WorldWideScience

Sample records for chlordecone

  1. Microbial degradation of a recalcitrant pesticide: chlordecone.

    Directory of Open Access Journals (Sweden)

    Sébastien Chaussonnerie

    2016-12-01

    Full Text Available Chlordecone (Kepone® is a synthetic organochlorine insecticide (C10Cl10O used worldwide mostly during the 1970s and 1980s. Its intensive application in the French West Indies to control the banana black weevil Cosmopolites sordidus led to a massive environmental pollution. Persistence of chlordecone in soils and water for numerous decades even centuries causes global public health and socio-economic concerns. In order to investigate the biodegradability of chlordecone, microbial enrichment cultures from soils contaminated by chlordecone or other organochlorines and from sludge of a wastewater treatment plant have been conducted. Different experimental procedures including original microcosms were carried out anaerobically over long periods of time. GC-MS monitoring resulted in the detection of chlorinated derivatives in several cultures, consistent with chlordecone biotransformation. More interestingly, disappearance of chlordecone (50 µg/mL in two bacterial consortia was concomitant with the accumulation of a major metabolite of formula C9Cl5H3 (named B1 as well as two minor metabolites C10Cl9HO (named A1 and C9Cl4H4 (named B3. Finally, we report the isolation and the complete genomic sequences of two new Citrobacter isolates, closely related to Citrobacter amalonaticus, and that were capable of reproducing chlordecone transformation. Further characterization of these Citrobacter strains should yield deeper insights into the mechanisms involved in this transformation process.

  2. Chlordecone retention in the fractal structure of volcanic clay

    Energy Technology Data Exchange (ETDEWEB)

    Woignier, Thierry, E-mail: thierry.woignier@imbe.fr [IRD, UMR 237, IMBE, PRAM B.P. 214 Petit Morne, 97232, Le Lamentin, Martinique (France); CNRS, UMR 7263, IMBE, PRAM B.P. 214 Petit Morne, 97232, Le Lamentin, Martinique (France); Aix Marseille Universite, IMBE, Faculte des Sciences et Techniques de Saint Jerome, avenue Escadrille Normandie Niemen, F-13397 Marseille Cedex 20 (France); Clostre, Florence [Cirad/PRAM, UPR fonctionnement agroecologique et performances des systemes de culture horticoles, B.P. 214 Petit Morne, 97232, Le Lamentin, Martinique (France); Macarie, Herve [IRD, UMR 237, IMBE, PRAM B.P. 214 Petit Morne, 97232, Le Lamentin, Martinique (France); Cirad UR HortSys, TA B-103/PS4, Boulevard de la Lironde, 34398, Montpellier Cedex 5 (France); Jannoyer, Magalie [Cirad/PRAM, UPR fonctionnement agroecologique et performances des systemes de culture horticoles, B.P. 214 Petit Morne, 97232, Le Lamentin, Martinique (France); Cirad UR HortSys, TA B-103/PS4, Boulevard de la Lironde, 34398, Montpellier Cedex 5 (France)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer Allophanic soils are highly polluted but less contaminant for cultivated vegetables. Black-Right-Pointing-Pointer SAXS and TEM show the fractal structure of allophane aggregates at the nanoscale. Black-Right-Pointing-Pointer Allophane aggregates play the role of a labyrinth which fixes and traps chlordecone. Black-Right-Pointing-Pointer Allophane physical properties contribute to chlordecone retention in andosols. - Abstract: Chlordecone (CHLD), a soil and foodstuff pollutant, as well as an environmentally persistent organochlorine insecticide, was used intensively in banana fields. The chlordecone uptake of three crops was measured for two types of polluted soils: allophanic and non-allophanic. The uptake is lower for allophanic soils even if their chlordecone content is higher than with non-allophanic soils. The fractal structure of the allophane aggregates was characterized at the nanoscale by small angle X-rays scattering, pore size distribution and transmission electron microscopy. We showed that clay microstructures should be an important physico-chemical factor governing the fate of chlordecone in the environment. Allophanic clays result in two counterintuitive findings: higher contaminant trappings yet lower contaminant availability. We propose that this specific, tortuous structure, along with its associated low accessibility, partly explains the low availability of chlordecone confined in allophanic soils. Capsule The fractal and tortuous microstructure of allophane clay favours the chlordecone retention in soils and disfavours the crop uptake.

  3. Soil microstructure and organic matter: keys for chlordecone sequestration.

    Science.gov (United States)

    Woignier, T; Fernandes, P; Soler, A; Clostre, F; Carles, C; Rangon, L; Lesueur-Jannoyer, M

    2013-11-15

    Past applications of chlordecone, a persistent organochlorine pesticide, have resulted in diffuse pollution of agricultural soils, and these have become sources of contamination of cultivated crops as well as terrestrial and marine ecosystems. Chlordecone is a very stable and recalcitrant molecule, mainly present in the solid phase, and has a strong affinity for organic matter. To prevent consumer and ecosystem exposure, factors that influence chlordecone migration in the environment need to be evaluated. In this study, we measured the impact of incorporating compost on chlordecone sequestration in andosols as a possible way to reduce plant contamination. We first characterized the transfer of chlordecone from soil to plants (radish, cucumber, and lettuce). Two months after incorporation of the compost, soil-plant transfers were reduced by a factor of 1.9-15 depending on the crop. Our results showed that adding compost modified the fractal microstructure of allophane clays thus favoring chlordecone retention in andosols. The complex structure of allophane and the associated low accessibility are important characteristics governing the fate of chlordecone. These results support our proposal for an alternative strategy that is quite the opposite of total soil decontamination: chlordecone sequestration.

  4. Chlordecone fate and mineralisation in a tropical soil (andosol) microcosm under aerobic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-Bayo, Jesus D., E-mail: fernanje@supagro.inra.fr [IRD, UMR LISAH Bât 24, 2 Place Viala, 34060 Montpellier cedex 1 (France); INRA, UMR LISAH Bât 24, 2 Place Viala, 34060 Montpellier cedex 1 (France); Saison, Carine [IRD, UMR LISAH Bât 24, 2 Place Viala, 34060 Montpellier cedex 1 (France); Voltz, Marc [INRA, UMR LISAH Bât 24, 2 Place Viala, 34060 Montpellier cedex 1 (France); Disko, Ulrich; Hofmann, Diana; Berns, Anne E. [Forschungszentrum Jülich GmbH, IBG 3, 52425 Jülich (Germany)

    2013-10-01

    Chlordecone is a persistent organochlorine insecticide that, even decades after its ban, poses a threat to the environment and human health. Nevertheless, its environmental fate in soils has scarcely been investigated, and elementary data on its degradation and behaviour in soil are lacking. The mineralisation and sorption of chlordecone and the formation of possible metabolites were evaluated in a tropical agricultural andosol. Soil microcosms with two different soil horizons (S-A and S-B) were incubated for 215 days with {sup 14}C-chlordecone. At five different times (1, 33, 88, 150 and 215 days) the extractability of {sup 14}C-chlordecone was analysed. Mineralisation was monitored using {sup 14}CO{sub 2} traps of NaOH. The appearance of metabolites was studied using thin layer and gas chromatography techniques. At the end of the experiment, the water soluble {sup 14}C-activity was 2% of the remaining {sup 14}C-chlordecone for S-A and 8% for S-B. Only 12% of the remaining activity was non extractable and more than 80% remained extractable with organic solvents. For the first time to our knowledge, a significant mineralisation of chlordecone was measured in a microcosm under aerobic conditions (4.9% for S-A and 3.2% for S-B of the initial {sup 14}C-activity). The drastically lower emission of {sup 14}CO{sub 2} in sterilised microcosms indicated the biological origin of chlordecone mineralisation in the non-sterilised microcosms. No metabolites could be detected in the soil extracts. The mineralisation rate of chlordecone decreased by one order of magnitude throughout the incubation period. Thus, the chlordecone content in the soil remained large. This study confirms the existence of chlordecone degrading organisms in a tropical andosol. The reasons why their activity is restricted should be elucidated to allow the development of bioremediation approaches. Possible reasons are a heterogeneous distribution a chlordecone between sub-compartments with different

