Air Quality Assessment: Determination of Heavy Metals and Radionuclides Concentration

Purpose: To assess the level of environmental pollution by radionuclides and heavy metals using the example of studying atmospheric precipitation near the municipal solid waste landfill in Yakutsk. Material and methods: Biomonitor mosses (Hylocomium splendens, Pleurozium Schreberi, and Brachythecium salebrosum), lichens, and soil were used as research samples, which were sampled in the territory surrounding the municipal waste landfill on the 9th km of the Vilyuysky tract in Yakutsk within a radius of 51 km. The PlasmaQuant PQ 9000 Elite optical emission spectrometry (Analytik Jena, Germany) and the direct mercury analyzer DMA-80 evo Milestone were used as methods for studying the presence and concentration of heavy metals. The radionuclide composition of the samples was studied using gamma-ray spectrometry on an ORTEC semiconductor gammaray spectrometer with a GEM-40 highpurity germanium detector and Maestro32 software. Results: According to the results of the study, in the territory within 51 km along the Vilyuysky tract from the landfill, the following microelementes were found in samples of biomonitor mosses: P, S, Al, Fe, Mn, Ba, Sr, Zn, Cu, Pb, Cr, V, Ni, Co, Cd, Hg, with the median values of the content Ba, Cr, Fe, and Pb exceed similar values for the relatively "clean" territory of Norway. During the study of radionuclide concentrations, concentrations of the following radioisotopes were detected and determined: 137Cs, cosmogenic radionuclide 7Be, radioisotopes of lead 212Pb, thallium 208Tl, Bi and actinium 228Ac – daughter products of thorium radionuclide 223Th and isotopes of lead 214Pb and bismuth 214Bi – daughter products of uranium 238U. Conclusion: The high concentrations of such heavy metals in moss samples in the territories nearby the city (near landfills) are comparable to the concentrations of heavy metals in vegetation samples from places located near, for example, industrial sites of mining and processing plants. The detection of the same heavy metals and radionuclides in the atmospheric environment, the soil of the city and in vegetation, the soil near the landfill may indicate that one of the sources of environmental pollution and effects on human health may be the combustion products of the contents of the landfill on the 9th km along the Vilyuysky tract.