Organohalogen exposure in a Eurasian Eagle owl (Bubo bubo) population from Southeastern Spain: Temporal–spatial trends and risk assessment

• Published in: Chemosphere (Oxford) Vol. 88; no. 8; pp. 903 - 911
• Main Authors: Gómez-Ramírez, P., Martínez-López, E., García-Fernández, A.J., Zweers, A.J., van den Brink, N.W.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2012; Elsevier
• Subjects: analysis; Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; birds of prey; Bubo; chemistry; Ecotoxicology, biological effects of pollution; egg shell; Egg Shell - chemistry; egg shell thickness; eggs; Eggshell thinning; Environmental Pollutants; Environmental Pollutants - analysis; Enzyme induction; ethers; females; Fundamental and applied biological sciences. Psychology; gene induction; General aspects; Halogenated Diphenyl Ethers; Halogenated Diphenyl Ethers - analysis; hexachlorobenzene; Hydrocarbons, Halogenated; Hydrocarbons, Halogenated - analysis; Insecticides; Insecticides - analysis; land use; metabolism; nests; organochlorine insecticides; Organohalogen; oviposition; Owls; pollution; polychlorinated biphenyls; Polychlorinated Biphenyls - analysis; population dynamics; Raptors; Receptors, Aryl Hydrocarbon; Receptors, Aryl Hydrocarbon - chemistry; Receptors, Aryl Hydrocarbon - metabolism; Risk Assessment; Space-temporal trends; Spain; Strigiformes; toxicity; Europe; Spain; Owls; Eggshell thinning; Space-temporal trends; Organohalogen; Risk assessment; Enzyme induction; Enzyme; Induction; Risk analysis; Time variation; Egg shell; Organic compounds; Halogen Organic compounds
• ISSN: 0045-6535; 1879-1298; 1879-1298
• DOI: 10.1016/j.chemosphere.2012.03.014

► Temporal–spatial trends of organohalogen compounds were evaluated using Eagle owl eggs. ► Our results seem to reflect the intensive agricultural practice in the study area. ► Dietary shifts and proximity to industry could cause the increase in the Southern area. ► pp′-DDE was correlated with eggshell thickness and 17% of samples exceeded the LOAEC for total TEQs. ► The correlation TEQ-metabolisable PCBs could indicate hepatic enzymes induction. Polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine insecticides (OCs) were analysed in 58 Eurasian Eagle owl (Bubo bubo) unhatched eggs collected between 2004 and 2009 in Southeastern Spain. Levels of p,p′-DDE were found to be higher than in eggs laid by other European owls in the same decade, probably due to the greater agricultural activity in our study area. Compared to other European raptors, exposure to PCBs can be considered intermediate, but low to PBDEs. Land use differences and prey availability were the rationale to divide the study area in two subareas in further assessments. Temporal trends of HCB, p,p′-DDE, β-HCH, PCBs and PBDEs were significantly different in each subarea, generally increasing over time in the Southern but decreasing or remaining stable in the Northern. On the contrary, levels of cyclodienes tended to decrease in both subareas. Dietary shifts with a greater amount of birds are suggested as a cause for increasing organochlorine loads in raptors. This may explain the increasing trend in the Southern territories. However, due to the proximity of most of these nests to Cartagena, an important industrial city, increasing environmental pollution cannot be ruled out. Although average levels of the compounds analysed are below threshold levels, 17% of the samples exceeded 400pgg−1ww (wet weight), the LOAEC for Total TEQs. Moreover, a negative correlation between TEQ concentrations and the metabolizable fraction of PCBs (Fprob=0.0018) was found when TEQs values were above 10pgg−1ww. This could be indicative of hepatic enzymes induction in the birds exposed at higher concentrations, which are mainly breeding in the Southern subarea. These females could be suffering from Ah-receptor-related toxic effects, some of which have been related to altered bird reproduction. Finally, a significant negative correlation between p,p′-DDE levels and eggshell thickness (r=−0.469, p<0.001) was observed, with about 17% of eggshell thinning for eggs with p,p′-DDE levels above 100μgg−1lw. The persistence of this degree of thinning over a period of time has been related to population declines in other raptor species.