Under atmospheric air understand a vital component of the environment, which is a natural mixture of atmospheric gases and located outside residential, industrial and other premises (Law of the Russian Federation "On the Protection of Atmospheric Air" of 02.04.99). The thickness of the air shell that surrounds the globe is not less than a thousand kilometers - almost a quarter of the earth's radius. Air is essential for all life on earth. A person daily consumes 12-15 kg of air, inhaling every minute from 5 to 100 liters, which significantly exceeds the average daily need for food and water. The atmosphere determines the light and regulates the thermal regimes of the Earth, contributes to the redistribution of heat on the globe. The gas envelope protects the Earth from excessive cooling and heating, saves everything living on Earth from the destructive ultraviolet, X-ray and cosmic rays. The atmosphere protects us from meteorites. The atmosphere serves as a conductor of sounds. The main consumer of air in nature is the flora and fauna of the Earth.

Under ambient air quality understand the totality of atmospheric properties that determine the degree of impact of physical, chemical and biological factors on people, flora and fauna, as well as on materials, structures and the environment as a whole.

Under air pollution understand any change in its composition and properties that has a negative impact on human and animal health, the condition of plants and ecosystems.

Pollutant- an admixture in the atmospheric air that, at certain concentrations, has an adverse effect on human health, plants and animals, other components of the natural environment or damages material objects.

Air pollution can be natural (natural) and anthropogenic (technogenic).

Natural air pollution caused by natural processes. These include volcanic activity, wind erosion, mass flowering of plants, smoke from forest and steppe fires.

Anthropogenic pollution associated with the release of pollutants from human activities. In terms of scale, it significantly exceeds natural air pollution and can be local characterized by an increased content of pollutants in small areas (city, district, etc.), regional when large areas of the planet are affected, and global are changes in the whole atmosphere.

According to the state of aggregation, emissions of harmful substances into the atmosphere are classified into: 1) gaseous (sulfur dioxide, nitrogen oxides, carbon monoxide, hydrocarbons); 2) liquid (acids, alkalis, salt solutions); 3) solid (carcinogenic substances, lead and its compounds, organic and inorganic dust, soot, tarry substances).

The main anthropogenic pollutants (pollutants) of the atmospheric air, which account for about 98% of the total emissions of harmful substances, are sulfur dioxide (SO 2), nitrogen dioxide (NO 2), carbon monoxide (CO) and particulate matter. It is the concentrations of these pollutants that most often exceed the permissible levels in many Russian cities. The total world emission of the main pollutants into the atmosphere in 1990 amounted to 401 million tons, in Russia in 1991 - 26.2 million tons. But besides them, more than 70 types of harmful substances are observed in the atmosphere of cities and towns, including lead, mercury, cadmium and other heavy metals (emission sources: cars, smelters); hydrocarbons, among them the most dangerous is benz (a) pyrene, which has a carcinogenic effect (exhaust gases, boiler furnaces, etc.), aldehydes (formaldehyde), hydrogen sulfide, toxic volatile solvents (gasolines, alcohols, ethers). Currently, millions of people are exposed to carcinogenic factors of atmospheric air.

The most dangerous air pollution - radioactive, mainly due to globally distributed long-lived radioactive isotopes - products of nuclear weapons tests carried out and from operating nuclear power plants during their operation. A special place is occupied by the release of radioactive substances as a result of the accident of the fourth block at the Chernobyl nuclear power plant in 1986. Their total release into the atmosphere amounted to 77 kg (740 g of them were formed during the atomic explosion over Hiroshima).

Currently, the main sources of atmospheric air pollution in Russia are the following industries: thermal power engineering (thermal and nuclear power plants, industrial and municipal boiler houses), motor transport, enterprises of ferrous and non-ferrous metallurgy, oil production and petrochemistry, mechanical engineering, production of building materials.

Air pollution affects human health and the natural environment in various ways - from a direct and immediate threat to the slow and gradual destruction of various life support systems of the body. In many cases, air pollution disrupts ecosystem components to such an extent that regulatory processes are unable to return them to their original state, and as a result, homeostatic mechanisms do not work.

The physiological impact on the human body of the main pollutants is fraught with the most serious consequences. So, sulfur dioxide, combining with moisture, forms sulfuric acid, which destroys the lung tissue of humans and animals. Dust containing silicon dioxide (SiO2) causes a severe lung disease called silicosis. Nitrogen oxides irritate and corrode the mucous membranes of the eyes and lungs, and are involved in the formation of poisonous mists. If they are contained in the air together with sulfur dioxide, then a synergistic effect occurs, i.e. increased toxicity of the entire gaseous mixture.

The effect of carbon monoxide (carbon monoxide) on the human body is widely known: in case of poisoning, a fatal outcome is possible. Due to the low concentration of carbon monoxide in the atmospheric air, it does not cause mass poisoning, although it is dangerous for those suffering from cardiovascular diseases.

Very unfavorable consequences, which can affect a huge time interval, are associated with insignificant emissions of such substances as lead, benzo (a) pyrene, phosphorus, cadmium, arsenic, cobalt. They inhibit the hematopoietic system, cause cancer, reduce the body's resistance to infections.

The consequences of exposure to the human body of harmful substances contained in the exhaust gases of cars are very serious and have the widest range of action: from coughing to death. Severe consequences in the body of living beings are caused by a toxic mixture of smoke, fog and dust - smog.

Anthropogenic emissions of pollutants in high concentrations and for a long time cause great harm not only to humans, but also to the rest of the biota. There are known cases of mass poisoning of wild animals, especially birds and insects, with emissions of harmful pollutants of high concentration.

Emissions of harmful substances act both directly on the green parts of plants, getting through the stomata into tissues, destroying chlorophyll and cell structure, and through the soil - on the root system. Sulfur dioxide is especially dangerous for plants, under the influence of which photosynthesis stops and many trees die, especially conifers.

The global environmental problems associated with atmospheric pollution are the "greenhouse effect", the formation of "ozone holes" and the fallout of "acid rain".

Since the second half of the 19th century, a gradual increase in the average annual temperature has been observed, which is associated with the accumulation in the atmosphere of the so-called "greenhouse gases" - carbon dioxide, methane, freons, ozone, nitrogen oxide. Greenhouse gases block long-wavelength thermal radiation from the Earth's surface, and an atmosphere saturated with them acts like the roof of a greenhouse. It, passing inside most of the solar radiation, almost does not let the heat radiated by the Earth out.

The "greenhouse effect" is the cause of the increase in the average global air temperature near the earth's surface. So, in 1988, the average annual temperature was 0.4°C higher than in 1950-1980, and by 2005, scientists predict its increase by 1.3°C. The report of the UN International Panel on Climate Change claims that by 2100 the temperature on Earth will increase by 2-4 0.4°C. The scale of warming in this relatively short period will be comparable to the warming that occurred on Earth after the Ice Age, and the environmental consequences could be catastrophic. First of all, this is an increase in the level of the World Ocean due to the melting of polar ice, a reduction in the areas of mountain glaciation. An increase in ocean level of only 0.5-2.0 meters by the end of the 21st century will lead to a violation of climatic equilibrium, flooding of coastal plains in more than 30 countries, degradation of permafrost, and swamping of vast areas.

At the International Conference in Toronto (Canada) in 1985, the world's energy industry was tasked with reducing by 2005 by 20% industrial carbon emissions into the atmosphere. At the UN conference in Kyoto (Japan) in 1997, the previously established barrier for greenhouse gas emissions was confirmed. But it is obvious that a tangible environmental effect can only be obtained by combining these measures with the global direction of environmental policy, the essence of which is the maximum possible preservation of communities of organisms, natural ecosystems and the entire biosphere of the Earth.