  5. Compost addition reduces porosity and chlordecone transfer in soil microstructure.

    Science.gov (United States)

    Woignier, Thierry; Clostre, Florence; Fernandes, Paula; Rangon, Luc; Soler, Alain; Lesueur-Jannoyer, Magalie

    2016-01-01

    Chlordecone, an organochlorine insecticide, pollutes soils and contaminates crops and water resources and is biomagnified by food chains. As chlordecone is partly trapped in the soil, one possible alternative to decontamination may be to increase its containment in the soil, thereby reducing its diffusion into the environment. Containing the pesticide in the soil could be achieved by adding compost because the pollutant has an affinity for organic matter. We hypothesized that adding compost would also change soil porosity, as well as transport and containment of the pesticide. We measured the pore features and studied the nanoscale structure to assess the effect of adding compost on soil microstructure. We simulated changes in the transport properties (hydraulic conductivity and diffusion) associated with changes in porosity. During compost incubation, the clay microstructure collapsed due to capillary stresses. Simulated data showed that the hydraulic conductivity and diffusion coefficient were reduced by 95 and 70% in the clay microstructure, respectively. Reduced transport properties affected pesticide mobility and thus helped reduce its transfer from the soil to water and to the crop. We propose that the containment effect is due not only to the high affinity of chlordecone for soil organic matter but also to a trapping mechanism in the soil porosity.

  6. Determination of soil content in chlordecone (organochlorine pesticide) using near infrared reflectance spectroscopy (NIRS)

    Energy Technology Data Exchange (ETDEWEB)

    Brunet, Didier, E-mail: didier.brunet@ird.f [IRD - Institut de Recherche pour le Developpement, UMR Eco and Sols (Ecologie Fonctionnelle et Biogeochimie des Sols), Montpellier SupAgro, Batiment 12, 2 place Viala, 34060 Montpellier Cedex 1 (France); Woignier, Thierry [IRD, UMR Eco and Sols, PRAM (Pole de Recherche Agronomique de la Martinique), BP 213, Petit Morne, 97232 Le Lamentin, Martinique (French West Indies) (France); CNRS - Centre National de la Recherche Scientifique, Universite Montpellier 2, place Eugene Bataillon, 34095 Montpellier Cedex 5 (France); Lesueur-Jannoyer, Magalie; Achard, Raphael [CIRAD (Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement), PRAM, BP 213, Petit Morne, 97232 Le Lamentin, Martinique (French West Indies) (France); Rangon, Luc [IRD, UMR Eco and Sols, PRAM (Pole de Recherche Agronomique de la Martinique), BP 213, Petit Morne, 97232 Le Lamentin, Martinique (French West Indies) (France); Barthes, Bernard G. [IRD - Institut de Recherche pour le Developpement, UMR Eco and Sols (Ecologie Fonctionnelle et Biogeochimie des Sols), Montpellier SupAgro, Batiment 12, 2 place Viala, 34060 Montpellier Cedex 1 (France)

    2009-11-15

    Chlordecone is a toxic organochlorine insecticide that was used in banana plantations until 1993 in the French West Indies. This study aimed at assessing the potential of near infrared reflectance spectroscopy (NIRS) for determining chlordecone content in Andosols, Nitisols and Ferralsols from Martinique. Using partial least square regression, chlordecone content conventionally determined through gas chromatography-mass spectrometry could be correctly predicted by NIRS (Q{sup 2} = 0.75, R{sup 2} = 0.82 for the total set), especially for samples with chlordecone content <12 mg kg{sup -1} or when the sample set was rather homogeneous (Q{sup 2} = 0.91, R{sup 2} = 0.82 for the Andosols). Conventional measures and NIRS predictions were poorly correlated for chlordecone content >12 mg kg{sup -1}, nevertheless ca. 80% samples were correctly predicted when the set was divided into three or four classes of chlordecone content. Thus NIRS could be considered a time- and cost-effective method for characterising soil contamination by chlordecone. - Soil content in chlordecone, an organochlorine insecticide, can be determined time- and cost-effectively using near infrared reflectance spectroscopy (NIRS).

  7. Contamination of Harvested Organs in Root Crops Grown on Chlordecone-Polluted Soils

    Institute of Scientific and Technical Information of China (English)

    Y. M. CABIDOCHE; M. LESUEUR-JANNOYER

    2012-01-01

    Chlordecone,one of the most persistent organochlorine pesticides,was applied between 1972 and 1993 in banana fields in the French West Indies,which results in long-term pollution of soils and contamination of waters,aquatic biota,and crops.As human exposure to chlordecone is mainly due to food contamination,early research was focused on chlordecone transfer to crops.Field trials were conducted to investigate chlordecone contamination of yam,sweet potato,turnip,and radish grown on a Ferralic Nitisol polluted by chlordecone.We also carried out trials on yam,courgette,and tomato under greenhouse conditions with homogenized Andosol and Nitisol,polluted by chlordecone to various extents.Our results indicated that i) all tubers were contaminated in accordance with the chlordecone content of the soils; ii) the plant contamination capacity of the Nitisol was greater than that of the Andosol; and iii) whatever the soil type,tuber contamination was related to the soil volumetric content of dissolved chlordecone.Nevertheless,no tubers showed sufficient chlordecone uptake for efficient soil decontamination by means of plant extraction.Soil contact accounted for most of the root crop contamination,which was inversely proportional to the tuber size.Internal transfer might also increase root crop contamination when the root central cylinder contained raw sap flow,as in the case of turnip or radish.Courgette fruits showed high contamination without soil contact.Thus,further research is needed to explore the pattern of both below- and aboveground plant chlordecone contamination and assess the hypothesis of its correlation with sap flow.Finally.we used our results to build a decisionmaking tool for farmers,relating soil pollution with the maximal contamination of the harvested organs to predict crop contamination and thus assisting farmers in making crop choices at planting in order to conform with the European Union's regulations.

  8. Expression of biotransformation and oxidative stress genes in the giant freshwater prawn Macrobrachium rosenbergii exposed to chlordecone.

