Heavy Metals and Arsenic in Soil and Cereal Grains and Potential Human Risk in the Central Region of Peru

The objective of this study was to analyze the content of heavy metals and arsenic in soil and cereal grains as well as to evaluate the possible human risk in the central region of Peru. The soil samples of corn and barley grains were collected from seven agricultural zones and the concentrations of Cu, Fe, Pb, Zn and As were determined with the method of atomic absorption flame spectrophotometry. PERMANOVA showed that the effect of the type of crop and the sampling zone significantly influence the concentrations of heavy metals and As in soil and corn and barley grains (p < 0.05). PCA for heavy metals and As in soil and grain samples of the cereals studied showed that the first two main components represented 81.03% and 94.77% of the total variance, respectively. Hazard Quotient (HQ) for ingestion was the most significant. The HQ values of Pb and As in crop soils indicated that detrimental health effects are unlikely (HQ < 1). The soil hazard index (HI) values of both crops did not exceed the threshold value of 1 (HI < 1). The carcinogenic risk level (CR) of As from ingestion of corn and barley crop soils contaminated by As was higher in children than in farmers and adults. The bioconcentration factor (BCF) of As was higher in barley grains than in corn grains. The THQ of As exceeded the target value of 1 in 100% of the barley and corn sampling sites. The RC of As in grains exceeded the acceptable risk level of 10–6 in all sampling zones.