"Ozone holes"- these are significant spaces in the ozone layer of the atmosphere at an altitude of 20-25 km with a noticeably reduced (up to 50% or more) ozone content. The depletion of the ozone layer is recognized by all as a serious threat to global environmental security. It weakens the ability of the atmosphere to protect all life from harsh ultraviolet radiation, the energy of a single photon of which is enough to destroy most organic molecules. Therefore, in areas with a low ozone content, sunburn is numerous, and the number of skin cancer cases is increasing.

Both natural and anthropogenic origin of "ozone holes" is assumed. The latter is probably due to the increased content of chlorofluorocarbons (freons) in the atmosphere. Freons are widely used in industrial production and in everyday life (cooling units, solvents, sprayers, aerosol packages). In the atmosphere, freons decompose with the release of chlorine oxide, which has a detrimental effect on ozone molecules. According to the international environmental organization Greenpeace, the main suppliers of chlorofluorocarbons (freons) are the USA (30.85%), Japan (12.42%), Great Britain (8.62%) and Russia (8.0%). Recently, factories have been built in the USA and in a number of Western countries for the production of new types of refrigerants (hydrochlorofluorocarbons) with a low potential for ozone depletion.

A number of scientists continue to insist on the natural origin of "ozone holes". The reasons for their occurrence are associated with the natural variability of the ozonosphere, the cyclic activity of the Sun, rifting and degassing of the Earth, i.e. with the breakthrough of deep gases (hydrogen, methane, nitrogen) through the rift faults of the earth's crust.

"Acid Rain" are formed during industrial emissions of sulfur dioxide and nitrogen oxides into the atmosphere, which, when combined with atmospheric moisture, form dilute sulfuric and nitric acids. As a result, rain and snow are acidified (pH value below 5.6). Acidification of the natural environment negatively affects the state of ecosystems. Under the influence of acid precipitation, not only nutrients are leached from the soil, but also toxic metals: lead, cadmium, aluminum. Further, they themselves or their toxic compounds are absorbed by plants and soil organisms, which leads to very negative consequences. The impact of acid rain reduces the resistance of forests to droughts, diseases, natural pollution, which leads to their degradation as natural ecosystems. There have been cases of damage to coniferous and deciduous forests in Karelia, Siberia and other regions of our country. An example of the negative impact of acid rain on natural ecosystems is the acidification of lakes. It is especially intense in Canada, Sweden, Norway and Finland. This is explained by the fact that a significant part of sulfur emissions in the US, Germany and the UK falls on their territory.

Atmospheric air protection is a key problem in the improvement of the natural environment.

Hygienic standard for ambient air quality– a criterion of atmospheric air quality, reflecting the maximum allowable maximum content of pollutants in the atmospheric air, at which there is no harmful effect on human health.

Environmental standard for atmospheric air quality- criterion of atmospheric air quality, reflecting the maximum allowable maximum content of pollutants in the atmospheric air, at which there is no harmful effect on the environment.

Maximum allowable (critical) load- an indicator of the impact of one or more pollutants on the environment, the excess of which can lead to harmful effects on it.

Harmful (polluting) substance- a chemical or biological substance (or a mixture thereof) contained in the atmospheric air, which, in certain concentrations, has a harmful effect on human health and the natural environment.

Air quality standards define the permissible limits for the content of harmful substances in:

production area, designed to accommodate industrial enterprises, pilot plants of research institutes, etc.;

residential area, designed to accommodate housing stock, public buildings and structures, settlements.

In GOST 17.2.1.03-84. "Protection of Nature. Atmosphere. Pollution control terms and definitions” presents the main terms and definitions related to atmospheric pollution indicators, monitoring programs, and the behavior of impurities in the atmospheric air.

For atmospheric air, two MPC standards are set - one-time and average daily.

Maximum allowable concentration of a harmful substance- this is the maximum single concentration, which should not cause reflex reactions in the human body (smell, change in light sensitivity of the eyes, etc.) in the air of populated areas when inhaling air for 20-30 minutes.

The concept of p maximum allowable concentration of a harmful substance used in setting scientific and technical standards for maximum permissible emissions of pollutants. As a result of the dispersion of impurities in the air under adverse meteorological conditions at the border of the sanitary protection zone of the enterprise, the concentration of a harmful substance at any time should not exceed the maximum allowable.

The maximum allowable concentration of a harmful substance is average daily - this is the concentration that should not have a direct or indirect harmful effect on a person for an indefinitely long (years) time. Thus, this concentration is calculated for all groups of the population for an indefinitely long period of exposure and, therefore, is the most stringent sanitary and hygienic standard that establishes the concentration of a harmful substance in the air. It is the value of the average daily maximum permissible concentration of a harmful substance that can act as a "standard" for assessing the well-being of the air environment in a residential area.

The maximum permissible concentration of a harmful substance in the air of the working area is the concentration that, during daily (except weekends) work for 8 hours, or for another duration, but not more than 41 hours a week, throughout the entire working experience should not cause illness or deviations in the state of health, detected by modern research methods, in the process of work or in the long-term life of the present and subsequent generations. A working area should be considered a space up to 2 meters high above the floor level or an area on which there are places for permanent or temporary stay of workers.

As follows from the definition, the maximum allowable concentration of the working area is a standard that limits the impact of a harmful substance on the adult working part of the population during the period of time established by labor legislation. It is absolutely unacceptable to compare the pollution levels of the residential area with the established maximum allowable concentrations in the working area, and also to talk about the maximum allowable concentration in the air in general, without specifying which standard is being discussed.

Permissible level of radiation and other physical impact on the environment- this is the level that does not pose a danger to human health, the condition of animals, plants, their genetic fund. The permissible level of radiation exposure is determined on the basis of radiation safety standards. Permissible levels of exposure to noise, vibration, and magnetic fields have also been established.

Currently, a number of complex indicators of atmospheric pollution (together by several pollutants) have been proposed. The most common and recommended methodological documentation of the State Committee for Ecology is the integrated air pollution index. It is calculated as the sum of the average concentrations of various substances normalized to the average daily maximum allowable concentration and reduced to the concentration of sulfur dioxide.

Maximum allowable release, or discharge- this is the maximum amount of pollutants that per unit of time is allowed to be emitted by this particular enterprise into the atmosphere or discharged into a reservoir, without causing them to exceed the maximum permissible concentrations of pollutants and adverse environmental consequences.

The maximum allowable emission is set for each source of air pollution and for each impurity emitted by this source in such a way that emissions of harmful substances from this source and from a combination of sources of a city or other settlement, taking into account the prospects for the development of industrial enterprises and dispersion of harmful substances in the atmosphere, do not create surface concentration exceeding their maximum one-time maximum allowable concentration.

The main values ​​of maximum allowable emissions - maximum one-time - are set under the condition of full load of process and gas cleaning equipment and their normal operation and should not be exceeded in any 20-minute period of time.

Along with the maximum one-time (control) values ​​of maximum allowable emissions, annual values ​​of maximum allowable emissions derived from them are established for individual sources and the enterprise as a whole, taking into account the temporary unevenness of emissions, including due to scheduled repairs of process and gas cleaning equipment.

If the values ​​of maximum allowable emissions for reasons of an objective nature cannot be achieved, for such enterprises, temporarily agreed emissions harmful substances and introduces a gradual reduction of emissions of harmful substances to values ​​that ensure compliance with the maximum allowable emissions.

Public environmental monitoring can solve the problems of assessing the compliance of the enterprise's activities with the established values ​​of maximum allowable emissions or temporarily agreed emissions by determining the concentrations of pollutants in the surface air layer (for example, at the border of the sanitary protection zone).

To compare data on air pollution by several substances in different cities or city districts complex indices of air pollution must be calculated for the same amount (n) of impurities. When compiling the annual list of cities with the highest level of air pollution, to calculate the complex index Yn, the values ​​of the unit indices Yi of those five substances for which these values ​​are the highest are used.

