Levels of air pollution. Reference

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There are various sources of air pollution, and some of them have a significant and extremely adverse impact on the environment. It is worth considering the main polluting factors in order to prevent serious consequences and save the environment.

Source classification

All sources of pollution are divided into two broad groups.

1. Natural or natural, which cover factors due to the activity of the planet itself and in no way dependent on humanity.
2. Artificial or anthropogenic pollutants associated with vigorous activity person.

If we take the degree of impact of the pollutant as the basis for the classification of sources, then we can distinguish powerful, medium and small ones. The latter include small boiler plants, local boilers. The category of powerful sources of pollution includes large industrial enterprises that emit tons of harmful compounds into the air every day.

By place of education

According to the features of the output of mixtures, pollutants are divided into non-stationary and stationary. The latter are constantly in one place and carry out emissions in a certain zone. Non-stationary sources of air pollution can move and thus spread hazardous compounds through the air. First of all, these are motor vehicles.

Spatial characteristics of emissions can also be taken as the basis for classification. There are high (pipes), low (drains and ventilation openings), areal (large accumulations of pipes) and linear (highways) pollutants.

By level of control

According to the level of control, pollution sources are divided into organized and unorganized. The impact of the former is regulated and subject to periodic monitoring. The latter carry out emissions in inappropriate places and without appropriate equipment, that is, illegally.

Another option for dividing the sources of air pollution is by the scale of distribution of pollutants. Pollutants can be local, affecting only certain small areas. There are also regional sources, the effect of which extends to entire regions and large zones. But the most dangerous are global sources that affect the entire atmosphere.

According to the nature of the pollution

If the nature of the negative polluting effect is used as the main classification criterion, then the following categories can be distinguished:

• Physical pollutants include noise, vibration, electromagnetic and thermal radiation, radiation, mechanical impacts.
• Biological contaminants can be viral, microbial or fungal in nature. These pollutants include both airborne pathogens and their waste products and toxins.
• Sources of chemical air pollution in the residential environment include gaseous mixtures and aerosols, for example, heavy metals, dioxides and oxides of various elements, aldehydes, ammonia. Such compounds are usually discarded by industrial enterprises.

Anthropogenic pollutants have their own classifications. The first assumes the nature of the sources and includes:

• Transport.
• Household - arising in the processes of waste processing or fuel combustion.
• Production, covering substances formed during technical processes.

By composition, all polluting components are divided into chemical (aerosol, dust-like, gaseous chemicals and substances), mechanical (dust, soot and other solid particles) and radioactive (isotopes and radiation).

natural springs

Consider the main sources of air pollution of natural origin:

• Volcanic activity. From the bowels earth's crust during eruptions, tons of boiling lava rise, during the combustion of which clouds of smoke are formed, containing particles of rocks and soil layers, soot and soot. Also, the combustion process can generate other hazardous compounds, such as sulfur oxides, hydrogen sulfide, sulfates. And all these substances under pressure are ejected from the crater and immediately rush into the air, contributing to its significant pollution.
• Fires that occur in peat bogs, in the steppes and forests. Every year they destroy tons of natural fuel, during the combustion of which harmful substances are released that clog the air basin. In most cases, fires are caused by the negligence of people, and it can be extremely difficult to stop the elements of fire.
• Plants and animals also unknowingly pollute the air. Flora can give off gases and spread pollen, all of which contribute to air pollution. Animals in the process of life also emit gaseous compounds and other substances, and after their death, decomposition processes have a detrimental effect on the environment.
• Dust storms. During such phenomena, tons of soil particles and other solid elements rise into the atmosphere, which inevitably and significantly pollute the environment.

Anthropogenic sources

Anthropogenic sources of pollution are global problem modern humanity, due to the rapid pace of development of civilization and all spheres of human life. Such pollutants are man-made, and although they were originally introduced for the good and to improve the quality and comfort of life, today they are a fundamental factor in global atmospheric pollution.

Consider the main artificial pollutants:

• Cars are the scourge of modern humanity. Today, many have them and have turned from luxury into necessary funds movement, but, unfortunately, few people think about how harmful the use of vehicles is for the atmosphere. When fuel is burned and during engine operation, carbon monoxide and carbon dioxide, benzapyrene, hydrocarbons, aldehydes, and nitrogen oxides are emitted from the exhaust pipe in a constant stream. But it is worth noting that they adversely affect the environment and air and other modes of transport, including rail, air, and water.
• The activity of industrial enterprises. They can be engaged in the processing of metals, chemical industry and any other activities, but almost all large factories constantly emit tons of chemicals, solid particles, combustion products into the air basin. And if we take into account that only a few enterprises use treatment facilities, then the scale of the negative impact of the constantly developing industry on the environment is simply enormous.
• Use of boiler plants, nuclear and thermal power plants. Fuel combustion is a process that is harmful and dangerous in terms of atmospheric pollution, during which a lot of various substances, including toxic ones, are released.
• Another factor in the pollution of the planet and its atmosphere is the widespread and active use of different types fuels such as gas, oil, coal, firewood. When they are burned and under the influence of oxygen, numerous compounds are formed, rushing up and rising into the air.

