Reference Levels for Heavy Metals in Soil in the City of Cerro de Pasco - Peru - 2020

Abstract

This research focuses on determining the reference levels for aluminum, barium, chromium, copper, manganese, lead and zinc were determined in the soils surrounding the city of Cerro de Pasco, considering the background levels of these metals and the physicochemical properties of the soil. The study area had an extension of 3201 ha of land, performing a simple random statistical sampling, obtaining 21 composite samples from 63 simple and superficial samples (0–30 cm deep), where the total concentrations of heavy metals are correlated with the physicochemical parameters of the soil. From the results, there is a correlation coefficient greater than 0.7 with respect to the cation exchange capacity (C.E.C.), organic matter (OM) and pH, for almost all the metals evaluated, except for chromium, manganese and lead. As a result of this correlation, linear equations were generated from CIC, OM and pH, to define the reference levels of aluminum (24439 mg/kg), barium (161 mg/kg), copper (29 mg/kg) and zinc. (552mg/kg). kg), considering UCL95 as the background level since it presented a better statistical fit with respect to the descriptive statistics. However, the expression ${\text{NR}}\, = \,\overline{X}\, + \,nDE$ was used to establish the reference levels of chromium (26 mg/kg), manganese (966 mg/kg) and lead (62 mg/kg), because they did not show a correlation with the physicochemical properties of the soil.