Accumulation of heavy metals and arsenic in Cladonia rangiferina in the European north of Russia
V.V. Elsakov, I.G. Zakhozhiy, A.S. Shuyskiy
Section: Chemistry of natural environments and objects
Lichens can accumulate different pollutants and serve as a source of that element’s migration in trophic chains. The content of heavy metals (HM) (Cu, Pb, Cd, Zn, Ni, Co, Mn, Fe, Hg) and As was estimated in samples of Cladonia rangiferina L. taken in the European North of Russia. Sampling areas included the territory of the western part of the Kola Peninsula, Kanin Peninsula, Timan, Malozemelskaya, Bolshezemelskaya and Yamal Peninsula tundras and the taiga zone of the Komi Republic. The content of HM and As in lichens thalli for native territories and diapasons of their variability in the zone of influence of industrial impacts facilities are established. The average content of main toxic elements in the lichen from the intact territories of the European North-East was in the range of 0.5–1.8 mg/kg for Pb; 1.0–2.7 mg/kg for Ni; 0.1–0.7 mg/kg for Co; 0.1–0.5 mg/kg for As and about 0.1 mg/kg for Cd. The content of Hg in lichen samples in the study area varied from 9.0 to 51.0 μg/kg. The distance from industrial pollutant emission sources (mainly ferrous and non-ferrous metallurgy) and proximity to technological sites and mineral dumping of engineering infrastructure were the most significant factors determining the level of TM accumulation. The average content of HM and As in the thalli from the impact zones of the copper-nickel processing plant (Kola Peninsula) was: Ni – 65.2 mg/kg; Cu – 44.4 mg/kg; Co – 2.3 mg/kg; As – 0.7 mg/kg. This is 1.4 – 22 times higher than the sanitary standards level given in the regulatory documents for grass feed of farm animals. Local areas with an increased concentration of several HMs were identified in the communities of the tundra and forest zones of the European Northeast. Significant deviations of the HM content in thalli were related with dust mineral particles deposits (on the surface and the intercellular space of thalli) of coming from emissions of industrial facilities and transport infrastructure. Elemental analysis of dust particles showed that Fe, Al, and Si compounds predominate in their composition. Some mineral particles are characterized by a relatively high content of Ca, Ti, and Ni.
Keywords: lichens, Cladonia rangiferina, European north of Russia, heavy metals