Análise de contaminação do solo no cemitério de Nova Hartz - RS

Abstract

The burial of the dead in most cases is done inadequately, causing soil contamination through the leaching of some heavy metals and infiltration of necrochorume (liquid released by the decomposing body) and consequently, causing numerous environmental and public health problems. To prove the occurrence of some of these problems, we studied a cemetery area with an approximate size of 2,608.53 m² in the municipality of Nova Hartz, metropolitan region of the State of Rio Grande do Sul. The studies carried out were related to the physicalchemical parameters of the local soil, in order to evaluate the environmental risks involved to the soil in the area occupied by the cemetery. The analysis of the results was done by identifying physical parameters in one sampling point (Granulometry and saturated hydraulic conductivity) and chemical parameters (Cadmium, Cobalt, Copper and Chromium concentrations) in samples from nine sampling points, at depths 0 (Superficial), 120 and 150 cm, using the ICP - OES technique. The results obtained indicated that the soil had average values of 78.34% sand, 8.25% silt and only 13.41% clay, being classified as sandy loam, and a saturated hydraulic conductivity of 5.7 x 10-4 cm.s-1 along the border (from 0 to 150 cm). The analyses indicated 10 values above the allowed values for cadmium (points 1, 4, 5, 6, 7, 8 and 9), cobalt was 8 values (points 2, 3, 4, 5, 7 and 8), copper was 10 values (points 4, 5, 6, 7 and 8) and chromium only 2 values (point 7). Statistically, Cadmium did not differ in depth, indicating the possibility that this element is not related to the activity. The other elements (Copper, Cobalt, and Chromium) showed an increase in concentration at depth. Based on this, we conclude that changes occurred mainly in the concentrations of cadmium, cobalt and copper, between the depths of 0 and 150 cm. It is recommended that groundwater quality monitoring wells be constructed to analyze the concentrations of chemical elements of interest and corroborate with the soil quality information obtained.