Sandimirov S.S. Chemical Composition of Bottom Sedimentary Deposits in Lakes in the Zone Impacted by Atmospheric Emissions from Severonickel Plant. Geochemistry International. 2010, Vol. 48, №11, p. 1148-1153.

1150 DAUVALTER et al. Concentrations of elements (ppm in dry residue) and LOI values (%) in the surface layers (0-1 cm) and the background con­ centrations of these elements in the BD of the lakes. Cf is the contamination coefficient and Cd is the degree of contamination (the values were calculated for eight elements: Cu, Ni, Zn, Co, Cd, Pb, As, and Hg) Lake, depth, m BD lay­ er, cm Fe Mn Cu Ni Zn Co Cd Pb As Hg Cd Pagel’ Lake, depth 5 m 0 -1 16529 511 148 549 87 30.1 0.39 11.9 2.73 1.13 127.4 9-10 12603 106 6 20 51 8.8 0.04 1.2 0.42 0.026 Cf 1.3 4.8 24.4 27.1 1.7 3.4 10.7 10.3 6.5 43.3 Mocheozero Lake, depth 8 m 0 -1 85448 5025 734 1638 119 113 0.51 15.2 12.4 0.062 84.9 19-20 17553 93 58 38 101 11 0.14 2.3 1.91 0.069 Cf 4.9 54.1 12.7 43.3 1.2 10.2 3.6 6.6 6.5 0.9 Malevoe Lake, depth 4 m 0 -1 14759 134 1063 2109 135 84 0.56 21.6 39.1 0.353 216.9 19-20 7875 200 16 27 45 8 0.15 4.9 1.10 0.024 Cf 1.9 0.7 66.0 78.6 3.0 11.0 3.7 4.4 35.6 14.6 These values are two orders of magnitude higher than the MPCf for Cu (1 jag/l). The Cu concentrations in the surface layers of BD of twenty lakes in the influ­ ence zone of atmospheric emissions of the Pechenga- nickel plant were 16-1949 ppm, at an average of 494 ppm (per dry weight of the sediments) [11]. Cu concentrations higher than 500 ppm were detected in BD within 10 km from the smelters of Pechengan- ickel, and the analogous values in the zone impacted by atmospheric emissions form SNP are analogous. The upper layer (0-1 cm) of BD in Siritkul’ Lake con­ tains 310 ppm Cu, whereas the background layers at depth of >1 m contain 23 ppm Cu [12]. This increase in the Cu concentration is explained by the effect of atmospheric emissions from the smelter in Karabash. Similar to Ni, the maximum Cu concentrations (460 ppm) occur not in the uppermost layers but within the depth range of 10-14 cm of BD. The sur­ face layer of BD in Macfarlane Lake have Cu concen­ trations lower than in the BD of Moncheozero and Malevoe lakes, although these concentrations are still high: close to 500 ppm [13]. Malevoe and Moncheozero lakes exhibit high con­ tamination coefficient of Co (table, figure). TheCf value of Co in Pagel’ Lake corresponds to significant contamination. The Co concentrations corresponding to significant contamination were detected in the water of Pagel’ Lake, and the highest Co concentra­ tions (3.4-8.6 ag/l) were detected in the water of Malevoe Lake [3] during the monitoring of the Monchegorsk area and when its BD were sampled (3.8 ag/l). These values are close to MPCf (10 ag/l). The surface layers of BD in twenty lakes in the influ­ ence zone of atmospheric emissions from Pechengan- ickel have Co concentrations of 8-365 ppm (at an average of 75 ppm) [11]. Co concentrations higher than 100 ppm were detected in the surface layers of the BD oflakes within 10 km from the smelters of Pechen- ganickel; analogous values were also detected in the influence zone of atmospheric emissions from SNP. The impact of atmospheric emissions of the smelter in Karabash induced an increase in the Co concentration from 7 ppm in the background sediments at a depth of >1 m to 15 ppm in the surface layer (0-1 cm) of BD in Siritkul’ Lake [12]. The maximum Co concentrations (26 ppm) and the maximum Ni concentrations were detected in the depth range of14 -18 cm of the BD. The maximum values of the contamination coeffi­ cient of Zn (table, figure) were encountered in Malevoe Lake, with these values corresponding to the boundary between moderate and significant contami­ nation. During the monitoring [3], the average Zn concentration in the water of this lake was 9.6 ag/l, which is close to the MPCffor Zn (10 ag/l). The other lakes display moderate contamination coefficient val­ ues (table). In the influence zone ofatmospheric emis­ sions from the Pechenganickel plant, the surface layers of the BD of twenty lakes contain 50-2004 ppm Zn at an average of 201 ppm (per dry weight) [11]. The Zn concentrations of the surface layers of the BD show a relatively significant scatter but are prone to generally decrease away from the smelters. Values greater than 200 ppm were detected in the surface layer of the BD of lakes at a distance of up to 35 km from the smelters of Pechenganickel. No Zn concentrations higher than 135 ppm (Malevoe Lake) were detected in the influ­ ence zone of atmospheric emissions from SNP. The Zn concentration in the surface layer (0-1 cm) of BD in Siritkul’ Lake is 340 ppm, and the Zn concentra­ tions in the background layers at depths of >1 m are 25 ppm [12]. Similar to Cu, the maximum Zn concen­ trations (460 ppm) occur not in the surface layers but in the depth range of 10-14 cm of BD. GEOCHEMISTRY INTERNATIONAL Vol. 48 No. 11 2010