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Nathaniel Rothman - One of the best experts on this subject based on the ideXlab platform.

  • risk of non hodgkin s lymphoma and prediagnostic serum organochlorines Beta Hexachlorocyclohexane chlordane heptachlor related compounds dieldrin and hexachlorobenzene
    Environmental Health Perspectives, 2002
    Co-Authors: Kenneth P Cantor, Larry L Needham, Paul T Strickland, John W Brock, David E Bush, Kathy J Helzlsouer, Shelia Hoar Zahm, George W Comstock, Nathaniel Rothman
    Abstract:

    Increases in non-Hodgkin's lymphoma (NHL) incidence and mortality rates during the past few decades remain largely unexplained. Studies suggest that organochlorine pesticides may contribute to an increased risk of NHL. In 1974, serum samples were obtained from 25,802 participants in the Campaign Against Cancer and Stroke in Washington County, Maryland (USA), and cryopreserved for future study. We measured prediagnostic levels of chlordane, lindane (gamma-Hexachlorocyclohexane), Beta-Hexachlorocyclohexane, transnonachlor, heptachlor, heptachlor epoxide, oxychlordane, dieldrin, and hexachlorobenzene in serum samples of 74 cases of NHL and 147 matched controls. Previously, we found an association between NHL and serum levels of total PCBs (polychlorinated biphenyls), but not DDT (dichlorodiphenyltrichloroethane) and related compounds. In this instance, there was no evidence of an association between NHL risk and serum levels of any of the individual lipid- and recovery-corrected organochlorines that we evaluated, nor of the summed chlordane-related compounds (transnonachlor, heptachlor, heptachlor epoxide, oxychlordane). These findings do not support the hypothesis that the organochlorine compounds included in this study are strongly linked to the development of NHL. The possibility of a weak association cannot be excluded by these data.

Sarra Gaspard - One of the best experts on this subject based on the ideXlab platform.

  • Degradation of chlordecone and Beta-Hexachlorocyclohexane by photolysis, (photo-)fenton oxidation and ozonation
    Journal of Environmental Science and Health Part B, 2018
    Co-Authors: Germán Cruz González, Sarra Gaspard, Carine Julcour-lebigue, Hélène Chaumat, Valérie Bourdon, Felipe Ramon-portugal, Ulises J. Jáuregui-haza, Henri Delmas
    Abstract:

    Intensive use of chlorinated pesticides from the 1960s to the 1990s has resulted in a diffuse contamination of soils and surface waters in the banana-producing areas of the French West Indies. The purpose of this research was, for the first time, to examine the degradation of two of these persistent pollutants – chlordecone (CLD) and Beta-Hexachlorocyclohexane (β-HCH) in 1 mg L−1 synthetic aqueous solutions by means of photolysis, (photo-) Fenton oxidation and ozonation processes. Fenton oxidation is not efficient for CLD and yields less than 15% reduction of β-HCH concentration in 5 h. Conversely, both molecules can be quantitatively converted under UV-Vis irradiation reaching 100% of degradation in 5 h, while combination with hydrogen peroxide and ferrous iron does not show any significant improvement except in high wavelength range (>280 nm). Ozonation exhibits comparable but lower degradation rates than UV processes. Preliminary identification of degradation products indicated that hydrochlordecone was formed during photo-Fenton oxidation of CLD, while for β-HCH the major product peak exhibited C3H3Cl2 as most abundant fragment.

  • improving of understanding of Beta Hexachlorocyclohexane hch adsorption on activated carbons by temperature programmed desorption studies
    Environmental Science and Pollution Research, 2016
    Co-Authors: Nady Passecoutrin, Laetitia Maisonneuve, Axelle Durimel, Joseph Dentzer, Roger Gadiou, Sarra Gaspard
    Abstract:

    In order to understand the interactions between Beta-Hexachlorocyclohexane (HCH) and chemical groups at activated carbon (AC) surface, the solid samples were hydrogenated aiming to decrease the amounts of oxygenated groups. Two AC samples designated by BagH2O and BagP1.5 were prepared by water vapor activation and phosphoric acid activation, respectively, of sugarcane bagasse used as an AC precursor. A more simple molecule 1,2,3-trichloropropane (TCP) is used as a model of chlorinated compound. The AC were characterized by infrared, X-ray photoelectron spectroscopy (XPS), Raman resonance spectroscopies, as well as temperature-programmed desorption coupled with mass spectrometry (TPD-MS). BagP1.5 and BagH2O AC surface contained oxygenated groups. Upon hydrogenation, a decrease of most of these group amxounts was observed for both samples, while hydroxyl groups increased. On the basis of temperature-programmed desorption data obtained for AC samples contaminated with TCP or HCH, it was possible to determine the type of hydrogen bond formed between each AC and HCH.

