Residents of Zvenigorod face gas poisoning
Inhaling fresh air on a summer cottage outside Moscow, you need to remember that the spicy smell of a thunderstorm is not always good for health. The very ozone with which we associate a pleasant, slightly sour smell on the street is safe only in small concentrations. Excess is fraught with health problems, the most common of which are respiratory disorders, bronchial asthma, and decreased immunity. Scientists from the Moscow State Machine-Building University (MAMI) and the Tambov State Technical University (authors V. G. Sister, A. N. Tsedilin, N. V. Vorobyova, Yu. V. Vorobyov) conducted a study of the ozone content in the air of the immediate vicinity of the capital in daylight and night hours. The laboratories toured five districts of Moscow and the Moscow region: Yuzhnoye Medvedkovo, Ramenki, Kosino, Zelenograd, Zvenigorod were in sight. The results were surprising.
Photo: morguefile.com
Each of us knows the smell of ozone - fresh, slightly spicy, reminiscent of a summer thunderstorm. Ozone, its chemical formula O3, is an integral part of the Earth's atmosphere. We have all heard about the ozone layer - a special zone in the stratosphere that shields the planet from cosmic rays.
The ozone molecule is like a baby rattle: three oxygen atoms joined hands in a round dance, making up a molecule of one of the most amazing gases in the atmosphere. In the stratosphere - high above the ground - ozone is generated by the effect of solar radiation on atmospheric oxygen (O 2). In the troposphere, the surface layer of the atmosphere, ozone is formed and decomposed as a result of numerous and varied photochemical and chemical reactions. Their course depends on a number of meteorological parameters - temperature, humidity, sunlight, "wind rose". And of course, on the level of atmospheric pollution with aerosols of various types.
Its main property is to oxidize everything and everyone, and instability - the oxygen "rattle" quickly decays into atoms. The high oxidizing ability of ozone contributes to the fact that this gas remarkably kills microbes and mold, therefore it is often used for disinfection of premises and materials, purification of water and air from microorganisms (ozonation), in obtaining many substances in laboratory and industrial practice, for bleaching paper.
It would seem - what a useful gas! However, due to the same high oxidizing capacity, ozone is highly toxic and belongs to the substances of the first hazard class. Tropospheric ozone is a pollutant that can threaten human and animal health and damage plants. Ozone enters the body with the inhaled air and has a general toxic, irritating, carcinogenic effect.
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One of the important problems of large cities and industrialized regions is a significant increase in ozone concentrations in the surface air layer. In Russia, the highest measured concentrations of ozone in the surface atmosphere are 600 μg / m³, which is almost 40 times higher than its natural concentrations.
The human smell threshold for ozone is about 10 µg / m³. At this concentration, we can smell it - the same, fresh, reminiscent of a summer thunderstorm. But if this level is exceeded only three times, problems begin. After the transition to the level of 30 µg / m³, a further increase in the ozone content in the air causes more and more calls to the ambulance service, as the statistics say. Scientists cite even more frightening figures: after passing the level of 70 µg / m³, a further increase in the average concentration of ozone for every 10 units increases the average mortality rate by 0.4%; an average ozone concentration of 100 µg / m³ increases mortality by another 1–2%, and then - in the same spirit and at an even greater rate.
We are all accustomed to considering urban air as a real concentration of pollution. However, ozone turned out to be a special gas. Statistical processing of the data obtained in Moscow and its environs showed an unexpected pattern: the probability of exceeding the permissible level of ozone in the air does not decrease, but increases with distance from the city limits - the ring road. In the areas located inside the Moscow Ring Road - Yuzhny Medvedkovo and Ramenki, measurements showed the lowest ozone level. Whereas in the most remote research area - Zvenigorod near Moscow - the probability of exceeding the MPC turned out to be about 3 times higher!
Ekaterina Golovina
