The Ecotoxicological State of Urban Soils of the Saint Petersburg City

The intensive urbanization of environments and technogenic activity has an effect on the accumulation of trace elements in the soil and increases the toxicological risk to the terrestrial ecosystems and human health. We studied the distribution of seven priority trace elements (As, Cd, Pb, Zn, Ni, Cu, Hg) in the soil of the northernmost city in the world with a population more than 1 million people. To identify the spatial distribution of the trace elements, the GIS technologies have been used. Based on the data obtained, interactive maps of soil pollutionSoil pollution were made. It was found that the content of the studied trace elements exceeds the background values for the region and has a “hot spots” character. Four of the studied elements (Cu, Zn, Pb, As) on average exceed values of maximum permissible concentrations in soil. The highest levels of pollution are concentrated in the central part of the city, and this is associated with the location of major transport roads, as well as railway stations located in the city center. Accumulation of trace elements occurs in bottom sediments in the rivers of St. Petersburg, and this is associated with lateral runoff of dust from roads and adjacent areas. The level of contamination of bottom sediments varied with the degree of proximity to major transportation hubs. According to the analysis of the index, Zc was found that 57.35% of all the points studied have extremely high levels of pollution. The data obtained indicates that the accumulation of extremely high concentrations of trace elements can lead to a deterioration in the quality of life of the population.