Ensaios ecotoxicológicos como auxílio na determinação de valores orientadores para cobre e chumbo

Abstract

The heavy metal contamination of soils requires compensatory and preventive measures. CONAMA (2009) established soil screen levels (valor’s guides) which determine the soil concentrations of substances that causes no change in its function. One of the tools that can help in determining these values are the ecotoxicological tests. This study tested metal concentrations that cause change in Eisenia andrei and Folsomia candida and compared the results with the values proposed by CONAMA (2009). It was used three soils of different physical and chemical characteristics located on the state of Rio de Janeiro. The copper and lead were added in soils at different concentrations. Were made Avoidance tests, mortality and reproduction to Eisenia andrei and reproduction and mortality for Folsomia candida. To Eisenia andrei was found for Planossolo and Argissolo an EC50 value 28 and 61 mg.kg-1, respectively, Latossolo could not be calculated. For same metal it got for Planossolo, Latossolo and Argissolo LC50 435, 690 and 691 mg.kg-1, respectively. To lead it was found for Planossolo and Argissolo an EC50 14 and 54 mg.kg-1, respectively, it was not possible to calculate for Latossolo, and LC50 for Planossolo, Latossolo and Argissolo of 437, 1825, 1869 mg.kg-1, respectively. Unlike the Folsomia candida presented an EC50 for copper in Planossolo, Latossolo and Argissolo of 117, 299, 138, mg.kg-1, respectively. In tests with lead for Folsomia candida, was found an EC50 of 552, 782 mg.kg-1 for Planossolo and Argissolo respectively. Could not calculate the results for the Latossolo. In Planossolo contaminated by lead Folsomia candida had a LC50 762 mg.kg-1, the other soils could not be calculated. Each soil was obtained a different EC50 value. The Eisenia Andrei was more sensitive to the metal than Folsomia candida. The Planossolo was the most restrictive soil to contamination, with EC50 and LC50 values lower in all tests. The concentrations of metals that cause changes in soil fauna are different from concentrations suggested by CONAMA (2009).