Evaluation of the danger of a tailings pile belonging to an active mine through its characterization and a dispersion model

Abstract

Mining is one of the principal economic activities in Mexico, which in addition to bringing benefits to the population, causes health and environmental problems. This activity produces many wastes, but the main is tailings. In Mexico, these wastes are disposed of in the open air, and there is no control over them, so the particles of these wastes are dispersed by wind currents to the surrounding population. In this research, tailings were characterized, being these particles smaller than 100 microns; in this way, tailings can enter the respiratory system and thence can cause diseases. Therefore, it is important to characterize these particles and identify the toxic components. The present work shows a qualitative characterization of the tailings from an active mine in Mexico using different analytical techniques. In addition, with the data obtained from the characterization of the tailings, as well as the concentration of the toxic elements found, which were Pb and As, a dispersal model was generated that was used to estimate the concentration of particles in the wind generated by the area study. Environmental Protection Agency (EPA) emission factors were used in the model. The air quality model used in this research is AERMOD, where available databases were used; in addition, the model was coupled with meteorological information from the latest generation WRF model. The modeling results estimated that the dispersion of particles from the tailings dam can contribute up to 10.15 µg/m3 of PM10 to the air quality of the site, which, according to the characterization of the samples obtained, could be dangerous for human health and can be estimated up to a concentration of 0.04 µg/m3 of Pb and 10.90 ng/m3 of As.