Can pollution be prevented?

Unfortunately, in the current modern conditions It is extremely difficult to completely eliminate air pollution in the life of most people, but it is still very difficult to try to stop or minimize some of the harmful effects exerted on it. And only comprehensive measures taken everywhere and jointly will help in this. These include:

1. The use of modern and high-quality treatment facilities at large industrial enterprises whose activities are related to emissions.
2. Rational use of vehicles: switching to high-quality fuel, the use of emission-reducing agents, stable operation of the machine and troubleshooting. And it is better, if possible, to abandon cars in favor of trams and trolleybuses.
3. Implementation of legislative measures at the state level. Some laws are already in force, but new ones with greater force are needed.
4. The introduction of ubiquitous pollution control points, which are especially needed within large enterprises.
5. Switching to alternative and less dangerous for environment energy sources. Yes, you should use more windmills, hydroelectric power plants, solar panels, electricity.
6. Timely and competent processing of waste will avoid emissions emitted by them.
7. Greening the planet will be an effective measure, as many plants emit oxygen and thereby purify the atmosphere.

The main sources of air pollution are considered, and such information will help to understand the essence of the problem of environmental degradation, as well as stop the impact and preserve nature.

Pollution of the Earth's atmosphere is a change in the natural concentration of gases and impurities in the air shell of the planet, as well as the introduction of alien substances into the environment.

For the first time about at the international level started talking forty years ago. In 1979, the Convention on Transfrontier Long Distances appeared in Geneva. The first international agreement to reduce emissions was the 1997 Kyoto Protocol.

Although these measures bring results, air pollution remains a serious problem for society.

Substances polluting the atmosphere

The main components of atmospheric air are nitrogen (78%) and oxygen (21%). The share of the inert gas argon is slightly less than a percent. The concentration of carbon dioxide is 0.03%. In small quantities in the atmosphere are also present:

• ozone,
• neon,
• methane,
• xenon,
• krypton,
• nitrous oxide,
• sulfur dioxide,
• helium and hydrogen.

In clean air masses, carbon monoxide and ammonia are present in the form of traces. In addition to gases, the atmosphere contains water vapor, salt crystals, and dust.

Main air pollutants:

• Carbon dioxide is a greenhouse gas that affects the heat exchange of the Earth with the surrounding space, and hence the climate.
• Carbon monoxide or carbon monoxide, entering the human or animal body, causes poisoning (up to death).
• Hydrocarbons are toxic chemicals that irritate the eyes and mucous membranes.
• Sulfur derivatives contribute to the formation and drying of plants, provoke respiratory diseases and allergies.
• Nitrogen derivatives lead to inflammation of the lungs, croup, bronchitis, frequent colds, and exacerbate the course of cardiovascular diseases.
• , accumulating in the body, cause cancer, gene changes, infertility, premature death.

Air containing heavy metals poses a particular danger to human health. Pollutants such as cadmium, lead, arsenic lead to oncology. Inhaled mercury vapor does not act with lightning speed, but, being deposited in the form of salts, destroy nervous system. In significant concentrations, volatile organic substances are also harmful: terpenoids, aldehydes, ketones, alcohols. Many of these air pollutants are mutagenic and carcinogenic compounds.

Sources and classification of atmospheric pollution

Based on the nature of the phenomenon, the following types of air pollution are distinguished: chemical, physical and biological.

• In the first case, an increased concentration of hydrocarbons, heavy metals, sulfur dioxide, ammonia, aldehydes, nitrogen and carbon oxides is observed in the atmosphere.
• With biological pollution, the air contains waste products of various organisms, toxins, viruses, spores of fungi and bacteria.
• A large amount of dust or radionuclides in the atmosphere indicates physical pollution. The same type includes the consequences of thermal, noise and electromagnetic emissions.

The composition of the air environment is influenced by both man and nature. Natural sources of air pollution: active volcanoes, forest fires, soil erosion, dust storms, decomposition of living organisms. A tiny fraction of the influence falls on cosmic dust formed as a result of the combustion of meteorites.

Anthropogenic sources of air pollution:

• enterprises of the chemical, fuel, metallurgical, machine-building industries;
• agricultural activities (spraying pesticides with the help of aircraft, animal waste);
• thermal power plants, residential heating with coal and wood;
• transport (the “dirtiest” types are airplanes and cars).

How is air pollution determined?

