nonachlor and 2-4-5-2--4--5--hexachlorobiphenyl

Topics: Animals; Aquaculture; Dichlorodiphenyl Dichloroethylene; Environmental Monitoring; Fishes; Flame Retardants; Food Contamination; Halogenated Diphenyl Ethers; Hydrocarbons, Chlorinated; Indian Ocean Islands; Pesticides; Pilot Projects; Polychlorinated Biphenyls; Tanzania; Water Pollutants, Chemical

Recently, California condors (Gymnogyps californianus) have been reintroduced to coastal regions of California where they feed on marine mammal carcasses. There is evidence that coastal-dwelling condors experience reproductive issues, such as eggshell thinning, likely resulting from exposure to endocrine-disrupting chemicals (EDCs). To address this problem, we have identified and cloned condor estrogen receptors (ESRs) 1 and 2 and characterized their activation by EDCs present in the coastal habitats where condors reside. Dichlorodiphenyltrichloroethane (DDT) and its metabolites all activated ESR1 and ESR2, although their relative potency differed between the receptors. Bisphenol A, dieldrin, trans-nonachlor, and polychlorinated biphenyl 52 (PCB52) moderately activated both ESRs, whereas PCB138 and PCB153 stimulated little to no activation. Overall, EDC activation of condor ESR2, which is the first ESR2 cloned from a raptor species, was greater than that of ESR1. Significant activation of both condor ESRs by EDCs occurred at high concentrations (≥1μM), which are within the range of plasma levels of certain EDCs (eg, dichlorodiphenyldichloroethylene [p'p-DDE]) in coastal-dwelling condors. Finally, phylogenetic analyses of ESRs of 41 avian species identified a single amino acid position in ESR2 under positive selection. Mutation of this amino acid affected receptor activation by EDCs, suggesting the identity of this amino acid may influence EDC sensitivity of avian species. Together, these findings broaden our understanding of EDC interactions with ESRs in avian species. For condors specifically, these data could be used to evaluate EDC exposure risk at future release sites to identify those least likely to compromise the continued recovery of this species.

Topics: Animals; Benzhydryl Compounds; Birds; California; DDT; Dieldrin; Endocrine Disruptors; Environmental Pollutants; Estrogen Receptor alpha; Estrogen Receptor beta; Hydrocarbons, Chlorinated; Mutation; Phenols; Phylogeny; Polychlorinated Biphenyls; Raptors

Chlorinated pesticides and metabolites (CPs) were quantified in the seabird species: little auk (Alle alle), Brünnich's guillemot (Uria lomvia), black guillemot (Cepphus grylle) and black-legged kittiwake (Rissa tridactyla). The purpose was to evaluate avian accumulation of selected CPs based on their concentrations and relative patterns, their relation to dietary descriptors (stable isotopes of carbon and nitrogen), to enzymes involved in biotransformation, as well as CPs' accumulation potential relative to the recalcitrant polychlorinated biphenyl PCB-153. In all species, the CP pattern was dominated by p,p'-dichlorodiphenyltrichloroethane (DDE) and hexachlorbenzene (HCB). Except for HCB, concentrations were not related to trophic position. Most CPs were quantified in black guillemot, indicating a slower elimination compared to other seabird species. Brünnich's guillemot showed efficient elimination of chlordanes, whereas the opposite was found for little auk. Kittiwake showed higher accumulation of persistent CP and metabolites than auks, whereas accumulation of less recalcitrant CPs was low.

Topics: Animals; Arctic Regions; Biotransformation; Birds; Chlordan; DDT; Dichlorodiphenyl Dichloroethylene; Dichlorodiphenyldichloroethane; Diet; Female; Fungicides, Industrial; Hexachlorobenzene; Hexachlorocyclohexane; Hydrocarbons, Chlorinated; Insecticides; Male; Pesticides; Polychlorinated Biphenyls; Sex Factors