  • role of acidic sites in Beta Hexachlorocyclohexane β hch adsorption by activated carbons molecular modelling and adsorption desorption studies
    RSC Advances, 2015
    Co-Authors: Axelle Durimel, Nady Passecoutrin, Roger Gadiou, C Jeanmarius, Carlos Enriquezvictorero, Daniel Hernandezvaldes, Ulises Jaureguihaza, Sarra Gaspard
    Abstract:

    The removal of β-HCH from contaminated water by adsorption on activated carbons is presented. Sugar cane bagasse activated carbons with different textural and surface chemical properties were prepared and characterized for studying the β-HCH adsorption process. The isotherms are correlated by six models, among which the Fowler–Guggenheim/Jovanovic–Freundlich model is found to provide the best fit for two of the studied activated carbons. The isotherm adsorption data were correlated with the surface functional group composition. β-HCH adsorption was favored by the presence of acidic groups at the AC surface of chemically activated carbons. A thorough theoretical exploration of the potential energy surface for the interaction of β-HCH with a graphene sheet alone or containing hydroxyl or carboxyl surface groups was carried out. Molecular modelling results showed that under neutral to slightly acidic conditions only carboxylic surface groups should significantly contribute to β-HCH adsorption, in qualitative agreement with the experimental results. The analysis of the most stable structures suggests that the hydrogen bonds between the axial hydrogens of β-HCH and the charged oxygens of the deprotonated acidic surface groups are the main interactions responsible for the adsorption. This result is confirmed by a Temperature-Programmed Desorption study, showing that β-HCH molecules are associated with carboxylic groups of the AC surface.

Kenneth P Cantor - One of the best experts on this subject based on the ideXlab platform.

  • risk of non hodgkin s lymphoma and prediagnostic serum organochlorines Beta Hexachlorocyclohexane chlordane heptachlor related compounds dieldrin and hexachlorobenzene
    Environmental Health Perspectives, 2002
    Co-Authors: Kenneth P Cantor, Larry L Needham, Paul T Strickland, John W Brock, David E Bush, Kathy J Helzlsouer, Shelia Hoar Zahm, George W Comstock, Nathaniel Rothman
    Abstract:

    Increases in non-Hodgkin's lymphoma (NHL) incidence and mortality rates during the past few decades remain largely unexplained. Studies suggest that organochlorine pesticides may contribute to an increased risk of NHL. In 1974, serum samples were obtained from 25,802 participants in the Campaign Against Cancer and Stroke in Washington County, Maryland (USA), and cryopreserved for future study. We measured prediagnostic levels of chlordane, lindane (gamma-Hexachlorocyclohexane), Beta-Hexachlorocyclohexane, transnonachlor, heptachlor, heptachlor epoxide, oxychlordane, dieldrin, and hexachlorobenzene in serum samples of 74 cases of NHL and 147 matched controls. Previously, we found an association between NHL and serum levels of total PCBs (polychlorinated biphenyls), but not DDT (dichlorodiphenyltrichloroethane) and related compounds. In this instance, there was no evidence of an association between NHL risk and serum levels of any of the individual lipid- and recovery-corrected organochlorines that we evaluated, nor of the summed chlordane-related compounds (transnonachlor, heptachlor, heptachlor epoxide, oxychlordane). These findings do not support the hypothesis that the organochlorine compounds included in this study are strongly linked to the development of NHL. The possibility of a weak association cannot be excluded by these data.

Duk Hee Lee - One of the best experts on this subject based on the ideXlab platform.

  • strong associations between low dose organochlorine pesticides and type 2 diabetes in korea
    Environment International, 2010
    Co-Authors: H K Son, David R Jacobs, S A Kim, J H Kang, Yoonseok Chang, S K Park, S K Lee, Duk Hee Lee
    Abstract:

    Abstract Low-dose organochlorine (OC) pesticides have recently been associated with type 2 diabetes in several non-Asian general populations. As there is currently epidemic type 2 diabetes in Asia, we investigated the associations between OC pesticides and type 2 diabetes in Koreans. Among subjects who participated in a community-based health survey, we randomly selected 40 diabetic patients and 40 normal controls. Ten OC pesticides (Beta-Hexachlorocyclohexane, hexachlorobenzene, heptachlor epoxide, p,p′-DDE, p,p′-DDD, p,p′-DDT, o,p′-DDT, oxychlordane, trans-nonachlor, and mirex) detectable in ≥ 70% of controls were analyzed in relation to diabetes. Most OC pesticides showed strong associations with type 2 diabetes after adjusting for age, sex, BMI, alcohol consumption, and cigarette smoking. Compared with subjects in the lowest tertile of each OC pesticide, adjusted odds ratios (ORs) in the 3rd tertile ranged from 3.1 (95% CI 0.8–12.1) for heptachlor epoxide to 26.0 (95% CI 1.3–517.4) for oxychlordane. In the case of chemicals belonging to the DDT family, adjusted ORs in the 3rd tertile were in the range of 10.6 (95% CI 1.3–84.9) for p,p′-DDT to 12.7 (95% CI 1.9–83.7) for p,p′-DDE. In this exploratory study with small sample, low-dose background exposure to OC pesticides was strongly associated with prevalent type 2 diabetes in Koreans even though absolute concentrations of OC pesticides were no higher than in other populations. Asians may be more susceptible to adverse effects of OC pesticides than other races.

Joan O Grimalt - One of the best experts on this subject based on the ideXlab platform.

