Soil contamination in a cemetery area: a case study in Nova Hartz City—RS, Brazil

Abstract

We conducted a study in a cemetery area covering 2608.53 m2 in the municipality of Nova Hartz, Metropolitan Region of the State of Rio Grande do Sul. Soil samples were collected to determine the physicochemical parameters of the local soil at nine points within the study area and at three different depths (0 cm, 50 cm, and 120 cm). Granulometry and saturated hydraulic conductivity of the soil were assessed, and chemical analyses for Cadmium, Cobalt, Copper, and Chromium were performed using the Atomic Absorption Spectrometry technique.The results revealed that the soil exhibited average values of 78.34% sand, 8.25% silt, and 13.41% clay, classifying it as sandy loam. The saturated hydraulic conductivity was measured at 5.7 × 10–4 cm s−1 across the profile (from 0 to 120 cm). Chemical analyses identified concentrations exceeding the allowed limits for Cadmium (points 1, 4, 5, 6, 7, 8, and 9), Cobalt (points 2, 3, 4, 5, 7, and 8), and Copper (points 4, 5, 6, 7, and 8), with only two values for Chromium (both at point 7). Some points exhibited concentrations above the maximum allowed values at multiple depths. Evaluating vertical distribution, Cadmium did not show depth variations, suggesting a possible natural origin unrelated to cemetery activities. Conversely, Copper, Cobalt, and Chromium displayed increased concentrations with depth. In conclusion, significant changes in concentrations of Cadmium, Cobalt, and Copper were observed, especially between depths of 0 and 120 cm.