High Levels of Heavy Metals detected in Feathers of an Avian Scavenger Warn of a High Pollution Risk in the Atacama Desert (Chile).

Abstract

The Atacama Desert represents the highest levels of mining exploitation in Chile, which inexorably results in high levels of pollution. Raptors, and particularly scavengers, have shown their usefulness to evaluate exposure to environmental contaminants in polluted scenarios. In this study, we used primary feathers from a local avian scavenger, turkey vulture Cathartes aura, to evaluate the exposure to cadmium (Cd), lead (Pb), copper (Cu) and zinc (Zn) in two locations from the southern Atacama Desert (coastal and inland) and a third location from the bordering semiarid region, in northern Chile. All metals were detected in all analyzed samples (n = 54). Mean concentrations in Coastal Atacama were 0.68 ± 0.84ppm for Cd; 1.97 ± 2.01ppm for Pb; 59.11 ± 80.69ppm for Cu; and 107.96 ± 51.00ppm for Zn, while mean concentrations in Inland Atacama were 0.55 ± 0.42ppm for Cd; 3.37 ± 2.61ppm for Pb; 91.66 ± 77.74ppm for Cu; and 214.03 ± 99.08ppm for Zn. Mean concentrations in Coastal Coquimbo were 0.63 ± 0.69ppm for Cd; 1.57 ± 0.92ppm for Pb; 18.09 ± 6.12ppm for Cu; and 149.37 ± 105.56ppm for Zn. These differences could be explained by differences on abundance of mining settlements among areas. According to the literature, these values are very high for all metals, exceeding in some cases those values referred as responsible of health disorders in birds. We strongly recommend further research looking at potential adverse effects caused by heavy metal pollution on the health of human and wildlife populations in the southern Atacama Desert.