Accumulation of heavy metals and arsenic in plants in the vicinity of the Chadan coal deposit (Republic of Tuva)

The content of copper, zinc, lead, cadmium and cobalt in plant samples from the vicinity of the Severny dump of the Chadansky coal mine in the Republic of Tuva was studied. Heavy metals in plant samples were determined by the Quantum-2mt atomic absorption spectrophotometer. Due to the extra-arid conditions, the studied area belongs to the zone of risky agriculture and there is developed cattle breeding. It was revealed that vegetation typical for steppe communities is developed on the territory of the Chadan coal deposit, represented by wormwood-cereal, grass-grass-wormwood, grass-wormwood-kovyl, wormwood-grass-grass steppes. In the dumps, deposits of different ages with small-scale, wormwood-cereal communities with typically steppe species are developed. For lead, cadmium and cobalt, the concentrations in vegetation samples from the CER and SWZ sites adjacent to the dump turned out to be close to their background values. The Cu content in the vegetation of the dump sites exceeds the natural content by 2–2,2 times, Zn – 2–2,7 times, Pb – 1,5 times. However, a comparison of the content of Cu, Cd, Zn, Pb, Co in vegetation from 2 sites of the Severny dump and the background territory with MDU for plant feeds showed that their concentrations in the studied samples are much lower than the maximum permissible level.