Chemical composition of lake sediments along a pollution gradient in a Subarctic watercourse / Dauvalter V., Kashulin N., Sandimiriv S. [et al.] // Journal of Environmental Science and Health. Part A. - 2011. - Vol. 46. - P. 1020-1033.

Downloaded by [Vladimir Dauvalter] at 21:54 24 November 2013 Lake sediment composition in Subarctic watercourse 1025 Fig. 2. Vertical distribution of concentration of heavy metals (^g /g, dry weight) in sediment cores from Lake Inari. various stations o f the lake (Fig. 4). A t station 7, closest to the mou th o f River Kolosjoki, background values o f con ­ centrations o f heavy metals could no t be reached, and data from this station were therefore no t considered in the cal­ culation o f average background contents. This is connected to the large input o f suspended mineral substances in the sewage from the Company and their sedimentation in the nearest water area in the lake. This assumption is also sup­ ported by the low contents o f organic material in sediments at station 7; no more than 2% up to depth o f 3 cm, and then towards the sediment surface the LOI value only increased up to 12%. Therefore, the sedimentation rate in this area o f the lake is exceedingly high. A t stations 6 (Gulf Stream) and 8 (Salmijarvi) the increases o f the contents o f Ni, Cu, Co and Zn were fixed above sediment depths o f 12 cm, and at station 9 (White Stone) above 8 cm. Hence, considering the 70-year history o f pollution o f the lake by wastewaters o f