When monitoring the quality of atmospheric air in the city, not only the concentration of substances harmful to human health is taken into account, but also the time period of their impact. Air pollution in Russian Federation evaluated according to the following criteria:

• The standard index (SI) is an indicator obtained by dividing the highest measured single concentration of a pollutant by the maximum allowable concentration of an impurity.
• The pollution index of our atmosphere (API) is a complex value, the calculation of which takes into account the hazard coefficient of a pollutant, as well as its concentration - the average annual and the maximum allowable average daily.
• The highest frequency (NP) - expressed as a percentage of the frequency of exceeding the maximum allowable concentration (maximum one-time) within a month or a year.

The level of air pollution is considered low when SI is less than 1, API varies between 0–4, and NP does not exceed 10%. Among the major Russian cities, according to Rosstat, the most environmentally friendly are Taganrog, Sochi, Grozny and Kostroma.

With an increased level of emissions into the atmosphere, SI is 1–5, API is 5–6, and NP is 10–20%. High degree air pollution differ regions with indicators: SI - 5-10, API - 7-13, NP - 20-50%. A very high level of atmospheric pollution is observed in Chita, Ulan-Ude, Magnitogorsk and Beloyarsk.

Cities and countries of the world with the dirtiest air

In May 2016, the World Health Organization published an annual ranking of cities with the dirtiest air. The leader of the list was the Iranian Zabol - a city in the south-east of the country, regularly suffering from sandstorms. This atmospheric phenomenon lasts about four months, repeating every year. The second and third positions were occupied by the Indian cities of Gwalior and Prayag. WHO gave the next place to the capital of Saudi Arabia - Riyadh.

Completing the top five cities with the dirtiest atmosphere is El Jubail - a relatively small place in terms of population on the Persian Gulf and at the same time a large industrial oil producing and refining center. On the sixth and seventh steps again were the Indian cities - Patna and Raipur. The main sources of air pollution there are industrial enterprises and transport.

In most cases, air pollution is an actual problem for developing countries. However, environmental degradation is caused not only by the rapidly growing industry and transport infrastructure, but also by man-made disasters. A vivid example of this is Japan, which survived a radiation accident in 2011.

The top 7 countries where the air condition is recognized as deplorable is as follows:

1. China. In some regions of the country, the level of air pollution exceeds the norm by 56 times.
2. India. The largest state of Hindustan leads in the number of cities with the worst ecology.
3. SOUTH AFRICA. The country's economy is dominated by heavy industry, which is also the main source of pollution.
4. Mexico. The ecological situation in the capital of the state, Mexico City, has improved markedly over the past twenty years, but smog in the city is still not uncommon.
5. Indonesia suffers not only from industrial emissions, but also from forest fires.
6. Japan. The country, despite the widespread landscaping and the use of scientific and technological achievements in the environmental field, regularly faces the problem of acid rain and smog.
7. Libya. Main source environmental woes of the North African state - the oil industry.

Consequences

Atmospheric pollution is one of the main reasons for the increase in the number of respiratory diseases, both acute and chronic. Harmful impurities contained in the air contribute to the development of lung cancer, heart disease, and stroke. The WHO estimates that 3.7 million people a year die prematurely due to air pollution worldwide. Most of these cases are recorded in countries South-East Asia and the Western Pacific region.

In large industrial centers, such an unpleasant phenomenon as smog is often observed. The accumulation of particles of dust, water and smoke in the air reduces visibility on the roads, which increases the number of accidents. Aggressive substances increase the corrosion of metal structures, adversely affect the state of flora and fauna. Smog poses the greatest danger to asthmatics, people suffering from emphysema, bronchitis, angina pectoris, hypertension, VVD. Even healthy people, inhaled aerosols, a severe headache, lacrimation and sore throat can be observed.

Saturation of the air with oxides of sulfur and nitrogen leads to the formation of acid rain. After precipitation with a low pH level, fish die in water bodies, and surviving individuals cannot give birth. As a result, the species and numerical composition of populations is reduced. Acid precipitation leaches out nutrients, thereby impoverishing the soil. They leave chemical burns on the leaves, weaken the plants. For the human habitat, such rains and fogs also pose a threat: acidic water corrodes pipes, cars, building facades, monuments.

An increased amount of greenhouse gases (carbon dioxide, ozone, methane, water vapor) in the air leads to an increase in the temperature of the lower layers of the Earth's atmosphere. A direct consequence is the warming of the climate that has been observed over the past sixty years.

Weather conditions are noticeably affected by and formed under the influence of bromine, chlorine, oxygen and hydrogen atoms. Apart from simple substances, ozone molecules can also destroy organic and inorganic compounds: freon derivatives, methane, hydrogen chloride. Why is the weakening of the shield dangerous for the environment and humans? Due to the thinning of the layer, solar activity is growing, which, in turn, leads to an increase in mortality among representatives of marine flora and fauna, an increase in the number of oncological diseases.

How to make the air cleaner?

To reduce air pollution allows the introduction of technologies that reduce emissions in production. In the field of thermal power engineering, one should rely on alternative energy sources: build solar, wind, geothermal, tidal and wave power plants. The state of the air environment is positively affected by the transition to combined generation of energy and heat.

