At all stages of his development, man has always been closely connected with the world around him, but for a long time he did not have any significant effect on the environment. With the emergence of a highly industrial society, human intervention in nature has increased dramatically. At present, the Earth's biosphere is exposed to an ever increasing anthropogenic impact.
The main sources of air pollution are industry, household boilers and transport. Industrial production pollutes the air the most. Thermal power plants, metallurgical plants, chemical and cement plants - the products of the "vital activity" of these institutions make significant changes in the composition of the atmosphere. As a result of the combustion of fuel for industrial needs, heating of dwellings and the operation of transport, the processing of household and industrial waste, harmful gases are released into the air. All pollutants are classified as primary and secondary. The former enter the atmosphere directly, the latter are formed in it through chemical reactions, for example, with water vapor. Harmful atmospheric impurities are carbon monoxide, sulfurous and sulfuric anhydrides, hydrogen sulfide and carbon disulfide, nitrogen oxides, fluorine and chlorine compounds. They are formed as a result of the combustion of certain substances and therefore are called pollutants of pyrogenic origin. Carbon monoxide, for example, is formed by incomplete combustion of carbon-containing chemicals. It is released into the air along with exhaust gases and industrial emissions. Carbon monoxide actively reacts with other components of the atmosphere, contributes to the creation of a greenhouse effect and an increase in the overall temperature of the planet. Sulfurous anhydride (sulfur dioxide, sulfur dioxide) is released during the combustion of sulfur-containing fuel or during the processing of sulfur ores. When oxidized, sulfuric anhydride is formed. Eventually, suspended particles of sulfuric acid enter rainwater, which can also dissolve in this water. Sulfuric acid dissolved in rainwater acidifies the soil and aggravates respiratory diseases. Sitting on the leaves of plants, it leaves necrotic spots on them. Tens of millions of tons of sulfur oxide are annually emitted into the atmosphere by thermal power plants and enterprises of ferrous and non-ferrous metallurgy. In addition to gas, there is also aerosol pollution of the atmosphere. Aerosols are solid and liquid particles suspended in the air. They are perceived as smoke, fog, haze or haze. In some cases, such components are especially dangerous for living organisms and can cause serious diseases. Dust-like particles of artificial origin, among which there is also a lot of organic dust, in large quantities enter the atmosphere in the course of human activities.
