Organochlorine Compounds in the Plasma of Peregrine Falcons and Gyrfalcons Nesting in Greenland

Levels of organochlorine compounds in the blood plasma of after-second-year female peregrine falcons (Falco peregrinus) were determined from samples collected from southern Greenland in 1985 and western Greenland from 1983 to 1989, and from adult and nestling gyrfalcons (Falco rusticolus) from western Greenland in 1989 and 1990. Samples were taken during nesting. Levels of p,p'-DDE (DDE) in peregrine plasma were 140 μg/kg wet weight geometric mean (GM) for the southern samples, and 220 μg/kg GM for the western samples. Calculated levels of DDE for eggs from plasma levels are below those associated with declining peregrine populations. Only DDE was found in the gyrfalcon plasma; levels were below 20 μg/kg. In addition to DDE, other organochlorines quantified in peregrine plasma included p,p'-DDD, p,p'-DDT, polychlorinated biphenyls, six chlordane compounds, β-HCH, HCB, and Mirex. There was no trend over time for any of the compounds reported in peregrines except HCB, which decreased over the study period. There was no significant difference in the levels of the compounds reported between the regions. Females, which were sampled more than once, showed no clear trends with respect to increasing or decreasing residues.