Lead in feathers and delta-aminolevulinic acid dehydratase activity in three raptor species from an unpolluted Mediterranean forest (Southeastern Spain).

This paper presents the levels of lead found in the feathers of adult and blood of nestlings of booted eagle (Hieraaetus pennatus), European buzzard ( Buteo buteo), and goshawk (Accipiter gentilis) sampled in the 1999 and 2000 breeding seasons in a Mediterranean forest of the Province of Murcia (Southeastern Spain) located far from potential sources of metal contamination. Levels of delta-aminolevulinic acid dehydratase activity (delta-ALAD) in blood were also measured in the nestlings. Lead concentrations ranged from 1.1 to 11.21 microg/dl in blood of nestlings and from 0.35 to 1.66 mg/kg d.w. in the feathers of their parents. A significant relationship was found between blood delta-ALAD and lead (rho = -568), showing a negative correlation with blood lead levels even at lead concentrations below 5 microg/dl. This fact suggests the usefulness of this enzymatic biomarker for low lead exposure in forest raptors. There were also positive relationships between the lead concentrations in blood of nestlings and those in feathers of their parents (rho = 0.817), suggesting the usefulness of feathers for biomonitoring environmental exposure to lead.