The relevance. The increase in concentrations of metals and metalloids in terrestrial ecosystems as a result of the activities of the mining and metallurgical industries is a serious problem for the environment – it leads to the accumulation of elements in soils, wild and agricultural plants and accompanies the pollution of food chains. 
The main aim of this study is to determine and evaluate the phytoremediation ability of oats Avena sativa to accumulate metals and metalloids from tailings with different physicochemical parameters. 
Objects of the study are the material of tailings (Dyukov Log, Talmovskiy Sands, Khovu-Aksy) and waste heaps (Ursk, Beloklyuch, Berikul). 
Methods. Root and shoot samples were analyzed for the content of a wide range of elements by ICP-MS on a NexION 300D mass spectrometer (PerkinElmer, USA) (PNL «Voda» GGC ISHPR TPU). The selection of solid samples was carried out in accordance with generally accepted methods. The solid samples were analyzed for the content of oxides of the silicate group by XRF on an X-ray fluorescence spectrometer ARL-9900-XP (Thermo Electron Corporation) at the Laboratory of X-ray Spectral Analysis Methods of the Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences; analysis of trace elements concentration was carried out by ICP-MS on an ELAN-9000 DRC-e instrument, Perkin Elmer, USA (HAC Plasma). 
Results. Experiments were carried out with the germination of seeds of a monocotyledonous plant – oats (Avena sativa) on the substrates of tailings located in Western Siberia and the Republic of Tuva. This plant belongs to the list of hosted tests of phytotoxicity and green manure, but its development on the presented technogenic objects has not been studied before. It is shown for the first time that on average, the concentration of metals and metalloids in oat seedlings exceeded the concentration of these elements in all samples compared to the control. The effect of acidity/alkalinity of tailings on the extraction of elements by plants was evaluated. It was shown that oat seeds did not germinate in samples with the addition of a substance that gives an acidic environment (pH<2) or high mineralization of the liquid phase. In the tailings with a pH range of 2–5 (acidic and slightly acidic environments), the seeds germinated, but the mass of seedlings was significantly less than in the material with a neutral-subalkaline environment (pH 6–8). Germination is not affected by the ratio of aluminosilicates minerals/pyrite, the main is the presence of carbonates and the degree of oxidation. In an acidic medium, at relatively high concentrations of metals (Fe, Mn, Cu, Zn) in the liquid phase, their proportion absorbed by plants was significantly lower than in a neutral subalkaline medium. The acidity of the environment did not affect the accumulation of most elements, their accumulation in the underground and aboveground parts depended on the content of their soluble forms. For arsenic and Bi, there is an increase in their content in oat seedlings with an increase in the pH of the aqueous extract. The influence of high concentrations of elements in the plant nutrition environment is ambiguous. For example, for a substance with a high content of mobile forms of Cd, Pb, Zn, the biomass and root length of oat seedlings were higher than for oats grown on another substance. The translocation index indicates that the accumulation of most metals and metalloids is higher in the roots than in the aerial parts of oats.