Environmental impact on soil, water and plants from the abandoned Pan de Azucar Mine

摘要

Pan de Azucar abandoned mine is located in Jujuy province, Argentina. The impact of that pollution was evaluated determining the density and the composition of the vegetation around the tailings. Also soil and plants samples were collected and their metal contents were determined. Deyeuxia breviaristata was the main native plant in the most polluted soils and its biomass had the highest concentration of zinc and lead. Acid mine drainage (AMD) samples were collected and their toxic effects were analyzed by ecotoxicology assays employed Lactuca sativa L. seeds; CI50_(120) of 0.03% v/v was determined. From mineral and AMD samples some iron- and sulphur-oxidizing microorganisms were isolated and also characterised by molecular techniques. AMD potential was evaluated for different tailing samples inoculating native microorganisms; deeper samples produced drainage with pH close to 1 and released iron above of 1000 ppm. AMD can reach Cincel River which is the main tributary of Laguna Pozuelos (just 25 km from the mine). Laguna Pozuelos is a Natural Monument, Biosphere Reserve and Ramsar site.