Raimo Heikkilä

Metal Distribution in Lakes Surrounding the Kostomuksha Iron Mine and Ore Dressing Mill in Northwestern Russia

Metal distributions in lakes surrounding Kostomuksha iron mine and ore dressing mill were explored to study the effects of the mill on the state of the lakes. Both surface water and 10 cm sediment core samples were taken from six lakes in the Russian side and another two in the Finnish side at a maximum distance of 70 kilometres from the plant. Concentrations of thirteen metals, phosphorus and sulphur were determined in waters and sediments by ICP-MS after filtration of the water samples and acid digestion of the sediment samples. No increase of these elements was observed in lakes in southwestern direction towards Finland where air transport was the only pathway. In the northwestern direction where there are also water releases from a waste pond of the plant increasing concentrations of Ca, Mn, S, Fe and As towards the plant were seen both in water and sediments phases. This was also the trend for Na, K and Mg in water and for Zn, Pb, Cd and Hg in the sediment. No systematic change was seen in case of Al, P and Ni. It is likely that elevated water concentrations of at least K, S and As are due to water releases from the waste pond but for other elements the source is not quite evident.