Monitoring of chemical elements in soils, waters and plants near the active mine tailing dam in the central zone, Chile

Abstract

Chile, the world's largest copper producer, generates massive amounts of mine tailings that are a source of ongoing environmental concern for local communities. The main objective of this work is to evaluate the concentration of elements: As, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Zn and SO42- in soils, water, and vegetation in the communities surrounding a mine tailings dam in central Chile. Soils, waters and plants samples were collected from the towns of Chacabuco, Huechún, Huertos Familiares, Punta Peuco and Santa Matilde, which are located at 3 to 8 km from the Ovejería mine tailings site, operated by CODELCO in operation since 1999. The results showed that the levels of metals/metalloids and SO42- in water (pH 6.69–7.95) met both WHO limits and Chilean water quality standards for miscellaneous uses. In soil (pH 7.67–8.39), total and available concentrations of metals/metalloids did not exceed common international reference values. Plants with acceptable levels of metals and S were Citrus limon, Eucalyptus, Schinus molle, Prunus persica, Medicago sativa, Citrus sinensis, and Ficus carica. The only species with a content of one metal (Fe) well above the reference value and high concentrations of other metals (Cu, Mn, Mo, and Pb) was Acacia caven. The concentrations of chemical elements determined between 2015–2018, in soils, water and plants in different locations near the active copper tailings dam Ovejeria, in Central Chile, allow us to conclude that in general the levels are comparable to national and international references and do not indicate contamination.