Variaciones de los niveles de mercurio y zinc en agua y sedimentos de la subcuenca del río Carrizal, Manabí

Excessive concentrations of mercury and zinc in natural sources are a risk to human health and to the development of adequate aquatic life. In the present study, the concentrations of Hg and Zn in samples of water and sediment from the Carrizal River (Cantón Bolívar, Manabí) were determined in two periods (August and October). In addition, 5 sampling points were characterized at La Esperanza reservoir, 7 at Carrizal river micro-basin, and 9 at the river sub-basin, covering an area of 51 km. The concentrations of Hg and Zn in the sediments were significantly higher than the concentrations obtained in the water. The contents of Hg in water and sediments of Carrizal River exceeded the safety limits established by national and international regulations; while the Zn concentrations obtained are considered to be a risk for aquatic life. Index Terms—bioaccumulation, adsorption, environmental pollution, heavy metals