The movement of pollutants in the atmosphere "does not respect state borders", i.e. cross-border. Transboundary pollution is pollution transferred from the territory of one country to the area of ​​another.

To protect the atmosphere from negative anthropogenic impact in the form of pollution with harmful substances, the following measures are used:

Ecologization of technological processes;

Purification of gas emissions from harmful impurities;

Dissipation of gaseous emissions in the atmosphere;

Arrangement of sanitary protection zones, architectural and planning solutions.

The most radical measure to protect the air basin from pollution is the greening of technological processes and, first of all, the creation of closed technological cycles, waste-free and low-waste technologies that exclude harmful pollutants from entering the atmosphere, in particular, the creation of continuous technological processes, preliminary purification of fuel or replacement its more environmentally friendly types, the use of hydro dust removal, the transfer to the electric drive of various units, gas recirculation.

Under wasteless technology understand such a principle of organization of production, in which the cycle "primary raw materials - production - consumption - secondary raw materials" is built with the rational use of all components of raw materials, all types of energy and without violating the ecological balance.

Today, the priority task is to combat air pollution by exhaust gases from vehicles. Currently, there is an active search for a "cleaner" fuel than gasoline. Development continues to replace the carburetor engine with more environmentally friendly types, and trial models of cars powered by electricity have been created. The current level of greening of technological processes is still insufficient to completely prevent gas emissions into the atmosphere. Therefore, various methods of cleaning exhaust gases from aerosols (dust) and toxic gas and vapor impurities are widely used. To clean emissions from aerosols, various types of devices are used depending on the degree of dust content in the air, the size of solid particles and the required level of purification: dry dust collectors (cyclones, dust settling chambers), wet dust collectors (scrubbers), filters, electrostatic precipitators, catalytic, absorption and other methods for purification of gases from toxic gas and vapor impurities.

Dispersion of gas impurities in the atmosphere- this is the reduction of their dangerous concentrations to the level of the corresponding maximum permissible concentration by dispersing dust and gas emissions with the help of high chimneys. The higher the pipe, the greater its scattering effect. But, as A. Gore (1993) points out: “The use of tall chimneys, while helping to reduce local smoke pollution, at the same time exacerbated the regional problems of acid rain.”

Sanitary protection zone- this is a strip separating sources of industrial pollution from residential or public buildings to protect the population from the influence of harmful production factors. The width of these zones is from 50 to 1000 m and depends on the class of production, the degree of harmfulness and the amount of substances released into the atmosphere. It should be noted that citizens whose dwelling is within the sanitary protection zone, protecting their constitutional right to a favorable environment, can demand either the termination of the environmentally hazardous activities of the enterprise, or relocation at the expense of the enterprise outside the sanitary protection zone.

Architectural and planning measures include the correct mutual placement of emission sources and populated areas, taking into account the direction of the winds, the choice of a flat, elevated place for the construction of an industrial enterprise, well blown by the winds.

The Law of the Russian Federation "On Environmental Protection" (2002) contains a separate article (Article 54) devoted to the problem of protecting the ozone layer, which indicates its exceptional importance. The law provides for the following set of measures to protect the ozone layer:

Organization of observations of changes in the ozone layer under the influence of economic activity and other processes;

Compliance with the standards for permissible emissions of substances that adversely affect the state of the ozone layer;

Regulation of the production and use of chemicals that deplete the ozone layer of the atmosphere.

So, the issue of human impact on the atmosphere is in the focus of attention of ecologists around the world, since the largest global environmental problems of our time - the "greenhouse effect", the violation of the ozone layer, acid rain, are associated precisely with anthropogenic pollution of the atmosphere. To assess and predict the impact of anthropogenic factors on the state of the natural environment of the Russian Federation, the background monitoring system operating within the Global Atmosphere Watch and Global Background Monitoring Network.

The issue of human impact on the atmosphere is in the center of attention of environmentalists around the world, because. the largest environmental problems of our time (“greenhouse effect”, ozone depletion, acid rain) are associated precisely with anthropogenic pollution of the atmosphere.

Atmospheric air also performs the most complex protective function, insulating the Earth from outer space and protecting it from harsh cosmic radiation. In the atmosphere there are global meteorological processes that shape the climate and weather, a mass of meteorites lingers (burns out).

However, in modern conditions, the ability of natural systems to self-cleanse is significantly undermined by the increased anthropogenic load. As a result, the air no longer fully fulfills its protective, thermoregulating and life-supporting ecological functions.

Atmospheric air pollution should be understood as any change in its composition and properties that have a negative impact on human and animal health, the condition of plants and ecosystems as a whole. Atmospheric pollution can be natural (natural) and anthropogenic (technogenic).

Natural pollution is caused by natural processes. These include volcanic activity, weathering of rocks, wind erosion, smoke from forest and steppe fires, etc.

Anthropogenic pollution is associated with the release of various pollutants (pollutants) in the process of human activity. It surpasses the natural in scale.

Depending on the scale, there are:

local (increase in the content of pollutants in a small area: city, industrial area, agricultural zone);

regional (significant areas are involved in the sphere of negative impact, but not the entire planet);

global (change in the state of the atmosphere as a whole).

According to the state of aggregation, emissions of pollutants into the atmosphere are classified as follows:

gaseous (SO2, NOx, CO, hydrocarbons, etc.);

liquid (acids, alkalis, salt solutions, etc.);

solid (organic and inorganic dust, lead and its compounds, soot, resinous substances, etc.).

The main pollutants (pollutants) of atmospheric air, formed in the process of industrial or other human activities, are sulfur dioxide (SO2), carbon monoxide (CO) and particulate matter. They account for about 98% of the total pollutant emissions.

In addition to these main pollutants, many other very dangerous pollutants enter the atmosphere: lead, mercury, cadmium and other heavy metals (HM) (emission sources: cars, smelters, etc.); hydrocarbons (CnH m), among which the most dangerous is benzo (a) pyrene, which has a carcinogenic effect (exhaust gases, boiler furnaces, etc.); aldehydes and, first of all, formaldehyde; hydrogen sulfide, toxic volatile solvents (gasolines, alcohols, ethers), etc.

The most dangerous pollution of the atmosphere is radioactive. At present, it is mainly due to globally distributed long-lived radioactive isotopes - the products of nuclear weapons tests conducted in the atmosphere and underground. The surface layer of the atmosphere is also polluted by emissions of radioactive substances into the atmosphere from operating nuclear power plants during their normal operation and other sources.

The following industries are the main contributors to air pollution:

thermal power engineering (hydroelectric power stations and nuclear power plants, industrial and municipal boiler houses);

ferrous metallurgy enterprises,

enterprises of coal mining and coal chemistry,

vehicles (the so-called mobile sources of pollution),

non-ferrous metallurgy enterprises,

production of building materials.

Air pollution affects human health and the natural environment in various ways - from a direct and immediate threat (smog, carbon monoxide, etc.) to a slow and gradual destruction of the body's life support systems.

The physiological impact on the human body of the main pollutants (pollutants) is fraught with the most serious consequences. So, sulfur dioxide, combining with atmospheric moisture, forms sulfuric acid, which destroys the lung tissue of humans and animals. Sulfur dioxide is especially dangerous when it is deposited on dust particles and in this form penetrates deep into the respiratory tract. Dust containing silicon dioxide (SiO2) causes a severe lung disease called silicosis.

Nitrogen oxides irritate, and in severe cases corrode the mucous membranes (eyes, lungs), participate in the formation of poisonous fogs, etc.; they are especially dangerous in the air together with sulfur dioxide and other toxic compounds (there is a synergistic effect, i.e. increasing the toxicity of the entire gaseous mixture).

The effect of carbon monoxide (carbon monoxide, CO) on the human body is widely known: in acute poisoning, general weakness, dizziness, nausea, drowsiness, loss of consciousness appear, death is possible (even three to seven days after poisoning).

