Air pollution. A Serious Problem for Humanity

One of the significant global problems is atmospheric pollution of the Earth. The danger of this is not only that people lack clean air, but also that air pollution leads to climate change on the planet.

Causes of air pollution

Various elements and substances enter the atmosphere, changing the composition and concentration of the air. The following sources contribute to air pollution:

• emissions and activities of industrial facilities;
• car exhausts;
• radioactive objects;
• agriculture;
• household and .

During the combustion of fuel, waste and other substances, combustion products enter the air, which significantly worsen the condition of the atmosphere. Dust generated at construction sites also pollutes the air. At thermal power plants, fuel burns and releases a significant concentration of elements that pollute the atmosphere. The more inventions humanity makes, the more sources of air pollution and the biosphere as a whole appear.

Effects of air pollution

When various types of fuel burn, carbon dioxide is released into the air. Along with other greenhouse gases, it gives rise to such a dangerous phenomenon on our planet as. This leads to the destruction of the ozone layer, which in turn protects our planet from intense exposure to ultraviolet rays. All this leads to global warming and climate change on the planet.

One of the consequences of the accumulation of carbon dioxide and global warming is the melting of glaciers. As a result, the water level of the World Ocean rises, and in the future, flooding of islands and coastal zones of continents may occur. Flooding will be a constant occurrence in some areas. Plants, animals and people will die.

By polluting the air, various elements fall to the ground in the form. This sediment falls into water bodies, changes the composition of the water, and this causes the death of flora and fauna in rivers and lakes.

Today, air pollution is a local problem in many cities, which has grown into a global one. It is difficult to find a place in the world where there is clean air left. In addition to the negative impact on the environment, atmospheric pollution leads to diseases in people that develop into chronic diseases and reduces the life expectancy of the population.

PLAN:

1. INTRODUCTION

2. CHEMICAL POLLUTION OF THE ATMOSPHERE

2.1

2.2 Aerosol pollution

2.3 Photochemical fog (smog)

2.4 Pollution Control

into the atmosphere (maximum permissible concentration)

3. ATMOSPHERE POLLUTION FROM MOBILE VEHICLES

SOURCES

3.1 Motor transport

3.2 Aircraft

3.3 Noises

4. IMPACT OF ATMOSPHERE POLLUTION

PER HUMAN, PLANT AND ANIMAL WORLD

4.1 Carbon monoxide

4.2 Sulfur dioxide and sulfuric anhydride

4.3 Nitrogen oxides and some other substances

4.4 The influence of radioactive substances on plants

body and animal world

1. INTRODUCTION

At all stages of his development, man was closely connected with the world around him. But since the emergence of a highly industrialized society, dangerous human intervention in nature has sharply increased, the scope of this intervention has expanded, it has become more diverse and now threatens to become a global danger to humanity. The consumption of non-renewable raw materials is increasing, more and more arable land is leaving the economy, so cities and factories are built on it. Man has to increasingly intervene in the economy of the biosphere - that part of our planet in which life exists. The Earth's biosphere is currently subject to increasing anthropogenic impact. At the same time, several of the most significant processes can be identified, any of which does not improve the ecological situation on the planet.

The most widespread and significant is chemical pollution of the environment with substances of a chemical nature that are unusual for it. Among them are gaseous and aerosol pollutants of industrial and domestic origin. The accumulation of carbon dioxide in the atmosphere is also progressing. The further development of this process will strengthen the undesirable trend towards an increase in the average annual temperature on the planet. Environmentalists are also concerned about the ongoing pollution of the World Ocean with oil and petroleum products, which has already reached 11/5 of its total surface. Oil pollution of this size can cause significant disruptions in gas and water exchange between the hydrosphere and the atmosphere. There is no doubt about the importance of chemical contamination of the soil with pesticides and its increased acidity, leading to the collapse of the ecosystem. In general, all the factors considered that can be attributed to the polluting effect have a noticeable impact on the processes occurring in the biosphere.

