Mineralogical and geochemical study of the Kirki mining wastes, Evros region, Greece -determination of the environmental impact by toxic and heavy metals

Abstract

Mining activity at the Kirki ore deposit has occurred over short periods, from 1974 to 1980 and 1990 to 1997. The mining wastes at the cracked tailing ponds and at other on-site locations of the plant, together with the remains of the mining concentrates, the piles of the unprocessed ore and the large number of destroyed and weathered barrels of chemical reagents, including sodium cyanide, are a great risk to public health. All these wastes are exposed to rain-water and constitute a permanent source of toxic metals and other materials, which are transported by the adjacent small river of Erini, contaminating the hydrologie system of the whole area including the city of Alexandroupolis. For example, the concentrations of toxic metals such as Pb, Cu, Zn, As and Cd in the clay fraction of the river sediments is 2100, 300, 50, 100 and 660 times, respectively, above the natural background concentrations.