    Science.gov (United States)

    Gaume, Béatrice; Dodet, Nathalie; Thomé, Jean-Pierre; Lemoine, Soazig

    2015-06-01

    Chlordecone is a persistent organochlorine pesticide widely used between 1972 and 1993 in the French West Indies to control the root borer in banana fields. Chlordecone use resulted in long-term pollution of soils, contamination of waters, of aquatic organisms, and of fields. Chlordecone is known to be neurotoxic, to increase prostate cancer, and to have negative effects on cognitive and motor development during infancy. In Guadeloupe, most of the freshwater species living in contaminated rivers exceed the French legal limit of 20 μg·kg(-1) wet weight. In the present study, we chose a transcriptomic approach to study the cellular effects of chlordecone in the giant freshwater prawn Macrobrachium rosenbergii, an important economical species in Guadeloupe. Quantitative PCR revealed an induction of genes involved in defense mechanism against oxidative stress (catalase and selenium-dependent glutathione peroxidase) in prawns exposed to low environmental concentrations of chlordecone after 12 and 24 h of exposure. In prawns reared in a contaminated farm, transcription of genes involved in the biotransformation process (cytochrome P450 and glutathione-S-transferase (GST)) were induced after 8 days of exposure. Our results provide information on the mechanims of defense induced by chlordecone in aquatic crustacean species. This gene expression study of selected genes should be further strengthened by proteomic analyses and enzymatic activity assays to confirm the response of these biomarkers of stress in crustaceans and to give new insights into the mechanism of toxicity by chlordecone.

  9. Evaluation of the ecotoxicological impact of the organochlorine chlordecone on soil microbial community structure, abundance, and function.

    Science.gov (United States)

    Merlin, Chloé; Devers, Marion; Béguet, Jérémie; Boggio, Baptiste; Rouard, Nadine; Martin-Laurent, Fabrice

    2016-03-01

    The insecticide chlordecone applied for decades in banana plantations currently contaminates 20,000 ha of arable land in the French West Indies. Although the impact of various pesticides on soil microorganisms has been studied, chlordecone toxicity to the soil microbial community has never been assessed. We investigated in two different soils (sandy loam and silty loam) exposed to different concentrations of CLD (D0, control; D1 and D10, 1 and 10 times the agronomical dose) over different periods of time (3, 7, and 32 days): (i) the fate of chlordecone by measuring (14)C-chlordecone mass balance and (ii) the impact of chlordecone on microbial community structure, abundance, and function, using standardized methods (-A-RISA, taxon-specific quantitative PCR (qPCR), and (14)C-compounds mineralizing activity). Mineralization of (14)C-chlordecone was inferior below 1 % of initial (14)C-activity. Less than 2 % of (14)C-activity was retrieved from the water-soluble fraction, while most of it remained in the organic-solvent-extractable fraction (75 % of initial (14)C-activity). Only 23 % of the remaining (14)C-activity was measured in nonextractable fraction. The fate of chlordecone significantly differed between the two soils. The soluble and nonextractable fractions were significantly higher in sandy loam soil than in silty loam soil. All the measured microbiological parameters allowed discriminating statistically the two soils and showed a variation over time. The genetic structure of the bacterial community remained insensitive to chlordecone exposure in silty loam soil. In response to chlordecone exposure, the abundance of Gram-negative bacterial groups (β-, γ-Proteobacteria, Planctomycetes, and Bacteroidetes) was significantly modified only in sandy loam soil. The mineralization of (14)C-sodium acetate and (14)C-2,4-D was insensitive to chlordecone exposure in silty loam soil. However, mineralization of (14)C-sodium acetate was significantly reduced in soil

  10. Co-transport of chlordecone and sulfadiazine in the presence of functionalized multi-walled carbon nanotubes in soils

    Science.gov (United States)

    Batch and saturated soil column experiments were conducted to investigate sorption and mobility of two 14C-labeled contaminants, the hydrophobic chlordecone (CLD) and the readily water-soluble sulfadiazine (SDZ), in the absence or presence of functionalized multi-walled carbon nanotubes (MWCNTs). Th...

  11. Effects of chlordecone on 20-hydroxyecdysone concentration and chitobiase activity in a decapod crustacean, Macrobrachium rosenbergii.

    Science.gov (United States)

    Lafontaine, Anne; Gismondi, Eric; Boulangé-Lecomte, Céline; Geraudie, Perrine; Dodet, Nathalie; Caupos, Fanny; Lemoine, Soazig; Lagadic, Laurent; Thomé, Jean-Pierre; Forget-Leray, Joëlle

    2016-07-01

    Chlordecone (CLD) is an organochlorine insecticide abundant in aquatic environment of the French West Indies. However, few studies have investigated its impact on freshwater invertebrates. Whereas CLD is suspected of inducing endocrine disruption, this work aimed to study the effects of environmentally relevant concentrations of CLD on the 20-hydroxyecdysone (20-HE) hormone concentration and on the chitobiase activity, both having key roles in the molting process of crustaceans. In addition, the bioaccumulation of CLD was measured in the muscle tissue of Macrobrachium rosenbergii to underline potential dose-response relationship. The results have shown that CLD was bioaccumulated in exposed organisms according to a trend to a dose-response relationship. Moreover, it was observed that CLD decreased the 20-HE concentration in exposed prawns when compared to control, whatever the duration of exposure, as well as it inhibited the chitobiase activity after 30days of exposure. The present study indicates that CLD could interfere with molting process of M. rosenbergii by disturbing the 20-HE concentration and the activity of chitobiase, suggesting consequences at the long term on the shrimp development. This study also confirmed that CLD could be an endocrine disruptor in decapod crustaceans, as it was already observed in vertebrates.

  12. The Chlordecone crisis in the French West Indies : Its fate in soils and water

    Science.gov (United States)

    Voltz, Marc; Cattan, Philippe; Saison, Carine; Berns, Anne E.; Colin, François; Crabit, Armand; Crevoisier, David; Fernandez-Bayo, Jesus; Levillain, Joseph; Pak, Lai-Ting; Samouelian, Anatja; Cabidoche, Yves-Marie

    2013-04-01

    In the French West Indies, chlordecone (CLD), an organochlorine pesticide, which is highly persistent in the environment, was applied in banana plantations from 1972 to 1993 against the banana weevil Cosmopolites sordidus. Pollution surveys conducted in 2001 by the French Department of Health revealed the presence of chlordecone in soils, rivers, springs over large areas in Guadeloupe and Martinique islands. Contamination of drinking water, food crops, aquatic species by CLD has been observed as well as its presence in blood of men, pregnant women and newborns. There is therefore a large social concern about the extent and evolution of CLD pollution in the French West Indies and its impact on human health and ecosystems. From 2008 to 2012 a multidisciplinary project CHLORDEXCO took place to study the CLD fate in water, soils and the contamination characteristics of aquatic species and food crops. Here, we summarize results obtained on the processes controlling the spatial and temporal patterns of soil and water contamination at the scale of the banana cropping area in Guadeloupe and of the Perou catchment. The main soils in the contaminated areas are andosols and nitisols and formed from the weathering of volcanic ashes. They have a high organic carbon content and high content of secondary minerals, allophane for andosols and halloysite for nitisols. An analysis of the spatial distribution of CLD in soil over 1045 field plots showed that the soil type had a strong impact. Andosols, with a high sorption capacity (Koc 20 000 L/kg), had the highest CLD concentrations and stocks, unlike Nitisols, which had 10-fold lower sorption capacities. A significant « farm effect », due to between-farm variations of application times and amounts, was also noticed. The observed stocks of CLD clearly correspond to the accumulation in soil of successive treatments and thereby confirm the high persistence of CLD in soil also observed in incubation studies in soil microcosms. Soil

