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Heavy metals are transferred from the abiotic environment to living organisms, accumulate in food, contaminate the food chain, and are an important route of human exposure involving a potential health risk. In this study, the concentrations of heavy metals (Cd, Fe, Pb, Zn and As) in agricultural soils and tubers of Solanum tuberosum spp. andigena (native potato) were evaluated. Also, an assessment of the health risk associated with the daily intake by the local population was performed in the four districts of the department of Junín, between altitudes of 3800 m to 4200 m. The heavy metals concentrations in soils with native potato cultivation followed the following decreasing order of Fe > Zn > Pb > As > Cd, with values below national standards. The heavy metals content in native potatoes was below the limits recommended by international standards with the exception of Pb. The bioconcentration factor (BCF) for the two native potato varieties in decreasing order was Zn > Cd > Pb > As > Fe, all less than 0.5. The estimated daily intake of metals (EDIM) in adults and children through the consumption of native potatoes was higher for Fe and Zn. The threshold carcinogenic risk values (TCR) for As exceeded the safety limits 1 × 10 −4. It is concluded that the residents in the four high Andean localities would be exposed to carcinogenic adverse health effects associated with the intake of native potatoes. It is important to monitor the concentration of As and other heavy metals in the Andean soils and crops in order to implement a soil and crop management program to ensure food quality.

Agricultural soils that have been irrigated with the contaminated water from metallurgical mining activities for more than 70 years constitute an environmental problem as well as a concern for food security and human health. The presence of lead in the soil and cultivated pastures is highly dangerous, due to its toxicity, persistence and accumulation in plants and animals (cattle). This element enters the trophic chain of humans due to the intake of meat, milk and its derivatives. The concentration of lead was determined in the soil and the cultivated pastures with Lolium x hybridum Hausskn and Medicago sativa L. The soil and pastures samples collected from plots irrigated with river water contaminated with heavy metals at a depth of 0-20 cm. The content of Pb determined by the atomic absorption spectrophotometry. The results showed the lead concentrations in soil in the range of environmental quality standards for soils according to Peruvian regulations. In the soil with L. x hybridum and M. sativa the average content of lead was 57.17 ± 6.29 mg.kg -1 and 57.19 ± 8.99 mg.kg -1 ; in the above-ground tissues were 1.17 ± 0.69 mg.kg -1 and 1.62 ± 0.68 mg.kg -1 , respectively. In addition, no significant differences were observed in the Pb content in the soil and plant tissues. The bioconcentration factor (BCF) in the above-ground tissues of L. x hybridum and M. sativa was less than one and they were not significant. Therefore, irrigation with long-term contaminated water is not a concern for the farmers in the Mantaro Valley.

Soil is exposed to heavy metals that are associated with the anthropogenic activities, and is currently an environmental and food safety problem. The concentration and source of heavy metals in soils, the level of contamination and the potential for ecological risk in high Andean ecosystems were evaluated. The soil samples were collected from the surface part in which Andean crops were sown and the concentration of As, Cd, Pb, Fe and Zn was quantified. The concentrations of heavy metals in soils did not exceed the threshold of the national and international standard, while As, Pb and Zn exceeded the values of the background. The contamination factor (CF) values showed a high level of contamination for As and moderate for Pb and Zn. The geoaccumulation index (Igeo) values showed that As had the highest load of accumulated pollutants in soils by anthropogenic contribution. A moderate degree of contamination (CD) was found in 61.5% of the sampling sites. The potential ecological risk index (RI) showed that the soils of the study area presented a moderate to low potential ecological risk, and As was the main pollutant in high Andean soils. As, Pb and Zn occurring in high Andean soils mainly originated from human activities such as agricultural practices, whereas Fe mainly originated from the parent material of the soil. The effects of the use of organic and inorganic fertilizers on the accumulation of heavy metals in and Andean agricultural products must be analyzed and verified to protect the health of the inhabitants and the environment.