The assessment of metal contamination status using the Nemro integrated pollution index

This study aimed to evaluate and zoning the status of metal contamination using the Nemro integrated pollution index (NIPI) in the vineyards of Malayer county. For the study, 286 geolocated soil samples were excerpted based on a random systematic method; each with a weight of 1 kg collected both from a depth of 0-20 cm and a surface of 20 × 20 cm, and then stored in the polyethylene bags to be transferred to the laboratory getting further analyzed. The concentrations of Mn, Zn, Cu, Ni, Cr, As, and Hg were measured using a spectrophotometer; the average concentrations of the sampled metals were respectively 597, 109, 87.86, 84.32, 67.12, 47.1, and 0.344 mg/kg. Based on the results, the measured values were below the NIPI index thresholds for each element remarking the relatively unpolluted condition of the study area. Having evaluated the NIPI-based map in line with low concentrations of the heavy metals in the soil of the study area and a semi-homogeneous distribution of the heavy metals concentration, unfold that the geological processes are the governing factors in controlling the concentration of measured metals. By contrast, human-made changes are mostly responsible for the heterogeneous distribution of metal concentrations in small parts of the region.