Potential Toxic Elements Pollution Status in Zones of Technogenic Impact in Central Regions of Perú

Abstract

Soil is a component of the environment. An environmental policy should identify the sources of trace metals in the soil and their effects on people and living beings. The concentrations of 29 surface soil samples (0–25 cm) were determined using the methods EPA 3050B. The data were analyzed using simple and robust statistical analysis that allowed for determining geochemical baseline values. Principal component and correlation analyses were performed, which, together with a spatial analysis, allowed us to distinguish between geogenic and anthropogenic sources. The degree of soil contamination was evaluated using different ecological indices, and the health risks to children and adults were calculated using formulas proposed by the United States Environmental Protection Agency (USEPA). The median concentrations of the analyzed elements correspond to Al 17,666 (mg/kg), As 8.7 (mg/kg), Ba 61.4 (mg/kg), Cd 0.17 (mg/kg), Cr 11.3 (mg/kg), Cu 20.5 (mg/kg), Fe 25,953 (mg/kg), Hg 0.06 (mg/kg), Mn 499 (mg/kg), Ni 20.8 (mg/kg), Pb 15.9 (mg/kg), and Zn 60.6 (mg/kg). In the principal component analysis, four factors were identified that explain 70.3% of the variability of the elements, which, together with the correlation analysis, suggest that the origin of the elements is mainly geogenic with some possible anthropic contributions. The elements analyzed in the soil with moderate contamination correspond to As, Cd, and Pb, in addition, As is the only element that indicated a value above the limit for carcinogenic risk in children. The estimated geochemical baseline values correspond to Al 34,734 (mg/kg), As 15.3 (mg/kg), Ba 113 (mg/kg), Cd 0.41 (mg/kg), Cr 33.8 (mg/kg), Cu 42.9 (mg/kg), Fe 46,181 (mg/kg), Hg 0.12 (mg/kg), Mn 1015 (mg/kg), Ni 42.2 (mg/kg), Pb 21.6 (mg/kg), and Zn 121 (mg/kg). 89.7% of the total samples are at a low level of contamination. The carcinogenic risk due to As in children represents 3.4% of the total samples, so it is considered insignificant.