rh. Differences in effects of humic matter among the PGE may be explained by formation of metal complexes with different fractions of humic substances. PMID:17018243

  15. Bioaccumulation Patterns Of PCBs In A Temperate, Freshwater Food Web And Their Relationshop To The Octanol-Water Partition Coefficient (Presentation)

    Science.gov (United States)

    We investigated polychlorinated biphenyl (PCB) bioaccumulation relative to octanol-water partition coefficient (KOW) and organism tropic position (TP) at the Lake Hartwell Superfund site (South Carolina, USA). We measured PCBs (127 congeners) and stable isotopes (δ

  16. Inhibition of hydroxyl radical reaction with aromatics by dissolved natural organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Lindsey, M.E.; Tarr, M.A.

    2000-02-01

    Remediation of hydrophobic pollutants is complicated by sorption of these compounds to hydrophobic sites of dissolved natural organic matter (NOM), suspended particulates, soil, and sediment. This sorption causes the pollutants to be less easily degraded by remediation techniques. Reaction of aromatic compounds with hydroxyl radical is inhibited by dissolved natural organic matter (NOM). The degree of inhibition is significantly greater than that expected based on a simple model in which aromatic compound molecules bound to NOM are considered to be unreactive. In this study, hydroxyl radical was produced at steady-state concentrations using Fenton chemistry (H{sub 2}O{sub 2} + Fe{sup 2+} {yields} Fe{sup 3+} + HO{sup {minus}} + HO{sm_bullet}). Suwannee River fulvic acid and humic acid were used as NOM. The most likely mechanism for the observed inhibition is that hydroxyl radical formation occurs in microenvironmental sites remote from the aromatic compounds. In addition to changes in kinetics, pyrene hydroxyl radical reaction also exhibited a mechanistic change in the presence of fulvic acid. The mechanism changed from a reaction that was apparently first-order in pyrene to one that was apparently second-order in pyrene, indicating that pyrene self-reaction may have become the dominant mechanism in the presence of fulvic acid. Dissolved NOM causes significant changes in the rate and mechanism of hydroxyl radical degradation of aromatic compounds. Consequently, literature rate constants measured in pure water will not be useful for predicting the degradation of pollutants in environmental systems. The kinetic and mechanistic information in this study will be useful for developing improved degradation methods involving Fenton chemistry.

  17. Influence of body size on Cu bioaccumulation in zebra mussels Dreissena polymorpha exposed to different sources of particle-associated Cu

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Huan, E-mail: huanzhong1982@hotmail.com [Environmental and Resource Studies Program, Trent University, Peterborough, Ontario (Canada); Nanjing University, School of Environment, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province (China); Kraemer, Lisa; Evans, Douglas [Environmental and Resource Studies Program, Trent University, Peterborough, Ontario (Canada)

    2013-10-15

    Highlights: • Mussels exposed to algal/sediment-Cu have different size-related Cu accumulation. • Size-related Cu accumulation in mussels could be more dependant on algal-Cu uptake. • Importance of algal/sediment-Cu to Cu bioaccumulation varies with mussel body size. • Cu sources (algae and sediments) should be considered in “mussel watch” programs. • Cu stable isotope offers many advantages in Cu bioaccumulation studies. -- Abstract: Size of organisms is critical in controlling metal bioavailability and bioaccumulation, while mechanisms of size-related metal bioaccumulation are not fully understood. To investigate the influences of different sources of particle-associated Cu on body size-related Cu bioavailability and bioaccumulation, zebra mussels (Dreissena polymorpha) of different sizes were exposed to stable Cu isotope ({sup 65}Cu) spiked algae (Chlorella vulgaris) or sediments in the laboratory and the Cu tissue concentration-size relationships were compared with that in unexposed mussels. Copper tissue concentrations decreased with mussel size (tissue or shell dry weight) in both unexposed and algal-exposed mussels with similar decreasing patterns, but were independent of size in sediment-exposed mussels. Furthermore, the relative contribution of Cu uptake from algae (65–91%) to Cu bioaccumulation is always higher than that from sediments (9–35%), possibly due to the higher bioavailability of algal-Cu. Therefore, the size-related ingestion of algae could be more important in influencing the size-related variations in Cu bioaccumulation. However, the relative contribution of sediment-Cu to Cu bioaccumulation increased with body size and thus sediment ingestion may also affect the size-related Cu variations in larger mussels (tissue weight >7.5 mg). This study highlights the importance of considering exposure pathways in normalization of metal concentration variation when using bivalves as biomonitors.

  18. Bioaccumulation Pattern of Cadmium and Lead in the Head Capsule and Body Muscle of Clarias gariepinus [Burchell, 1822] Exposed to Paint Emulsion Effluent

    OpenAIRE

    S. O. Dahunsi; S.U. Oranusi; R.O. Ishola

    2012-01-01

    The toxicity of Sub-lethal concentrations of effluents from a paint emulsion industry were investigated on African catfish Clarias gariepinus in order to determine the bioaccumulation pattern of two heavy metals i.e., Lead and Cadmium in the Head capsule and Body muscle using a renewable static bioassay. The trend of bioconcentration of metals in the head capsule and muscle of the test organisms differs significantly (phead capsule. In the muscle, the highest bioaccumulation of lead was 0.468...

  19. BIOACCUMULATION OF ARSENIC IN CHLORELLA VULGARIS (CHLOROPHYTA: CHLORELLACEAE) IN EFFLUENT FROM INDUSTRIAL PARK RÍO SECO (IPRS) AND ACUTE TOXICITY IN DAPHNIA MAGNA (CRUSTACEA: DAPHNIIDAE), AREQUIPA, PERU

    OpenAIRE

    A. Dueñas; Huarachi, R.; Yapo, U.; Apfata, P.; Gonzalez, R.

    2014-01-01

    Bioaccumulation of Arsenic III (As III), was determined in the microalgae Chlorella vulgaris in effluent samples from Industrial Park Rio Seco (IPRS) at laboratory scale. Through serial dilutions, a pure microalgae culture was obtained from effluents from the Chilpina treatment station; the resistance was tested through the growth of C. vulgaris in flasks of 250 mL with the application of As III in the form of Na HAsO . The C. vulgaris bioaccumulation capacity was 2 3 tested th...

  20. A comparative review towards potential of microbial cells for heavy metal removal with emphasis on biosorption and bioaccumulation.

    Science.gov (United States)

    Hansda, Arti; Kumar, Vipin; Anshumali

    2016-10-01

    The threat of heavy metal pollution to environmental health is getting worldwide attention due to their persistence and non-biodegradable nature. Ineffectiveness of various physicochemical methods due to economical and technical constraints resulted in the search for a cost-effective and eco-friendly biological technique for heavy metal removal from the environment. The two effective biotic methods used are biosorption and bioaccumulation. A comparison between these two processes demonstrated that biosorption is a better heavy metal removal process than bioaccumulation. This is due to the intoxication of heavy metal by inhibiting their entry into the microbial cell. Genes and enzymes related to bioremoval process are also discussed. On comparing the removal rate, bacteria are surpassed by algae and fungi. The aim of this review is to understand the biotic processes and to compare their metal removal efficiency. PMID:27565780

  1. A comparative review towards potential of microbial cells for heavy metal removal with emphasis on biosorption and bioaccumulation.