In the fight for clean air, an important element of the strategy is a comprehensive waste management program. It should be aimed at reducing the amount of waste, as well as its sorting, processing or reuse. Urban planning aimed at improving the environment, including the air, involves improving the energy efficiency of buildings, building cycling infrastructure, and developing high-speed urban transport.

The degree of air pollution varies greatly in time and space. Relatively high concentrations at relatively low average levels may appear at the same point in the area in short periods of time. How longer time averaging, the lower the concentration. For hygienic assessment of the degree of air pollution, both the average levels, which determine the long-term resorptive effect of pollution, and the relatively short-term peak concentrations, which are associated with the appearance of odors, irritating effects on the mucous membranes of the respiratory tract and eyes, are important. In this regard, for a hygienic assessment of the degree of air pollution, it is not enough to know only the concentration, but it is necessary to establish for what averaging time this concentration was obtained. In our country, to characterize the degree of atmospheric pollution, the maximum one-time concentrations are accepted, i.e. reliable maximum concentrations that appear at a specific point in the territory over a 20-30 minute period, and daily averages, i.e. average concentration for 24 hours. Thus, characterizing the degree of air pollution, we use the maximum one-time or average daily concentrations, which allows us to conduct operational control over air pollution

The degree of air pollution depends on many different factors and conditions:

1. the amount of emissions of harmful substances (distinguish between powerful, large, small industries

TO powerful sources of pollution include production such as metallurgical and chemical plants, building materials plants, thermal power plants. A large number of small sources can significantly pollute the air. The greater the amount of emission per unit time, the more, other things being equal, pollutants enter the air stream and, consequently, a higher concentration of pollutants is created in it. There is no direct proportional relationship between the emission value and concentration, since other factors also influence the level of pollutant concentration, the degree of influence of which varies in different cases.

The magnitude of the release is the main factor that determines the level of ground concentration. In this regard, in the course of hygienic assessment of atmospheric pollution sources, the sanitary doctor should be interested in the quantitative characteristics of each emission component. Emission is expressed in units per unit of time (kg/day, g/s, t/year) or other units, such as kg/t of products, mg/m3 of industrial emissions. In this case, it is necessary to recalculate per unit of time, taking into account the amount of products received per hour, day, etc. or the maximum volume of exhaust gases for a specific time interval.

Pollutants enter the atmosphere as an organized or unorganized release. Organized emissions include tail gases, off-gases, gases from aspiration and ventilation systems. Tail gases are formed at the final stage of the production process and are characterized, as a rule, by relatively high concentrations and a significant absolute mass of pollutants. Emissions enter the atmosphere through a pipe. Typical examples of tail gases are flue gases from boilers and power plants.

Off-gases are formed in the intermediate stages of the production process and are removed by special off-gas lines. Since the purpose of these technological lines is to equalize the pressure in various closed apparatuses, to release gases in case of violations of the technological process and the need to quickly release the equipment, off-gases are characterized by periodic emission, small volume at relatively high concentrations of pollutants. Especially a lot of waste gases are emitted at the enterprises of the chemical, petrochemical and oil refining industries.

Gases of aspiration systems are formed as a result of local ventilation from various shelters (casings, chambers, umbrellas) and are characterized by relatively high concentrations. Ventilation systems often remove air from workshops through aeration lanterns. Ventilation emissions are characterized by huge volumes and low concentrations of pollutants, which makes their treatment difficult. At the same time, the total mass of pollutants entering the atmosphere can be quite large.

Fugitive emissions are generated by off-shop equipment and structures and during outdoor work. These include loading and unloading of dusty and evaporating raw materials and finished products, open storage of dusty materials and finished products, open storage of dusty materials and evaporating liquids, cooling towers, sludge storages, waste dumps, open sewage channels, leaks in joints and glands of external technological lines, etc. The peculiarity of such emissions is that they are difficult to quantify. At the same time, practice confirms high levels of air pollution in areas adjacent to enterprises characterized by the presence of fugitive emissions.

It is also necessary to classify emissions into organized and unorganized because the former must be fully taken into account when predicting atmospheric air pollution, and the sanitary doctor, both in the order of preventive and current sanitary supervision, must be able to check the completeness of accounting for emissions in the calculation. There are also prerequisites for accounting for fugitive emissions in the near future.

Direct and indirect methods are used to qualitatively and quantitatively characterize emissions. Direct methods are based on measuring the concentration of a pollutant in organized emissions and on this basis calculating the mass of the pollutant per unit of time. Indirect methods are based on the material balance, which takes into account the necessary raw materials and resulting products.

Direct methods for determining the release are used, as a rule, at enterprises with a prevailing value of organized emissions. These determinations are made by a specialized organization or laboratory of the enterprise. Indirect methods are best used at enterprises characterized by fugitive emissions. The material balance is part of the technological regulations. Direct and indirect methods for determining emissions should be used by the enterprise to inventory sources of air pollution.

