Assess of contamination of the snow cover for detecting the zones of inhalation chemical risk

Abstract

Introduction. On the territory with a resistant snow cover, atmospheric pollution accumulates over several months; solid precipitation in the form of snow is an indicator object for assessing the state of the urban environment. Materials and methods. The sampling of snow was carried out on trial plots close to the monitoring points of atmospheric air and reflecting the influence of various stationary and mobile sources of pollution. The methods of gas chromatography-mass spectrometry and the atomic absorption spectrometry were used. Results. The results were obtained on the content of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in snow cover to identify risk zones in the city of Ulan-Ude of the Republic of Buryatiya. The widest range of metals is recorded at points located near a major traffic interchange and in a residential area near the low-rise buildings of the private sector. The determined PAHs in large quantities were established to be contained in the solid sediment of snow samples. Discussion. Snow cover is a depositing and transit component of the environment. Its study gives important information about the chemical state of industrial ecosystems. About 30 thousand tons of chemical impurities enter the air basin of Ulan-Ude from stationary sources per year. Emissions of the total amount of hydrocarbons averaged of 1,741.96 tons over the study period, soot - 822.41 tons, which is by tens and hundreds times higher than that of other toxic substances, therefore, the PAH content in snow samples is higher than that of heavy metals. Conclusion. The accumulation of chemicals of 13 priority PAHs, of which 60-80% of the total amount falls on 3-,4- nuclear counterparts (phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, chrysene) occurs in accumulating media. PAHs are associated with water-insoluble (solid phase) PAHs, which indicates to the unity of the main source of pollution (vehicle exhaust gases).