Assessment of contamination of recent sediments of a large reservoir in the catchment of Arctic Ocean, Northern Europe

Abstract

The chemical composition of recent sediments of the Vygozero Reservoir, located in the North of Europe, in the Republic of Karelia (the catchment of Arctic Ocean), has been analysed. The level of enrichment and depletion of chemical elements, including trace elements, of the sediments relative to the Clarke numbers for the continental crust has been estimated. Elevated levels of Sb, Pb, Sn, Bi, W, Cu, and other elements in the sediments of the Vygozero Reservoir have been revealed in comparison with the concentrations of these elements in the background layers of the reservoir's sediments and their content in the sediments of small lakes of the south of the Republic of Karelia. It has been established that the main factor in the accumulation of these metals in the lake is the long-distance transport of pollutants from local anthropogenic sources located in Karelia, and from sources in neighbouring regions. In the vicinity of the town of Segezha, elevated V and Ni contents were revealed in the cores of the studied sediments, which indicates the impact on the reservoir of emissions from the fuel-oil thermal power plant. Based on the calculation of the geoaccumulation index (Igeo) and pollution load index (PLI), the level of pollution of the Vygozero Reservoir in the study areas was estimated. It was found that the northern part of the waterbody, where the settlements Segezha and Nadvoitsy and industrial enterprises associated with these towns are located, are subject to the greatest load.

Keywords

• arctic
• vygozero reservoir
• freshwater sediments
• trace elements
• long-range transport of pollutants