Evaluación de la Calidad Ambiental en Zonas Influenciadas por la Minería de Oro en el Sur de Ecuador.

Abstract

Gold mining has a bad reputation due to past bad practices. The use of mercury in gold mining is prohibited, but illegal mining is known to maintain this bad practice. The PIMI 16-05 project produced analytical results of the content of metals in water, soil and sediments in areas of influence of mining in the provinces of Zamora Chinchipe and El Oro. The concentrations of metals in water and soil samples were compared with limits maximum allowable. The enrichment factor (EF) of metals in soils and sediments was calculated. The values of the enrichment factor for some of the soils/sediments of the province of Zamora Chinchipe reached values of enrichment degrees of level 5, 6 and 7 (high, very high and extremely high) for the metals Ni, Cu, Zn, As, Mo, Cd and Pb. For the province of El Oro, the soils/sediments reached enrichment degrees 5, 6 and 7 for the metals Ni, Co, Cu, Zn, As, Mo and Pb. In water, the metals As, Cd and Pb were found in higher concentration in the province of Zamora Chinchipe, while As and Pb reached concentrations above the regulations in water samples from the province of El Oro. Hg was found in concentrations above the maximum permissible limit in water, soil and sediment samples from both provinces. These results suggest that (illegal) gold mining negatively impacts environmental quality.