Contaminantes ambientales persistentes (metales pesados y plaguicidas organoclorados) en rapaces del sur de España

Zusammenfassung

The objectives of this study were: 1) to evaluate the exposure to heavy metals and organochlorine pesticides in raptors from southern Spain, 2) to estimate risks and 3) to propose reference levels for management decision making. A total of 439 blood samples from 16 raptor species and 55 non-hatched eggs of Montagu's harrier (Circus pygargus) were analyzed. The samples were collected between 2003 and 2006 in Andalusia. The species studied were: Spanish Imperial eagle (Aquila adalberti), Bonelli's eagle (Aquila fasciata), Egyptian vulture (Neophron percnopterus), Griffon vulture (Gyps fulvus), Black vulture (Aegypus monachus), Black kite (Milvus migrans), Eurasian sparrowhawk (Accipiter nisus), Eurasian buzzard (Buteo buteo), Bearded vulture (Gypaetus barbatus), Eagle owl (Bubo bubo), Red kite (Milvus milvus), Goshawk (Accipiter gentilis), Montagu's harrier (Circus pygargus), Booted eagle (Aquila pennata) and Barn owl (Tyto alba). Lead, cadmium, copper and zinc analyses were performed by ASV; and the following organochlorines by GC/ECD: ?-HCH, ?-HCH, ?-HCH, lindane, dieldrin, aldrin, endrin, ? and ? endosulfan, endosulfan sulfate, heptachlor and heptachlor epoxide, p,p'-DDT, p,p'-DDE and p,p'-DDD. The results suggest that the environmental exposure to cadmium in raptors is continuous and at low doses. It is recommended to pay more attention to certain species such as the Spanish Imperial eagle, Bonelli's eagle, Griffon vulture, Black vulture, Black kite and Bearded vulture. Raptors from the south of Spain were chronically exposed to lead suffering sublethal effects, mainly associated with the inhibition of ?-aminolevulinic dehydratase activity (?-ALAD), in addition to other biochemical and subclinical effects. Taking into account the lead exposure from leaded ammunition, it is necessary to study whether obligate scavenger species are more resistant to lead effects. About 90% of non-scavenger individuals had blood lead levels below 20 ?g/dL (subclinical threshold). On the contrary, about 13% of the population of obligate scavengers would require intervention. These data suggest the need for a more intensive monitoring in order to establish measures to avoid effects on populations. Exposure to organochlorine pesticides is different depending on the compound and the species involved. Griffon vultures, Bonelli's eagles and Goshawks were the most exposed to organochlorines; followed by Black vultures, Imperial eagles, Black kites and Eurasian sparrowhawks; and, finally, the species less exposed was the Egyptian vulture. The most common organochlorine compounds in the Andalusian raptors were ?-HCH, lindane, endosulfan I, endosulfan sulfate and p,p'-DDE. The exposure to organochlorine pesticides in Griffon vultures from Andalusia (2003-2006) follows a pattern similar to that described in vultures from Greece (2003-2004) and very different from that of the vultures from India (2005-2007), which suggests the existence of a "Mediterranean pattern of exposure to organochlorine pesticides". There is a decrease over time in the levels present in the medium of organochlorine pesticides. The pattern of exposure observed in this study is usual in areas where DDT has not been used for years. Due to its bioaccumulation and biomagnification characteristics, DDE levels in scavengers should be periodically monitored. P,p'-DDE was the most detected pesticide in the content of unhatched eggs of Montagu's harrier, while p,p'-DDT was not detected in any egg analyzed. An inverse relationship between p,p'-DDE concentrations and the eggshell index in fertilized eggs has been found, suggesting a potential effect on productivity and breeding of the species. A NOAEC was estimated in Montagu's harrier eggs for p,p'-DDE of 3000 ng/g (wet weight).