  13. Toxicokinetics of chlordecone in goats: Implications for risk management in French West Indies.

    Science.gov (United States)

    Fournier, Agnès; Feidt, Cyril; Lastel, Marie-Laure; Archimede, Harry; Thome, Jean-Pierre; Mahieu, Maurice; Rychen, Guido

    2017-03-01

    The former use of chlordecone (CLD) in the French West Indies has resulted in long-term pollution of soils. CLD is known to be potentially transferred towards animal products of animals reared outdoors, mainly through accidental soil ingestion. Several studies indicate that soil bound CLD is bioavailable when administered to farm animals. Currently there is a need to quantify the level of CLD absorption and its toxicokinetic characteristics in the ruminant and particularly in the goat. These are considered as important farm species in the French West Indies. The objective of this study was to evaluate the absorption rate and the half-life of CLD in the non-lactating goat. The goats were administered either intravenously (i.v., n = 6) or orally (p.o., n = 6) one dose (1 mg kg(-1) body weight) of CLD. Blood samples were collected at defined times up to 160 days post-dosing. CLD was analyzed in serum by high-resolution gas chromatography. A comparison of the area under the serum concentration-time curves (AUC) showed that the i.v. route is equivalent to the oral route. Thus, CLD is considered almost completely absorbed after p.o. administration, as shown by the mean absolute bioavailability. The comparison between the pharmacokinetic profiles of CLD following oral and intravenous dose showed a difference during the first 14 days and a similar kinetic after this period. The half-life of CLD in serum was close to 20 days. These results highlight a possible strategy of decontamination due to the short half-life of CLD, obtained in dry goats that did not excrete fat matter.

  14. In vivo metabolism of CCl sub 4 by gerbils pretreated with chlordecone, phenobarbital, or mirex

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Z.; Mehendale, H.M. (Univ. of Mississippi, Jackson (United States))

    1990-02-26

    Gerbils are known to be much more sensitive to CCl{sub 4} lethality than rats as indicated by 48 hours LD{sub 50} (0.08 vs 2.8 ml/kg). On the other hand, gerbils are refractory to chlordecone (CD) potentiation of CCl{sub 4} toxicity. To investigate the possible mechanism underlying gerbil's high sensitivity to CCl{sub 4} lethality, the authors studied in vivo metabolism of CCl{sub 4} in gerbils pretreated with dietary CD (10 ppm), phenobarbital (PB, 225 ppm) or mirex (M, 10 ppm). The hepatic content of CCl{sub 4}, the expiration of {sup 14}CCl{sub 4} and {sup 14}CCl{sub 4}-derived Co{sub 2}, and lipid peroxidation were measured and the results were compared with our previous data for rats. After 15-day dietary pretreatment, male gerbils (60-80 g) received {sup 14}CCl{sub 4} (80 ml/kg; sp act: 0.04 mCi/mmol) ip in corn oil and the expired air was collected for 6 hours. More than 80% of the dose administered was expired as parent compound in 6 hours regardless of pretreatments. Expiration of {sup 14}CCl{sub 4} derived {sup 14}CO{sub 2} in control gerbils was 3.5-fold more than in control rats and was increased significantly in pretreated gerbils (M>PB>CD). PB and M pretreatments resulted in significant increase of {sup 14}C label bound to non-lipid fraction of hepatic content as compared with CD or control gerbils. The radiolabel present in hepatic content of control gerbils was 5-fold higher than that of control rats. In vivo liquid peroxidation measured as diene conjugation in lipid extracts from the livers was lower in gerbils than in rats, and there were no significant differences among control and pretreated gerbils. These data indicate that the more extensive metabolism of CCl{sub 4} in gerbils may partially explain their high sensitivity to CCl{sub 4} toxicity. However, the significantly enhanced metabolism of CCl{sub 4} found in CD, PB, or M pretreated gerbils did not lead to amplification of CCl{sub 4} hepatotoxic and lethal effects.

  15. Theoretical study of chlordecone and surface groups interaction in an activated carbon model under acidic and neutral conditions.

    Science.gov (United States)

    Gamboa-Carballo, Juan José; Melchor-Rodríguez, Kenia; Hernández-Valdés, Daniel; Enriquez-Victorero, Carlos; Montero-Alejo, Ana Lilian; Gaspard, Sarra; Jáuregui-Haza, Ulises Javier

    2016-04-01

    Activated carbons (ACs) are widely used in the purification of drinking water without almost any knowledge about the adsorption mechanisms of the persistent organic pollutants. Chlordecone (CLD, Kepone) is an organochlorinated synthetic compound that has been used mainly as agricultural insecticide. CLD has been identified and listed as a persistent organic pollutant by the Stockholm Convention. The selection of the best suited AC for this type of contaminants is mainly an empirical and costly process. A theoretical study of the influence of AC surface groups (SGs) on CLD adsorption is done in order to help understanding the process. This may provide a first selection criteria for the preparation of AC with suitable surface properties. A model of AC consisting of a seven membered ring graphene sheet (coronene) with a functional group on the edge was used to evaluate the influence of the SGs over the adsorption. Multiple Minima Hypersurface methodology (MMH) coupled with PM7 semiempirical Hamiltonian was employed in order to study the interactions of the chlordecone with SGs (hydroxyl and carboxyl) at acidic and neutral pH and different hydration conditions. Selected structures were re-optimized using CAM-B3LYP to achieve a well-defined electron density to characterize the interactions by the Quantum Theory of Atoms in Molecules approach. The deprotonated form of surface carboxyl and hydroxyl groups of AC models show the strongest interactions, suggesting a chemical adsorption. An increase in carboxylic SGs content is proposed to enhance CLD adsorption onto AC at neutral pH conditions.

  16. Chlordecone, a mixed pregnane X receptor (PXR) and estrogen receptor alpha (ERα) agonist, alters cholesterol homeostasis and lipoprotein metabolism in C57BL/6 mice

    OpenAIRE

    2008-01-01

    Chlordecone (CD) is one of many banned organochlorine (OC) insecticides that are widespread persistent organic pollutants. OC insecticides alter lipid homeostasis in rodents at doses that are not neurotoxic or carcinogenic. Pretreatment of mice or rats with CD altered tissue distribution of a subsequent dose of [14C]CD or [14C]cholesterol (CH). Nuclear receptors regulate expression of genes important in the homeostasis of CH and other lipids. In this study, we report that CD suppresses in vit...