    Science.gov (United States)

    Hansda, Arti; Kumar, Vipin; Anshumali

    2016-10-01

    The threat of heavy metal pollution to environmental health is getting worldwide attention due to their persistence and non-biodegradable nature. Ineffectiveness of various physicochemical methods due to economical and technical constraints resulted in the search for a cost-effective and eco-friendly biological technique for heavy metal removal from the environment. The two effective biotic methods used are biosorption and bioaccumulation. A comparison between these two processes demonstrated that biosorption is a better heavy metal removal process than bioaccumulation. This is due to the intoxication of heavy metal by inhibiting their entry into the microbial cell. Genes and enzymes related to bioremoval process are also discussed. On comparing the removal rate, bacteria are surpassed by algae and fungi. The aim of this review is to understand the biotic processes and to compare their metal removal efficiency.

  2. Influence of phosphate on toxicity and bioaccumulation of arsenic in a soil isolate of microalga Chlorella sp.

    Science.gov (United States)

    Bahar, Md Mezbaul; Megharaj, Mallavarapu; Naidu, Ravi

    2016-02-01

    In this study, the toxicity, biotransformation and bioaccumulation of arsenite and arsenate in a soil microalga, Chlorella sp., were investigated using different phosphate levels. The results indicated that arsenate was highly toxic than arsenite to the alga, and the phosphate limitation in growth media greatly enhanced arsenate toxicity. The uptake of arsenate in algal cells was more than that of arsenite, and the predominant species in the growth media was arsenate after 8 days of exposure to arsenite or arsenate, indicating arsenite oxidation by this microalga. Arsenate reduction was also observed when the alga was incubated in a phosphate-limiting growth medium. Similar to the process of biotransformation, the alga accumulated more arsenic when it was exposed to arsenate and preferably more in a phosphate-limiting condition. Although phosphate significantly influences the biotransformation and bioaccumulation of arsenic, the oxidizing ability and higher accumulation capacity of this alga have great potential for its application in arsenic bioremediation.

  3. Influence of copper oxide nanoparticle form and shape on toxicity and bioaccumulation in the deposit feeder, Capitella teleta

    DEFF Research Database (Denmark)

    Dai, Lina; Banta, Gary Thomas; Selck, Henriette;

    2015-01-01

    Few in vivo studies have been conducted to assess how nanoparticle (NP) characteristics such as particle form and shape affect their toxicity and bioaccumulation. In the present study, the deposit feeder, Capitella teleta, was used to investigate the influence of copper form (CuO NPs, micron......-sized CuO particles, and aqueous Cu) and CuO NP shape (spheres, rods and platelets) on toxicity and bioaccumulation through sediment exposures of approximately 250 μg Cu/g dw sed. There were no effects of nanoparticle form or shape on mortality or growth rate during the exposure period. However, mortality...... increased to approximately 26.3% on average in all Cu treatments after the depuration period indicating a delayed effect of Cu exposure, despite more than 90% depuration of Cu during this period. A significant effect of nanoparticle shape was detected on body burden, the gross uptake rate constant...

  4. Distribution and bioaccumulation of heavy metals in marine organisms in east and west Guangdong coastal regions, South China.

    Science.gov (United States)

    Zhang, Ling; Shi, Zhen; Jiang, Zhijian; Zhang, Jingping; Wang, Fei; Huang, Xiaoping

    2015-12-30

    Heavy metal (Cu, Pb, Zn, Cr, Cd, As) concentrations, distribution and bioaccumulation were studied in marine organisms in Guangdong coastal regions. Heavy metal concentrations and distribution in organisms showed characteristics according to areas and species. Heavy metal concentrations in most organisms were higher in west than in east, tightly related to the local industry structure and the disequilibrium of metal discharge. Generally, high heavy metal concentrations were detected in molluscs and low concentrations were detected in fish. Bioaccumulation factor was used to assess the accumulation level of marine organisms to heavy metals, of which Cd, Cu and As were the most accumulated elements. Accumulation abilities to heavy metals varied among organism species, such as Distorsio reticulate accumulating Cu, Zn, Cd, As, Loligo beka Sasaki accumulating Pb, Cu, Cr, and Turritella bacillum Kiener accumulating Zn, Cd, As. By comparison, Johnius belengeri, Argyrosomus argentatus, Cynoglossus sinicus Wu had relatively low accumulation abilities.

  5. Characteristics of the phytoplankton community and bioaccumulation of heavy metals during algal blooms in Xiangjiang River (Hunan, China).

    Science.gov (United States)

    Li, Jie; Peng, Fuli; Ding, Dongbo; Zhang, Shubing; Li, Deliang; Zhang, Ting

    2011-10-01

    The frequency of algal blooms has increased in the mid and downstream reaches of the Xiangjiang River (Hunan, China), one of the most heavily polluted rivers in China. We identified the bloom-forming species in a bloom that occurred mid-late September 2010. In addition, we determined the extent of metal bioaccumulation in the algae and measured the toxicity of the algae using a mouse bioassay. Water samples were collected at upstream (Yongzhou), midstream (Hengyang), and downstream (Zhuzhou, Xiangtan, and Changsha) sites. The dominant species was Aulacoseira granulata, formerly known as Melosira granulata. The heaviest bloom occurred at Xiangtan and Changsha, where the number of A. granulata peaked at 1.3×10(5) filaments L(-1) and chlorophyll a at 0.04 mg L(-1). Concentrations of Al, Fe, and Mn were 4.4×10(3), 768.4, and 138.7 mg kg(-1) dry weight in the phytoplankton. The bioaccumulation factor was 4.0×10(5), 7.7×10(5), and 3.2×10(3), respectively. The heavy metal Pb had the greatest tendency to bioaccumulate among the highly toxic heavy metals, with a concentration of 19.2 mg kg(-1) dry weight and bioaccumulation factor of 9.6×10(3). The mouse bioassay suggested the bloom was toxic. The LD(50) was 384 mg kg(-1) and all surviving mice lost weight during the first 72 h after exposure. Our results demonstrate that blooms of A. granulata in rivers contaminated with heavy metals pose a threat to freshwater ecosystems and human health. Thus, measures should be taken to control eutrophication and heavy metal pollution in such rivers. PMID:22038005

  6. KINETICS AND EQUILIBRIUM PARAMETERS OF BIOSORPTION AND BIOACCUMULATION OF LEAD IONS FROM AQUEOUS SOLUTIONS BY TRICHODERMA LONGIBRACHIATUM

    OpenAIRE

    Enitan S. Balogun; John B. Durosanya; Sarafadeen O. Kareem; Abideen I. Adeogun

    2012-01-01

    Biosorption and bioaccumulation of Lead ions (Pb(II)) by Trichoderma longibrachiatum were investigated in a batch system. The effects of some important parameters such as pH, initial metal concentration, temperature and inoculum concerntration on biosorption capacity were also studied. The maximum biosorption capacity of Trichoderma longibrachiatum was at 25 ppm of lead, showed 100 % removal at pH 7 and 25 oC after fifteen days. Biosorption equilibrium was established in 150 minutes. The proc...

  7. Bioaccumulation and trophic dilution of human pharmaceuticals across trophic positions of an effluent-dependent wadeable stream

    OpenAIRE

    Du, Bowen; Haddad, Samuel P.; Luek, Andreas; Scott, W. Casan; Saari, Gavin N.; Kristofco, Lauren A.; Connors, Kristin A.; Rash, Christopher; Rasmussen, Joseph B.; Chambliss, C. Kevin; Brooks, Bryan W.

    2014-01-01

    Though pharmaceuticals are increasingly observed in a variety of organisms from coastal and inland aquatic systems, trophic transfer of pharmaceuticals in aquatic food webs have not been reported. In this study, bioaccumulation of select pharmaceuticals was investigated in a lower order effluent-dependent stream in central Texas, USA, using isotope dilution liquid chromatography–tandem mass spectrometry (MS). A fish plasma model, initially developed from laboratory studies, was tested to exam...

