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

Table 13. The organic matter contents (LOI, %) and heavy metal concentra­ tions ftjg/g, dry weight) in the surface (0-1 cm) and pre-industrial (14-15 cm) sediment layers. Cf and Cdare contamina­ tion factor and degree of contamination values, respectively. of total N 112 l^g/1- The colour values, and organic matter (2.8 mg/l) and Fe concentrations (mean 71 |ig/l) of the lake water are typical of the small water bodies in the region. During episodes of high precipitation in the summer the concentrations of species of mineral nu­ trients (PO.3 and NO ') that determine the lake productivity are low. The watershed of Lake Sarijarvi is subjected to strong anthropogenic im­ pacts from the “Pechenganikel” smelter. The main pollutants are sulphur com­ pounds and heavy metals (Ni. Cu, Cd, Cr, Zn, As, Hg, etc.). In spite of the fact that emissions from the smelter have been reduced to approximately one third of the peak levels in the late 1970s, the deposition of pollutants still has an im­ pact on the water body. The concentra­ tions of Cu (up to 4.5 |ag/l) and Ni (up to 28.6 |_ig/l) in the vicinity of the smelter are substantially higher than in other par 1.13.2. Lake bottom sediments The sediments of Lake Sarijarvi have relatively high organic matter contents: the LOI value in the uppermost 1 cm layer is about 30% (Table 13). The lake is located at a distance of 6 km from the Pechenganikel smelter and subjected to high airborne pollu­ tion by heavy metals (Ni, Cu, Co) and chalcophile elements (Pb, As, Cd and Hg).The top 3-4 cm layer of the lake sediment is the most heavily polluted by Ni, Cu and Co, as well as by chalcophile elements (Fig. 10).This means that pollution by chalcophile ele­ ments started at the same time as the pollution by heavy metals emitted by the smelter. The contamination factor values for these toxic elements range from 4.8 to 43.2 (Table 13), i.e. the values correspond to considerable and high contamination. Nickel has the highest Cfvalue. The degree of contamination value (105.9) for this lake corresponds to high contamination. Lake Layer, cm LOI Cu Ni Zn Co Cd Pb As Hq c. Sarijarvi 0-1 14-15 28.05 22.92 540 21 1157 27 116 66 60.0 10.7 0.66 0.14 10.2 0.96 7.50 1.62 0.154 0.016 cf 25.5 43.2 1.8 5.6 4.8 10.7 4.6 9.8 105.9 Water colour, deg. 5 5-5 NH4, цд/І 22 16-28 N03, цд/І 5 4-5 Total N, цд/І 112 96-129 P04, цд/І 1 1-2 Total P, цд/І 14 7-20 Fe, цд/І Z l 67-75 Cu, цд/І І 5 4.4-4.5 Ni, цд/І 25 23-28 Al, цд/І 25 25-25 Pb, цд/І 03 0.3-0.4 of the region. 42 Catalogue o f Lakes in the Russian, Finnish and Norwegian BorderArea