  17. Long-term pollution by chlordecone of tropical volcanic soils in the French West Indies: A simple leaching model accounts for current residue

    Energy Technology Data Exchange (ETDEWEB)

    Cabidoche, Y.-M., E-mail: cabidoch@antilles.inra.f [INRA, UR 135 Agropedoclimatique de la Zone Caraibe, Environment and Agronomy, Domaine Duclos, 97170 Petit-Bourg, Guadeloupe (France); Achard, R., E-mail: achard@cirad.f [CIRAD, UPR Systemes Bananes et Ananas (Martinique), 97285 Le Lamentin (France); Cattan, P., E-mail: cattan@cirad.f [CIRAD, UPR Systemes Bananes et Ananas (Guadeloupe), 97130 Capesterre-Belle-Eau (France); Clermont-Dauphin, C., E-mail: clermont@ird.f [INRA, UR 135 Agropedoclimatique de la Zone Caraibe, Environment and Agronomy, Domaine Duclos, 97170 Petit-Bourg, Guadeloupe (France); Massat, F., E-mail: fmassat@ladrome.f [Laboratoire Departemental d' Analyses de la Drome, LDA26, 26000 Valence (France); Sansoulet, J., E-mail: Julie.Sansoulet@cirad.f [INRA, UR 135 Agropedoclimatique de la Zone Caraibe, Environment and Agronomy, Domaine Duclos, 97170 Petit-Bourg, Guadeloupe (France)

    2009-05-15

    Chlordecone was applied between 1972 and 1993 in banana fields of the French West Indies. This resulted in long-term pollution of soils and contamination of waters, aquatic biota, and crops. To assess pollution level and duration according to soil type, WISORCH, a leaching model based on first-order desorption kinetics, was developed and run. Its input parameters are soil organic carbon content (SOC) and SOC/water partitioning coefficient (K{sub oc}). It accounts for current chlordecone soil contents and drainage water concentrations. The model was valid for andosol, which indicates that neither physico-chemical nor microbial degradation occurred. Dilution by previous deep tillages makes soil scrapping unrealistic. Lixiviation appeared the main way to reduce pollution. Besides the SOC and rainfall increases, K{sub oc} increased from nitisol to ferralsol and then andosol while lixiviation efficiency decreased. Consequently, pollution is bound to last for several decades for nitisol, centuries for ferralsol, and half a millennium for andosol. - Soil and water contamination by chlordecone will persist for several centuries in the French West Indies, because the only decontamination is through leaching by drainage water.

  18. Soil and river contamination patterns of chlordecone in a tropical volcanic catchment in the French West Indies (Guadeloupe).

    Science.gov (United States)

    Crabit, A; Cattan, P; Colin, F; Voltz, M

    2016-05-01

    The aim of this study was to identify primary flow paths involved in the chlordecone (CLD) river contamination and quantify the CLD fluxes to assess CLD pollution levels and duration according to a typical catchment of the banana cropping area in the French Indies (Guadeloupe): the Pérou Catchment (12 km(2)) characterized by heavy rainfall (5686 mm year(-1)). Three sub-catchments (SC1, SC2 and SC3) were studied during the hydrological year 2009-2010: a pedological survey combined with a spatialized hydrochemical approach was conducted. The average soil concentration is higher in the Pérou Catchment (3400 μg kg(-1)) than in the entire banana cropping area in Guadeloupe (2100 μg kg(-1)). The results showed that CLD stocks in soils vary largely among soil types and farming systems: the weakest stocks are located upstream in SC1 (5 kg ha(-1)), where a majority of the area is non-cultivated; medium stocks are located in Nitisols downstream in SC3 (9 kg ha(-1)); and the greatest stocks are observed in SC2 on Andosols (12 kg ha(-1)) characterized by large farms. The annual water balance and the hydro-chemical analysis revealed that the three sub-catchments exhibited different behaviors. Pérou River contamination was high during low flows, which highlighted that contamination primarily originated from groundwater contributions. The results showed that only a small part of the catchment (SC2), contributing little to the water flow, comprises a major CLD contribution, which is in agreement with the highly contaminated andosol soils observed there. Another significant result considers that at least 50 years would be required to export the totality of the actual CLD soil stocks retained in the topsoil layer. The actual time for soil remediation will however be much longer considering (i) the necessary time for the chlordecone to percolate and be stored in the shallow aquifers and (ii) its travel time to reach the river.

  19. Comparison of the inhibition of biliary excretion produced by certain inducing agents including 2,3,7,8-tetrachlorodibenzo-p-dioxin

    Energy Technology Data Exchange (ETDEWEB)

    Berman, E.F.; Schaus, P.; Fujimoto, J.M.

    1986-01-01

    Rats were treated with chlordecone, mirex, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and respective solvent vehicle. Under urethane or pentobarbital anesthesia, the bile duct was cannulated and radioactive morphine, imipramine, or ouabain was given by segmented retrograde intrabiliary injection. The spectrum of inhibition of biliary excretion by chlordecone and mirex were similar in that morphine glucuronide and in part polar imipramine metabolite recoveries in bile were decreased; ouabain recovery was unaffected. TCDD was different in that it markedly decreased the recovery of ouabain. Thus, it appears that chlordecone, mirex, and TCDD inhibit the canalicular transport of the glucuronide metabolites of morphine and imipramine into bile, and TCDD affects in addition the canalicular transport of ouabain into bile.

  20. Pesticide contamination of the coastline of Martinique.

    Science.gov (United States)

    Bocquené, Gilles; Franco, Alain

    2005-01-01

    In January and February 2002, the presence of certain agricultural pesticides throughout the coastline of the Caribbean island of Martinique was investigated. The tropical climate of the French West Indies is suitable for banana production, which requires intensive use of pesticides. An inventory of all pesticides used on the island (compounds and tonnage) was compiled. Surveys and analyses revealed the presence of pesticides in the plumes of seven rivers. The organochlorine chlordecone and metabolites of aldicarb were detected at nearly all of the monitored sites, even though the use of chlordecone has been prohibited since 1993. Two triazines (ametryn and simazine) were also identified. The concentrations of carbamates and triazines detected in the water and sediment samples from Martinique are comparable to those reported for mainland France. Chlordecone concentrations in the sediment and particulate matter samples were, however, particularly high in the samples from Martinique. Toxicological implications are discussed. Of particular concern are the high levels of chlordecone (which is bioaccumulating and carcinogenic) and further monitoring of this compound is recommended, especially in fish and other sea-food products.

  1. On the rumors about the silent spring: review of the scientific evidence linking occupational and environmental pesticide exposure to endocrine disruption health effects Rumores de uma primavera silenciosa: uma revisão das evidências científicas sobre a associação entre exposição ocupacional e ambiental a pesticidas e distúrbios endócrinos

    OpenAIRE

    2002-01-01

    Occupational exposure to some pesticides, and particularly DBCP and chlordecone, may adversely affect male fertility. However, apart from the therapeutic use of diethylstilbestrol, the threat to human reproduction posed by "endocrine disrupting" environmental contaminants has not been supported by epidemiological evidence thus far. As it concerns other endocrine effects described in experimental animals, only thyroid inhibition following occupational exposure to amitrole and mancozeb has been...

  2. Investigating apical adverse effects of four endocrine active substances in the freshwater gastropod Lymnaea stagnalis.

    Science.gov (United States)

    Giusti, Arnaud; Lagadic, Laurent; Barsi, Alpar; Thomé, Jean-Pierre; Joaquim-Justo, Célia; Ducrot, Virginie

    2014-09-15

    The hermaphroditic gastropod Lymnaea stagnalis is proposed as a candidate species for the development of OECD guidelines for testing of the reprotoxicity of chemicals, including endocrine active substances (EASs). Up to now, only a few putative EASs have been tested for their reproductive toxicity in this species. In this study, we investigate the effects of four EASs with different affinities to the vertebrate estrogen and androgen receptors (chlordecone as an estrogen; cyproterone acetate, fenitrothion and vinclozolin as anti-androgens) on the reproduction of L. stagnalis in a 21-day semi-static test. Testosterone and 17α-ethinylestradiol (EE2) were used as the reference compounds. The tested EASs had no significant effect on growth and survival at the tested concentration ranges (ng to μg/L). Classical reproduction endpoints (i.e., oviposition and fecundity) were not responsive to the tested chemicals, except for chlordecone and 17α-ethinylestradiol, which hampered reproduction from 19.6 μg/L and 17.6 μg/L, respectively. The frequency of polyembryonic eggs, used as an additional endpoint, demonstrated the effects of all compounds except EE2. The molecular pathways, which are involved in such reproduction impairments, remain unknown. Our results suggest that egg quality is a more sensitive endpoint as compared to other reproductive endpoints commonly assessed in mollusk toxicity tests.