  8. EURL ECVAM Strategy to replace, reduce and refine the use of fish in aquatic toxicity and bioaccumulation testing

    OpenAIRE

    HALDER MARIA ELISABETH; KIENZLER AUDE; Whelan, Maurice; Worth, Andrew

    2014-01-01

    The assessment of aquatic toxicity and bioaccumulation are important components of the environmental hazard and risk assessment of all types of chemicals, and are therefore included in several pieces of European Union and international legislation. In this document, the European Union Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM) outlines approaches which will deliver an impact on the replacement, reduction and refinement (3Rs) of fish tests used for aquatic toxicity...

  9. Mercury in western North America: A synthesis of environmental contamination, fluxes, bioaccumulation, and risk to fish and wildlife

    Science.gov (United States)

    Eagles-Smith, Collin A.; Wiener, James G.; Eckley, Chris S.; Willacker, James J.; Evers, David C.; Marvin-DiPasquale, Mark C.; Obrist, Daniel; Fleck, Jacob; Aiken, George R.; Lepak, Jesse M.; Jackson, Allyson K.; Webster, Jackson; Stewart, Robin; Davis, Jay; Alpers, Charles N.; Ackerman, Josh

    2016-01-01

    Western North America is a region defined by extreme gradients in geomorphology and climate, which support a diverse array of ecological communities and natural resources. The region also has extreme gradients in mercury (Hg) contamination due to a broad distribution of inorganic Hg sources. These diverse Hg sources and a varied landscape create a unique and complex mosaic of ecological risk from Hg impairment associated with differential methylmercury (MeHg) production and bioaccumulation. Understanding the landscape-scale variation in the magnitude and relative importance of processes associated with Hg transport, methylation, and MeHg bioaccumulation requires a multidisciplinary synthesis that transcends small-scale variability. The Western North America Mercury Synthesis compiled, analyzed, and interpreted spatial and temporal patterns and drivers of Hg and MeHg in air, soil, vegetation, sediments, fish, and wildlife across western North America. This collaboration evaluated the potential risk from Hg to fish, and wildlife health, human exposure, and examined resource management activities that influenced the risk of Hg contamination. This paper integrates the key information presented across the individual papers that comprise the synthesis. The compiled information indicates that Hg contamination is widespread, but heterogeneous, across western North America. The storage and transport of inorganic Hg across landscape gradients are largely regulated by climate and land-cover factors such as plant productivity and precipitation. Importantly, there was a striking lack of concordance between pools and sources of inorganic Hg, and MeHg in aquatic food webs. Additionally, water management had a widespread influence on MeHg bioaccumulation in aquatic ecosystems, whereas mining impacts where relatively localized. These results highlight the decoupling of inorganic Hg sources with MeHg production and bioaccumulation. Together the findings indicate that developing

  10. Fluoride bioaccumulation and toxic effects on the survival and behavior of the endangered white-clawed crayfish Austropotamobius pallipes (Lereboullet).

    Science.gov (United States)

    Aguirre-Sierra, Arantxa; Alonso, Alvaro; Camargo, Julio A

    2013-08-01

    Laboratory experiments were performed to examine the toxic effects of fluoride (F(-)) on the survival and behavior of white-clawed crayfish (Austropotamobius pallipes). Body fluoride contents (bioaccumulation) of test crayfish were also examined. No significant differences between male and female crayfish regarding mortality, escape (tail-flip) response, and fluoride bioaccumulation were detected. For mortality, 48-, 72-, 96-, 120-, 144-, 168-, and 192-h median lethal concentrations (LC50) were estimated to be 93.0, 55.3, 42.7, 36.5, 32.9, 30.6, and 28.9 mg F(-)/l, respectively. For the escape response, 48-, 72-, 96-, 120-, 144-, 168- and 192-h median effective concentrations (EC50) were estimated to be 18.4, 11.1, 8.6, 7.4, 6.7, 6.2 and 5.9 mg F(-)/l, respectively. Average food consumption in test crayfish tended to decrease with increasing water fluoride concentration with a 192-h lowest-observed effect concentration of 10.7 mg F(-)/l. These results indicate that the escape response was the most sensitive end point to fluoride toxicity followed by food consumption and mortality. Fluoride bioaccumulation in test crayfish increased with increasing water fluoride concentration and exposure time. The exoskeleton accumulated more fluoride than muscle. A comparison of the obtained results with previous data for other freshwater invertebrates shows that white-clawed crayfish are relatively tolerant to fluoride toxicity. We conclude that fluoride pollution in freshwater ecosystems should not be viewed as an important risk factor contributing to the catastrophic decrease of A. pallipes in many European countries. Our results indicate that fluoride bioaccumulation in A. pallipes might be used as a bioindicator of fluoride pollution in freshwater ecosystems where it is present. PMID:23532451

  11. Metals bioaccumulation and biomarkers responses in the Neotropical freshwater clam Anodontites trapesialis: Implications for monitoring coal mining areas.

    Science.gov (United States)

    Oliveira, Luciana Fernandes de; Cabral, Millena Terezinha; Vieira, Carlos Eduardo Delfino; Antoniazzi, Matheus Henrique; Risso, Wagner Ezequiel; Martinez, Claudia Bueno Dos Reis

    2016-11-15

    As one of the most impactful industries, coal mining can promote several alterations at surrounding environment. In surface water, elevated concentrations of metals like Mn, Zn, Fe and Al are often observed. Thus, the aim of this study was to investigate the bioaccumulation and the sub-lethal effects of these metals on various organs of the Neotropical bivalve Anodontites trapesialis confined along a stream located near a coal mine, in order to assess a set of biomarkers that could be used for effectively monitoring coal mining areas. Clams were caged, for 96h, at two sites located upstream (Up1 and Up2) and two sites downstream (Dw1 and Dw2) from the mine. Metals bioaccumulation was determined in gills, mantle, digestive gland, muscle and hemolymph and the following biomarkers were measured in A. trapesialis tissues: total antioxidant capacity against peroxyl radicals, metallothionein content, lipid peroxidation (LPO), proteins carbonylation, glutathione S-transferase activity, superoxide dismutase activity and acetylcholinesterase (AChE) activity. The results showed that Al and Fe bioaccumulation in the gills and hemolymph, Al bioaccumulation in the mantle and muscle, increased LPO in the gills (Dw1 and Dw2) and mantle (Dw1), as well as reduced AChE activity in the muscle (Dw1 and Dw2) should be considered effective biomarkers for monitoring coal mining areas. A. trapesialis proved to be an efficient biological model, considering that biomarkers responses were observed in the clams after only 96h of confinement at Dw sites, accordingly this species could be a good candidate for monitoring Neotropical freshwaters. PMID:27453135

  12. Effect of coastal eutrophication on heavy metal bioaccumulation and oral bioavailability in the razor clam, Sinonovacula constricta

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Razor clams are often exposed to coastal eutrophication. • The bioaccumulation of Fe, Ni, V, and As was promoted by eutrophication. • Bionic gastrointestinal tract was used for metal oral bioavailability assessment. • Eutrophication decreased oral bioavailability of Fe and Pb but enhanced for V. • The daily maximum allowable intakes are controlled by eutrophication levels. - Abstract: As traditional seafoods, the razor clams are widely distributed from tropical to temperate areas. Coastal razor clams are often exposed to eutrophication. Heavy metal contamination is critical for seafood safety. However, how eutrophication affects bioaccumulation and oral bioavailability of heavy metals in the razor clams is unknown. After a four-month field experimental cultivation, heavy metals (Fe, Cu, Ni, V, As, and Pb) could be bioaccumulated by the razor clams (Sinonovacula constricta) through exposure to metals present in water and sediments or in the food chain, and then transferred to human via consumption of razor clams. Bionic gastrointestinal digestion and monolayer liposome extraction are used for metal oral bioavailability (OBA) assessment. The influence of eutrophication on OBA is decreased for Fe and Pb and increased for V. A significant positive linear correlation was observed between the bioaccumulation factors of Fe, Ni, V, and As in razor clams and the coastal eutrophication. These results may be due to the effect of eutrophication on metal species transformation in coastal seawater and subcellular distribution in razor clams. The maximum allowable daily intakes of razor clams are controlled by eutrophication status and the concentration of affinity-liposome As in razor clams

