Polychlorinated biphenyls and chlorinated pesticides in bird eggs from Calabria (southern Italy)

Polychlorinated biphenyl (PCB) and chlorinaed pesticide levels in eggs of two terrestrial (kestrel and sparrowhawk) and two aquatic (heron and mallard) birds were determined in inhabited areas and woodlands of Calabria. The eggs of the two terrestrial raptors were more polluted than those of the aquatic birds. Among the raptors, the kestrel demonstrated the highest level of pollution because it lives close to villages, whereas sparrowhawk lives in forests. The highest PCB and DDT residue concentrations found in kestrel (11.3 and 8.7 mg g-1 lipid, respectively) could cause shell thinning. Aquatic species show a higher DDT/DDE ratio than terrestrial species, probably because DDT is degraded more slowly in aquatic environments. However, point DDT sources seem to be present in this region.