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.

Fig. 1. Distribution o f Cd (contamination degree) values in Russian, Norwegian and Finnish lakes depending on the distance from the smelters o f the “Pechenganickel” Company. Thus, the analysis o f territorial distribution o f heavy metals in sediments o f researched lakes has shown that areas o f high values o f concentration closely correlated elements Ni, Cu, Co and Hg coincide and are limited to 50-km local zone around o f the metallurgical enterprises. The in crease in contents o f Pb is traced from the east to the west that reflects the general flux o f pollut­ ing substances from the center o f Europe on northeast to Arctic regions. Alongside with Pb, Cd, As and Hg are also the global pollutants. The maximum Ni and Cu concentrations, which ex­ ceed their background values by a factor o f 10 to 130, were recorded within 10 km o f the “Pechenganickel” Company. Within 10 to 30 km o f the source o f contamination, these concen­ trations are only 3-7 times as high as their background values. Concentrations of Co were 4-10 times greater than their background values within 15 km o f the contamination source and up to 3 times greater in other lakes on the distance more than 15 km, which is indicative o f the effect o f emissions from melting furnaces. Lakes Kuetsjarvi, LN-2, LN-3, LN-4 receive the basic part o f emissions o f the “Pechenganickel” Company and have maximal concentration o f Ni, Cu, Co, Zn, Cd, Hg and As in superficial layers o f sediments. High concentrations o f Cd, Pb, Hg and As are marked as well in some lakes removed from the “Pechenganickel” Company that is con­ nected to global pollution by these elements last decades. The significant part o f heavy metals entering in a lake in composition o f waste water and pre­ cipitated on watershed territory are connected and buried in sediments. Therefore their contents in sediments characterize total loading, allow to determine sources o f pollution and to establish historical trends. In the majority o f water systems, the element concentrations in the top several centimetres o f sediments are much higher, than element concentrations in water column. The close connection of microelements (for example, heavy metals) with seston and sediments means, that distribution, transport and availability o f these elements cannot be correctly appreci­ ated extremely by means o f only collection o f water samples and analysis o f a soluble phase. Therefore, the investigations o f chemical composition o f lake sediments have shown the effi­ ciency for estimation o f influence o f the "Pechenganickel" Company on water ecosystems, and these researches are necessary for continuing. 9