HEAVY-METALS IN LAKE-SEDIMENTS OF THE KOLA-PENINSULA, RUSSIA

Investigations of heavy metal content in lake sediments in the Kola Peninsula, Russia, were carried out from 1989 to 1992. The study lakes were situated at varying distances from two heavy metal pollution sources - smelters of the Pechenganickel and Severonickel Companies. Four aspects were considered: (1) values of background concentrations of heavy metals in the sediments; (2) historical trends in heavy metal concentrations; (3) regional distribution of the concentrations in surficial sediments; (4) degree of contamination and Hakanson's risk index values. Atmospheric emissions from smelters of the Murmansk, region were the main sources for the increased concentrations of Ni, Cu, Co, Cd and Hg observed in young sediments within a distance of 30 km, presenting a considerable ecological risk to aquatic ecosystems. Surface sediment concentrations declined considerably away from the smelters and differences between upper and lower layers decreased. Pb concentrations increased from east to west owing to the deposition of atmospheric Pb from automobile exhaust in northern Finland and north-eastern Norway.