2. CHEMICAL POLLUTION OF THE ATMOSPHERE

2.1. Main pollutants

I will begin my test with a review of those factors that lead to the deterioration of one of the most important components of the biosphere - the atmosphere. Man has been polluting the atmosphere for thousands of years, but the consequences of the use of fire, which he used throughout this period, were insignificant. I had to put up with the fact that smoke interfered with breathing and that soot lay a black cover on the ceiling and walls of the home. The resulting heat was more important to humans than clean air and smoke-free cave walls. This initial air pollution was not a problem, since people then lived in small groups, occupying an immeasurably vast, untouched natural environment. And even a significant concentration of people in a relatively small area, as was the case in classical antiquity, was not yet accompanied by serious consequences.

This was the case until the beginning of the nineteenth century. Only over the last hundred years, the development of industry has “gifted” us with such production processes, the consequences of which at first people could not yet imagine. Millionaire cities have emerged whose growth cannot be stopped. All this is the result of great inventions and conquests of man.

There are basically three main sources of air pollution: industry, domestic boilers, and transport. The contribution of each of these sources to total air pollution varies greatly from place to place. It is now generally accepted that industrial production produces the most air pollution. Sources of pollution are thermal power plants, which, along with smoke, emit sulfur dioxide and carbon dioxide into the air; metallurgical enterprises, especially non-ferrous metallurgy, which emit nitrogen oxides, hydrogen sulfide, chlorine, fluorine, ammonia, phosphorus compounds, particles and compounds of mercury and arsenic into the air; chemical and cement factories. Harmful gases enter the air as a result of burning fuel for industrial needs, heating homes, operating transport, burning and processing household and industrial waste. Atmospheric pollutants are divided into primary, which enter directly into the atmosphere, and secondary, which are the result of the transformation of the latter. Thus, sulfur dioxide gas entering the atmosphere is oxidized to sulfuric anhydride, which reacts with water vapor and forms droplets of sulfuric acid. When sulfuric anhydride reacts with ammonia, ammonium sulfate crystals are formed. Similarly, as a result of chemical, photochemical, physicochemical reactions between pollutants and atmospheric components, other secondary characteristics are formed. The main sources of pyrogenic pollution on the planet are thermal power plants, metallurgical and chemical enterprises, and boiler plants, which consume more than 170% of the annually produced solid and liquid fuel. The main harmful impurities of pyrogenic origin are the following:

3a) Carbon monoxide. 0. Produced by incomplete combustion of carbonaceous substances. It enters the air as a result of the combustion of solid waste, exhaust gases and emissions from industrial enterprises. Every year, at least 1250 million tons of this gas enter the atmosphere. 0Carbon monoxide is a compound that actively reacts with components of the atmosphere and contributes to an increase in temperature on the planet and the creation of a greenhouse effect.

3b) Sulfur dioxide. . 0Emitted during the combustion of sulfur-containing fuel or processing of sulfur ores (up to 170 million tons per year). Some sulfur compounds are released during the combustion of organic residues in mining dumps. In the United States alone, the total amount of sulfur dioxide released into the atmosphere amounted to 65 percent of global emissions.

3c) Sulfuric anhydride. Formed by the oxidation of sulfur dioxide. The final product of the reaction is an aerosol or solution of sulfuric acid in rainwater, which acidifies the soil and aggravates diseases of the human respiratory tract. The fallout of sulfuric acid aerosol from smoke flares of chemical plants is observed under low clouds and high air humidity. Leaf blades of plants growing at a distance of less than 11 km. from such enterprises are usually densely dotted with small necrotic spots formed in places where drops of sulfuric acid settled. Pyrometallurgical enterprises of non-ferrous and ferrous metallurgy, as well as thermal power plants, annually emit tens of millions of tons of sulfuric anhydride into the atmosphere.

3d) Hydrogen sulfide and carbon disulfide. They enter the atmosphere separately or together with other sulfur compounds. The main sources of emissions are enterprises producing artificial fiber, sugar, coke plants, oil refineries, and oil fields. In the atmosphere, when interacting with other pollutants, they undergo slow oxidation to sulfuric anhydride.

