Sandimirov S. Screening studies of POP levels in bottom sediments from selected lakes in the Paz watercourse / In State of the environment in the Norwegian, Finnish and Russian border area. The Finnish Environment. Finland, Jyvaskyla: Kopijyva Oy. 2007, №6.

Screening studies of PO P levels in bottom sediments from selected lakes in the Paz watercourse 7. Conclusions/Recommendations This screening study o f POPs in bottom sediments carried out in the Paz watercourse reveals higher levels o f all environmental contaminants studied in the bottom sediments from Lake Kuetsjarvi. There was a clear trend that the contamination levels decreased with increasing distance from the smelters. Trace elements All trace element levels decreased with increasing distance from the smelters. According to SFT environmental classification (Andersen et al., 1997) o f freshwater sediments, Lake Kuetsjarvi sediments can be considered as “strongly contaminated” with Cu and Ni, “markedly contaminated” with Hg, and “moderately contaminated” with Cd. The sediments from the stations downstream Lake Kuetsjarvi can be classified as “markedly contaminated” with Ni and Cu, “moderately contaminated” with Cd, and Hg levels were as low as “background” levels (Andersen et al., 1997). PAHs High levels o f PAHs were measured in sediments from the Paz watercourse compared to other studies in Northern Norway. PAH levels in the sediments decreased with increasing distance from the smelters. Sediments from Lake Kuetsjarvi are classified as “markedly contaminated” . POPs Among the chlorinated pesticides analysed, the highest levels were found for DDT with a tendency o f decreasing levels with increasing distance from the smelter. The levels o f IDDT detected in this study are high compared to other studies from the Arctic and from Norway. The highest PCB levels were detected in the bottom sediments from Lake Kuetsjarvi, and there was a tendency o f decreasing PCB levels (including planar and mono-ortho substituted PCB congeners) with increasing distance from the smelter. The levels o f PCB in Paz watercourse were high compared to levels measured in surface sediments from other lakes in Northern Norway. The highest PBDE levels were found in sediment samples from Lake Inari and from Lake Kuetsjarvi. However, differences in PBDE compositions found in the compared areas suggesting different source o f PBDE contamination. The levels in Lake Stuorajavri and Paz watercourse are lower compared to studies from the Great lakes in Canada and from Ellasj 0 en on Bj 0 rn 0 ya, Svalbard. The highest levels o f PCDD/PCDFs were found in the bottom sediments from Lake Kuetsjarvi. There was no significant difference in levels o f PCDD/PCDFs between the lakes and no correlation between distance from the smelter and levels o f PCDD/PCDFs. The PAHs contribute 83-99% to the total toxic equivalent (TEQPAH) in all sediment samples and greatly exceed sum o f TEQPCDD/F and TEQPCB, Thus, the results from this screening study indicate that smelter can be considered as a potential source o f POPs for the freshwater environment. However, more detailed survey is needed. Rapport APN- 514.3665.01 27