HYGIENIC ASSESSMENT OF THE CONTENT OF CHEMICALS IN THE SOIL OF MINING AREAS OF THE TRANS-BAIKAL REGION

Abstract

Introduction. Intensive exploration and processing of mineral raw materials in the Trans-Baikal territory has caused the accumulation of considerable amount of industrial mining waste with high content of chemical elements of different classes of hazard. Currently 33 tailings storage facilities (TSF) accumulating approximately 3 milliard tons of different industrial waste are located in the territory of the region. The aim of the research is the hygienic assessment of soil contamination in the residential areas adjacent to TSFs. Material and methods. Atomic absorption spectrophotometry method was used for the determination of heavy metals. The study presents the results of analyses of 444 samples of gross content of lead, zinc, copper, mercury, arsenic, and cadmium in the soil of Khapcheranga, Sherlovaya Gora, Kadaya, Vershino-Darasunsky, and Vershino-Shakhtaminsky mining villages throughout the duration of 2012 - 2015. Results. During the period of the study the total value of soil contamination with Zc calculated by the median concentrations in Khapcheranga Village amounted to 4.7 6.9, in Vershino-Shakhtaminaky - to 6.7 8.8, which corresponds to the «allowable» level of the contamination. Zc calculation by maximum concentrations has shown the soil to be referred to the category from “moderately dangerous” to “extremely dangerous”; this value in Khapcheranga Village amounted to 48.7 - 235.3, in Vershino-Shakhtaminsky Village - to 23.76 - 164.8. Discussion. In the residential areas the allowable degree of soil contamination was determined to be predominantly observed; Khapcheranga and Vershino-Shakhtaminsky villages are the exceptions. The results of the assessment give the evidence of tge increased lead, cadmium and arsenic content throughout the entire area of the villages, while the highest levels of accumulated toxic substances are registered in the areas located near the TSF Conclusion. Thus, several zones of natural and anthropogenous contamination with increased concentrations of heavy metals and arsenic have been formed in the Trans-Baikal Territory. This dictates the need to study the influence of geochemical anomalies on the health of population.