P. Their chemical composition (distinguished by the composition of emissions of the 5th class of production by danger).

The efficiency of the treatment facilities has a great influence on the magnitude of the emission. Thus, the decrease in efficiency from 98 to 96:, i.e. by only 2%, increases the emission by 2 times. In this regard, when assessing the sources of air pollution, the sanitary doctor must know both the design and real odds cleaning and for evaluation use the latter.

Height at which emissions occur (low, medium, high). Under low emission sources consider those industries that carry out emissions from pipes whose height is below 50 m and under high- above 50m. heated emissions are called, in which the temperature of the gas-air mixture is higher than 50 0 С, at a lower temperature, emissions are considered cold.

The higher the pollutants are emitted from the surface of the earth, the lower their concentration in the surface layer, all other things being equal. The decrease in concentration with an increase in the height of the release is associated with two regularities in the distribution of contaminants in the torch: a decrease in concentration due to an increase in the cross section of the torch and a distance from its axial line, which carries the bulk of the pollution, from which they spread to the periphery of the torch. Higher wind speeds above the mouth of a high pipe are also important, since the braking effect of the earth's surface is weakened. The high chimney not only reduces the level of ground concentration, but also removes the beginning of the smoke zone. At the same time, it should be taken into account that a high pipe increases the smoke radius, although at lower concentrations. Zone of maximum contamination, although at lower concentrations. The zone of maximum pollution is within a distance equal to 10-40 pipe heights for high-heated emissions and 5-20 pipe heights for cold and low ones. In connection with the construction of high pipes (180-320 m), the range of influence of individual sources can be 10 km or more. For high sources, in the absence of fugitive emissions, there are transfer zones, since the point where the torch touches the earth's surface is the farther, the higher the pipe.

1U. Climatic and geographical conditions that determine the transfer, dispersion and transformation of emitted substances:

2. conditions of transfer and distribution of emissions in the atmosphere (temperature inversion, barometric pressure in the atmosphere, etc.)

3. the intensity of solar radiation, which determines the photochemical transformations of impurities and the occurrence of secondary products of air pollution

4. Quantity and duration of precipitation, leading to the leaching of impurities from the atmosphere, as well as the degree of air humidity.

With the same absolute emission, the degree of atmospheric air pollution may vary depending on meteorological factors, since the dispersion of emissions occurs under the influence of turbulence, i.e. mixing different layers of air. Turbulence is associated with the influx of heat radiated by the sun and reaching the earth's surface, and has its own patterns of air mass transfer depending on latitude and season. Among the meteorological factors, the direction and speed of the wind, temperature stratification of the atmosphere and air humidity deserve special consideration.

Due to the continuous change in wind direction, the observation point either enters the plume of the pollution source located near this point, or leaves it. Therefore, the level of pollution varies with the direction of the wind. This dependence is important for sanitary practice in solving the issues of locating industrial enterprises in the city plan and allocating an industrial zone.

This pattern of "behavior" of industrial emissions in the surface layer of the atmosphere is the basis for the sanitary requirements for the functional zoning of the territory of populated areas with the placement of industrial enterprises downwind from the residential area, i.e. so that the prevailing wind direction is from the residential area to the industrial enterprise.

This relationship is of particular importance in practical activities sanitary service of large industrial centers in addressing the issue of the leading sources of pollution. Very indicative for the analysis of the sanitary situation is a diagram built on the principle of a wind rose and therefore called the “smoke rose” (V.A. Ryazanov).

To build a smoke rose, it is necessary to have the results of systematic observations of atmospheric air pollution for at least a year. All data are divided into groups according to the direction of the wind during the sampling period. For each wind direction, average concentrations are calculated, according to which a graph is plotted on an arbitrary scale. The protruding tops of the graph indicate the main source of air pollution in this area. A separate graph is built for each pollutant. As an example of constructing smoke roses are given in Table 2 and in fig. 1. Based on the results of systematic observations of one of the industrial centers of the country. The concentration of pollutants during the calm period was 0.14 mg/m 3

table 2

Dependence of sulfur dioxide concentration on wind direction

Rumb	Concentration, mg / m 3	Rumb	Concentration, mg / m 3
WITH	0,11	her	0,06
SW	0,19	SW	0,06
IN	0,26	Z	0,09
SE	0,12	NW	0,09

Fig.1 "Smoke Rose"

The top indicates the direction of the leading source (N-E)

From the above data, it can be seen that the main source of air pollution with sulfur dioxide is located to the east of the study area. The method for determining background concentrations is based on the same principle, but taking into account wind speed and 4 gradations of cardinal points. Determination of background concentrations taking into account the direction of the wind helps to objectively resolve the issues of the location of industrial enterprises in the city plan, i.e. do not place them in directions where the winds bring the highest levels of pollution.

