Metal concentrations measured in surface soil samples collected on Sepetiba Bay watershed, Rio de Janeiro, Brazil

Resumo

Environmentalists all over the world are concerned about how to cope with the increased disposal of pollutants in rivers, lakes, and landfills surrounding cities. In response to this concern, a survey was conducted to determine metal concentrations in surface soil samples collected in the Sepetiba Bay watershed, Rio de Janeiro, Brazil. Soil samples were collected in representative points in the study area. For control, samples from presumably unpolluted zones outside the direct influence of the chemical industries were used. In Brazil, in 2001, the State of São Paulo through the Environmental Company (CETESB) pioneered the publication of guidance values for pollutants in soils and groundwater. Concentrations of arsenic, chromium, copper, nickel, lead, zinc, cobalt, and cadmium were determined in the samples. Soils samples showed detectable concentrations for all the chemicals analysed. However, even though deserving attention, the pollutant levels for these chemicals in the soil still present levels below the maximum allowed concentrations established by the Brazilian reference. The result of this study can be used to intervene in the pollution Sepetiba bay watershed, guiding direct actions in the effluents discharged by industries as well as in environmental management.