3e) Nitrogen oxides. .The main sources of emissions are enterprises producing nitrogen fertilizers, nitric acid and nitrates, aniline dyes, nitro compounds, viscose silk, celluloid. The amount of nitrogen oxides entering the atmosphere is 20 million tons. per year.

3e) Fluorine compounds. Sources of pollution are enterprises producing aluminum, enamels, glass, ceramics, steel, and phosphate fertilizers. Fluorine-containing substances enter the atmosphere in the form of gaseous compounds - hydrogen fluoride or sodium and calcium fluoride dust. The compounds are characterized by a toxic effect. Fluoride derivatives are strong insecticides.

3g) Chlorine compounds. They enter the atmosphere from chemical plants producing hydrochloric acid, chlorine-containing pesticides, organic dyes, hydrolytic alcohol, bleach, and soda. In the atmosphere they are found as impurities of chlorine molecules and hydrochloric acid vapors. The toxicity of chlorine is determined by the type of compounds and their concentration. In the metallurgical industry, when smelting cast iron and processing it into steel, various heavy metals and toxic gases are released into the atmosphere. So, per 11 tons of pig iron, 12.7 kg is released. 0 sulfur dioxide and 14.5 kg. 0dust particles that determine the amount of compounds of arsenic, phosphorus, antimony, lead, mercury vapor and rare metals, resin substances and hydrogen cyanide.

2.2. Aerosol air pollution

Aerosols are solid or liquid particles suspended in the air. In some cases, solid components of aerosols are especially dangerous for organisms and cause specific diseases in people. In the atmosphere, aerosol pollution is perceived as smoke, fog, haze or haze. A significant portion of aerosols are formed in the atmosphere through the interaction of solid and liquid particles with each other or with water vapor. The average size of aerosol particles is 11-5 1 microns. About 11 cubic km enter the Earth's atmosphere annually. 0 dust particles of artificial origin. A large number of dust particles are also formed during human production activities. Information about some sources of industrial dust is given below:

PRODUCTION PROCESS DUST EMISSION, MILLION TONS/YEAR

11. Coal combustion 93.60

12. Iron smelting 20.21

13. Copper smelting (without purification) 6.23

Introduction 3

1.Atmospheric pollution 4

2. Maximum permissible concentrations (MPC) of harmful substances in the air 25

3.Atmospheric protection means 30

4. Conclusion 33

5. List of references. 34

Introduction

The rapid growth of humankind and its scientific and technological equipment has radically changed the situation on Earth. If in the recent past all human activity manifested itself negatively only in limited, albeit numerous territories, and the force of impact was incomparably less than the powerful cycle of substances in nature, now the scales of natural and anthropogenic processes have become comparable, and the ratio between them continues to change with acceleration towards increasing power of anthropogenic influence on the biosphere.

The danger of unpredictable changes in the stable state of the biosphere, to which natural communities and species, including man himself, have historically been adapted, is so great while maintaining the usual methods of management that the current generations of people inhabiting the Earth have been faced with the task of urgent improvement of all aspects of their lives in accordance with the need maintaining the existing cycle of matter and energy in the biosphere. In addition, widespread pollution of our environment with various substances, sometimes completely alien to the normal existence of the human body, poses a serious danger to our health and the well-being of future generations.

1. Air pollution

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, which developed during the evolution of the Earth, human activity and is located outside of residential, industrial and other premises. The results of environmental studies, both in Russia and abroad, clearly indicate that ground-level atmospheric pollution is the most powerful, constantly acting factor affecting humans, the food chain and the environment. Atmospheric air has unlimited capacity and plays the role of the most mobile, chemically aggressive and pervasive interaction agent near the surface of the components of the biosphere, hydrosphere and lithosphere.

The atmosphere has an intense impact not only on humans and biota, but also on the hydrosphere, soil and vegetation cover, geological environment, buildings, structures and other man-made objects. Therefore, the protection of atmospheric air and the ozone layer is the highest priority environmental problem and is given close attention in all developed countries.