Among suspended particles (dusts), the most dangerous particles are less than 5 microns in size, which can penetrate into the lymph nodes, linger in the alveoli of the lungs, and clog the mucous membranes.

Very unfavorable consequences can be accompanied by such minor emissions as those containing lead, benzo(a)pyrene, phosphorus, cadmium, arsenic, cobalt, etc. These pollutants depress the hematopoietic system, cause oncological diseases, reduce immunity, etc. Dust containing lead and mercury compounds has mutagenic properties and causes genetic changes in body cells.

The consequences of exposure to the human body of harmful substances contained in the exhaust gases of cars have the widest range of action: From coughing to death.

Anthropogenic emissions of pollutants also cause great harm to plants, animals and ecosystems of the planet as a whole. Cases of mass poisoning of wild animals, birds, and insects are described as a result of emissions of harmful pollutants of high concentration (especially volleys).

The most important environmental consequences of global air pollution include:

1) possible climate warming (“greenhouse effect”);

2) violation of the ozone layer;

3) acid rain.

Possible climate warming (“greenhouse effect”) is expressed in a gradual increase in the average annual temperature, starting from the second half of the last century. Most scientists associate it with the accumulation in the atmosphere of the so-called. greenhouse gases - carbon dioxide, methane, chlorofluorocarbons (freons), ozone, nitrogen oxides, etc. Greenhouse gases prevent long-wave thermal radiation from the Earth's surface, i.e. an atmosphere saturated with greenhouse gases acts like the roof of a greenhouse: it lets in most of the solar radiation, on the other hand, almost does not let out the heat reradiated by the Earth.

According to another opinion, the most important factor in the anthropogenic impact on the global climate is atmospheric degradation, i.e. violation of the composition and condition of ecosystems due to violation of ecological balance. Man, using a power of about 10 TW, destroyed or severely disrupted the normal functioning of natural communities of organisms on 60% of the land. As a result, a significant amount of them was removed from the biogenic cycle of substances, which was previously spent by the biota on stabilizing climatic conditions.

Violation of the ozone layer - a decrease in ozone concentration at altitudes from 10 to 50 km (with a maximum at an altitude of 20 - 25 km), in some places up to 50% (the so-called "ozone holes"). A decrease in ozone concentration reduces the ability of the atmosphere to protect all life on earth from harsh ultraviolet radiation. In the human body, excessive ultraviolet exposure causes burns, skin cancer, eye diseases, immune suppression, etc. Plants under the influence of strong ultraviolet radiation gradually lose their ability to photosynthesis, and disruption of the vital activity of plankton leads to a break in the food chains of the biota of aquatic ecosystems, etc.

Acid rain is caused by the combination of atmospheric moisture with gaseous emissions of sulfur dioxide and nitrogen oxides into the atmosphere to form sulfuric and nitric acids. As a result, the precipitation is acidified (pH below 5.6). The total global emissions of the two main air pollutants that cause acidification of precipitation amount to more than 255 million tons annually. for a person.

The danger is, as a rule, not the acid precipitation itself, but the processes occurring under their influence: not only the nutrients necessary for plants, but also toxic heavy and light metals - lead, cadmium, aluminum, etc. are leached from the soil. Subsequently, they themselves or formed by them toxic compounds are assimilated by plants or other soil organisms, which leads to very negative consequences. Fifty million hectares of forests in 25 European countries are affected by a complex mixture of pollutants (toxic metals, ozone), acid rain. A striking example of the action of acid rain is the acidification of lakes, which is especially intense in Canada, Sweden, Norway and southern Finland. This is explained by the fact that a significant part of the emissions from such industrialized countries as the USA, Germany and Great Britain fall on their territory.

Pollution of atmospheric air with various harmful substances leads to the occurrence of diseases of human organs and, above all, respiratory organs.

The atmosphere always contains a certain amount of impurities coming from natural and anthropogenic sources. Impurities emitted by natural sources include: dust (of vegetable, volcanic, cosmic origin; arising from soil erosion, particles of sea salt), smoke, gases from forest and steppe fires and volcanic origin. Natural sources of pollution are either distributed, for example, cosmic dust fallout, or short-term, spontaneous, for example, forest and steppe fires, volcanic eruptions, etc. The level of atmospheric pollution by natural sources is background and changes little over time.

The main anthropogenic pollution of atmospheric air is created by enterprises of a number of industries, transport and thermal power engineering.

The most common toxic substances polluting the atmosphere are: carbon monoxide (CO), sulfur dioxide (S0 2), nitrogen oxides (No x), hydrocarbons (C P H t) and solids (dust).

In addition to CO, S0 2 , NO x , C n H m and dust, other, more toxic substances are emitted into the atmosphere: fluorine compounds, chlorine, lead, mercury, benzo (a) pyrene. Ventilation emissions from the electronics industry plant contain vapors of hydrofluoric, sulfuric, chromic and other mineral acids, organic solvents, etc. Currently, there are more than 500 harmful substances polluting the atmosphere, and their number is increasing. Emissions of toxic substances into the atmosphere lead, as a rule, to the excess of the current concentrations of substances over the maximum permissible concentrations.

High concentrations of impurities and their migration in the atmospheric air lead to the formation of secondary, more toxic compounds (smog, acids) or to phenomena such as the "greenhouse effect" and the destruction of the ozone layer.

Smog- severe air pollution observed in large cities and industrial centers. There are two types of smog:

Dense fog with an admixture of smoke or gas waste from production;

Photochemical smog is a veil of corrosive gases and aerosols of increased concentration (without fog), resulting from photochemical reactions in gaseous emissions under the influence of ultraviolet radiation from the Sun.

Smog reduces visibility, increases the corrosion of metal and structures, adversely affects health and is the cause of increased morbidity and mortality.

acid rain known for more than 100 years, however, the problem of acid rain began to pay due attention relatively recently. The expression "acid rain" was first used by Robert Angus Smith (Great Britain) in 1872.

Essentially, acid rain results from the chemical and physical transformations of sulfur and nitrogen compounds in the atmosphere. The end result of these chemical transformations is, respectively, sulfuric (H 2 S0 4) and nitric (HN0 3) acid. Subsequently, vapors or molecules of acids, absorbed by cloud droplets or aerosol particles, fall to the ground in the form of dry or wet sediment (sedimentation). At the same time, near sources of pollution, the proportion of dry acid precipitation exceeds the proportion of wet ones for sulfur-containing substances by 1.1 and for nitrogen-containing substances by 1.9 times. However, as the distance from the immediate sources of pollution increases, wet precipitation may contain more pollutants than dry precipitation.

If anthropogenic and natural air pollutants were evenly distributed over the Earth's surface, then the impact of acid precipitation on the biosphere would be less detrimental. There are direct and indirect effects of acid precipitation on the biosphere. Direct impact is manifested in the direct death of plants and trees, which occurs to the greatest extent near the source of pollution, within a radius of up to 100 km from it.

Air pollution and acid rain accelerate the corrosion of metal structures (up to 100 microns/year), destroy buildings and monuments, and especially those built from sandstone and limestone.

The indirect impact of acid precipitation on the environment is carried out through processes occurring in nature as a result of changes in the acidity (pH) of water and soil. Moreover, it manifests itself not only in the immediate vicinity of the source of pollution, but also at considerable distances, hundreds of kilometers.

