ORGANOCHLORINES, INCLUDING CHLORDANE COMPOUNDS AND THEIR METABOLITES, IN PEREGRINE-FALCON, PRAIRIE-FALCON, AND CLAPPER-RAIL EGGS FROM THE USA

Four compounds present in technical chlordane (trans- and cis-nonachlor, and tentatively MC-2 and MC-5) and three metabolites of chlordane (heptachlor epoxide, oxychlordane, and U-4) were identified by GC/MS in peregrine-falcon (Falco peregrinus anatum) eggs. Levels of Heptachlor epoxide, oxychlordane, trans- and cischlordane, trans- and cis-nonachlor, MC-2, and MC-5 were quantified by GC/ECD in peregrine-falcon eggs from the US east coast, Colorado, and California; and in prairie-falcon (Falco mexicanus) and light-footed-clapper-rail (Rallus longirostris levipes) eggs from California. The eggs were collected between 1986 and 1989. Oxychlordane, heptachlor epoxide, trans- and cis-nonachlor, MC-2, and MC-5 were detected in every egg analyzed. Heptachlor, trans-, and cis-chlordane were either not detected, or present at low levels in the eggs. The highest SIGMAchlordane levels were found in the East Coast peregrine-falcon eggs at a geometric mean (geom. mean) concentrations of 1800 mug/kg (ppb); the lowest levels of SIGMAchlordane were found in the prairie-falcon eggs at a concentration of 120 mug/kg (geom. mean). Of the technical chlordane compounds measured, MC-2 bioaccumulated to the greatest degree. SIGMADDT levels in the falcons ranged from 11 000 mug/kg (geom. mean) in the Colorado samples to 8800 mug/kg (geom. mean) in the East Coast and California peregrines. SIGMADDT levels in the rail eggs were 3000 mug/kg (geom. mean). The highest SIGMAPCB levels were found in the East Coast peregrine-falcon eggs at a concentration of 14000 mug/kg (geom. mean); the lowest levels of SIGMAPCB were found in the prairie-falcon eggs at a concentration of 350 mug/kg (geom. mean).