The polluted ground atmosphere causes cancer of the lungs, throat and skin, disorders of the central nervous system, allergic and respiratory diseases, defects in newborns and many other diseases, the list of which is determined by the pollutants present in the air and their combined effects on the human body. The results of special studies carried out in Russia and abroad have shown that there is a close positive relationship between the health of the population and the quality of atmospheric air.

The main agents of atmospheric influence on the hydrosphere are precipitation in the form of rain and snow, and to a lesser extent, smog and fog. Surface and underground waters of land are mainly fed by the atmosphere and, as a result, their chemical composition depends mainly on the state of the atmosphere.

Sources of air pollution

Natural sources of pollution include: volcanic eruptions, dust storms, forest fires, dust of cosmic origin, sea salt particles, products of plant, animal and microbiological origin. The level of such pollution is considered as background, which changes little over time.

The main natural process of pollution of the surface atmosphere is the volcanic and fluid activity of the Earth. Large volcanic eruptions lead to global and long-term atmospheric pollution, as evidenced by chronicles and modern observational data (the eruption of Mount Pinatubo in the Philippines in 1991). This is due to the fact that huge amounts of gases are instantly released into the high layers of the atmosphere, which are picked up at high altitudes by air currents moving at high speeds and quickly spread throughout the globe. The duration of the polluted state of the atmosphere after large volcanic eruptions reaches several years.

Anthropogenic sources of pollution are caused by human economic activities. These include:

1. Combustion of fossil fuels, which is accompanied by the release of 5 billion tons of carbon dioxide per year. As a result, over 100 years (1860 - 1960), the CO2 content increased by 18% (from 0.027 to 0.032%). The rate of these emissions has increased significantly over the past three decades. At this rate, by 2000 the amount of carbon dioxide in the atmosphere will be at least 0.05%.

2. Operation of thermal power plants, when the combustion of high-sulfur coals results in the formation of acid rain as a result of the release of sulfur dioxide and fuel oil.

3. Exhausts from modern turbojet aircraft contain nitrogen oxides and gaseous fluorocarbons from aerosols, which can lead to damage to the ozone layer of the atmosphere (ozonosphere).

4. Production activities.

5. Pollution with suspended particles (during grinding, packaging and loading, from boiler houses, power plants, mine shafts, quarries when burning waste).

6. Emissions of various gases by enterprises.

7. Combustion of fuel in flares, resulting in the formation of the most common pollutant - carbon monoxide.

8. Combustion of fuel in boilers and vehicle engines, accompanied by the formation of nitrogen oxides, which cause smog.

9. Ventilation emissions (mine shafts).

10. Ventilation emissions with excessive ozone concentrations from premises with high-energy installations (accelerators, ultraviolet sources and nuclear reactors) with a maximum permissible concentration in working premises of 0.1 mg/m3. In large quantities, ozone is a highly toxic gas.

During fuel combustion processes, the most intense pollution of the surface layer of the atmosphere occurs in megalopolises and large cities, industrial centers due to the widespread use of vehicles, thermal power plants, boiler houses and other power plants operating on coal, fuel oil, diesel fuel, natural gas and gasoline. The contribution of motor transport to total air pollution here reaches 40-50%. A powerful and extremely dangerous factor in air pollution are disasters at nuclear power plants (Chernobyl accident) and testing of nuclear weapons in the atmosphere. This is due both to the rapid spread of radionuclides over long distances and to the long-term nature of contamination of the territory.

The high danger of chemical and biochemical production lies in the potential for emergency releases into the atmosphere of extremely toxic substances, as well as microbes and viruses, which can cause epidemics among the population and animals.

