No abstract

Introduction. The article presents the results of the study of the quality of soil cover in the cities located in the mountainous areas of the Trans-Urals in the Republic of Bashkortostan. The object of the study was the soil of lands for various purposes in cities of Uchaly, Sibay, and Baymak. In the study of soils of industrial zones, there were taken samples adjacent to the dumps and tailing dumps of mining production at a distance of up to 500 m. In the recreational zone there were included the territories of parks, in the residential zone - all micro-districts where the population of the city resides. There were investigated territories of collective gardens located near sources of pollution. Material and methods. The gross content of heavy metals and their mobile forms extracted from the soil of ammonium acetate buffer at pH 4.8 were determined by atomic absorption. Generally accepted ecological values of maximum permissible concentrations (MPC) and regional geochemical background (RGF) were used to estimate the degree of soil pollution. To assess the degree of soil pollution, the total ZC index was calculated using the formula proposed by Yu. E. Saet. Results. As a result of the study, in all studied samples of the soil excess of MPC on gross forms on the content of Cu, Zn, in some cases, Mn, Cd, Co was revealed. Calculations of the General norm of Zc showed urban soil lands of all types of purpose by gross content to belong to the category of permissible pollution. The level of soil contamination with heavy metals in all the studied cities is higher in soils for industrial purposes. Increased level of mobile forms of Cu, Zn, Mn, Cd was revealed in all studied soil samples. The soils of the residential zone of Baymak according to the content of mobile forms belong to the moderately dangerous category of pollution, the rest of the studied soils had an acceptable category of pollution. In the cities of Sibay and Uchaly, the territories adjacent to the quarry dumps belong to a particularly dangerous category of pollution. Conclusion. The level of soil contamination with heavy metals in urban areas of the Mountainous region of the Republic of Bashkortostan is determined by the type of destination of urban land. The most polluted are the soils of industrial zones located in close proximity to mining enterprises. The ecological danger of pollution is that in this zone there is a part of residential neighborhoods with knots, as well as garden cooperatives, where potatoes, vegetables and fruit and berry crops are grown.

Dumps of quarries for the extraction of copper pyrite in Urals region of the Bashkortostan Republic are the problem object, which represents a main technogenic source of environmental pollution. Soils of Sibaisky quarry dumps are characterized by the elevated content of heavy metals relatively to maximum permissible concentrations and regional geochemical background. In sanitary hygienic evaluation of the pollution by studied technosols according to the total pollution index (Zc) it was revealed that according to the content of total forms studied technosols are referred to moderately hazard, while in regards of the same index concerning the content of the mobile forms technosols are referred to the category of hazardous. In this regard, in plant products grown in the area adjacent to the dumps, there was revealed an excess on cadmium. The biological activity of soils is very low, due to the low microbial community development. Soil formation in the dumps is almost not expressed, appearing in the formation of low-thick underdeveloped humus horizon with a little diversity of species and projective cover. Sanitary-hygienic situation in conditions in the quarry dump area is unfavorable, that does not allow newly formed soils to carry out environmental functions effectively

The research studies the content of heavy metals (HM) in soils of residential zones of Sibay - the mining industry center of the South-East of the Republic of Bashkortostan. It is shown that in soils under herbaceous vegetation there is an increased content of a number of HMS, such as copper, zinc and cadmium. At the same time the areas located under the crown of Betula pendula Roth. are less contaminated with HM compared to open areas. Reduced content of a number of metals (iron, cadmium, cobalt and mobile forms of Nickel) in soils under the crown of the Roth confirms the barrier role of woody plants that protect the soil from airborne toxicants. The study showed the prospects of using a birch as a type of accumulator-phytoremediant in the greening of the mining region urban areas of the Republic of Bashkortostan. Studies of TM content in organs and tissues have shown that representatives of the species growing in Sibay can accumulate a significant amount of phytotoxicants, especially zinc, the content of which ranged 1041-1855 mg/kg. One of the sources of the increased TM content in the leaves and the bark of trees is dust. The paper presents a comparative study of the dustiness of birch leaves growing in the Central part of the city with heavy traffic and in the vicinity of the Sibay quarry, developing a Deposit of copper-zinc ore. The amount of dust on the leaves collected near the dumps of the Sibay quarry was 3,53 0,64 g/m, which is less than in the Central part of the city, where this figure reached 41,04 10,38 g/m. Obviously, this is due to the fact that the dumps of the Sibay quarry are located in an open and intensively ventilated area, which explains the strong dispersion of dust. At the same time dust particles near the quarry dumps are much more contaminated with manganese, cobalt and cadmium than in the Central part of the city.

No abstract