  13. The antihistamine hydroxyzine and Odonata : Bioaccumulation and effects on predator-prey interactions between dragonfly and damselfly larvae

    OpenAIRE

    Bomark, Ellinor

    2014-01-01

    Through wastewater entering aquatic environments, aquatic insects are continuously exposed to pharmaceuticals including neurologically active antihistamines. The antihistamine hydroxyzine has previously been found to lower activity in damselflies and to reach 2000 times the concentration of surrounding water in damselfly tissue. The purpose of this short-term exposure study was to investigate if hydroxyzine also bioaccumulates in dragonflies and if dilute hydroxyzine (362 ± 50, mean ng/l ± SD...

  14. Mercury in western North America: A synthesis of environmental contamination, fluxes, bioaccumulation, and risk to fish and wildlife.

    Science.gov (United States)

    Eagles-Smith, Collin A; Wiener, James G; Eckley, Chris S; Willacker, James J; Evers, David C; Marvin-DiPasquale, Mark; Obrist, Daniel; Fleck, Jacob A; Aiken, George R; Lepak, Jesse M; Jackson, Allyson K; Webster, Jackson P; Stewart, A Robin; Davis, Jay A; Alpers, Charles N; Ackerman, Joshua T

    2016-10-15

    Western North America is a region defined by extreme gradients in geomorphology and climate, which support a diverse array of ecological communities and natural resources. The region also has extreme gradients in mercury (Hg) contamination due to a broad distribution of inorganic Hg sources. These diverse Hg sources and a varied landscape create a unique and complex mosaic of ecological risk from Hg impairment associated with differential methylmercury (MeHg) production and bioaccumulation. Understanding the landscape-scale variation in the magnitude and relative importance of processes associated with Hg transport, methylation, and MeHg bioaccumulation requires a multidisciplinary synthesis that transcends small-scale variability. The Western North America Mercury Synthesis compiled, analyzed, and interpreted spatial and temporal patterns and drivers of Hg and MeHg in air, soil, vegetation, sediments, fish, and wildlife across western North America. This collaboration evaluated the potential risk from Hg to fish, and wildlife health, human exposure, and examined resource management activities that influenced the risk of Hg contamination. This paper integrates the key information presented across the individual papers that comprise the synthesis. The compiled information indicates that Hg contamination is widespread, but heterogeneous, across western North America. The storage and transport of inorganic Hg across landscape gradients are largely regulated by climate and land-cover factors such as plant productivity and precipitation. Importantly, there was a striking lack of concordance between pools and sources of inorganic Hg, and MeHg in aquatic food webs. Additionally, water management had a widespread influence on MeHg bioaccumulation in aquatic ecosystems, whereas mining impacts where relatively localized. These results highlight the decoupling of inorganic Hg sources with MeHg production and bioaccumulation. Together the findings indicate that developing

  15. Effect of coastal eutrophication on heavy metal bioaccumulation and oral bioavailability in the razor clam, Sinonovacula constricta

    Energy Technology Data Exchange (ETDEWEB)

    Tu, Tengxiu [College of Chemistry and Environment, Minnan Normal University, Zhangzhou 363000 (China); Li, Shunxing, E-mail: lishunxing@mnnu.edu.cn [College of Chemistry and Environment, Minnan Normal University, Zhangzhou 363000 (China); Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology (China); Chen, Lihui [College of Chemistry and Environment, Minnan Normal University, Zhangzhou 363000 (China); Zheng, Fengying; Huang, Xu-Guang [College of Chemistry and Environment, Minnan Normal University, Zhangzhou 363000 (China); Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology (China)

    2014-10-15

    Graphical abstract: - Highlights: • Razor clams are often exposed to coastal eutrophication. • The bioaccumulation of Fe, Ni, V, and As was promoted by eutrophication. • Bionic gastrointestinal tract was used for metal oral bioavailability assessment. • Eutrophication decreased oral bioavailability of Fe and Pb but enhanced for V. • The daily maximum allowable intakes are controlled by eutrophication levels. - Abstract: As traditional seafoods, the razor clams are widely distributed from tropical to temperate areas. Coastal razor clams are often exposed to eutrophication. Heavy metal contamination is critical for seafood safety. However, how eutrophication affects bioaccumulation and oral bioavailability of heavy metals in the razor clams is unknown. After a four-month field experimental cultivation, heavy metals (Fe, Cu, Ni, V, As, and Pb) could be bioaccumulated by the razor clams (Sinonovacula constricta) through exposure to metals present in water and sediments or in the food chain, and then transferred to human via consumption of razor clams. Bionic gastrointestinal digestion and monolayer liposome extraction are used for metal oral bioavailability (OBA) assessment. The influence of eutrophication on OBA is decreased for Fe and Pb and increased for V. A significant positive linear correlation was observed between the bioaccumulation factors of Fe, Ni, V, and As in razor clams and the coastal eutrophication. These results may be due to the effect of eutrophication on metal species transformation in coastal seawater and subcellular distribution in razor clams. The maximum allowable daily intakes of razor clams are controlled by eutrophication status and the concentration of affinity-liposome As in razor clams.

  16. Bioaccumulation of Zn and Ag Nanoparticles in the Earthworms (Eisenia fetida)

    Science.gov (United States)

    Ha, Lee Seung; Sung-Dae, Kim; Yi, Yang Song; Byeong-Gweon, Lee

    2014-05-01

    Many studies are carried out to evaluate environmental effects of engineered nanoparticles (ENPs). Most of the previous studies primarily focused on the effects of nanoparticles into the aquatic environment and human. Model studies predict that ENPs released into environment would transferred primarily to the soil of the terrestrial environment. Despite this prediction, biogeochemical behavior of ENPs in soil environment as well as bioavailability of ENPs to soil-dwelling organisms such as earthworm, springtail, isopod and nematodes are poorly understood. The main goal of this study was to compare the bioaccumulation factor (BAFs) and subcellular partitioning of nanoparticles in the soil-dwelling earthworm (Eisenia fetida) from ENP (ZnO and Ag nanoparticles) or ionic metal (Zn2+, Ag+) contaminated soil. And the sequential extraction was also used to determine the mobility of metals in soil which could be used as to predict bioavailability and compare that with bioaccumulation factor. The radiotracer method was employed to trace the transfer of ENPs and ionic metal among different environmental media and animals. Radiolabeled 65ZnO, 110mAgNPs coated with PVP or citrate were synthesized in the laboratory and their chemical and biological behavior was compared to ionic 65Zn and 110mAg. The BAFs of Zn and Ag in the earthworms were determined after animals exposed to the contaminated soils. After the 7 days of elimination phase, subcellular partitioning of metals were also obtained. BAF for ZnO(0.06) was 31 times lower than that for Zn ion (1.86), suggesting that ZnO was less bioavailable than its ionic form from contaminated soil. On the other hands, BAFs for AgNPs coated with PVP (0.12) or with citrate (0.11) were comparable to those for Ag ion (0.17), indicating that Ag from contaminated soil was bioavailable in a similar rate regardless of chemical forms. The subcellular partitioning results showed that bioaccumulated Zn from Zn ion and ZnO contaminated soil were

  17. Aquatic bioaccumulation and trophic transfer of tetrabromobisphenol-A flame retardant introduced from a typical e-waste recycling site.

