Organochlorine contaminants in body tissue of free-ranging white-tailed eagles from northern regions of Germany.

Concentrations of the organochlorine pesticides hexachlorobenzene (HCB), gamma-hexachlorocyclohexane (gamma-HCH), DDT and its metabolite p,p'-dichlorodiphenyldichloroethylene (DDE), and seven polychlorinated biphenyl (PCB) congeners were analyzed in livers and adipose tissue samples of 145 white-tailed eagles found dead or moribund in Germany from 1979 to 2001. Most birds were found in the region of the former German Democratic Republic where the insecticide DDT was used until 1988. Therefore, our samples represent mainly residue data of specimens following the ban of DDT in these regions. Contaminant levels of 127 immature and adult birds found between the years 1990 and 2001 were in general below threshold levels known for detrimental effects. The highest level of sigmaDDT was detected in an adult bird found dead in 1979. Residues of most organochlorines were highly significantly correlated between hepatic and adipose tissue. Concentrations of sigmaDDT increase during aging, whereas only the levels of the higher-chlorinated PCBs were higher in tissues of adult birds compared with the younger age classes. Hepatic residues of sigmaDDT and HCB and the ratio of sigmaDDT to sigmaPCB, respectively, were significantly declining from 1990 to 2001. The indices given for body condition of specimen were significantly correlated with liver concentrations, indicating higher residues in more emaciated birds.