Toxic element contamination in waters from the massive sulfde deposits and wastes around Giresun, Turkey

Abstract

Tis study assessed the quality of water polluted with mine drainage waters, some of which is used for drinking and agriculture,in the urban areas of the Giresun region, Turkey. A total of 40 water samples were collected from the main rivers and stream, spring, anddrainage waters. All samples were analyzed for physical and chemical parameters. Te tectonically controlled massive sulfde depositshosted in the Maastrichtian Eocene magmatic rocks are either active or have been abandoned. Te main ore mineral assemblagesare chalcopyrite, sphalerite, galena, and pyrite. Te oxidation of the sulfde minerals in the deposits and wastes has caused acid minedrainage (AMD). Most of the spring, stream, and drainage waters have a strongly acidic pH and high sulfate content, and concentrationsof Pb, Zn, Fe, and Cu can reach extremely high values. In addition to these elements, the concentrations of Cd, As, Mo, Se, Sb, Tl, andBi are higher than the international and national drinking water guideline limits. Fe, Al, and Zn levels in stream, spring, and drainagewaters are substantially higher than those in the rivers. Te risk index values of hazardous elements in the river water show no or lowrisk, while most of the stream, spring, and drainage waters show high and/or extremely high risk values. Te concentrations of themetals and pollution levels of most of the stream, spring, and drainage waters may pose great environmental risks through the changesthey cause and disturbances brought to the living things in the area.