    Science.gov (United States)

    Tao, Lin; Wu, Jiang-Ping; Zhi, Hui; Zhang, Ying; Ren, Zi-He; Luo, Xiao-Jun; Mai, Bi-Xian

    2016-07-01

    While the flame retardant chemical, tetrabromobisphenol-A (TBBP-A), has been frequently detected in the environment, knowledge regarding its species-specific bioaccumulation and trophic transfer is limited, especially in the highly contaminated sites. In this study, the components of an aquatic food web, including two invertebrates, two prey fish, and one predator fish, collected from a natural pond at an electronic waste (e-waste) recycling site in South China were analyzed for TBBP-A, using liquid chromatography-tandem mass spectrometry. The aquatic species had TBBP-A concentrations ranging from 350 to 1970 pg/g wet weight, with higher concentrations in the invertebrates relative to the fish species. Field-determined bioaccumulation factors of TBBP-A in the two aquatic invertebrates were nearly or greater than 5000, suggesting that TBBP-A is highly bioaccumulative in the two species. The lipid-normalized concentrations of TBBP-A in the aquatic species were negatively correlated with the trophic levels determined from stable nitrogen isotope (δ(15)N) (r = -0.82, p = 0.09), indicating that this compound experienced trophic dilution in the current food web. PMID:27234832

  18. Removal mechanisms and plant species selection by bioaccumulative factors in surface flow constructed wetlands (CWs): In the case of triclosan.

    Science.gov (United States)

    Zhao, Congcong; Xie, HuiJun; Xu, Jingtao; Zhang, Jian; Liang, Shuang; Hao, Jingcheng; Ngo, Huu Hao; Guo, Wenshan; Xu, Xiaoli; Wang, Qian; Wang, Jingmin

    2016-03-15

    Plants can bioaccumulate triclosan and bond with microbes and sediments in constructed wetlands (CWs) as well. However, little is known regarding the species-specific removal mechanism of CWs components and the selection of suitable wetland plant species for triclosan disposal. In this work, the use of bioaccumulation factors (BAFs) and biota to sediment accumulation factors (BSAFs) for choosing the best triclosan removal plant species was studied in laboratory-scale CWs. By the end of the experiment, over 80% of triclosan was removed and a specie-effect distribution was revealed in CWs with emergent, submerged and floating plants. By mass balance calculation, negative correlation between triclosan concentration in plants and degradation process was observed. The significant correlations between Log BSAFs values and triclosan concentration in plants or degradation contribution made it possible and reasonable in wetland plants selection. Introductions on plant species were provided considering the target removal process or regulation method. This work provided new information on plant species selection in CWs for triclosan removal or its emergency remediation by using bioaccumulative factors. PMID:26780127

  19. Bioaccumulation of glyphosate and its formulation Roundup Ultra in Lumbriculus variegatus and its effects on biotransformation and antioxidant enzymes

    International Nuclear Information System (INIS)

    The bioaccumulation potential of glyphosate and the formulation Roundup Ultra, as well as possible effects on biotransformation and antioxidant enzymes in Lumbriculus variegatus were compared by four days exposure to concentrations between 0.05 and 5 mg L-1 pure glyphosate and its formulation. Bioaccumulation was determined using 14C labeled glyphosate. The bioaccumulation factor (BCF) varied between 1.4 and 5.9 for the different concentrations, and was higher than estimated from log Pow. Glyphosate and its surfactant POEA caused elevation of biotransformation enzyme soluble glutathione S-transferase at non-toxic concentrations. Membrane bound glutathione S-transferase activity was significantly elevated in Roundup Ultra exposed worms, compared to treatment with equal glyphosate concentrations, but did not significantly differ from the control. Antioxidant enzyme superoxide dismutase was significantly increased by glyphosate but in particular by Roundup Ultra exposure indicating oxidative stress. The results show that the formulation Roundup Ultra is of more ecotoxicological relevance than the glyphosate itself. - Roundup Ultra is of more ecotoxicological relevance than the active ingredient, glyphosate, to Lumbriculus variegatus regarding accumulation potential and enzymatic responses

  20. Bioaccumulation of glyphosate and its formulation Roundup Ultra in Lumbriculus variegatus and its effects on biotransformation and antioxidant enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Contardo-Jara, Valeska [Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Department of Inland Fisheries, Biochemical Regulation, Mueggelseedamm 301, 12587 Berlin (Germany)], E-mail: contardo@igb-berlin.de; Klingelmann, Eva [Technische Universitaet Berlin/Berlin Institute of Technology, Department of Ecology, Chair of Soil Protection, Salzufer 12, 10587 Berlin (Germany)], E-mail: eva.klingelmann@TU-Berlin.de; Wiegand, Claudia [Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Department of Inland Fisheries, Biochemical Regulation, Mueggelseedamm 301, 12587 Berlin (Germany); Humboldt University Berlin, Faculty of Biology, Unter den Linden 6, 10099 Berlin (Germany)], E-mail: cwiegand@igb-berlin.de

    2009-01-15

    The bioaccumulation potential of glyphosate and the formulation Roundup Ultra, as well as possible effects on biotransformation and antioxidant enzymes in Lumbriculus variegatus were compared by four days exposure to concentrations between 0.05 and 5 mg L{sup -1} pure glyphosate and its formulation. Bioaccumulation was determined using {sup 14}C labeled glyphosate. The bioaccumulation factor (BCF) varied between 1.4 and 5.9 for the different concentrations, and was higher than estimated from log P{sub ow}. Glyphosate and its surfactant POEA caused elevation of biotransformation enzyme soluble glutathione S-transferase at non-toxic concentrations. Membrane bound glutathione S-transferase activity was significantly elevated in Roundup Ultra exposed worms, compared to treatment with equal glyphosate concentrations, but did not significantly differ from the control. Antioxidant enzyme superoxide dismutase was significantly increased by glyphosate but in particular by Roundup Ultra exposure indicating oxidative stress. The results show that the formulation Roundup Ultra is of more ecotoxicological relevance than the glyphosate itself. - Roundup Ultra is of more ecotoxicological relevance than the active ingredient, glyphosate, to Lumbriculus variegatus regarding accumulation potential and enzymatic responses.

  1. Removal mechanisms and plant species selection by bioaccumulative factors in surface flow constructed wetlands (CWs): In the case of triclosan.

    Science.gov (United States)

    Zhao, Congcong; Xie, HuiJun; Xu, Jingtao; Zhang, Jian; Liang, Shuang; Hao, Jingcheng; Ngo, Huu Hao; Guo, Wenshan; Xu, Xiaoli; Wang, Qian; Wang, Jingmin

    2016-03-15

    Plants can bioaccumulate triclosan and bond with microbes and sediments in constructed wetlands (CWs) as well. However, little is known regarding the species-specific removal mechanism of CWs components and the selection of suitable wetland plant species for triclosan disposal. In this work, the use of bioaccumulation factors (BAFs) and biota to sediment accumulation factors (BSAFs) for choosing the best triclosan removal plant species was studied in laboratory-scale CWs. By the end of the experiment, over 80% of triclosan was removed and a specie-effect distribution was revealed in CWs with emergent, submerged and floating plants. By mass balance calculation, negative correlation between triclosan concentration in plants and degradation process was observed. The significant correlations between Log BSAFs values and triclosan concentration in plants or degradation contribution made it possible and reasonable in wetland plants selection. Introductions on plant species were provided considering the target removal process or regulation method. This work provided new information on plant species selection in CWs for triclosan removal or its emergency remediation by using bioaccumulative factors.

