Heavy metals and selenium in pastures of a high Andean mining area and its relationship with their content in water and soil

The aim of this study was to determine whether high levels of heavy metals and selenium in water and soil affected pastures in Peru's high Andean mining zone beyond the maximum permitted levels.Data on heavy metals and selenium were collected from water (n = 25), soil (n = 95), and pastures (n = 20) in areas suspected of contamination and in control zones, using specific sampling protocols and laboratory analyses compared to environmental standards.Although elevated concentrations of manganese were detected in groundwater (0.47 mg/l) and surface waters of rivers (0.3 mg/l), no increase exceeding the maximum permissible limits of this metal was recorded in the soils or pastures of the affected areas.Similarly, despite the presence of high concentrations of arsenic, lead, and selenium in the soils of areas impacted by mining activity, the levels of these metals in the evaluated pastures did not exceed the maximum permissible limits.Correlation analysis revealed highly significant negative correlations (P 0.01) for iron in soil with arsenic in pastures (r = -0,701) and copper in soil with cadmium in pastures (r = -0,81).The results indicate that despite the existence of metal and selenium values exceeding established limits in both soil and water, no toxicity levels for these minerals were observed in the pastures that could pose a risk to the health of grazing animals.