  • thyroid disruption at birth due to prenatal exposure to β Hexachlorocyclohexane
    Environment International, 2008
    Co-Authors: Mar Alvarezpedrerol, Nuria Ribasfito, Maties Torrent, Daniel Carrizo, Raquel Garciaesteban, Joan O Grimalt, Jordi Sunyer
    Abstract:

    Abstract Objective Thyroid hormones play an important role in human brain development, and some organochlorine compounds (OCs) act as thyroid disruptors. The objective of the present study was to evaluate the association between prenatal exposure to organochlorine compounds and thyroid function in newborns from a general population birth cohort in Menorca, with an a-priori specific focus on β-HCH. Methods Levels of polychlorinated biphenyls (PCB congeners 28, 52, 101, 118, 138, 153 and 180), hexachlorobenzene (HCB), Beta-Hexachlorocyclohexane (β-HCH), dichlorodiphenyl dichloroethylene ( p ′ p ′-DDE) and dichlorodiphenyl trichloroethane ( p ′ p -DDT) in cord serum, and thyrotropin (TSH) concentration in plasma three days after birth were measured in 387 newborns from Menorca. The TSH concentration was categorized (high or low), except for 27 children whose TSH levels were quantified. Results Levels of β-HCH and PCB-153 were positively related to TSH concentrations (gestational age-adjusted coefficient ( p -value): 0.26 ( p = 0.006) and 0.31 ( p = 0.050), respectively). Conclusions β-HCH is potentially a new thyroid disrupting compound, deserving special interest in future studies given its high body burden in humans.

  • the influence of lipid and lifestyle factors upon correlations between highly prevalent organochlorine compounds in patients with exocrine pancreatic cancer
    Environment International, 2007
    Co-Authors: Miquel Porta, Joan O Grimalt, Núria Malats, Laura Ruiz, Manuel Jariod, Esther Marco, Tomás Undabeytia López, Elisa Puigdomènech, Ekhine Zumeta
    Abstract:

    We aimed to analyse the influence of cholesterol and triglycerides, and of tobacco, coffee and alcohol consumption upon correlations between serum concentrations of organochlorine compounds (OCs) in patients with exocrine pancreatic cancer (EPC). Incident cases of EPC diagnosed in eastern Spain were prospectively identified (N=144). OCs were analysed by high-resolution gas chromatography with electron-capture detection. A strong correlation was observed between hexachlorobenzene (HCB) and Beta-Hexachlorocyclohexane (Beta-HCH) (Spearman's rho=0.758). Beta-HCH showed rho>0.4 with p,p'-DDT, p,p'-DDE, PCB138 and PCB153 (all p<0.001). Some correlations among compounds were slightly affected by tobacco, coffee or alcohol consumption. We observed a striking diversity of correlation patterns by strata of cholesterol and triglycerides. Most correlations were higher in the lowest category of triglycerides than in the lowest category of cholesterol. Most coefficients above 0.7 were seen in the lowest category of triglycerides (e.g., OC pairs p,p'-DDT and HCB, p,p'-DDT and Beta-HCH, p,p'-DDE and Beta-HCH, or HCB and Beta-HCH). Correlations among OCs may be stronger when concentrations of triglycerides are low than when they are high. This is compatible with a dilution in the early phases of cancer and with a concentration effect as triglycerides become lower in the advanced phases of the disease.

  • levels of hexachlorobenzene and other organochlorine compounds in cord blood exposure across placenta
    Chemosphere, 2001
    Co-Authors: Maria Sala, Nuria Ribasfito, Joan O Grimalt, Esther Marco, E Cardo, M E De Muga, Carlos Mazon, Antoni Verdu, J Sunyer
    Abstract:

    Hexachlorobenzene (HCB) is an organochlorine compound widespread in the environment, highly lipophilic, that accumulates in biological systems. It has been suggested that it should be classified as a dioxin-like compound. Newborns are exposed to organochlorine compounds across the placenta and through breastfeeding. Although HCB is one of the most common organochlorine compounds, the transplacental transference of HCB from mother to fetus during pregnancy has been scarcely documented. This study reports the levels of HCB, dichlorodiphenyl trichloroethane (DDT) and its metabolite p,p′DDE, polychlorinated biphenyls (PCBs), and Beta-Hexachlorocyclohexane (β-HCH) in 72 maternal blood samples at delivery and in 69 cord blood samples, from which 62 corresponded to mother–infant pairs born between May 1997 and September 1999 in a rural area highly exposed to HCB. Results show that all newborns presented detectable levels of HCB, PCBs, and p,p′DDE, and, to a lesser extent, of β-HCH, the HCB levels being the highest. The geometric mean of HCB was 1.1 ng/ml, ranging from 0.3 to 5.7 ng/ml. Concentrations of HCB levels in cord blood (log ng/ml) were positively associated with concentrations in maternal blood (log ng/ml) (coefficient=0.45, P<0.01). Gestational age was not associated with the transplacental transfer of HCB. Maternal p,p′DDE and β-HCH levels were also associated with newborn levels, but levels of PCBs were not. We conclude that HCB, similar to other organochlorinated compounds, has a transplacental transfer.