A change in the acidity of the soil disrupts its structure, affects fertility and leads to the death of plants. An increase in the acidity of fresh water bodies leads to a decrease in fresh water reserves and causes the death of living organisms (the most sensitive ones begin to die already at pH = 6.5, and at pH = 4.5 only a few species of insects and plants are able to live).

the greenhouse effect. The composition and state of the atmosphere influence many processes of radiant heat exchange between the Cosmos and the Earth. The process of energy transfer from the Sun to the Earth and from the Earth to Space keeps the temperature of the biosphere at a certain level - on average +15°. At the same time, the main role in maintaining the temperature conditions in the biosphere belongs to solar radiation, which carries the decisive part of the thermal energy to the Earth, in comparison with other heat sources:

Heat from solar radiation 25 10 23 99.80

Heat from natural sources

(from the bowels of the Earth, from animals, etc.) 37.46 10 20 0.18

Heat from anthropogenic sources

(electrical installations, fires, etc.) 4.2 10 20 0.02

The violation of the Earth's heat balance, leading to an increase in the average temperature of the biosphere, which has been observed in recent decades, occurs due to the intensive release of anthropogenic impurities and their accumulation in the atmospheric layers. Most gases are transparent to solar radiation. However, carbon dioxide (C0 2), methane (CH 4), ozone (0 3), water vapor (H 2 0) and some other gases in the lower layers of the atmosphere, passing the sun's rays in the optical wavelength range - 0.38 .. .0.77 microns, prevent the passage of thermal radiation reflected from the Earth's surface in the infrared wavelength range - 0.77 ... 340 microns into outer space. The greater the concentration of gases and other impurities in the atmosphere, the smaller the proportion of heat from the Earth's surface goes into space, and the more, consequently, it is retained in the biosphere, causing climate warming.

Modeling of various climatic parameters shows that by 2050 the average temperature on Earth may increase by 1.5...4.5°C. Such warming will cause the melting of polar ice and mountain glaciers, which will lead to a rise in the level of the World Ocean by 0.5 ... 1.5 m. At the same time, the level of rivers flowing into the seas will also rise (principle of communicating vessels). All this will cause flooding of island countries, the coastal strip and territories located below sea level. Millions of refugees will appear, forced to leave their homes and migrate inland. All ports will need to be rebuilt or refurbished to accommodate the new sea level. Global warming can have an even stronger impact on the distribution of precipitation and agriculture, due to the disruption of circulation links in the atmosphere. Further climate warming by 2100 may raise the level of the World Ocean by two meters, which will lead to flooding of 5 million km 2 of land, which is 3% of all land and 30% of all productive land on the planet.

The greenhouse effect in the atmosphere is a fairly common phenomenon at the regional level as well. Anthropogenic sources of heat (thermal power plants, transport, industry) concentrated in large cities and industrial centers, intensive influx of "greenhouse" gases and dust, a stable state of the atmosphere create space near cities with a radius of up to 50 km or more with increased by 1 ... 5 ° With temperatures and high concentrations of contaminants. These zones (domes) above the cities are clearly visible from outer space. They are destroyed only with intensive movements of large masses of atmospheric air.

Destruction of the ozone layer. The main substances that destroy the ozone layer are compounds of chlorine and nitrogen. According to estimates, one chlorine molecule can destroy up to 10 5 molecules, and one molecule of nitrogen oxides - up to 10 ozone molecules. The sources of chlorine and nitrogen compounds entering the ozone layer are:

Freons, whose life expectancy reaches 100 years or more, have a significant impact on the ozone layer. Remaining unchanged for a long time, they at the same time gradually move to higher layers of the atmosphere, where short-wave ultraviolet rays knock out chlorine and fluorine atoms from them. These atoms react with ozone in the stratosphere and accelerate its decay, while remaining unchanged. Thus, freon plays the role of a catalyst here.

Sources and levels of pollution of the hydrosphere. Water is the most important environmental factor, which has a diverse impact on all vital processes of the body, including human morbidity. It is a universal solvent of gaseous, liquid and solid substances, and also participates in the processes of oxidation, intermediate metabolism, digestion. Without food, but with water, a person can live for about two months, and without water - for several days.

The daily balance of water in the human body is about 2.5 liters.

The hygienic value of water is great. It is used to maintain the human body, household items, housing in proper sanitary condition, and has a beneficial effect on the climatic conditions of the population's recreation and life. But it can also be a source of danger to humans.

Currently, about half of the world's population is deprived of the opportunity to consume enough clean fresh water. Developing countries suffer the most from this, where 61% of rural residents are forced to use epidemiologically unsafe water, and 87% do not have sewerage.

It has long been noted that the water factor in the spread of acute intestinal infections and invasions is of exceptionally great importance. Salmonella, Escherichia coli, Vibrio cholerae, etc. may be present in the water of water sources. Some pathogenic microorganisms persist for a long time and even multiply in natural water.

The source of contamination of surface water bodies can be untreated sewage.

Water epidemics are considered to be characterized by a sudden rise in the incidence, maintaining a high level for some time, limiting the epidemic outbreak to a circle of people using a common water supply source, and the absence of diseases among residents of the same settlement, but using a different source of water supply.

Recently, the initial quality of natural water has been changing due to irrational human activities. The penetration into the aquatic environment of various toxicants and substances that change the natural composition of water poses an exceptional danger to natural ecosystems and humans.

There are two directions in human use of the Earth's water resources: water use and water consumption.

At water use water, as a rule, is not withdrawn from water bodies, but its quality may vary. Water use includes the use of water resources for hydropower, shipping, fishing and fish farming, recreation, tourism and sports.

At water consumption water is withdrawn from water bodies and either included in the composition of the produced products (and together with evaporation losses in the production process is included in irretrievable water consumption), or partially returned to the reservoir, but usually of a much worse quality.

Wastewater annually carries a large number of various chemical and biological contaminants into the water bodies of Kazakhstan: copper, zinc, nickel, mercury, phosphorus, lead, manganese, petroleum products, detergents, fluorine, nitrate and ammonium nitrogen, arsenic, pesticides - this is far from complete and an ever-growing list of substances entering the aquatic environment.

Ultimately, water pollution poses a threat to human health through the consumption of fish and water.

Not only primary pollution of surface waters is dangerous, but also secondary pollution, the occurrence of which is possible as a result of chemical reactions of substances in the aquatic environment.

The consequences of pollution of natural waters are diverse, but, in the end, they reduce the supply of drinking water, cause diseases of people and all living things, and disrupt the circulation of many substances in the biosphere.

Sources and levels of pollution of the lithosphere. As a result of economic (domestic and industrial) human activities, various amounts of chemicals enter the soil: pesticides, mineral fertilizers, plant growth stimulants, surface-active substances (surfactants), polycyclic aromatic hydrocarbons (PAHs), industrial and domestic wastewater, industrial emissions enterprises and transport, etc. Accumulating in the soil, they adversely affect all metabolic processes occurring in it, and prevent its self-purification.

The problem of household waste disposal is becoming more and more difficult. Huge garbage dumps have become a characteristic feature of urban outskirts. It is no coincidence that the term "garbage civilization" is sometimes used in relation to our time.

In Kazakhstan, on average, up to 90% of all toxic production waste is subject to annual burial and organized storage. These wastes contain arsenic, lead, zinc, asbestos, fluorine, phosphorus, manganese, petroleum products, radioactive isotopes and electroplating waste.

Severe soil pollution in the Republic of Kazakhstan occurs due to the lack of necessary control over the use, storage, transportation of mineral fertilizers and pesticides. The fertilizers used, as a rule, are not purified, therefore, many toxic chemical elements and their compounds enter the soil with them: arsenic, cadmium, chromium, cobalt, lead, nickel, zinc, selenium. In addition, an excess of nitrogen fertilizers leads to the saturation of vegetables with nitrates, which causes human poisoning. Currently, there are many different pesticides (pesticides). Only in Kazakhstan more than 100 types of pesticides are used annually (Metaphos, Decis, BI-58, Vitovax, Vitothiuram, etc.), which have a wide spectrum of activity, although they are used for a limited number of crops and insects. They remain in the soil for a long time and exhibit a toxic effect on all organisms.

