Soil pollution status of urban soils in St. Petersburg city, North-west of Russia

The intensive urbanisation of terrestrial environments and industrial activity have an effect on the accumulation of risky metals in the soil and increase the toxicological risk to the terrestrial ecosystems and human health. Ninety-six topsoil samples from of St. Petersburg Russia as the source of the content of seven key risky metals (As, Cd, Pb, Zn, Ni, Cu, Hg) and polycyclic aromatic hydrocarbons (PAHs) have been investigated. To identify the spatial distribution of the risky metals and PAHs, GIS technologies have been used. Based on the data obtained, interactive maps of urban soil pollution were made. The spatial distribution of seven metals and their metalloids greatly varied from the local anthropic inputs. The results indicate that the highest concentrations of copper, mercury and lead were found in the urban environment. The most polluted areas were located in the city centre and the areas adjacent to industrial zones. The topsoil in this area represents an environmental pollution risk with regards to the elements Cu > Pb > As > Zn > Ni > Hg > Cd. The contents of the risk-type elements in the industrial area were higher than those in other land-use types in the north of city, indicating a considerable risk of metal migration and accumulation to the Neva River, the Gulf of Finland and the groundwater.