Sandimirov S.S. Catalogue of lakes in the Russian, Finnish and Norwegian Border Area. Finland, Jyvaskyla: Kopijyva Oy, 2008.

main pollutants are sulphur compounds and heavy metals (Ni, Cu, Al, etc.). De­ spite the fact that emissions from the smelter have decreased to approximately to one third of the peak levels during the late 1970s, the deposition of pollutants still has an effect on the water body. The average Cu, Ni and Al concentrations are 1.1 pg/1,0.8 pg/1 and 21 pg/1, respec­ tively. 3.1.2. Lake bottom sediments The sediments of Lake Aittojarvi have high organic matter contents: the LOI value in the uppermost 1 cm layer is more than 56% (Table 40). The lake is Fig. 58. Vertical distribution of the concentrations ofNi, As, Pb and Cd (цд/д, dry weight) in the sediment core from Lake Aittojarvi. located at a distance of 52 km from the Pechenganikel smelter. As a result, airborne pollution from the smelter has had a relatively smaller impact on the lake, and it is mainly polluted by chalcophile elements (Pb, As and Cd). The maximum concentra­ tions of chalcophile elements occur at depths of 6 to 10 cm, and the concentrations decrease on moving towards the surface (Fig. 58). The uppermost 10 cm layer of the lake sediments is also polluted by Ni. The contamination factor values for these chal­ cophile elements and Ni range from 1.2 to 2.1 (Table 40), i.e. the values correspond to Cu, цд/І L I 1.0-1.3 Ni, ng/l 08 0.5-1.4 Al, цд/І 21 11-26 Pb, мд/і 0.05 0.03-0.10 Water colour, deg. 12 5-30 NH4, Mg/I 26 5-97 N03, мд/І 4 2-12 Total N, |jg/l 175 140-230 Total P, мд/і 4 3-6 Fe, мд/І 173 8-770 112 Catalogue o f Lakes in the Russian, Finnish and Norwegian BorderArea