Heavy metal pollution of forest soils by atmospheric emissions of Pechenganikel smelter

The continuous impact of Pechenganikel smelter atmospheric emissions has resulted in soil pollution with nickel (Ni) and copper (Cu) over an area more than 3000 km(2) in the northwest of the Kola Peninsula. Near the enterprise, the Litter of podzols was found to have accumulated 2000-2600 mg/kg of metals, whereas their exchangeable forms varied from 1000 to 1400 mg/kg. This is 17-23% of soil cation exchange capacity. Meanwhile, the content of Ni and Cu was by almost two orders of magnitude lower in the background soils. An exponential formula can be applied to describe the relationship between soil concentrations of heavy metals and the distance from the emission source. Current Ni and Cu accumulation in the soil root-inhabited zone seem to be toxic for forest vegetation within a range of 25-35 km from the smelter.