  2. Metal and metalloid bioaccumulation in the Pacific blue shrimp Litopenaeus stylirostris (Stimpson) from New Caledonia: laboratory and field studies.

    Science.gov (United States)

    Metian, Marc; Hédouin, Laetitia; Eltayeb, Mohamed M; Lacoue-Labarthe, Thomas; Teyssié, Jean-Louis; Mugnier, Chantal; Bustamante, Paco; Warnau, Michel

    2010-01-01

    The present work aimed at better understanding metal and metalloid bioaccumulation in the edible Pacific blue shrimp Litopenaeus stylirostris, using both laboratory and field approaches. In the laboratory, the bioaccumulation kinetics of Ag, Cd, Co, Cr, and Zn have been investigated in shrimp exposed via seawater and food, using the corresponding gamma-emitting radiotracers ((110 m)Ag, (109)Cd, (57)Co, (51)Cr, and (65)Zn) and highly sensitive nuclear detection techniques. Results showed that hepatopancreas and intestine concentrated the metals to the highest extent among the blue shrimp organs and tissues. Moulting was found to play a non negligible detoxification role for Co, Cr and, to a lesser extent, Zn. Metal retention by L. stylirostris widely varied (from a few days to several months), according to the element and exposure pathway considered (a given metal was usually less strongly retained when ingested with food than when it was taken up from the dissolved phase). In the field study, Ag, As, Cd, Co, Cr, Cu, Mn, Ni, and Zn were analysed in shrimp collected from a New Caledonian aquaculture pond. Metal concentrations in the shrimp muscles were generally relatively low and results confirmed the role played by the digestive organs and tissues in the bioaccumulation/storage/detoxification of metals in the Pacific blue shrimp. Preliminary risk considerations indicate that consumption of the shrimp farmed in New Caledonia is not of particular concern for human health. PMID:20637480

  3. Bioaccumulation of metallic trace elements and organic pollutants in marine sponges from the South Brittany Coast, France.

    Science.gov (United States)

    Gentric, Charline; Rehel, Karine; Dufour, Alain; Sauleau, Pierre

    2016-01-01

    The purpose of this study was to compare the accumulation of metallic and organic pollutants in marine sponges with the oyster Crassostrea gigas used as sentinel species. The concentrations of 12 Metallic Trace Elements (MTEs), 16 Polycyclic Aromatic Hydrocarbons (PAHs), 7 PolyChlorinated Biphenyls (PCBs), and 3 organotin derivatives were measured in 7 marine sponges collected in the Etel River (South Brittany, France). Results indicated Al, Co, Cr, Fe, Pb, and Ti particularly accumulated in marine sponges such as Hymeniacidon perlevis and Raspailia ramosa at higher levels compared to oysters. At the opposite, Cu and Zn accumulated significantly at higher concentrations in oysters. Among PAHs analyzed, benzo(a)pyrene bioaccumulated in H. perlevis at levels up to 17-fold higher than in oysters. In contrast, PCBs bioaccumulated preferentially in oysters. Significant differences exist in the abilities of marine phyla and sponge species to accumulate organic and metallic pollutants however, among the few sponge species studied, H. perlevis showed impressive bioaccumulation properties. The use of this species as bioindicator and/or bioremediator near shellfish farming areas is also discussed.

  4. A Novel Fluorescence Probe for the Determination of Hydroxyl Radicals%一种表征羟基自由基的新型荧光探针

    Institute of Scientific and Technical Information of China (English)

    杨小峰; 郭祥群

    2001-01-01

    A novel technique for the determination of the hydroxyl radical is described in this paper. The method employed the reaction of hydroxyl radical with dimethyl sulfoxide to generate a methyl radical quantitatively, which then coupled with the nitroxide-linked naphthalene and led to a large increase in fluorescence intensity. The proposed method was demonstrated to be capable of detecting hydroxyl radicals generated in the Fenton systems. It proved to be a simple and sensitive technique for the determination of hydroxyl radicals.

  5. Bioaccumulation and elimination of mercury in juvenile seabass (Dicentrarchus labrax) in a warmer environment.

    Science.gov (United States)

    Maulvault, Ana Luísa; Custódio, Ana; Anacleto, Patrícia; Repolho, Tiago; Pousão, Pedro; Nunes, Maria Leonor; Diniz, Mário; Rosa, Rui; Marques, António

    2016-08-01

    Warming is an expected impact of climate change that will affect coastal areas in the future. These areas are also subjected to strong anthropogenic pressures leading to chemical contamination. Yet, the consequences of both factors for marine ecosystems, biota and consumers are still unknown. The present work aims to investigate, for the first time, the effect of temperature increase on bioaccumulation and elimination of mercury [(total mercury (THg) and methylmercury (MeHg)] in three tissues (muscle, liver, and brain) of a commercially important seafood species - European seabass (Dicentrarchus labrax). Fish were exposed to the ambient temperature currently used in seabass rearing (18°C) and to the expected ocean warming (+4°C, i.e. 22°C), as well as dietary MeHg during 28 days, followed by a depuration period of 28 days fed with a control diet. In both temperature exposures, higher MeHg contents were observed in the brain, followed by the muscle and liver. Liver registered the highest elimination percentages (EF; up to 64% in the liver, 20% in the brain, and 3% in the muscle). Overall, the results clearly indicate that a warming environment promotes MeHg bioaccumulation in all tissues (e.g. highest levels in brain: 8.1mgkg(-1) ww at 22°C against 6.2mgkg(-1) ww at 18°C after 28 days of MeHg exposure) and hampers MeHg elimination (e.g. liver EF decreases after 28 days of depuration: from 64.2% at 18°C to 50.3% at 22°C). These findings suggest that seafood safety may be compromised in a warming context, particularly for seafood species with contaminant concentrations close to the current regulatory levels. Hence, results point out the need to strengthen research in this area and to revise and/or adapt the current recommendations regarding human exposure to chemical contaminants through seafood consumption, in order to integrate the expected effects of climate change. PMID:27179934

  6. Correlation of transcriptomic responses and metal bioaccumulation in Mytilus edulis L. reveals early indicators of stress

    Energy Technology Data Exchange (ETDEWEB)

    Poynton, Helen C., E-mail: helen.poynton@umb.edu; Robinson, William E.; Blalock, Bonnie J.; Hannigan, Robyn E.