Currently, there are many tens of thousands of pollutants of anthropogenic origin in the surface atmosphere. Due to the continued growth of industrial and agricultural production, new chemical compounds are emerging, including highly toxic ones. The main anthropogenic pollutants of atmospheric air, in addition to large-scale oxides of sulfur, nitrogen, carbon, dust and soot, are complex organic, organochlorine and nitro compounds, man-made radionuclides, viruses and microbes. The most dangerous are dioxin, benzo(a)pyrene, phenols, formaldehyde, and carbon disulfide, which are widespread in the Russian air basin. Solid suspended particles are represented mainly by soot, calcite, quartz, hydromica, kaolinite, feldspar, and less often by sulfates and chlorides. Oxides, sulfates and sulfites, sulfides of heavy metals, as well as alloys and metals in native form were discovered in snow dust using specially developed methods.

The atmosphere is characterized by extremely high dynamism, due to both the rapid movement of air masses in the lateral and vertical directions, and high speeds and the variety of physical and chemical reactions occurring in it. The atmosphere is now considered as a huge “chemical cauldron”, which is under the influence of numerous and variable anthropogenic and natural factors. Gases and aerosols emitted into the atmosphere are characterized by high reactivity. Dust and soot arising from fuel combustion and forest fires absorb heavy metals and radionuclides and, when deposited on the surface, can pollute large areas and enter the human body through the respiratory system.

A tendency has been revealed for the joint accumulation of lead and tin in solid suspended particles of the surface atmosphere of European Russia; chromium, cobalt and nickel; strontium, phosphorus, scandium, rare earths and calcium; beryllium, tin, niobium, tungsten and molybdenum; lithium, beryllium and gallium; barium, zinc, manganese and copper. High concentrations of heavy metals in snow dust are due to both the presence of their mineral phases formed during the combustion of coal, fuel oil and other types of fuel, and the sorption of gaseous compounds such as tin halides by soot and clay particles.

The “lifetime” of gases and aerosols in the atmosphere varies over a very wide range (from 1 – 3 minutes to several months) and depends mainly on their chemical stability, size (for aerosols) and the presence of reactive components (ozone, hydrogen peroxide, etc. .).

Assessing and, even more so, forecasting the state of the surface atmosphere is a very difficult problem. Currently, its condition is assessed mainly using a normative approach. The maximum concentration limits for toxic chemicals and other standard air quality indicators are given in many reference books and manuals. Such guidelines for Europe, in addition to the toxicity of pollutants (carcinogenic, mutagenic, allergenic and other effects), take into account their prevalence and ability to accumulate in the human body and the food chain. The disadvantages of the normative approach are the unreliability of the accepted values ​​of maximum permissible concentrations and other indicators due to the poor development of their empirical observational base, the lack of taking into account the joint impact of pollutants and sudden changes in the state of the surface layer of the atmosphere in time and space. There are few stationary air monitoring posts, and they do not allow us to adequately assess its condition in large industrial and urban centers. Needles, lichens, and mosses can be used as indicators of the chemical composition of the surface atmosphere. At the initial stage of identifying sources of radioactive contamination associated with the Chernobyl accident, pine needles, which have the ability to accumulate radionuclides in the air, were studied. The reddening of coniferous tree needles during periods of smog in cities is widely known.

The most sensitive and reliable indicator of the state of the surface atmosphere is snow cover, which deposits pollutants over a relatively long period of time and makes it possible to determine the location of sources of dust and gas emissions using a set of indicators. Snowfalls contain pollutants that are not captured by direct measurements or calculated data on dust and gas emissions.

Promising directions for assessing the state of the surface atmosphere of large industrial and urban areas include multichannel remote sensing. The advantage of this method is its ability to characterize large areas quickly, repeatedly, and in “one key.” To date, methods have been developed to assess the content of aerosols in the atmosphere. The development of scientific and technological progress allows us to hope for the development of such methods for other pollutants.

The forecast of the state of the surface atmosphere is carried out using complex data. These primarily include the results of monitoring observations, patterns of migration and transformation of pollutants in the atmosphere, features of anthropogenic and natural processes of air pollution in the study area, the influence of meteorological parameters, topography and other factors on the distribution of pollutants in the environment. For this purpose, heuristic models of changes in the surface atmosphere in time and space are developed for a specific region. The greatest success in solving this complex problem has been achieved in areas where nuclear power plants are located. The end result of using such models is to quantify the risk of air pollution and assess its acceptability from a socio-economic point of view.