  3. Pollution of soils and ecosystems by a permanent toxic organochlorine pesticide: chlordecone—numerical simulation of allophane nanoclay microstructure and calculation of its transport properties

    Directory of Open Access Journals (Sweden)

    Thierry Woignier

    2015-06-01

    Full Text Available Pest control technology was introduced into the tropics without considering the specificity of their ecosystems and the risk of pollution was underestimated. Some volcanic soils (andosols contain nanoclay (allophane with a unique structure and porous properties compared to crystalline clays. Andosols are characterized by large pore volume and pore size distribution, a high specific surface area, and a fractal structure. These soils are more polluted than the other kinds of tropical soils but release less pollutants (chlordecone to water and plants. The literature shows that the allophane microstructure favors accumulation and sequestration of chlordecone, an organochlorine pesticide, in andosols.We used a numerical model to simulate the structure of allophane aggregates. The algorithm is based on a cluster-cluster aggregation model. From the simulated data, we derived the structural features, pore volume and tortuosity, and its transport properties, hydraulic conductivity and diffusion. We show that transport properties decrease because of the presence of allophane. We propose that low hydraulic conductivity and diffusion are important parameters to explain the high concentrations and trapping of pollutants in andosols.

  4. Behavioral toxicology, risk assessment, and chlorinated hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Evangelista de Duffard, A.M.; Duffard, R. [Laboratorio de Toxicologia Experimental, Santa Fe (Argentina)

    1996-04-01

    Behavioral end points are being used with greater frequency in neurotoxicology to detect and characterize the adverse effects of chemicals on the nervous system. Behavioral measures are particularly important for neurotoxicity risk assessment since many known neurotoxicants do not result in neuropathology. The chlorinated hydrocarbon class consists of a wide variety of chemicals including polychlorinated biphenyls, clioquinol, trichloroethylene, hexachlorophene, organochlorine insecticides (DDT, dicofol, chlordecone, dieldrin, and lindane), and phenoxyherbicides. Each of these chemicals has effects on motor, sensory, or cognitive function that are detectable using functional measures such as behavior. Furthermore, there is evidence that if exposure occurs during critical periods of development, many of the chlorinated hydrocarbons are developmental neurotoxicants. Developmental neurotoxicity is frequently expressed as alterations in motor function or cognitive abilities or charges in the ontogeny of sensorimotor reflexes. Neurotoxicity risk assessment should include assessments of the full range of possible neurotoxicological effects, including both structural and functional indicators of neurotoxicity. 121 refs., 1 tab.

  5. Proteomic Analysis of the Reproductive Organs of the Hermaphroditic Gastropod Lymnaea stagnalis Exposed to Different Endocrine Disrupting Chemicals

    Science.gov (United States)

    Giusti, Arnaud; Leprince, Pierre; Mazzucchelli, Gabriel; Thomé, Jean-Pierre; Lagadic, Laurent; Ducrot, Virginie; Joaquim-Justo, Célia

    2013-01-01

    Many studies have reported perturbations of mollusc reproduction following exposure to low concentrations (ng/L range) of endocrine disrupting chemicals (EDCs). However, the mechanisms of action of these molecules on molluscs are still poorly understood. Investigation of the modifications of protein expression in organisms exposed to chemicals using proteomic methods can provide a broader and more comprehensive understanding of adverse impacts of pollution on organisms than conventional biochemical biomarkers (e.g., heat-shock proteins, metallothioneins, GST, EROD). In this study we have investigated the impacts of four chemicals, which exhibit different endocrine disrupting properties in vertebrates, on the proteome of the hermaphroditic freshwater pulmonate gastropod Lymnaea stagnalis after 21 days of exposure. Testosterone, tributyltin, chlordecone and cyproterone acetate were chosen as tested compounds as they can induce adverse effects on the reproduction of this snail. The 2D-DIGE method was used to identify proteins whose expression was affected by these compounds. In addition to modifying the expression of proteins involved in the structure and function of the cytoskeleton, chemicals had impacts on the expression of proteins involved in the reproduction of L. stagnalis. Exposure to 19.2 µg/L of chlordecone increased the abundance of ovipostatin, a peptide transmitted during mating through seminal fluid, which reduces oviposition in this species. The expression of yolk ferritin, the vitellogenin equivalent in L. stagnalis, was reduced after exposure to 94.2 ng Sn/L of tributyltin. The identification of yolk ferritin and the modification of its expression in snails exposed to chemicals were refined using western blot analysis. Our results showed that the tested compounds influenced the abundance of yolk ferritin in the reproductive organs. Alteration in proteins involved in reproductive pathways (e.g., ovipostatin and yolk ferritin) could constitute relevant

  6. Proteomic analysis of the reproductive organs of the hermaphroditic gastropod Lymnaea stagnalis exposed to different endocrine disrupting chemicals.

    Directory of Open Access Journals (Sweden)

    Arnaud Giusti

    Full Text Available Many studies have reported perturbations of mollusc reproduction following exposure to low concentrations (ng/L range of endocrine disrupting chemicals (EDCs. However, the mechanisms of action of these molecules on molluscs are still poorly understood. Investigation of the modifications of protein expression in organisms exposed to chemicals using proteomic methods can provide a broader and more comprehensive understanding of adverse impacts of pollution on organisms than conventional biochemical biomarkers (e.g., heat-shock proteins, metallothioneins, GST, EROD. In this study we have investigated the impacts of four chemicals, which exhibit different endocrine disrupting properties in vertebrates, on the proteome of the hermaphroditic freshwater pulmonate gastropod Lymnaea stagnalis after 21 days of exposure. Testosterone, tributyltin, chlordecone and cyproterone acetate were chosen as tested compounds as they can induce adverse effects on the reproduction of this snail. The 2D-DIGE method was used to identify proteins whose expression was affected by these compounds. In addition to modifying the expression of proteins involved in the structure and function of the cytoskeleton, chemicals had impacts on the expression of proteins involved in the reproduction of L. stagnalis. Exposure to 19.2 µg/L of chlordecone increased the abundance of ovipostatin, a peptide transmitted during mating through seminal fluid, which reduces oviposition in this species. The expression of yolk ferritin, the vitellogenin equivalent in L. stagnalis, was reduced after exposure to 94.2 ng Sn/L of tributyltin. The identification of yolk ferritin and the modification of its expression in snails exposed to chemicals were refined using western blot analysis. Our results showed that the tested compounds influenced the abundance of yolk ferritin in the reproductive organs. Alteration in proteins involved in reproductive pathways (e.g., ovipostatin and yolk ferritin could

  7. Current Status and Regulatory Aspects of Pesticides Considered to be Persistent Organic Pollutants (POPs in Taiwan

    Directory of Open Access Journals (Sweden)

    Wen-Tien Tsai

    2010-10-01

    Full Text Available Organochlorine pesticides (OCPs are capable of persisting in the environment, transporting between phase media and accumulating to high levels, implying that they could pose a risk of causing adverse effects to human health and the environment. Consequently, most OCPs are designated as persistent organic pollutants (POPs and even as endocrine disrupting chemicals (EDCs. The objective of this paper was to review the current status of pesticide POPs in Taiwan, including aldrin, chlordane, chlordecone, DDT, dieldrin, endrin, heptachlor, hexachlorobenzene, α/β-hexachlorocyclohexanes, lindane, mirex, pentachloro-benzene, and toxaphene. The information about their environmental properties, banned use, carcinogenic toxicity and environmental levels, can be connected with the regulatory infrastructure, which has been established by the joint-venture of the central competent authorities (i.e., Environmental Protection Administration, Department of Health, Council of Agriculture, and Council of Labor Affairs. The significant progress to be reported is that the residual levels of these pesticide-POPs, ranging from trace amounts to a few ppb, have declined notably in recent years.

