SANITARY EVALUATION OF SOIL COVER OF THE SAINT PETERSBURG STATE UNIVERSITY CAMPUS

Abstract

The aim of the study. To assess the contamination of the soil cover of the St. Petersburg State University campus. To accomplish the goal, tasks are set concerning the determination of the content of heavy metals in selected soil samples and their comparison with the available regulatory documents, estimates of the basal respiration of the soil and humus content. Materials and methods. In 2016-2017 there were executed investigations on the study of the state of soils on the campus of the St. Petersburg State University. Studies were carried out in the Vasileostrovsky and Petrodvorets districts of the city of St. Petersburg. 39 soil samples were taken from a depth of 0-30 cm. The content values of heavy metals (Pb, As, Zn, Cu, Ni, Co, Cr, V) and arsenic (As) were determined and compared with the available Maximum Allowable Concentrations (MAC) adopted in Russia. The biological activity of soil samples and the humus content were also investigated. Results. Analysis of heavy metals in soils and their comparison with available MPCs are given for soil samples from two campus areas of the St. Petersburg State University. Discussion. The investigation of soil samples of two different territories made it possible to identify the features of soil contamination with heavy metals and arsenic and to compare these areas with each other. The predominant majority of samples are characterized by exceeding the MAC limit for arsenic, zinc, nickel, chromium. To clarify the estimation of the levels of total contamination of soils, Zc, also Zst(g) were used in these calculations. Zst(g) takes into account the geometric mean of the concentration coefficients of elements and the toxicity of heavy elements Conclusion. Samples of soils selected in the Vasileostrovsky district are characterized by a higher pollution category in terms of Zc and Zst(g) than the soils of the Petrodvorets district. For all soil samples, the value of soil pollution index is more than 1, which characterizes the soils as contaminated. The indices of the microbiological activity are similar in the soils of the two investigated areas; the humus content is characterized as an average also in both campus areas.