Ecological assessment of the contamination level of soils and substrates surface layer of the North-West Altai mining landscapes with priority heavy metals
S. V. Baboshkina, A. V. Puzanov, T. A. Rozhdestvenskaya, I. A. Troshkova
Institute for Water and Environmental Problems, Siberian Branch of the Russian Academy of Sciences, Barnaul, Russia
Keywords: heavy metals, tailings, soil pollution, pollution indices, mining landscapes, reclamation
Abstract
The main ore and associated elements contamination level of the tailings dumps substrates of the Altai Mining and Processing Plant (AMPP), soils of their reclaimed surfaces and soils located in the zone of technogenic impact is studied. Heavy metals in the upper horizons of soils and grounds were determined using atomic absorption spectrometry. Single pollution indices and complex soil contamination indices of the territory are calculated. A comparison with 18-year-old data is made. It is found that the metal content in the upper layers of dumps in areas where at least single plant species grow and in the soils of adjacent landscapes vary widely: Zn - from 164 to 1287 mg/kg, Cd - from 0.50 to 6.97 mg/kg, Cu - from 67 to 1516 mg/kg, Pb - from 69 to 1827 mg/kg and significantly exceed the background values. The highest Zn and Cd content is detected in the substrate on the new dump surface of the near the spontaneous dump of household waste. The highest Cu and Pb concentrations, tens of times exceeding the background contents in the chernozems of the Northwestern Altai, are found in meadow soils of landscapes geochemically associated with the dumps tailings, containing toxic material washed up from the eroded sides of the tailings ponds. Their upper horizons are characterized by extremely hazardous (Z c = 165) and high (Z c = 79) levels of total metal contamination. High metal contamination (especially Cd and Pb) is established for the upper horizon of ordinary chernozem at a distance of 2 km from the dumps to the north, in the direction of the southern winds prevailing in the region, which is explained by additional airborne dust saturated with heavy metals brought to this territory from the unreclaimed surfaces of the AMPP dumps. The lowest single pollution indexes of soil and substrate and the smallest proportion of samples with their high values are established for zinc. Pollution of soils and substrates of tailings with lead and copper, judging by single pollution indexes, is the most significant. Compared to 2005, a decrease in the concentration of heavy metals in the substrates of dumps of those areas where plants grow is noted.
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