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.

particularly, lakes located close to the smelters o f the Pechenganickel Company - Lampi 222, Aitojarvi 2, Mellalompolo, Nitsijarvi, Inari Vasikanselka, Kantojarvi, Suovaselkajarvi, Sieram- jarvi, Pahtajarvi, Kivijarvi. Decreasing contents o f Ni in the upper sediment layers relatively to background values were noticed in Nammijarvi (Fig. 14). The vertical distribution of concentrations o f Cd and Pb in the sediment cores o f the Finnish lakes o f the Inari Lake Paz River basin show usually subsurface maximum on the depth 3 - 12 cm (Fig. 10 - 20). Two reasons are again responsible for this fact - decreasing atmospheric emissions o f anthropogenic sources (the decreased use o f Pb in gasoline) and influences o f acidification processes on the behaviour o f these mobile heavy metals. Chalcophile non-metal As shows usually surface and subsurface (2 - 10 cm) maximum concen­ trations in sediment cores o f the investigated Finnish lakes (Fig. 10 - 20). Arsenic (as well as other chalcophile elements) is highly toxic element and is very dangerous for the environment and people. As (and Hg, Cd, Pb) can migrate in air and aquatic media over large distances ow­ ing to their geochemical properties, e.g., relatively low melting temperature, high ability to form organometallic compounds, etc. During the latest decades, these elements have become the main global contaminating agents (Dauvalter, 2006). Decreased concentrations o f Al from lower to higher layers o f sediment cores o f the investi­ gated Finnish lakes may indicate the demonstration o f acidification processes (Dauvalter, 1997). All investigated Finnish lakes (with exception o f Inari Vasikanselka) show this decreasing o f Al concentrations towards sediment surface (Fig. 10 - 20), that may suggest beginning or develop­ ment o f acidification processes in these lakes. 5.3. Distribution of Heavy Metals in the Top Layers of Lake Sediments Metals, emitted to the atmosphere by smelters o f the Pechenganickel Compony in elevated con­ centrations (Cu, Ni, Co, Zn), show the highest contents in the top layers o f lake sediments close to the smelters that is confirmed by relatively high values o f the correlation coefficient in re­ gression equation (Fig. 21). Particularly this fact was noticed for Ni and Cu, distribution o f them has a view o f power function with very high values o f correlation coefficient. Maximal concen­ trations o f Ni, Cu and Zn were fixed in the top layers o f the sediment Mellalompolo, situated in 54 km from the smelters o f the Pechenganickel Company (Table 12), Co - in sediments o f Kan­ tojarvi - 78 km. The highest concentrations o f Cd and Pb were found in the top layer o f sedi­ ment core o f the largest lake o f the Finland Lapland - Inari; As - in the Sieramjarvi. Other ele­ ments Cd, Pb, As) have no reliable values o f the correlation coefficient (with distance increasing from the smelters (Fig. 21). This fact suggests about insignificant influence o f the smelter emis­ sion on concentrations o f these latter fore elements in sediment o f the investigated Finnish lake o f the Inari Lake - Paz River system. Increased concentrations o f Cd, Pb and As were recorded in the surface or subsurface layers o f the sediments in almost all investigated Finnish lakes o f the Inari Lake - Paz River watershed (Table 11). This indicates that these elements now re­ ceived the status of global pollutants. The Pb contents o f the environment are controlled by tet­ raethyl lead, an antiknock component o f gasoline. Another, rather small (several t/year) source of Pb (as well as Cd and As) pollution is the emissions o f melting furnaces, and also by trans­ boundary transport from as Scandinavian countries, as well as from Central Europe. 5.4. The Factor and Degree of Contamination of Lake Sediments Almost all investigated Finnish lakes o f the Inari Lake - Paz River watershed have very high values o f contamination factor (Cf) for more polluted heavy metals - Pb, considerable and mod­ erate values for Cd and As (Table 12). Considerable contamination by Ni was found only in up- 34