The atmosphere, as an ecological component, is a layer of air in the subsoil and above its surface, within which the mutual influence of all environmental components (including the air itself) is observed. Therefore, air pollution affects changes in the composition and properties of natural components and human health.

Pollutants enter the atmosphere from natural and anthropogenic sources.

Substances emitted from natural sources include: dust of plant, volcanic and cosmic origin; dust arising from soil erosion; sea ​​salt particles; fog; combustion products from forest and steppe fires; gases of volcanic origin; various products of plant, animal and microbiological origin, etc. These pollution create a natural background.

As industrial production increases, anthropogenic pollution of the Earth's atmosphere increases.

Currently, in industrialized countries, over 2.25 kg/person of various pollutants are emitted into the atmosphere annually, including 1.5 kg/person of gaseous and 0.75 kg/person of solid substances.

Emissions from power plants consuming coal are especially dangerous - they amount to 133 million kg per year of sulfur oxides, 21 million kg of nitrogen oxides, 5 million kg of particulate matter, which are mainly the cause of acid rain..

The distribution of the share of harmful emissions between industrial sectors in individual countries is different (Table 2.1.).

The level of air pollution in cities is especially high; for example, in 1996, 171.1 thousand tons of harmful substances entered the atmosphere of Moscow from stationary sources, and 204.4 thousand tons in the Moscow region.

The dynamics of changes in emissions of pollutants into the atmosphere of Moscow are presented on rice. 2.1.

A clear trend towards an increase in the total amount of pollutants is visible. The main source of air pollution (Fig. 2.2.) became road transport - it accounts for up to 83% of emissions of harmful substances into the city's polluted air. Car exhaust poses a particular danger to architectural monuments located along major highways.

Comparison of concentrations of some gaseous pollutants for rural areas and cities of Russia, presented in table 2.2, shows that a critical situation has arisen in cities regarding this air quality indicator.

These figures indicate that the ecosystems of a large city can no longer fulfill the function of providing it with clean air.

Cases of exceeding maximum concentrations of up to 10 MPCs were registered in 70 cities of Russia.

Atmospheric pollution and saturation of the biosphere with heavy metals is progressing. It is estimated that over the entire history of human society, about 20 billion tons of iron have been smelted. The amount of iron in structures, machines, equipment, etc. is now estimated at approximately 6 billion tons. Consequently, approximately 14 billion tons are dispersed in the environment due to corrosion and other processes. Other metals dissipate even more significantly. For example, the dispersion of mercury and lead accounts for 80–90% of their annual production. When coal is burned, some economically important elements are released into the environment along with ash and waste gases. For example, more is supplied than is extracted from the subsoil: magnesium - 1.5 times, molybdenum - 3 times, arsenic - 7 times, uranium, titanium - 10 times, aluminum, iodine, cobalt - 15 times, mercury - 50 times, lithium, vanadium, strontium, beryllium, zirconium - hundreds of times, gallium, germanium - thousands of times, sodium - tens of thousands of times.

“Secondary” pollutants have become a particular danger in cities. Atmospheric photochemistry is characterized by the formation of undesirable compounds that serve as the basis for photochemical smog. The main products of these photochemical reactions are aldehydes, ketones, aromatic hydrocarbons, carbon monoxide - CO, acid oxides CO 2, SO 2, NO 2, organic nitrates and oxidants - ozone, nitrogen dioxide, compounds such as peroxyacetyl nitrates, etc. It is known that peroxyacetyl nitrate ( PAN) strongly irritates the mucous membrane of the eyes and has a negative effect on the assimilation apparatus of plants. Irradiation of olefins and aromatic compounds results in the formation of significant amounts of aerosols. The listed acid oxides oxidize and, reacting with water, form acids. The problem of acid rain has become really noticeable not only in industrial cities, but also everywhere in urbanized areas of cities.