  8. How environmental hazards in childhood have been discovered: carcinogens, teratogens, neurotoxicants, and others.

    Science.gov (United States)

    Miller, Robert W

    2004-04-01

    Review of the literature reveals that environmental hazards cause adverse health effects that include sterility, infertility, embryotoxicity, low birth weight, skin lesions, neurodevelopmental defects, immunologic disorders, cancer, and fear of late effects. They have been identified mostly by astute practitioners but also by a bacteriologist, an animal experimentalist, 5 factory workers in childless marriages, and a tipsy bystander in an economically impoverished area of Baltimore. Dust on a parent's work clothes has transported a hazard at work to a hazard at home (lead, asbestos, and chlordecone). Causality is established by showing a dose-response effect and reproducing the effect in studies of other exposed groups or by using another epidemiologic method, eg, prospective instead of retrospective study. Also, the findings should be biologically plausible and not attributable to a concomitant variable such as cigarette smoking. Contrary to front-page newspaper headlines, incidence rates for childhood leukemia are not rising. Preserving specimens for future studies has been valuable: blood from people who were exposed to dioxin in Seveso, Italy; mummified umbilical cords containing methyl mercury at Minamata Bay, Japan; and Guthrie dried blood spots to screen retrospectively for 43 genetic disorders and a specific prenatal cytogenetic abnormality in some children with 1 form of leukemia. Recommendations are given for enhancing interest in environmental hazards and their discovery by clinicians.

  9. Biodegradability of HCH in agricultural soils from Guadeloupe (French West Indies): identification of the lin genes involved in the HCH degradation pathway.

    Science.gov (United States)

    Laquitaine, L; Durimel, A; de Alencastro, L F; Jean-Marius, C; Gros, O; Gaspard, S

    2016-01-01

    Banana has been a main agricultural product in the French West Indies (Guadeloupe and Martinique) since the 1960s. This crop requires the intensive use of pesticides to prevent attacks by insect pests. Chlorinated pesticides, such as hexachlorocyclohexane (HCH), chlordecone and dieldrin, were used until the beginning of the 1990s, resulting in a generalized diffuse contamination of the soil and water in the areas of banana production, hence the need to develop solutions for cleanup of the polluted sites. The aims of this work were (i) to assess lindane degradation in soil slurry microcosms treated with lindane at 10 mg/L and (ii) to detect the catabolic genes involved in the HCH degradation pathway. The soil slurry microcosm system showed a 40% lindane degradation efficiency at the end of a 30-day experiment. Lower lindane removal was also detected in the abiotic controls, probably caused by pesticide adsorption to soil particles. Indeed, the lindane concentration decreased from 6000 to 1330 ng/mL and from 800 to 340 ng/mL for the biotic and abiotic soils, respectively. Nevertheless, some of the genes involved in the HCH degradation pathway were amplified by polymerase chain reaction (PCR) from crude deoxyribonucleic acid (DNA) extracted from the Guadeloupe agricultural soil, suggesting that HCH degradation is probably mediated by bacteria closely related to the family Sphingomonadaceae.

  10. On the rumors about the silent spring: review of the scientific evidence linking occupational and environmental pesticide exposure to endocrine disruption health effects

    Directory of Open Access Journals (Sweden)

    Cocco Pierluigi

    2002-01-01

    Full Text Available Occupational exposure to some pesticides, and particularly DBCP and chlordecone, may adversely affect male fertility. However, apart from the therapeutic use of diethylstilbestrol, the threat to human reproduction posed by "endocrine disrupting" environmental contaminants has not been supported by epidemiological evidence thus far. As it concerns other endocrine effects described in experimental animals, only thyroid inhibition following occupational exposure to amitrole and mancozeb has been confirmed in humans. Cancer of the breast, endometrium, ovary, prostate, testis, and thyroid are hormone-dependent, which fostered research on the potential risk associated with occupational and environmental exposure to the so-called endocrine-disrupting pesticides. The most recent studies have ruled out the hypothesis of DDT derivatives as responsible for excess risks of cancer of the reproductive organs. Still, we cannot exclude a role for high level exposure to o,p'-DDE, particularly in post-menopausal ER+ breast cancer. On the other hand, other organochlorine pesticides and triazine herbicides require further investigation for a possible etiologic role in some hormone-dependent cancers.

  11. Environmental endocrine disruptors: A proposed classification scheme

    Energy Technology Data Exchange (ETDEWEB)

    Fur, P.L. de; Roberts, J. [Environmental Defense Fund, Washington, DC (United States)

    1995-12-31

    A number of chemicals known to act on animal systems through the endocrine system have been termed environmental endocrine disruptors. This group includes some of the PCBs and TCDDs, as well as lead, mercury and a large number of pesticides. The common feature is that the chemicals interact with endogenous endocrine systems at the cellular and/or molecular level to alter normal processes that are controlled or regulated by hormones. Although the existence of artificial or environmental estrogens (e.g. chlordecone and DES) has been known for some time, recent data indicate that this phenomenon is widespread. Indeed, anti-androgens have been held responsible for reproductive dysfunction in alligator populations in Florida. But the significance of endocrine disruption was recognized by pesticide manufacturers when insect growth regulators were developed to interfere with hormonal control of growth. Controlling, regulating or managing these chemicals depends in no small part on the ability to identify, screen or otherwise know that a chemical is an endocrine disrupter. Two possible classifications schemes are: using the effects caused in an animal, or animals as an exposure indicator; and using a known screen for the point of contact with the animal. The former would require extensive knowledge of cause and effect relationships in dozens of animal groups; the latter would require a screening tool comparable to an estrogen binding assay. The authors present a possible classification based on chemicals known to disrupt estrogenic, androgenic and ecdysone regulated hormonal systems.

  12. Isolation and identification of dieldrin-degrading Pseudonocardia sp. strain KSF27 using a soil-charcoal perfusion method with aldrin trans-diol as a structural analog of dieldrin.

