Chemical Composition of Water and Sediments of Tundra Lakes as the Background Area of the North of Murmansk Region (Arctic)

Abstract

The article presents new data on the chemical composition of water and recent sediments of six small lakes located in the Natural Park “Rybachy and Sredny Peninsulas” (the Russian Arctic). The main hydrochemistry parameters, including pH, conductivity, alkalinity, the content of main ions (Ca, Mg, Na, K, HCO3, SO4, Cl), and trace elements were measured in the water of selected lakes. Furthermore, concentrations of heavy metals (Pb, Sb, Cd, Ni, Cu, and others) were estimated in the upper layers of recent sediments of the lakes. The integral index PLI, designed for geochemicalstudies of sediments, was calculated to determine the level of chemical pollution of the lakes. The results showed that, in general, the studied parameters did not exceed the background level. There was no serious impact of the Kola Mining and Metallurgical Company, which is situated several dozen kilometers to the west from the lakes. It was revealed that the studied lakes were less contaminated with heavy metals in comparison with the previously researched lakes of urban territories of the Russian Arctic zone. However, the analysis of distribution of concentrations of Ni, Cu, Pb revealed the influence of long-range atmospheric pollution on lakes of the Natural Park “Rybachy and Sredny Peninsulas”. The fractional analysis of the metals in the sediments showed that the elements were mainly associated with stable compounds of the sediments and, thus, there was an only potential environmental risk for the biota of the studied lakes.