Accumulation and health risk from heavy metals in agricultural crops in the Mantaro Valley in the central Andes of Peru

Abstract

Cultivation of food crops in soils contaminated with heavy metals (HMs) can pose serious risks to human health. In this study, we evaluated HMs accumulation in soils and agricultural products (corn, broad beans, artichoke and alfalfa), the degree of soil contamination, and the associated health risks from three food crops using the Monte Carlo simulation model. The results revealed elevated concentrations of As, Cd, Cu, Pb and Zn in the soils, exceeding the maximum permissible limits established by both national and international standards. Soil contamination levels were particularly high for Cd, Pb and Zn. Ecological risk was also found to be very high for Cd, with artichoke-cultivated soils contributing most significantly to ecological risk. Alfalfa and artichoke tissues showed higher concentrations of As, Cd and Pb, whilst broad beans accumulated more Zn and Cu. Artichoke and alfalfa samples exceeded food safety limits for Pb. Artichoke, broad beans and corn are not HMs accumulators, as their accumulation factors were below 1. Non-carcinogenic health risks from broad beans consumption were close to the threshold hazard index of 1, suggesting a probability of adverse health effects due to HMs exposure. Broad beans and corn posed the highest carcinogenic risks, with unacceptable risk probabilities exceeding 55% in both children and adults. Arsenic and nickel showed the greatest contribution rates to carcinogenic risk in both groups. These findings suggest that food crops cultivated in HMs-contaminated soils present significant health risks for consumers. Therefore, it is necessary to adequately inform the population about these risks and to promote monitoring and management strategies that ensure food safety.