    Science.gov (United States)

    Sakakibara, Futa; Takagi, Kazuhiro; Kataoka, Ryota; Kiyota, Hiromasa; Sato, Yuuki; Okada, Sanae

    2011-07-22

    We isolated a novel aerobic dieldrin-degrading bacterium from an enrichment culture in a soil-charcoal perfusion system. Enrichment culture using a soil-charcoal perfusion system was an effective way to obtain microorganisms that degrade recalcitrant compounds. The soil-charcoal perfusion was performed using aldrin trans-diol, which was a metabolite of dieldrin. Aldrin trans-diol had higher bioavailability (2.5 mg/l) than dieldrin (0.1-0.25 mg/l), therefore it is possible for microorganisms to utilize it as a substrate in soil. After 100 days of circulation and three exchanges of the medium, the enriched charcoal was harvested and a bacterium isolated. The isolate was designated as strain KSF27 and was found to be closely related to Pseudonocardia spp. as determined by 16S rRNA sequencing analysis. Strain KSF27 degraded aldrin trans-diol by 0.05 μmol/l from an initial concentration of 25.5 μmol/l. The metabolite of aldrin trans-diol was detected by HPLC/MS and determined to be aldrindicarboxylic acid based on retention time and the MS fragment. Moreover, strain KSF27 degraded dieldrin from 14.06 μmol/l to 2.01 μmol/l over a 10-day incubation at 30°C. This strain degraded dieldrin and other persistent organochlorine pesticides, such as α-endosulfan, β-endosulfan, endosulfan sulfate, heptachlor, heptachlor epoxide and chlordecone.

  13. Hormonal action of plant derived and anthropogenic non-steroidal estrogenic compounds: phytoestrogens and xenoestrogens.

    Science.gov (United States)

    Lóránd, T; Vigh, E; Garai, J

    2010-01-01

    Herbivorous and omnivorous vertebrates have evolved in the presence of a variety of phytoestrogens, i.e., plant-derived compounds that can mimic, modulate or disrupt the actions of endogenous estrogens. Since the discovery of the estrus-inducing effects of some plant products in 1926, considerable effort has been devoted to the isolation and structural and pharmacological characterization of phytoestrogens. Recently, agricultural and industrial pollution has added anthropogenic estrogenic compounds to the list of environmental estrogens. Unlike phytoestrogens, these xenoestrogens tend to accumulate and persist in adipose tissue for decades and may cause long-lasting, adverse endocrine effects. Here we review the endocrine effects of known phytoestrogens and xenoestrogens with special emphasis on molecular structure-activity relationships. Phytoestrogens include flavonoids, isoflavonoids, chalcons, coumestans, stilbenes, lignans, ginsenosides and other saponins, as well as the recently discovered tetrahydrofurandiols. Fungal estrogenic compounds may enter the food chain via infested crops. Since some phytoestrogens have been shown to display organ-specific actions, pharmaceutical estrogen analogues with similar properties (selective estrogen receptor modulators, SERMs) are also discussed. Xenoestrogens include dichlorodiphenyltrichloroethane (DDT) and its metabolites, bisphenols, alkylphenols, dichlorophenols, methoxychlor, chlordecone, polychlorinated benzol derivatives (PCBs), and dioxins. While most of these compounds act through estrogen receptors alpha and beta, some of their effects may be mediated by other nuclear or membrane-bound receptors or receptor-independent mechanisms. Some might also interfere with the production and metabolism of ovarian estrogens. Better understanding of the molecular pharmacology of phyto- and xenoestrogens may result in the development of novel compounds with therapeutic utility and improved environmental protection.

  14. Estrogenic potencies of several environmental pollutants, as determined by vitellogenin induction in a carp hepatocyte assay.

    Science.gov (United States)

    Smeets, J M; van Holsteijn, I; Giesy, J P; Seinen, W; van den Berg, M

    1999-08-01

    Estrogenic potencies of several xenoestrogens were determined in vitro, using cultured hepatocytes from a genetically uniform male carp strain (Cyprinus carpio). Estrogenicity was measured as induction of the yolk protein precursor vitellogenin (Vtg), and compared to Vtg induction by 17beta-estradiol (E2). The order of estrogenic potency was: methoxychlor (MXCL) > o,p-DDT > chlordecone approximately/= bisphenol-A approximately/= 4-t-pentylphenol. Estrogenic potencies of these compounds varied from 1 x 10(-3) to 1 x 10(-4) relative to E2. The synthetic estrogen DES had a relative estrogenic potency of 0.5, whereas dieldrin, beta-endosulfan, o,p-DDE, and toxaphene (technical mixture) did not induce vitellogenesis at concentrations up to 100 microM. Experiments in which cells were simultaneously exposed to E2 and these xenoestrogens showed that the Vtg-inducing activities of E2 and 4-t-pentylphenol or bisphenol-A were (partially) additive, whereas E2 antagonized the estrogenic effects of MXCL and o,p-DDT. The effect of cytochrome P4501A (CYP1A)-induction on the estrogenicity of MXCL was studied by co-exposing cells to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). TCDD (10 pM) caused a greater than 50-fold induction of CYP1A, measured as ethoxyresorufin O-deethylase (EROD) activity, but Vtg induction by MXCL was not significantly affected. This indicates that CYP1A is not involved in the bioactivation of MXCL to more potent estrogenic metabolites in carp. The CARP-HEP (hepatocyte) assay can detect xenoestrogens with a potency > or = 2 x 10(-5) relative to E2. It allows simultaneous testing of more than 10 compounds for both estrogenic and antiestrogenic effects, which makes it a promising tool for the screening of suspected xenoestrogens.

  15. On the rumors about the silent spring: review of the scientific evidence linking occupational and environmental pesticide exposure to endocrine disruption health effects Rumores de uma primavera silenciosa: uma revisão das evidências científicas sobre a associação entre exposição ocupacional e ambiental a pesticidas e distúrbios endócrinos

    Directory of Open Access Journals (Sweden)

    Pierluigi Cocco

    2002-04-01

    Full Text Available Occupational exposure to some pesticides, and particularly DBCP and chlordecone, may adversely affect male fertility. However, apart from the therapeutic use of diethylstilbestrol, the threat to human reproduction posed by "endocrine disrupting" environmental contaminants has not been supported by epidemiological evidence thus far. As it concerns other endocrine effects described in experimental animals, only thyroid inhibition following occupational exposure to amitrole and mancozeb has been confirmed in humans. Cancer of the breast, endometrium, ovary, prostate, testis, and thyroid are hormone-dependent, which fostered research on the potential risk associated with occupational and environmental exposure to the so-called endocrine-disrupting pesticides. The most recent studies have ruled out the hypothesis of DDT derivatives as responsible for excess risks of cancer of the reproductive organs. Still, we cannot exclude a role for high level exposure to o,p'-DDE, particularly in post-menopausal ER+ breast cancer. On the other hand, other organochlorine pesticides and triazine herbicides require further investigation for a possible etiologic role in some hormone-dependent cancers.A exposição ocupacional a determinados pesticidas, particularmente ao DBCP e à clordecona, pode ter efeitos adversos sobre a fertilidade masculina. Entretanto, com exceção do uso terapêutico do dietil-estilbestrol, a ameaça à reprodução humana através da "desregulação endócrina" por contaminantes ambientais ainda não foi comprovada através de evidências epidemiológicas. A questão diz respeito a outros efeitos endócrinos descritos em animais experimentais, e apenas a inibição tireóide foi confirmada em seres humanos, após exposição ocupacional a amitrole e mancozeb. O fato de serem hormônio-dependentes os cânceres de mama, endométrio, ovário, próstata, testículos e tireóide motivou pesquisas sobre o risco potencial associado à exposi