There are cases of chronic and acute poisoning of people during agricultural work in fields, vegetable gardens, orchards treated with pesticides or contaminated with chemicals contained in atmospheric emissions from industrial enterprises.

The entry of mercury into the soil, even in small amounts, has a great impact on its biological properties. Thus, it has been established that mercury reduces the ammonifying and nitrifying activity of the soil. The increased content of mercury in the soil of populated areas adversely affects the human body: there are frequent diseases of the nervous and endocrine systems, genitourinary organs, and reduced fertility.

When lead enters the soil, it inhibits the activity of not only nitrifying bacteria, but also antagonist microorganisms of the Flexner and Sonne coli and dysentery, and prolongs the period of soil self-purification.

The chemical compounds in the soil are washed off its surface into open water bodies or enter the ground water flow, thereby affecting the qualitative composition of domestic and drinking water, as well as food products of plant origin. The qualitative composition and quantity of chemicals in these products is largely determined by the type of soil and its chemical composition.

The special hygienic importance of the soil is associated with the risk of transmission to humans of pathogens of various infectious diseases. Despite the antagonism of the soil microflora, pathogens of many infectious diseases are able to remain viable and virulent in it for a long time. During this time, they can pollute underground water sources and infect humans.

With soil dust, pathogens of a number of other infectious diseases can spread: tuberculosis microbacteria, poliomyelitis viruses, Coxsackie, ECHO, etc. Soil also plays an important role in the spread of epidemics caused by helminths.

3. Industrial enterprises, energy facilities, communications and transport are the main sources of energy pollution in industrial regions, the urban environment, housing and natural areas. Energy pollution includes vibration and acoustic effects, electromagnetic fields and radiation, exposure to radionuclides and ionizing radiation.

Vibrations in the urban environment and residential buildings, the source of which is technological impact equipment, rail vehicles, construction machines and heavy vehicles, propagate through the ground.

Noise in the urban environment and residential buildings is generated by vehicles, industrial equipment, sanitary installations and devices, etc. On urban highways and in adjacent areas, sound levels can reach 70 ... 80 dB A, and in some cases 90 dB A and more. Sound levels are even higher near airports.

Sources of infrasound can be both natural (wind blowing of building structures and the water surface) and anthropogenic (moving mechanisms with large surfaces - vibrating platforms, vibrating screens; rocket engines, high-power internal combustion engines, gas turbines, vehicles). In some cases, the sound pressure levels of infrasound can reach the standard values ​​of 90 dB, and even exceed them, at considerable distances from the source.

The main sources of electromagnetic fields (EMF) of radio frequencies are radio engineering facilities (RTO), television and radar stations (RLS), thermal shops and sites (in areas adjacent to enterprises).

In everyday life, sources of EMF and radiation are televisions, displays, microwave ovens and other devices. Electrostatic fields in conditions of low humidity (less than 70%) create carpets, capes, curtains, etc.

The radiation dose generated by anthropogenic sources (with the exception of radiation exposure during medical examinations) is small compared to the natural background of ionizing radiation, which is achieved by using collective protective equipment. In those cases when regulatory requirements and radiation safety rules are not observed at economic facilities, the levels of ionizing impact increase sharply.

Dispersion in the atmosphere of radionuclides contained in emissions leads to the formation of pollution zones near the source of emissions. Usually, the zones of anthropogenic exposure of residents living around nuclear fuel processing facilities at a distance of up to 200 km range from 0.1 to 65% of the natural radiation background.

The migration of radioactive substances in the soil is determined mainly by its hydrological regime, the chemical composition of the soil and radionuclides. Sandy soils have a lower sorption capacity, while clay soils, loams and chernozems have a larger one. 90 Sr and l 37 Cs have high retention strength in soil.

The experience of liquidating the consequences of the accident at the Chernobyl nuclear power plant shows that agricultural production is unacceptable in areas with a pollution density above 80 Ci / km 2, and in areas contaminated up to 40 ... 50 Ci / km 2, it is necessary to limit the production of seed and industrial crops, as well as feed for young and fattening beef cattle. With a pollution density of 15...20 Ci/kg for 137 Cs, agricultural production is quite acceptable.

Of the considered energy pollution in modern conditions, radioactive and acoustic pollution have the greatest negative impact on humans.

Negative factors in emergency situations. Emergencies arise during natural phenomena (earthquakes, floods, landslides, etc.) and man-made accidents. To the greatest extent, the accident rate is characteristic of the coal, mining, chemical, oil and gas and metallurgical industries, geological exploration, boiler supervision, gas and material handling facilities, as well as transport.

Destruction or depressurization of high pressure systems, depending on the physical and chemical properties of the working environment, can lead to the appearance of one or a combination of damaging factors:

Shock wave (consequences - injuries, destruction of equipment and supporting structures, etc.);

Fire of buildings, materials, etc. (consequences - thermal burns, loss of structural strength, etc.);

Chemical pollution of the environment (consequences - suffocation, poisoning, chemical burns, etc.);

Pollution of the environment with radioactive substances. Emergencies also arise as a result of unregulated storage and transportation of explosives, flammable liquids, chemical and radioactive substances, supercooled and heated liquids, etc. Explosions, fires, spills of chemically active liquids, emissions of gas mixtures are the consequences of violations of the rules of operations.

One of the common causes of fires and explosions, especially at oil and gas and chemical production facilities and during the operation of vehicles, is static electricity discharges. Static electricity is a set of phenomena associated with the formation and preservation of a free electric charge on the surface and in the volume of dielectric and semiconductor substances. The cause of static electricity is the processes of electrification.

Natural static electricity is generated on the surface of clouds as a result of complex atmospheric processes. Charges of atmospheric (natural) static electricity form a potential relative to the Earth of several million volts, leading to lightning strikes.

Spark discharges of artificial static electricity are common causes of fires, and spark discharges of atmospheric static electricity (lightning) are common causes of larger emergencies. They can cause both fires and mechanical damage to equipment, disruptions in communication lines and power supply to certain areas.

Discharges of static electricity and sparks in electrical circuits create a great danger in conditions of high content of combustible gases (for example, methane in mines, natural gas in residential premises) or combustible vapors and dust in premises.

The main causes of major man-made accidents are:

Failures of technical systems due to manufacturing defects and violations of operating modes; many modern potentially hazardous industries are designed in such a way that the probability of a major accident is very high and is estimated at a risk value of 10 4 or more;

Erroneous actions of operators of technical systems; statistics show that more than 60% of accidents occurred as a result of errors of maintenance personnel;

The concentration of various industries in industrial zones without a proper study of their mutual influence;

High energy level of technical systems;

External negative impacts on energy facilities, transport, etc.

Practice shows that it is impossible to solve the problem of complete elimination of negative impacts in the technosphere. To ensure protection in the conditions of the technosphere, it is only realistic to limit the impact of negative factors to their permissible levels, taking into account their combined (simultaneous) action. Compliance with the maximum permissible levels of exposure is one of the main ways to ensure the safety of human life in the technosphere.

4. Production environment and its characteristics. About 15 thousand people die in production every year. and about 670 thousand people are injured. According to Deputy Chairman of the Council of Ministers of the USSR Dogudzhiev V.X. in 1988, there were 790 major accidents and 1 million cases of group injuries in the country. This determines the importance of the safety of human activity, which distinguishes it from all living things - Mankind at all stages of its development paid serious attention to the conditions of activity. In the works of Aristotle, Hippocrates (III-V) century BC), working conditions are considered. During the Renaissance, the physician Paracelsus studied the dangers of mining, the Italian physician Ramazzini (XVII century) laid the foundations of professional hygiene. And society's interest in these problems is growing, because behind the term "safety of activity" is a person, and "man is the measure of all things" (philosopher Protagoras, V century BC).

