title: How much do PCB toxic equivalents account for PHAH toxicity in predatory birds?
abstract: Various diffuse polyhalogenated aromatic hydrocarbons (PHAHs) exert common toxicity through the aryl hydrocarbon receptor (AhR). Apex predators spatially and temporally integrate diffuse contamination and simultaneous exposure can cause additive toxicity. We investigated the extent to which PCBs, still amongst the most prevalent PHAHs accumulated by predators, accounted for total PHAH toxicity in raptors and fish eating birds from Britain. We analysed egg or liver extracts from six species and compared chemically determined ΣPCB-TEQs concentrations with total AhR-mediated toxicity determined using the chemical-activated luciferase gene expression bioassay (CALUX-TEQ). Dioxin-like PCB profiles in eggs and livers were dominated by congeners 118, 105 and 167. ΣPCB-TEQ and CALUX-TEQ concentrations were positively associated but not in a 1:1 relationship. ΣPCB-TEQ were broadly similar to CALUX-TEQ concentrations in eggs and livers with CALUX-TEQ concentrations >50-80 and 160-320 pg g(-1) lipid respectively, but were lower than CALUX-TEQ concentrations in less contaminated samples.
authors: NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP, UK. Electronic address: mdgds@ceh.ac.uk.
authors: M Glória
authors: MG
authors: Pereira
authors: Division of Toxicology, Wageningen University, The Netherlands.
authors: A J
authors: AJ
authors: Murk
authors: Division of Toxicology, Wageningen University, The Netherlands.
authors: H
authors: H
authors: Van den Berg
authors: NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP, UK.
authors: Lee A
authors: LA
authors: Walker
authors: NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP, UK.
authors: Richard F
authors: RF
authors: Shore
mesh_terms: D000818:Animals; D001681:Biological Assay; D001717:Birds / Q000502:physiology*; D004531:Eggs / Q000032:analysis; D004785:Environmental Pollutants / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D020387:Food Chain; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D000072317:Polychlorinated Dibenzodioxins / Q000032:analysis; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism; D006113:United Kingdom
chemical_list: D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins; D018336:Receptors, Aryl Hydrocarbon; D011078:Polychlorinated Biphenyls
keywords: Ah receptor; CALUX-assay; Dioxin-like PCBs; Gannet; Herons; Kestrel; Merlin and Peregrine falcon; Sparrowhawk; TEQs