Geochemical features of lakes located in an urbanised area of the Russian Arctic (Murmansk region)

Murmansk is a significant industrial region with developed infrastructure located in the Russian Arctic. Small lakes of the city are actively used by the population for economic purposes. Therefore, comprehensive geochemical research of lake systems is one of the crucial aspects of environmental monitoring. We analyzed trace metal content and petroleum hydrocarbons content in sediments of Murmansk five lakes. Fieldwork was conducted in 2019. Sediment cores were divided into 5-cm layers. For analysis, we used the ICP-MS and FTIR-methods. The research results showed that Lake Ledovoe is one of the most polluted urban lakes in Murmansk. Its sediment is highly enriched in petroleum hydrocarbons and trace metals. Potential bioavailability of some toxic metals increases in the most recent sediment layers. Therefore, there is a high risk of secondary pollution of the lake and migration of pollutants along the food chains of the aquatic ecosystem.