    2014-10-15

    Highlights: • Gene expression and metal tissue concentrations were compared in Mytilus edulis. • Expression levels of several transcripts correlated with metal concentrations. • Transcripts involved in the unfolded protein response (UPR) were induced. • Integration of transcriptomics and tissue levels provides insight to toxicity. - Abstract: Marine biomonitoring programs in the U.S. and Europe have historically relied on monitoring tissue concentrations of bivalves to monitor contaminant levels and ecosystem health. By integrating ‘omic methods with these tissue residue approaches we can uncover mechanistic insight to link tissue concentrations to potential toxic effects. In an effort to identify novel biomarkers and better understand the molecular toxicology of metal bioaccumulation in bivalves, we exposed the blue mussel, Mytilus edulis L., to sub-lethal concentrations (0.54 μM) of cadmium, lead, and a Cd + Pb mixture. Metal concentrations were measured in gill tissues at 1, 2, and 4 weeks, and increased linearly over the 4 week duration. In addition, there was evidence that Pb interfered with Cd uptake in the mixture treatment. Using a 3025 sequence microarray for M. edulis, we performed transcriptomic analysis, identifying 57 differentially expressed sequences. Hierarchical clustering of these sequences successfully distinguished the different treatment groups demonstrating that the expression profiles were reproducible among the treatments. Enrichment analysis of gene ontology terms identified several biological processes that were perturbed by the treatments, including nucleoside phosphate biosynthetic processes, mRNA metabolic processes, and response to stress. To identify transcripts whose expression level correlated with metal bioaccumulation, we performed Pearson correlation analysis. Several transcripts correlated with gill metal concentrations including mt10, mt20, and contig 48, an unknown transcript containing a wsc domain. In addition

  7. Effects of iron on Vitamin C/copper-induced hydroxyl radical generation in bicarbonate-rich water.

    Science.gov (United States)

    Jansson, Patric J; Del Castillo, Urko; Lindqvist, Christer; Nordström, Tommy

    2005-05-01

    The aim of this study was to evaluate whether iron, like copper, could support Vitamin C mediated hydroxyl radical formation in bicarbonate-rich water. By using the hydroxyl radical indicator coumarin-3-carboxylic acid, we found that iron, in contrast to copper, was not capable to support Vitamin C induced hydroxyl radical formation. However, when 0.2 mg/l iron and 0.1 mg/l copper were both added to bicarbonate supplemented Milli-Q water, the Vitamin C induced formation of 7-hydroxycoumarin, as measured by HPLC analysis, was inhibited by 47.5%. The inhibition of hydroxyl radical formation by iron was also evident in the experiments performed on copper contaminated bicarbonate-rich household drinking water samples. In the presence of 0.2 mg/l of ferric iron the ascorbic acid induced hydroxyl radical formation was inhibited by 36.0-44.6%. This inhibition was even more significant, 47.0-59.2%, when 0.8 mg/l of ferric iron was present. None of the other redox-active metals, e.g. manganese, nickel or cobalt, could support ascorbic acid induced hydroxyl radical formation and did not have any impact on the ascorbic acid/copper-induced hydroxyl radical generation. Our results show, that iron cannot by itself produce hydroxyl radicals in bicarbonate rich water but can significantly reduce Vitamin C/copper-induced hydroxyl radical formation. These findings might partly explain the mechanism for the iron-induced protective effect on various copper related degenerative disorders that earlier has been observed in animal model systems. PMID:16036332

  8. Genetical and biochemical evidence that the hydroxylation pattern of the anthocyanin B-ring in Silene dioica is determined at the p-coumaroyl-coenzyme a stage

    NARCIS (Netherlands)

    Kamsteeg, J.; Brederode, J. van; Nigtevecht, G. van

    1980-01-01

    In petals of Silene dioica, gene P controls the 3′-hydroxylation of the anthocyanin B-ring and the hydroxylation pattern of the hydroxycinnamoyl acyl group bound to the 4″'-hydroxyl group of rhamnose of anthocyanidin 3-rhamnosyl(1→6)glucoside-5-glucoside. In this paper, experiments are presented whi

  9. Interaction of hydrogen with ZnO nanopowders--evidence of hydroxyl group formation.

    Science.gov (United States)

    Wong, Kester W J; Field, Matthew R; Ou, Jian Zhen; Latham, Kay; Spencer, Michelle J S; Yarovsky, Irene; Kalantar-zadeh, Kourosh

    2012-01-13

    There have been many investigations to reveal the nature of the hydrogen gas and ZnO nanopowder interaction at elevated temperatures, while at present no conclusive description of such an interaction has been confidently reported. In this work, we demonstrate that a hydroxyl group is formed during this interaction, depending on size and relative crystallinity of nanopowders. Our in situ Raman spectroscopy investigations show that the interaction directly affects the intensity of the Raman signal at 483 cm(-1), relative to the peak at 519 cm(-1). Ex situ x-ray diffraction (XRD) and infrared spectroscopy also show extra peaks at 44° and 1618 cm(-1), respectively, after hydrogenation. These peaks were all identified as surface hydroxyl groups, which can be related to the formation of water on the ZnO nanopowder surfaces.

  10. Organocatalytic chemo- and regioselective oxyarylation of styrenes via a cascade reaction: remote activation of hydroxyl groups.

    Science.gov (United States)

    Zhang, Yu-Chen; Jiang, Fei; Wang, Shu-Liang; Shi, Feng; Tu, Shu-Jiang

    2014-07-01

    The first organocatalytic oxyarylation of styrenes has been established through a cascade of vinylogous Michael addition/alkoxyl transfer reactions of o- or p-hydroxylstyrenes with quinone imine ketals. The process leads to a highly chemo- and regioselective oxyarylation of styrenes and provides access to m-alkylated anilines in generally high yields and excellent diastereoselectivity (up to 99% yield, >95:5 dr). An investigation of the reaction pathway revealed that the existence and position of the hydroxyl group of styrene played crucial roles in the cascade reaction, suggesting that the two reactants were simultaneously activated by binaphthyl-derived phosphoric acid via hydrogen bonding interactions and long-distance conjugative effects. In addition, the activating group of the hydroxyl functionality in the products can be easily removed or transformed, demonstrating the applicability and utility of this strategy in styrene oxyarylation and in the synthesis of styrene-based compounds.

  11. Spectral Response and Diagnostics of Biological Activity of Hydroxyl-Containing Aromatic Compounds

    Science.gov (United States)

    Tolstorozhev, G. B.; Mayer, G. V.; Bel'kov, M. V.; Shadyro, O. I.

    2016-08-01

    Using IR Fourier spectra and employing quantum-chemical calculations of electronic structure, spectra, and proton-acceptor properties, synthetic derivatives of aminophenol exhibiting biological activity in the suppression of herpes, influenza, and HIV viruses have been investigated from a new perspective, with the aim of establishing the spectral response of biological activity of the molecules. It has been experimentally established that the participation of the aminophenol hydroxyl group in intramolecular hydrogen bonds is characteristic of structures with antiviral properties. A quantum-chemical calculation of the proton-acceptor ability of the investigated aminophenol derivatives has shown that biologically active structures are characterized by a high proton-acceptor ability of oxygen of the hydroxyl group. A correlation that has been obtained among the formation of an intramolecular hydrogen bond, high proton-acceptor ability, and antiviral activity of substituted aminophenols enables us to predict the pharmacological properties of new medical preparations of the given class of compounds.

  12. Complexation Between Borate ion and Hydroxyl Groups of Phenol-Formaldehyde Resol Resin

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The complexation reaction between borate ions and phenol-formaldehyde resol resin in aqueous solution was studied by pH measurement, small model molecules and infrared spectroscopy.The results show that the complexation can proceed completely and rapidly at room temperature.Borate ion attacks phenol hydroxyl groups and adjacent position hydroxymethyl groups on the phenol ring of the resin, and forms the coordinate bond between boron atom in borate ion and oxygen atom in the hydroxyl groups. The complexation is a quantitative reaction. The complex is a six member ring containing two oxygens and one boron. The complexation can release hydrogen ions resulting in the decreasing pH in the resin solution.

  13. Stability, electrochemical behaviors and electronic structures of iron hydroxyl-phosphate

    International Nuclear Information System (INIS)

    Iron hydroxyl-phosphate with a uniform spherical particle size of around 1 μm, a compound of the type Fe2-y□y(PO4)(OH)3-3y(H2O)3y-2 (where □ represents a vacancy), has been synthesized by hydrothermal methods. The particles are composed of spheres of diameter -1 and 120 mAh g-1 at current densities of 170 mA g-1 and 680 mA g-1, respectively. The stability of crystal structure of this material was studied by TGA and XRD which show that the material remains stable at least up to the temperature 200 deg. C. Investigation of the electronic structure of the iron hydroxyl-phosphate by GGA + U calculation has indicated that it has a better electronic conductivity than LiFePO4.