Activity is the process of human interaction with nature and the built environment. The totality of factors affecting a person in the process of activity (labor) in production and in everyday life constitutes the conditions of activity (labor). Moreover, the action of the factors of conditions can be favorable and unfavorable for a person. The impact of a factor that could pose a threat to life or damage to human health is called a hazard. Practice shows that any activity is potentially dangerous. This is an axiom about the potential danger of activity.

The growth of industrial production is accompanied by a continuous increase in the impact of the production environment on the biosphere. It is believed that every 10 ... 12 years the volume of production doubles, respectively, the volume of emissions into the environment also increases: gaseous, solid and liquid, as well as energy. At the same time, pollution of the atmosphere, water basin and soil takes place.

An analysis of the composition of pollutants emitted into the atmosphere by a machine-building enterprise shows that, in addition to the main pollutants (СО, S0 2 , NO n , C n H m , dust), the emissions contain toxic compounds that have a significant negative impact on the environment. The concentration of harmful substances in ventilation emissions is low, but the total amount of harmful substances is significant. Emissions are produced with variable frequency and intensity, but due to the low height of the release, dispersal and poor purification, they greatly pollute the air on the territory of enterprises. With a small width of the sanitary protection zone, difficulties arise in ensuring clean air in residential areas. A significant contribution to air pollution is made by the power plants of the enterprise. They emit CO 2 , CO, soot, hydrocarbons, SO 2 , S0 3 PbO, ash and particles of unburned solid fuel into the atmosphere.

The noise generated by an industrial enterprise should not exceed the maximum allowable spectra. At enterprises, mechanisms that are a source of infrasound (internal combustion engines, fans, compressors, etc.) can operate. Permissible sound pressure levels of infrasound are established by sanitary standards.

Technological impact equipment (hammers, presses), powerful pumps and compressors, engines are sources of vibrations in the environment. Vibrations propagate along the ground and can reach the foundations of public and residential buildings.

Test questions:

1. How are energy sources divided?

2. What energy sources are natural?

3. What are the physical hazards and harmful factors?

4. How are chemical hazards and harmful factors divided?

5. What do biological factors include?

6. What are the consequences of atmospheric air pollution by various harmful substances?

7. What is the number of impurities emitted by natural sources?

8. What sources create the main anthropogenic air pollution?

9. What are the most common toxic substances polluting the atmosphere?

10. What is smog?

11. What types of smog are distinguished?

12. What causes acid rain?

13. What causes the destruction of the ozone layer?

14. What are the sources of pollution of the hydrosphere?

15. What are the sources of pollution of the lithosphere?

16. What is a surfactant?

17. What is the source of vibration in the urban environment and residential buildings?

18. What level can sound reach on city highways and in the areas adjacent to them?

Outdoor air pollution

Atmospheric air pollution should be understood as any change in its composition and properties that has a negative impact on human and animal health, the state of plants and ecosystems.

Atmospheric pollution can be natural (natural) and anthropogenic (technogenic).

natural pollution air is caused by natural processes. These include volcanic activity, weathering of rocks, wind erosion, mass flowering of plants, smoke from forest and steppe fires, etc. Anthropogenic pollution associated with the release of various pollutants in the process of human activity. In terms of its scale, it significantly exceeds natural air pollution.

Depending on the scale of distribution, various types of atmospheric pollution are distinguished: local, regional and global. local pollution is characterized by an increased content of pollutants in small areas (city, industrial area, agricultural zone, etc.). regional pollution significant areas are involved in the sphere of negative impact, but not the entire planet. Global pollution associated with changes in the state of the atmosphere as a whole.

According to the state of aggregation, emissions of harmful substances into the atmosphere are classified into:

1) gaseous (sulfur dioxide, nitrogen oxides, carbon monoxide, hydrocarbons, etc.)

2) liquid (acids, alkalis, salt solutions, etc.);

3) solid (carcinogenic substances, lead and its compounds, organic and inorganic dust, soot, tarry substances, etc.).

The most dangerous pollution of the atmosphere is radioactive. At present, it is mainly due to globally distributed long-lived radioactive isotopes - products of nuclear weapons tests conducted in the atmosphere and underground. The surface layer of the atmosphere is also polluted by emissions of radioactive substances into the atmosphere from operating nuclear power plants during their normal operation and other sources.

Another form of atmospheric pollution is local excess heat input from anthropogenic sources. A sign of thermal (thermal) pollution of the atmosphere is the so-called thermal tones, for example, a “heat island” in cities, warming of water bodies, etc.

In general, judging by official data for 1997-1999, the level of atmospheric air pollution in our country, especially in Russian cities, remains high, despite a significant decline in production, which is associated primarily with an increase in the number of cars, including - faulty.

Environmental effects of atmospheric pollution

Air pollution affects human health and the natural environment in various ways - from a direct and immediate threat (smog, etc.) to a slow and gradual destruction of various life support systems of the body. In many cases, air pollution disrupts the structural components of the ecosystem to such an extent that regulatory processes are unable to return them to their original state, and as a result, the homeostasis mechanism does not work.

First, consider how it affects the environment local (local) pollution atmosphere, and then global.

The physiological impact on the human body of the main pollutants (pollutants) is fraught with the most serious consequences. So, sulfur dioxide, combining with moisture, forms sulfuric acid, which destroys the lung tissue of humans and animals. This relationship is especially clearly seen in the analysis of childhood pulmonary pathology and the degree of sulfur dioxide concentration in the atmosphere of large cities.

Dust containing silicon dioxide (SiO 2 ) causes severe lung disease - silicosis. Nitrogen oxides irritate and, in severe cases, corrode mucous membranes, for example, eyes, lungs, participate in the formation of poisonous mists, etc. They are especially dangerous if they are contained in polluted air together with sulfur dioxide and other toxic compounds. In these cases, even at low concentrations of pollutants, a synergistic effect occurs, i.e., an increase in the toxicity of the entire gaseous mixture.

The effect of carbon monoxide (carbon monoxide) on the human body is widely known. In acute poisoning, general weakness, dizziness, nausea, drowsiness, loss of consciousness appear, and death is possible (even after three to seven days). However, due to the low concentration of CO in the atmospheric air, as a rule, it does not cause mass poisoning, although it is very dangerous for people suffering from anemia and cardiovascular diseases.

Among the suspended solid particles, the most dangerous particles are less than 5 microns in size, which can penetrate the lymph nodes, linger in the alveoli of the lungs, and clog the mucous membranes.

Anabiosis- temporary suspension of all vital processes.

Very unfavorable consequences, which can affect a huge time interval, are also associated with such minor emissions as lead, benzo (a) pyrene, phosphorus, cadmium, arsenic, cobalt, etc. They depress the hematopoietic system, cause oncological diseases, reduce the body's resistance to infections, etc. Dust containing lead and mercury compounds has mutagenic properties and causes genetic changes in the cells of the body.

The consequences of exposure to the human body of harmful substances contained in the exhaust gases of cars are very serious and have the widest range of action:

London type of smog occurs in winter in large industrial cities under adverse weather conditions (lack of wind and temperature inversion). Temperature inversion manifests itself in an increase in air temperature with height in a certain layer of the atmosphere (usually in the range of 300-400 m from the earth's surface) instead of the usual decrease. As a result, atmospheric air circulation is severely disrupted, smoke and pollutants cannot rise up and are not dispersed. Often there are fogs. Concentrations of sulfur oxides, suspended dust, carbon monoxide reach dangerous levels for human health, lead to circulatory and respiratory disorders, and often to death.

Los Angeles type of smog or photochemical smog, no less dangerous than London. It occurs in the summer with intense exposure to solar radiation on air saturated, or rather supersaturated with car exhaust gases.

Anthropogenic emissions of pollutants in high concentrations and for a long time cause great harm not only to humans, but also negatively affect animals, the state of plants and ecosystems as a whole.

