Sandimirov S. Pollution of the Sediments of the Paz River basin / In State of the environment in the Norwegian, Finnish and Russian border area. The Finnish Environment. Finland, Jyvaskyla: Kopijyva Oy. 2007, №6, 98p.

Increased concentrations o f Cd, Pb and As were recorded in the upper layers o f the sediments in almost all investigated lakes. This indicates that these elements now are the status o f global pol­ lutants. The lead content of the environment is controlled by tetraethyl lead, an antiknock com­ ponent o f gasoline. Another, rather small (several t/year) source o f Pb (as well as Cd and As) pollution is the emissions o f melting furnaces. Since the melting point o f Pb, Cd and As is lower than that o f other heavy metals (including Ni and Cu), these elements virtually completely goes into aerosol, which, on emission by melting furnaces, spreads (similar to SO2) over greater distances than any other heavy metal. Therefore, near the plant, elevated concentrations o f Pb, Cd and As can be absent. In Figure 7 the distribution o f heavy metals concentrations in superficial layers (0 - 1 cm) o f lake sediments when moving away from the metallurgical plants is shown. Concentration o f Ni and Cu are sharply reduced when moving away from pollution sources and on distance more than 40 km they do not exceed 100 ^g/g (Fig. 7). The lakes which are taking place to northeast from the smelters are considerably more polluted by Ni and Cu while other lakes have much smaller concentration Ni and Cu. The similar pattern o f distribution o f concentrations o f Ni and Cu in superficial lake sediments is marked also around o f the world's largest copper-nickel smelters - Norilsk in Siberia and Sudbury in Canada. Concentration o f Ni in superficial lake sediments around o f Norilsk plants are sharply reduced from 2142 up to 37 ^g/g (Blais et al., 1998), excess over background con­ tents make from 0.71 up to 22.6, and last value is marked in lake in 17 km from smelters. The same decrease is observed and around o f Sudbury where influence o f emissions o f copper- nickel plants on concentration Ni and Cu in superficial lake sediments is limited 30 - 40 km (Bradley, Morris, 1986; Palmer et al., 1989; Semkin, Kramer, 1976; Nriagu et al., 1982), while impact zone around o f Norilsk smelters is distributed up to 60 km (Blais et al., 1998). Spatial distribution o f Ni and Cu has northeast-southwest elliptic character with the center in Sudbury (Controy et al., 1975; Semkin, Kramer, 1976). The similar trend for Ni and Cu is marked for atmospheric precipitation and for hydrochemistry o f lakes, including water pH (Controy et al., 1975). Therefore, distribution o f Ni and Cu in superficial lake sediments o f Kola Peninsula and Sudbury completely coincides, as well as distribution o f these elements in an atmospheric pre­ cipitation (Kruchkov, Makarova, 1989) and water o f lakes (Moissenko et al., 1996). In Figure 7 also it is visible, that Pechenganickel Company, besides Ni and Cu, is also a source o f emissions o f other heavy metals - Zn, Co, Cd, Hg, and also As, concentrations o f which in the top layers o f sediments o f the Russian lakes o f the watershed o f the river Paz are reduced when moving away from pollution sources. Except for heavy metals and As, the smelters are as well a source o f emission in atmosphere in increased concentrations o f Cr, Fe, Na, Mg, Al (Fig. 7), since Ni-Cu ores and gob rocks in the increased concentrations contain all abovementioned elements. 3.4. The Factor and Degree of Contamination of Lake Sediments Maximum values o f contamination factor (Cf) for heavy metals (Ni, Cu, Zn, Co, Cd, Pb and Hg) and As were noticed for sediments o f Kuetsjarvi and lakes (LN-2, LN-3, LN-4, Palojarvi, Zapoljarny, Kirikovanjarvi, Pikku-Heynjarvi, Peschanoe, Shuonijaur) at distances up to 20 km from the “Pechenganickel” smelters (Table5). These lakes have very high Cf values for Ni, Cu, Cd, Pb, Hg and As according to the Hakanson (1980) classification. In the lakes (Kochejaur, Virtuovoshjaur, Alla-Akkajarvi), situated on the greater distance from the “Pechenganickel” smelters, the main polluting elements are Cd, Pb, Hg and As which on o f classification Hakan­ son have contamination factors from very high up to moderate (Table 6). Kuetsjarvi and lakes at distances up to 20 km (including Alla-Akkajarvi and Virtuovoschjaur lakes - 45 and 90 km, respectively) from the “Pechenganickel” smelters have maximum values 21