Resumen en español

HM contamination is one of the biggest environmental concerns today. One of the main generating sources is mining, specifically, gold mining. Gold mining is, for Colombia, one of the key factors to its economic development. Official reports state that 86% of mining areas operate without proper permits. This informal mining generates a great impact on the environment. Therefore, it was proposed to evaluate the total, bioavailable contents and determine the enrichement factor (EF) and Geoacumaltion Index (Igeo) for Hg, Cd and Pb. In order to proceed with the proposed analysis 156 types of soils in high mining areas were selected in three different Departments. The total contents was determined by means of Atomic Absorption Spectrometry with cold steam for Hg and graphite furnace for Cd and Pb, and Bioavailability using the Method Rhizosphere-based (CaCl2). The departments of Antioquia and Bolívar presented higher averages for the three metals, Hg> Cd> Pb, and a large percentage of soils with values higher tan reference values (VR), in both urban soils and mining areas. The agricultural soils with the greatest number of sites with values higher than the VR for Hg stand out, however, these present a lower average. For bioavailability, the percentages for Hg-bd and Pb-bd are within those reported in the literature, while Cd-bd was quite high for most soils. Finally, the Department of Bolívar has the highest number of soils with high degrees of contamination according to the Igeo for Cd and Pb, while for Hg it was the Department of Antioquia. In regard to the usage of soils, the urban soils had the greatest number of sites with high degrees of contamination in the three elements.