  14. The Hydroxyl-Water Megamaser Connection. I. Water Emission Toward OH Megamaser Hosts

    CERN Document Server

    Wiggins, Brandon K; Smidt, Joseph M

    2015-01-01

    Though megamasers are used to probe extragalactic phenomena, questions remain regarding their production and connection to galactic processes. The observation that water and hydroxyl megamasers rarely coexist in the same galaxy has given rise to the hypothesis that the two megamaser species appear in different phases of nuclear activity or that somehow their presence distinguishes different physical conditions in the medium. However, simultaneous hydroxyl and water megamaser emission has recently been detected in IC 694. Studies of this object are underway but, because many megamasers have not been surveyed for emission in the other molecule, it remains unclear whether IC 694 occupies a narrow phase of galaxy evolution or whether the relationship between megamaser species and galactic processes is more complicated than previously believed. In this paper, we present preliminary results of a systematic search for 22 GHz water maser emission among OH megamaser hosts to identify additional objects hosting both me...

  15. Properties of the Nafion membrane impregnated with hydroxyl ammonium based ionic liquids

    Science.gov (United States)

    Garaev, Valeriy; Kleperis, Janis; Pavlovica, Sanita; Vaivars, Guntars

    2012-08-01

    In this work, the Nafion 112 membrane impregnated with nine various hydroxyl ammonium based ionic liquids have been investigated. The used ionic liquids were combined from hydroxyl ammonium cations (2-hydroxyethylammonium/HEA, bis(2- hydroxyethyl)ammonium/BHEA, tris(2-hydroxyethyl)ammonium/THEA) and carboxylate anions (formate, acetate, lactate). The membranes are characterized by conductivity and thermal stability measurements. It was found, that almost all composites have 10 times higher ion conductivity than a pure Nafion 112 at 90 °C in ambient environment due to the higher thermal stability. The thermal stability of Nafion membrane was increased by all studied nine ionic liquids. In this work, only biodegradable ionic liquids were used for composite preparation.

  16. Hydroxylated polychlorinated biphenyls decrease circulating steroids in female polar bears (Ursus maritimus)

    DEFF Research Database (Denmark)

    Gustavson, Lisa; Ciesielski, Tomasz M; Bytingsvik, Jenny;

    2015-01-01

    -metabolites (hydroxylated PCBs [OH-PCBs] and hydroxylated PBDEs [OH-PBDEs]), steroid hormones, biological and capture variables in female polar bears. Inverse correlations were found between circulating levels of PRE and AN, and circulating levels of OH-PCBs. There were no significant relationships between the steroid......As a top predator in the Arctic food chain, polar bears (Ursus maritimus) are exposed to high levels of persistent organic pollutants (POPs). Because several of these compounds have been reported to alter endocrine pathways, such as the steroidogenesis, potential disruption of the sex steroid...... synthesis by POPs may cause implications for reproduction by interfering with ovulation, implantation and fertility. Blood samples were collected from 15 female polar bears in Svalbard (Norway) in April 2008. The concentrations of nine circulating steroid hormones; dehydroepiandrosterone (DHEA...

  17. XPS study of PBO fiber surface modified by incorporation of hydroxyl polar groups in main chains

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Tao; Hu Dayong; Jin Junhong; Yang Shenglin [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620 (China); Li Guang, E-mail: lig@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620 (China); Jiang Jianming [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620 (China)

    2010-01-15

    Dihydroxy poly(p-phenylene benzobisoxazole) (DHPBO), a modified poly(p-phenylene benzoxazole) (PBO) polymer containing double hydroxyl groups in polymer chains, was synthesized by copolymerization of 4,6-diamino resorcinol dihydrochloride (DAR), purified terephthalic acid (TA) and 2,5-dihydroxyterephthalic acid (DHTA). DHPBO fibers were prepared by dry-jet wet-spinning method. The effects of hydroxyl polar groups on the surface elemental compositions of PBO fiber were investigated by X-ray photoelectron spectroscopy (XPS). The results show that the ratio of oxygen/carbon on the surface of DHPBO fibers is higher than that on the surface of PBO fibers, which indicates the content of polar groups on the surface of DHPBO fiber increase compared with PBO fiber.

  18. Formation of hydroxyl radicals in the human lens is related to the severity of nuclear cataract

    DEFF Research Database (Denmark)

    Garner, B; Davies, Michael Jonathan; Truscott, R J

    2000-01-01

    homogenates to catalyse HO. production in the presence of H(2)O(2)was investigated using electron paramagnetic resonance (EPR) spectroscopy with the free radical trap, 5,5-dimethyl-1-pyrroline- N -oxide (DMPO). Cataractous lens homogenates incubated with 1 m m H(2)O(2)generated a distinct HO. signal, which......Recent studies have identified specific hydroxylated amino acid oxidation products which strongly suggest the presence of hydroxyl radical (HO.)-damaged proteins in human cataractous lenses. In the present study, the ability of early stage (type II) and advanced (type IV) nuclear cataractous lens....... formation and not DMPO-OOH degradation. The metal ion chelator, diethylenetriaminepentaacetic acid, also inhibited HO. formation, indicating that lenticular metal ions play a key role in HO. formation. Cataractous lens homogenates also stimulated ascorbyl radical production, further suggesting the presence...

  19. Adsorption of uranyl species on hydroxylated titanium carbide nanosheet: A first-principles study.

    Science.gov (United States)

    Zhang, Yu-Juan; Lan, Jian-Hui; Wang, Lin; Wu, Qun-Yan; Wang, Cong-Zhi; Bo, Tao; Chai, Zhi-Fang; Shi, Wei-Qun

    2016-05-01

    In this work, hydroxylated titanium carbide Ti3C2(OH)2, a representative of the two-dimensional transition metal carbides, has been predicted to be an effective adsorbent for uranyl ions in aqueous environments for the first time using density functional theory simulations. The calculations revealed that the uranyl ion can strongly bind with Ti3C2(OH)2 nanosheet in aqueous solution regardless of the presence of anionic ligands such as OH(-), Cl(-) and NO3(-). The bidentate coordination of uranyl to the surface is energetically more favorable than other adsorption configurations, and the uranyl ion prefers to bind with the deprotonated O adsorption site rather than the protonated one on the hydroxylated surface. During the adsorption process, the chemical adsorption as well as the formation of hydrogen bonds is the dominant factor.

  20. Molecular dynamics simulation study of water adsorption on hydroxylated graphite surfaces.

    Science.gov (United States)

    Picaud, Sylvain; Collignon, B; Hoang, Paul N M; Rayez, J C

    2006-04-27

    In this paper, we present results from molecular dynamic simulations devoted to the characterization of the interaction between water molecules and hydroxylated graphite surfaces considered as models for surfaces of soot emitted by aircraft. The hydroxylated graphite surfaces are modeled by anchoring several OH groups on an infinite graphite plane. The molecular dynamics simulations are based on a classical potential issued from quantum chemical calculations. They are performed at three temperatures (100, 200, and 250 K) to provide a view of the structure and dynamics of water clusters on the model soot surface. These simulations show that the water-OH sites interaction is quite weak compared to the water-water interaction. This leads to the clustering of the water molecules above the surface, and the corresponding water aggregate can only be trapped by the OH sites when the temperature is sufficiently low, or when the density of OH sites is sufficiently high.