Presença de metais pesados em área de disposição de resíduos sólidos urbanos em Indianópolis-MG

Abstract

The disposal and accumulation of urban solid waste in inappropriate areas cause different impacts on the population and environment. The most unsettling factor is contamination by leachate, consisting of potentially toxic products, heavy metals in particular, which can contaminate soil, surface and groundwater, as well as cause the inhibition of enzymatic activity, reduction of fauna diversity and flora, bioaccumulation and biomagnification. In addition, the present study aimed to estimate the level of pollution by heavy metals in the area of irregular disposal of urban solid waste in Indianópolis, Minas Gerais, Brazil, according to the Geoaccumulation Index (Igeo) and the contribution of landfill in the contribution of these metals through the Contamination Factor (Cf). The collection of soil samples was carried out in the controlled landfill and its surroundings – 24 points systematically distributed in a rectangular grid –, from where composite samples were taken at a depth of 0 to 20 cm. The samples were digested according to the USEPA 3051A method, and the total levels of metals chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn) was performed on ICP-OES. Thus, low levels of pollution were pointed out, in which Igeo ≤ 2 was classified as unpolluted to moderately polluted. Due to quality reference value, the area presented moderate contamination by Cr, attributed to the source material, and low contamination of other elements, without offering risks to the population. However, based on the background value, low contamination to moderate contamination was pointed out – in this case, Cf ≤ 3 demonstrated the influence of landfill on soil quality.