If pollution concentrations depended only on the magnitude of the emission and wind direction, then they would not change with the same emission and wind direction. However, the process of diluting the emission with atmospheric air, in which the wind speed plays an important role, is of primary importance. The higher the wind speed, the more intense the mixing of the emission with atmospheric air and the lower, other things being equal, the concentration of pollutants. High concentrations are found during the calm period.

Wind speed contributes to the transfer and dispersion of impurities, since with increased wind in the region of high sources, the intensity of mixing of air layers increases. At light wind in the area of ​​high emission sources, concentrations near the ground decrease due to an increase in the rise of the flare and the carry-over of impurities upwards.

At strong wind the impurity rise decreases, but there is an increase in the impurity transfer rate over considerable distances. The maximum impurity concentrations are observed at a certain speed, which is called dangerous and depends on the emission parameters. For powerful emission sources with high superheat flue gases, relative to the surrounding air, it is 5-7 m / s. For sources with comparatively low emissions and low temperature gases, it is close to 1-2 m/s.

Wind direction instability contributes to increased horizontal dispersion and the concentration of impurities near the ground decreases.

The sanitary doctor should use this regularity. When deciding on the allotment of a site for the construction of an industrial enterprise, considering materials for the reconstruction of an existing enterprise, it is important to take into account both the direction and speed of the wind, in particular, so that the “dangerous” wind speed for the source in question does not coincide with that often encountered in the direction from the source to the residential area. It is important to take this pattern into account when organizing laboratory control.

The scattering power of the atmosphere depends on the vertical distribution of temperature and wind speed. For example, most often the unstable state of the atmosphere is observed in summer during the daytime. Under such conditions, high concentrations are noted near the earth's surface.

The temperature stratification of the atmosphere has a great influence on the dilution of industrial emissions. The ability of the earth's surface to absorb or radiate heat affects the vertical distribution of temperature in the surface layer of the atmosphere. Under normal conditions, as you go up, the temperature drops. This process is considered as adiabatic, i.e. flowing without the influx or release of heat: the rising air stream will be cooled due to an increase in volume due to a decrease in pressure, and, conversely, the descending stream will heat up due to an increase in pressure. The change in temperature, expressed in degrees for every 100 m of ascent, is called the temperature gradient. In an adiabatic process, the temperature gradient is approximately 1 0C.

There are periods when, with increasing altitude, the temperature drops faster than 1 0 C per 100 m, as a result of which warm air masses rise to a great height from the sun-warmed surface of the earth, which is accompanied by a rapid descent of cold air flows. Such a state, related to the superdiabatic temperature gradient, is called convective. It is characterized by strong air mixing.

In real conditions, the air temperature does not always fall with height, and the overlying layers of air can have a higher temperature than the underlying ones, i.e. possible perversion of the temperature gradient.

The state of the atmosphere with a perverted temperature gradient is called a temperature inversion. During periods of inversions, the turbulent exchange is weakened, in connection with which the conditions for the dispersion of industrial emissions worsen, which can lead to the accumulation of harmful substances in the surface layer of the atmosphere.

Distinguish between surface and elevated inversions. Surface inversions are characterized by a perversion of the temperature gradient near the earth's surface, while elevated inversions are characterized by the appearance of a warmer layer of air at some distance from the earth's surface.

In the case of an elevated inversion, surface concentrations depend on the height of the source of pollution in relation to their lower boundary. If the source is located below the elevated inversion layer, then the main part of the admixture is concentrated near the earth's surface.

In the inversion layer, vertical air currents become practically impossible, since the turbulent diffusion coefficient decreases, as a result of which the emission under the inversion layer cannot rise upwards and is distributed in the surface layer. Therefore, temperature inversions, as a rule, are accompanied by a significant increase in the concentration of pollutants in the surface layer. As is known, mass poisonings of the population in the Meuse Valley, as well as in Donor and London, were observed during a period of stable temperature inversion, which lasted several days. The longer the inversion, the higher the concentration atmospheric pollution, because the accumulation of atmospheric emissions occurs in a limited, as if closed, space of the atmosphere.

Of great importance is not only the duration, but also the height of the inversion. Naturally, low surface (up to 15-20m) and very elevated (above 600m) inversions may not have a significant effect on the level of concentrations: the first - due to the fact that the height of the emission of some pollution sources may be above the inversion layer and it will not prevent them from dissipation, and the second - because with very elevated inversions, the layer of the atmosphere under them is sufficient to dilute industrial emissions.

So the vertical temperature gradient is the most important factor, which determines the intensity of the processes of mixing pollutants with atmospheric air and has a large practical value. For example, if surface inversions in a layer of 150-200 m are frequent in some areas, then the construction of pipes 120-150 m high does not make sense, since this will not affect the decrease in concentrations during periods of inversions. It is advisable to build a pipe above 200 m. If elevated inversions are frequent at a height of 300-400 m, then the construction of a pipe even at a height of 250 m will not contribute to a decrease in concentrations during the inversion period.

