Contamination by mercury in air of the mining district of San Martin de Loba in Bolivar's Department, Colombia

Mercury (Hg) is a heavy metal, considered a highly toxic pollutant. In its elemental state is volatile, making it easy to transport over long distances through the atmosphere, so that environmental pollution caused by it is a serious problem worldwide. Activities such as gold mining, where metallic Hg is used, have contributed with its global distribution, affecting ecosystems and human health. The aim of this study was to determine the levels of total mercury (T-Hg) in air in gold mining areas in Southern Bolivar, particularly in the mining district of San Martin de Loba, in the municipalities of San Martin de Loba and Barranco de Loba (Mina Santa Cruz), Colombia. In situ analyses were performed by atomic absorption spectroscopy, using a portable Ra-915 + Zeeman mercury analyzer. In Mina Santa Cruz, one of the most important gold mines in Colombia, concentrations of Hg in air ranged between 163.7 ± 6.6 and 40 455 ± 2154 mg/m3, while in the urban area of San Martin de Loba varied from 223.6 ± 20.8 to 27 140 ± 212.5 ng/m3. In those places where an amalgam burning process was taking place at the time of the measurements, Hg concentrations reached values of 40 455 ± 2154 ng/m3. These data imply a severe occupational exposure to Hg for operators and citizens living in cities located near mines. Therefore, it is important to regulate and control the use of Hg in gold mining, avoiding a chronic impact of the metal on the health of people and the environment. (author)