Risk assessment for the presence of potentially toxic elements in the vicinity of a former lead smelter in Bahia, Brazil

Environmental and human health risk analyses of contamination by toxic elements in soil are important tools to manage remediation initiatives or population resettling. In Brazil, a primary lead smelter operated in Bahia state from 1960 to 1993 generating several environment and health concerns. This work presents an analysis of the estimated ecological and human health risk for the region around the smelter. Concentration data from three studies were used to evaluate ecological and health risk indexes. Geostatistical analysis using maps identified a high concentration of potentially toxic elements: Pb, Cd and Zn around the chimney of the old smelter, exceeding the regulatory limits for industrial soil. The soil pollution and ecological risk analyses showed high values around the chimney of the old plant. The analysis of risk to human health showed that the risk for disease through soil contamination by Cd and Zn is low and non-existent around the old plant. However, the risk for disease through soil contamination by Pb is very high for children and moderately high for adults around the old plant. It is estimated that more than 7000 people are at risk in this region due to the toxic elements in the soil (about 12% of the population of the city). Due to the pollution and the ecological and health risks of the contaminated soil in the Santo Amaro region, the authorities should urgently undertake remediation and resettlement programs for the population of the region.