Accumulation of heavy metals in the soil – plant system in areas with the developed mining industry

Introduction. The proximity of mining enterprises to settlements contributes to the pollution of the soil cover with heavy metals. Crops grown in garden plots accumulate chemical elements and are an intermediate link in the “soil – plant – human” chain.

Purpose of the work. Аssessment of the level of anthropogenic load on the territory adjacent to the mining enterprise, based on the study of the translocation of metals in the soil – plant system.

Materials and methods. For the purpose of hygienic assessment of the chemical composition of the soil and vegetable products grown on it, the content of 7 microelements was determined by atomic absorption spectrometry. With the help of the coefficient of concentration of a chemical substance (K_c) and the total indicator of pollution (Z_c), the level of chemical contamination of soils was determined. Using the total coefficient of anthropogenic load (K_a.n. = ∑C_i/PDU_i), the territory was ranked according to the contamination of vegetables with toxic elements. The rate of accumulation of metals by vegetable crops was assessed by the coefficient of biological absorption (A_x) and the index of biochemical activity of the species (BAS).

Results. The soil cover in the district is contaminated with a complex of metals, the content of gross forms of which exceeds the MPC by up to 1.9 times, mobile – up to 4.6 times. At a distance of up to 5 km around the mining enterprise, the maximum indicators of the total soil pollution (Zс = 44–65) have been established. Lead and zinc are elements of “biological accumulation” for all types of studied vegetable products grown in the zone of influence of the mining enterprise; cadmium is additionally concentrated in beets and carrots, and nickel in carrots. In vegetable samples, exceeding the permissible levels of cadmium and lead was noted. The most significant accumulation of heavy metals was found in the southern, southeastern, northern and northwestern directions from emissions.

Conclusion. To eliminate the toxic effects of heavy metals in vegetables produced in the zone of influence of mining enterprises, it is recommended to include additional monitoring of nickel and zinc content in the social and hygienic monitoring system.

Contribution:
Allayarova G.R. — the concept and design of the study, statistical processing, writing the text and editing;
Larionova T.K. — the concept and design of the study, writing the text and editing;
Daukаev R.A. — the concept and design of the study;
Afonkina S.R., Zelenkovskaya E.E. — collection of literature data;
Aukhadieva E.A. — statistical processing;
Kurilov M.V., Musabirov D.E., Fazlieva A.S. — collection and processing of material. All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Conflict of interest. The authors declare no conflict of interest.

Acknowledgement. The work was carried out within the framework of the sectoral research program of the Federal Service for Supervision in Protection of the Rights of Consumer and Man Wellbeing (Rospotrebnadzor) for 2021–2025. “Scientific substantiation of the national system for ensuring sanitary and epidemiological well-being, health risk management and improving the quality of life of the population of Russia”, item 4.1.3 “Improving the monitoring of the quality and safety of food products based on the toxic and hygienic assessment of priority contaminants.”

Received: July 07, 2021 / Accepted: September 28, 2021 / Published: November 30, 2021