Every year, millions of tons of acids and other pollutants fall with precipitation, which is dangerous in terms of global changes in the chemistry of the natural environment. Emissions of sulfur dioxide (SO 2) from industrial exhaust gases also cause great economic damage, since such a valuable substance as sulfur is lost. The world's proven reserves of this raw material are close to depletion. At the same time, the amount of technogenic sulfur entering the atmosphere in 2000 amounted, according to various sources, from 275 to 400 million tons.

There are two main sources of air pollution: natural and anthropogenic.

Naturalsource- these are volcanoes, dust storms, weathering, forest fires, decomposition processes of plants and animals.

Anthropogenic, are mainly divided into three main sources of air pollution: industry, domestic boiler houses, and transport. The contribution of each of these sources to total air pollution varies greatly depending on location.

It is now generally accepted that industrial production produces the most air pollution. Sources of pollution are thermal power plants, which, along with smoke, emit sulfur dioxide and carbon dioxide into the air; metallurgical enterprises, especially non-ferrous metallurgy, which emit nitrogen oxides, hydrogen sulfide, chlorine, fluorine, ammonia, phosphorus compounds, particles and compounds of mercury and arsenic into the air; chemical and cement factories. Harmful gases enter the air as a result of burning fuel for industrial needs, heating homes, operating transport, burning and processing household and industrial waste.

According to scientists (1990s), every year in the world as a result of human activity, 25.5 billion tons of carbon oxides, 190 million tons of sulfur oxides, 65 million tons of nitrogen oxides, 1.4 million tons of chlorofluorocarbons (freons), organic lead compounds, hydrocarbons, including carcinogenic (cancer-causing) 1.

The most common air pollutants enter the atmosphere mainly in two forms: either in the form of suspended particles (aerosols) or in the form of gases. By weight, the lion's share - 80-90 percent - of all emissions into the atmosphere due to human activities are gaseous emissions. There are 3 main sources of gaseous pollution: combustion of combustible materials, industrial production processes and natural sources.

Let's consider the main harmful impurities of anthropogenic origin 2.

Carbon monoxide. It is produced by incomplete combustion of carbonaceous substances. It enters the air as a result of the combustion of solid waste, exhaust gases and emissions from industrial enterprises. Every year, at least 1250 million tons of this gas enter the atmosphere. Carbon monoxide is a compound that actively reacts with components of the atmosphere and contributes to an increase in temperature on the planet and the creation of a greenhouse effect.

Sulfur dioxide. Released during the combustion of sulfur-containing fuel or processing of sulfur ores (up to 170 million tons per year). Some sulfur compounds are released during the combustion of organic residues in mining dumps. In the United States alone, the total amount of sulfur dioxide released into the atmosphere amounted to 65% of global emissions.

Sulfuric anhydride. Formed by the oxidation of sulfur dioxide. The final product of the reaction is an aerosol or solution of sulfuric acid in rainwater, which acidifies the soil and aggravates diseases of the human respiratory tract. The fallout of sulfuric acid aerosol from smoke flares of chemical plants is observed under low clouds and high air humidity. Leaf blades of plants growing at a distance of less than 11 km. from such enterprises are usually densely dotted with small necrotic spots formed in places where drops of sulfuric acid settled. Pyrometallurgical enterprises of non-ferrous and ferrous metallurgy, as well as thermal power plants, annually emit tens of millions of tons of sulfuric anhydride into the atmosphere.

Hydrogen sulfide and carbon disulfide. They enter the atmosphere separately or together with other sulfur compounds. The main sources of emissions are enterprises producing artificial fiber, sugar, coke plants, oil refineries, and oil fields. In the atmosphere, when interacting with other pollutants, they undergo slow oxidation to sulfuric anhydride.

Nitrogen oxides. The main sources of emissions are enterprises producing nitrogen fertilizers, nitric acid and nitrates, aniline dyes, nitro compounds, viscose silk, and celluloid. The amount of nitrogen oxides entering the atmosphere is 20 million tons per year.

