Airpollution
Life begins with breathing and ends with its cessation. A person may refuse to take poor-quality food, not drink contaminated water, but he cannot not to breathe. The rapid growth of the number of mankind and scientific and technological armament radically changed the situation on Earth. Modern civilization has an unprecedented impact on nature. Environmental pollution from industrial emissions has a harmful effect on people, animals, plants, soil, buildings, structures, reduces atmospheric transparency, increases air humidity, increases the number of days with fogs, etc. Nowadays, atmospheric air is polluted by harmful substances all over the world. Unfortunately, a person creates for himself what kills him. For example, a car, its exhaust gases contain lead and other substances harmful to human health. In large quantities, these substances are sediment on the ground near freeways and highways. You can’t pick mushrooms, healthy herbs, berries less than a hundred meters from the road, as all plants absorb toxic substances. In cities, the air is very polluted by harmful emissions from industrial enterprises.
There are norms of maximum permissible concentrations, the so-called maximum permissible concentrations of substances in the air. This should be monitored by special bodies, for example, an environmental pollution laboratory, and take any measures from a fine to the closure of an enterprise.
Chemical pollution of the atmosphere.
Atmospheric air is the most important life-supporting natural environment and is a mixture of gases and aerosols of the surface layer of the atmosphere formed during the evolution of the Earth, human activity and located outside residential, industrial and other premises.
Atmospheric pollution is a change in its composition upon receipt of impurities of natural or anthropogenic origin. There are three types of pollutants: gases, aerosols and dust. Aerosols include dispersed solid particles released into the atmosphere and suspended in it for a long time.
The main atmospheric pollutants include carbon dioxide, carbon monoxide, sulfur dioxide and nitrogen dioxide, as well as small gas components that can affect the temperature regime of the troposphere: nitrogen dioxide, chlorofluorocarbons (freons), methane and tropospheric ozone.
The main contribution to the high level of air pollution is made by the enterprises of ferrous and non-ferrous metallurgy, chemistry and petro chemistry, the construction industry, energy, the pulp and paper industry, and in some cities, boiler houses.
Sources of pollution are thermal power plants, which together with smoke emit sulfur dioxide and carbon dioxide, metallurgical enterprises, especially non-ferrous metallurgy, which emit nitrogen oxides, hydrogen sulfide, chlorine, fluorine, ammonia, phosphorus compounds, particles and compounds of mercury and arsenic; chemical and cement plants. Harmful gases enter the air as a result of burning fuel for industrial needs, heating homes, transport, burning and processing household and industrial waste.
Atmospheric pollutants are divided into primary pollutants entering directly into the atmosphere, and secondary, resulting from the conversion of the latter. So, sulfur dioxide gas entering the atmosphere is oxidized to sulfuric anhydride, which interacts with water vapor and forms droplets of sulfuric acid. When sulfuric anhydride reacts with ammonia, ammonium sulfate crystals form. Similarly, as a result of chemical, photochemical, physico-chemical reactions between pollutants and atmospheric components, other secondary symptoms are formed. The main source of pyrogenic pollution on the planet are thermal power plants, metallurgical and chemical enterprises, boiler plants that consume more than 70% of the annual extracted solid and liquid fuels.
Source;
Agency for Hydrometeorology under the Government of the Republic Tajikistan.