The accumulation of harmful emissions in the surface layer during the period of surface inversions will occur at low emissions. Pollution concentrations especially increase in the case of elevated inversions located directly above the emission source, i.e. the mouth of the pipe. The sanitary doctor must know the features of the temperature stratification of the atmosphere of the served area in order to take them into account when solving issues of preventive and current supervision in atmospheric air hygiene.

Due to changes in the temperature and radiation regime of the air in the urban area, the formation of inversions above the city is more likely than in the surrounding areas. In the cold period of the year, more frequent and prolonged inversions are observed. The temperature gradient varies not only by season, but also throughout the day. Due to the cooling of the earth's surface by radiation, nighttime inversions are often formed, which is favored by a clear sky and dry air. Nighttime inversions can also occur in the summer, reaching a maximum in the early morning hours.

Quite often inversions are formed in valleys between heights. The cold air descending into them flows under the warmer air of the valley and a "lake" of cold is formed. Under such conditions, the solution of the question of the location of industrial enterprises is particularly difficult.

The highest concentrations of atmospheric pollutants are observed at low temperatures during winter inversions.

Air humidity has a certain value for the distribution of pollution in the surface layer of the atmosphere. For most pollutants there is a direct relationship, i.e. with increasing humidity, their concentrations increase. The only exceptions are compounds that can hydrolyze. Particularly high concentrations of atmospheric pollution are observed during periods of fog. The connection between the level of pollution and humidity is explained by the fact that in the urban atmosphere there is a significant amount of hygroscopic particles, moisture condensation on which begins at a relative humidity of less than 100%. Due to the weighting of particles due to moisture condensation, they descend and concentrate in a narrower layer of the surface atmosphere. Gaseous pollution, dissolving in the condensate of particles, also accumulates in the lower layers of the atmosphere.

Thus, with the same emission, the level of surface concentration of pollutants can vary significantly depending on meteorological conditions.

The city itself has a significant impact on the dispersion of emissions, changing the temperature-radiation, humidity and wind regimes. On the one hand, the city is a “heat island”, which results in local convective updrafts and downdrafts, on the other hand, fogs occur more often in the city (often due to its pollution), which worsens the dispersion of pollution. The direction and speed of the wind are deformed due to changes in the underlying surface and the shielding effect of tall buildings. In such conditions, calculations created for flat terrain are unsuitable, and special calculation methods are used, taking into account the aerodynamic shadow created by buildings.

The dispersion of impurities in urban conditions is significantly affected by street layout, their width, direction, height of buildings, the presence of green areas and water bodies.

Therefore, even with constant industrial and transport emissions, as a result of the influence of meteorological conditions, air pollution levels can vary by several times.

A certain role in the release of the atmosphere from pollution is played by green vegetation due to both mechanical sorption on the surface and chemical binding of certain compounds.

U1. The spread of impurities is affected by terrain. On windward slopes with the wind, ascending air movements are formed, and the leeward slopes- descending. Downdrafts of air mass movement form over reservoirs in summer. In descending flows, surface concentrations increase, while in ascending flows, they decrease. In some landforms, such as pits, the air stagnates, leading to the accumulation of toxins from low emission sources. In hilly terrain, the maxima of the surface impurity concentration are usually greater than in the absence of uneven terrain.

The influence of terrain irregularities on the level of surface concentration is associated with a change in the nature of air movement, which leads to a change in the concentration field. Air stagnation phenomena are observed in the lowlands, which increases the risk of pollution accumulation. At elevations of 50–100 m with an inclination angle of 5–6 0, the difference in maximum concentrations can reach 50% with relatively low pipes. The influence of the relief decreases with increasing height of the ejection. Of great importance is the location of the source on the leeward or windward slope. An increase in concentration can also be observed when the emission source is located on a hill, but near the leeward slope, where wind speeds decrease and downward currents arise.

The influence of terrain irregularities on the nature of air movement is so complex that it sometimes requires modeling conditions in order to determine the nature of the distribution of industrial emissions. At present, there are proposals for the introduction of coefficients that take into account the influence of the relief on the dispersion of emissions.

UP. From the time of year (in winter more than in summer, because heating systems are turned on, and during their operation pollution by emissions increases and pollutants accumulate more on the lower layers of the air, because air convection slows down).

USh. Depending on the time of the day (the maximum pollution is observed during the day, because the work of all industries and vehicles falls on the daytime).

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Atmospheric air pollution is any change in its composition and properties that has a negative impact on human and animal health, the condition of plants and ecosystems. Air pollution is one of the most significant problems of our time.

