Lead pollution from waterfowl hunting in wetlands and rice fields in Argentina

The pollution of wetlands by lead derived from waterfowl hunting with lead shot was investigated. We determined soil pellet density and Pb concentration in soil, water and vegetation in natural wetlands and rice fields in central-eastern Santa Fe province, Argentina. Pellet density varied greatly among hunting sites (between 5.5-141 pellets/m2) and pellets were present in some control sites. Soil Pb concentration in most hunting sites (approximately 10-20mgkg-1) was not much higher than in control sites (~5-10mgkg-1), with the exception of the site with highest pellet density, which also had a high Pb soil concentration. In water, on the other hand, Pb concentration was similar in all sites (~4-7μgL-1), both control and hunting, and higher than reference values for aquatic media. Lead was also present in vegetation, including grasses and rice crops, in almost all cases. Most soil-collection sites were slightly acidic, and were frequently flooded. These results strongly suggest that metallic Pb from spent shot is oxidized and dissolved due to wetland conditions. Thus, the pollutant is readily mobilized and distributed across all wetland areas, effectively homogenizing its concentration in locations with and without hunting activities. The replacement of lead by nontoxic materials in pellets appears to be the only effective way to prevent Pb pollution in wetlands.

Fil: Romano, Marcelo. Centro de Investigaciones En Biodiversidad y Ambiente; Argentina

Fil: Ferreyra, Hebe. Global Health Program; Argentina. Wildlife Conservation Society; Estados Unidos

Fil: Ferreyroa, Gisele Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina

Fil: Molina, Fernando Víctor. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina

Fil: Caselli, Andrea. Global Health Program; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina

Fil: Barberis, Ignacio Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentina

Fil: Beldomenico, Pablo Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Ciencias Veterinarias del Litoral. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Instituto de Ciencias Veterinarias del Litoral; Argentina

Fil: Uhart, Marcela. University of California; Estados Unidos