Fluorine compounds. Sources of pollution are enterprises producing aluminum, enamels, glass, ceramics, steel, and phosphate fertilizers. Fluorine-containing substances enter the atmosphere in the form of gaseous compounds - hydrogen fluoride or sodium and calcium fluoride dust. The compounds are characterized by a toxic effect. Fluorine derivatives are strong insecticides.

Chlorine compounds. They enter the atmosphere from chemical plants producing hydrochloric acid, chlorine-containing pesticides, organic dyes, hydrolytic alcohol, bleach, and soda. In the atmosphere they are found as impurities of chlorine molecules and hydrochloric acid vapors. The toxicity of chlorine is determined by the type of compounds and their concentration. In the metallurgical industry, when smelting cast iron and processing it into steel, various heavy metals and toxic gases are released into the atmosphere. So, per 1 ton of pig iron, 12.7 kg is released. sulfur dioxide and 14.5 kg of dust particles, which determine the amount of compounds of arsenic, phosphorus, antimony, lead, mercury vapor and rare metals, resin substances and hydrogen cyanide.

In addition to gaseous pollutants, large amounts of particulate matter are released into the atmosphere. This is dust, soot and soot. Pollution of the natural environment with heavy metals poses a great danger. Lead, cadmium, mercury, copper, nickel, zinc, chromium, and vanadium have become almost constant components of the air in industrial centers.

Aerosols- These are solid or liquid particles suspended in the air. In some cases, solid components of aerosols are especially dangerous for organisms and cause specific diseases in people. In the atmosphere, aerosol pollution is perceived as smoke, fog, haze or haze. A significant portion of aerosols are formed in the atmosphere through the interaction of solid and liquid particles with each other or with water vapor. The average size of aerosol particles is 1-5 microns. About 1 cubic meter enters the Earth's atmosphere annually. km of dust particles of artificial origin. A large number of dust particles are also formed during human production activities. Information on some sources of man-made dust is given in Appendix 3.

The main sources of artificial aerosol air pollution are thermal power plants that consume high-ash coal, washing plants, metallurgical, cement, magnesite and soot factories. Aerosol particles from these sources have a wide variety of chemical compositions. Most often, compounds of silicon, calcium and carbon are found in their composition, less often - metal oxides: iron, magnesium, manganese, zinc, copper, nickel, lead, antimony, bismuth, selenium, arsenic, beryllium, cadmium, chromium, cobalt, molybdenum, as well as asbestos.

Constant sources of aerosol pollution are industrial dumps - artificial embankments of redeposited material, mainly overburden rocks formed during mining or from waste from processing industry enterprises, thermal power plants.

Massive blasting operations serve as a source of dust and toxic gases. Thus, as a result of one average-mass explosion (250-300 tons of explosives), about 2 thousand cubic meters are released into the atmosphere. m. of carbon monoxide and more than 150 tons of dust.

The production of cement and other building materials is also a source of dust pollution. The main technological processes of these industries - grinding and chemical processing of semi-finished products and resulting products in streams of hot gases - are always accompanied by emissions of dust and other harmful substances into the atmosphere.

The main atmospheric pollutants today are carbon monoxide and sulfur dioxide (Appendix 2).

But, of course, we must not forget about freons, or chlorofluorocarbons. Most scientists consider them to be the cause of the formation of so-called ozone holes in the atmosphere. Freons are widely used in production and in everyday life as refrigerants, foaming agents, solvents, and also in aerosol packaging. Namely, doctors associate an increase in the number of skin cancers with a decrease in ozone content in the upper layers of the atmosphere. It is known that atmospheric ozone is formed as a result of complex photochemical reactions under the influence of ultraviolet radiation from the Sun. Although its content is small, its importance for the biosphere is enormous. Ozone, by absorbing ultraviolet radiation, protects all life on earth from death. Freons, when entering the atmosphere, under the influence of solar radiation, decompose into a number of compounds, of which chlorine oxide most intensively destroys ozone.