Ecological literature describes cases of mass poisoning of wild animals, birds, and insects due to emissions of harmful pollutants of high concentration (especially salvos). Thus, for example, it has been established that when certain toxic types of dust settle on melliferous plants, a noticeable increase in the mortality of bees is observed. As for large animals, the poisonous dust in the atmosphere affects them mainly through the respiratory organs, as well as entering the body along with the dusty plants eaten.

Toxic substances enter plants in various ways. It has been established that emissions of harmful substances act both directly on the green parts of plants, getting through the stomata into tissues, destroying chlorophyll and cell structure, and through the soil to the root system. So, for example, soil contamination with dust of toxic metals, especially in combination with sulfuric acid, has a detrimental effect on the root system, and through it on the whole plant.

Gaseous pollutants affect vegetation in different ways. Some only slightly damage leaves, needles, shoots (carbon monoxide, ethylene, etc.), others have a detrimental effect on plants (sulfur dioxide, chlorine, mercury vapor, ammonia, hydrogen cyanide, etc.) Sulfur dioxide (SO 2 ), under the influence of which many trees die, and first of all conifers - pines, spruces, firs, cedars.

As a result of the impact of highly toxic pollutants on plants, there is a slowdown in their growth, the formation of necrosis at the ends of leaves and needles, failure of assimilation organs, etc. An increase in the surface of damaged leaves can lead to a decrease in moisture consumption from the soil, its general waterlogging, which will inevitably affect in her habitat.

Can vegetation recover after exposure to harmful pollutants is reduced? This will largely depend on the restoring capacity of the remaining green mass and the general condition of natural ecosystems. At the same time, it should be noted that low concentrations of individual pollutants not only do not harm plants, but, like cadmium salt, for example, stimulate seed germination, wood growth, and the growth of some plant organs.

The main pollutants of atmospheric air, formed both in the course of human economic activity and as a result of natural processes, are sulfur dioxide SO2, carbon dioxide CO2, nitrogen oxides NOx, particulate matter - aerosols. Their share is 98% in the total emissions of harmful substances. In addition to these main pollutants, more than 70 types of harmful substances are observed in the atmosphere: formaldehyde, phenol, benzene, compounds of lead and other heavy metals, ammonia, carbon disulfide, etc.

Environmental effects of atmospheric pollution

The most important environmental consequences of global air pollution include:

• possible climate warming (greenhouse effect);
• damage to the ozone layer
• Acid rainfall
• · deterioration of health.

the greenhouse effect

The greenhouse effect is an increase in the temperature of the lower layers of the Earth's atmosphere compared to the effective temperature, i.e. the temperature of the planet's thermal radiation observed from space.

The currently observed climate change, which is expressed in a gradual increase in the average annual temperature, starting from the second half of the 20th century, most scientists associate with the accumulation of so-called greenhouse gases in the atmosphere: CO2, CH4, chlorofluorocarbons (freons), ozone, nitrogen oxides, etc. The greenhouse gases of the atmosphere, and primarily CO2, let in most of the solar short-wave radiation (λ = 0.4-1.5 μm), but prevent long-wave radiation from the Earth's surface (λ = 7.8-28 μm).

Calculations show that in 2005 the average annual temperature is 1.3 °C higher than in 1950-1980, and by 2100 it will be 2-4 °C higher. The environmental consequences of such warming can be catastrophic. As a result of the melting of polar ice and mountain glaciers, the level of the World Ocean may rise by 0.5-2.0 m by the end of the 21st century, and this will lead to flooding of the coastal plains in more than 30 countries, swamping of vast territories, and disruption of the climatic balance.

From another point of view, the amount of precipitation formed as a result of warming, moisture accumulates in polar latitudes, as a result, the level of the World Ocean should decrease. The balance of polar glaciation will be upset if warming exceeds 5 °C.

In December 1997, at a meeting in Kyoto (Japan) dedicated to global climate change, delegates from more than 160 countries adopted a convention obliging developed countries to reduce CO2 emissions. The Kyoto Protocol obliges 38 industrialized countries to reduce by 2008-2012. CO2 emissions by 5% of 1990 levels:

The European Union is to cut CO2 and other greenhouse gas emissions by 8%, the US by 7% and Japan by 6%.

The protocol provides for a system of quotas for greenhouse gas emissions. Its essence lies in the fact that each of the countries (so far this applies only to thirty-eight countries that have committed themselves to reduce emissions) receives permission to emit a certain amount of greenhouse gases. At the same time, it is assumed that some countries or companies will exceed the emission quota. In such cases, these countries or companies will be able to buy the right to additional emissions from those countries or companies whose emissions are less than the allocated quota. Thus, it is assumed that the main goal of reducing greenhouse gas emissions in the next 15 years by 5% will be achieved.

As other causes of climate warming, scientists call the variability of solar activity, changes in the Earth's magnetic field and atmospheric electric field.

Ozone depletion

A decrease in ozone concentration weakens the ability of the atmosphere to protect all life on Earth from harsh UV radiation. Plants under the influence of strong UV radiation lose their ability to photosynthesis, there is an increase in skin cancer in humans, and a decrease in immunity.

The "ozone hole" is understood as a significant space in the ozone layer of the atmosphere with a markedly reduced (up to 50%) ozone content. The first "ozone hole" was discovered over Antarctica in the early 80s. XX century. Since then, measurements have confirmed the depletion of the ozone layer throughout the planet. It is believed that this phenomenon is of anthropogenic origin and is associated with an increase in the content of chlorofluorocarbons (CFCs) or freons in the atmosphere. Freons are widely used in industry and in everyday life as aerosols, refrigerants, solvents.

Freons are highly stable compounds. The lifetime of some freons is 70-100 years. They do not absorb long wavelength solar radiation and cannot be affected by it in the lower atmosphere. But, rising into the upper layers of the atmosphere, freons overcome the protective layer. Short-wave radiation releases free chlorine atoms from them. The chlorine atoms then react with ozone:

CFCl3 + hn > CFCl2 + Cl,

Cl + O3 > ClO + O2,

ClO + O > Cl + O2.

Thus, the decomposition of CFCs by solar radiation creates a chain reaction, according to which 1 chlorine atom can destroy up to 100,000 ozone molecules.

Other chemicals can also destroy ozone, such as carbon tetrachloride CCl4 and nitric oxide N2O:

O3 + NO> NO2 + O2,

N2O + O3 = 2NO + O2.

It should be noted that some scientists insist on the natural origin of ozone holes.

acid rain

Acid rain is formed as a result of industrial emissions of sulfur dioxide and nitrogen oxides into the atmosphere, which, when combined with atmospheric moisture, form sulfuric and nitric acids. Pure rainwater has a slightly acid reaction pH = 5.6, since CO2 easily dissolves in it with the formation of weak carbonic acid H2CO3. Acid precipitation has pH = 3-5, the maximum recorded acidity in Western Europe is pH = 2.3.

Sulfur oxides enter the air ~ 40% from natural sources (volcanic activity, waste products of microorganisms) and ~ 60% from anthropogenic sources (the product of burning fossil fuels containing sulfur at thermal power plants, in industry, during the operation of vehicles). Natural sources of nitrogen compounds are lightning discharges, soil emissions, biomass combustion (63%), anthropogenic - emissions from vehicles, industry, thermal power plants (37%).

The main reactions in the atmosphere:

2SO2 + O2 > 2SO3

SO3 + H2O > H2SO4

• 2NO + O2 > 2NO2
• 4NO2 + 2H2O + O2 > 4HNO3

The danger is not the acid precipitation itself, but the processes occurring under their influence. Acid precipitation poses the greatest danger when it enters water bodies and soils, which leads to a decrease in the pH of the environment. The solubility of aluminum and heavy metals that are toxic to living organisms depends on the pH value. When the pH changes, the structure of the soil changes, its fertility decreases.