Risk Assessment of Toxic Elements in Surface Soils Collected Near and Far from a Deactivated Lead Smelter in Bahia, Brazil.

Twenty-eight surface soil samples were collected in Santo Amaro, Brazil, to evaluate the current environmental impact caused by a lead smelter that operated in this city from 1960 to 1993. The smelter was deactivated after causing deaths and irreversible adverse effects on the health of the population due to contamination by lead and other elements. In this context, lead, cadmium, arsenic, chromium, copper, and zinc, six of the seven elements recommended by Hakanson in 1980 for ecological risk assessment, were determined using inductively coupled plasma – optical emission spectrometry (ICP OES). The contamination factor (CF), ecological risk index (Er), pollution load index (PLI), degree of contamination (mCdeg), and potential ecological risk index (PERI) were used to investigate the level of contamination and the ecological risk of the samples. The CF index demonstrated that the samples collected inside the smelter showed high contamination for lead, cadmium, and zinc, low contamination for chromium, and low to moderate contamination for arsenic and copper. In addition, the integrated PLI index demonstrated that all samples collected inside the foundry showed high pollution; however, of the other twenty-two samples investigated, only two showed pollution. The ecological risk index showed that the soil samples collected inside residences near the foundry denoted ecological risk due to cadmium contamination. The PERI demonstrated that samples collected on the city's access road and samples collected on streets close to the foundry denoted low ecological risk. The results obtained by applying the principal component analysis (PCA) and hierarchical cluster analysis (HCA) to data relating to the levels of chemical elements in the soil samples fully corroborate the results found using toxicological assessment indices. [ABSTRACT FROM AUTHOR]