The main pollutants (pollutants) of atmospheric air formed in the process of industrial and other human activities - sulfur dioxide, nitrogen oxides, carbon monoxide and particulate matter. They account for about 98% of the total emissions of harmful substances. In addition to the main pollutants in the atmosphere of cities and towns, there are more than 70 types of harmful substances, including - formaldehyde, hydrogen fluoride, lead compounds, ammonia, phenol, benzene, carbon disulfide, etc.. However, it is the concentrations of the main pollutants (sulfur dioxide, etc.) that most often exceed the permissible levels.

release into the atmosphere of the four main pollutants (pollutants) of the atmosphere - emissions into atmosphere of sulfur dioxide, nitrogen oxides, carbon monoxide and hydrocarbons. In addition to these main pollutants, many other very dangerous toxic substances enter the atmosphere: lead, mercury, cadmium and other heavy metals(emission sources: cars, smelters, etc.); hydrocarbons(CnHm), among them 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 air pollution - 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 zones, for example, a “heat island” in cities, warming of water bodies, etc. P.

13. Ecological consequences of global atmospheric pollution.

Greenhouse effect- the rise in temperature on the surface of the planet as a result of thermal energy that appears in the atmosphere due to the heating of gases. The main gases that lead to the greenhouse effect on Earth are water vapor and carbon dioxide.

The phenomenon of the greenhouse effect makes it possible to maintain a temperature on the Earth's surface at which the emergence and development of life is possible. If the greenhouse effect were absent, the average surface temperature of the globe would be much lower than it is now. However, as the concentration of greenhouse gases rises, the atmosphere's impermeability to infrared rays increases, which leads to an increase in the temperature of the Earth.

Ozone layer.

At 20 - 50 kilometers above the Earth's surface, there is a layer of ozone in the atmosphere. Ozone is a special form of oxygen. Most oxygen molecules in the air are made up of two atoms. The ozone molecule is made up of three oxygen atoms. Ozone is formed by the action of sunlight. When photons of ultraviolet light collide with oxygen molecules, an oxygen atom is split off from them, which, joining another O2 molecule, forms Oz (ozone). The ozone layer of the atmosphere is very thin. If all available atmospheric ozone evenly covers an area of ​​45 square kilometers, then a layer 0.3 centimeters thick will be obtained. A little ozone penetrates with air currents into the lower layers of the atmosphere. When light rays react with substances found in exhaust gases and industrial fumes, ozone is also formed.

Acid rain is a consequence of air pollution. The smoke generated during the combustion of coal, oil and gasoline contains gases - sulfur dioxide and nitrogen dioxide. These gases enter the atmosphere, where they dissolve in water droplets, forming weak solutions of acids, which then fall to the ground as rain. Acid rain kills fish and damages forests in North America and Europe. They also spoil crops and even the water we drink.

Plants, animals and buildings are harmed by acid rain. Their impact is especially noticeable near cities and industrial zones. The wind carries clouds with water droplets containing acids over long distances, so acid rain can fall thousands of miles from where it originally originated. For example, most of the acid rain that falls in Canada is caused by smoke from US factories and power plants. The consequences of acid rain are quite understandable, but no one knows exactly how they occur.

14 question The principles outlined for the formation and analysis of various forms of environmental environmental risk for public health are embodied in several interrelated stages: 1. Risk identification for certain types of industrial and agricultural loads with the allocation of chemical and physical factors in their structure according to the level of environmental safety and toxicity. 2. Evaluation of the real and potential impact of toxic substances on humans in certain areas, taking into account the complex of pollutants and natural factors. Particular importance is attached to the existing density of the rural population and the number of urban settlements. 3. Identification of quantitative patterns of the reaction of the human population (of different age cohorts) to a certain level of exposure. 4. Environmental risk is considered as one of the most important components of special modules of the geographic information system. In such modules, problematic medical and environmental situations are formed. GIS blocks include information about existing, planned and expected changes in the structure of territorial and production complexes. An information base of such content is necessary to perform the corresponding modeling. 5. Characteristics of the risk of the combined impact of natural and anthropogenic factors on public health. 6. Identification of spatial combinations of natural and anthropogenic factors, which can contribute to their more detailed forecasting and analysis of the possible dynamics of local and areal combinations of risk at the regional level. 7. Differentiation of territories according to levels and forms of ecological risk and allocation of medical and ecological regions according to regional levels of anthropogenic risk. When assessing the anthropogenic risk, a complex of priority toxicants and other anthropogenic factors is taken into account.

15question SMOG Smog (English smog, from smoke - smoke and fog - fog), severe air pollution in large cities and industrial centers. Smog can be of the following types: Wet London-type smog - a combination of fog with an admixture of smoke and gas waste from production. Ice smog of the Alaskan type - smog formed at low temperatures from the steam of heating systems and domestic gas emissions. Radiative fog - fog that appears as a result of radiative cooling of the earth's surface and a mass of moist surface air to the dew point. Radiation fog usually occurs at night in anticyclone conditions with cloudless weather and a light breeze. Radiation fog often occurs under conditions of temperature inversion, which prevents the rise of the air mass. In industrial areas, an extreme form of radiation fog, smog, can occur. Dry smog of the Los Angeles type - smog resulting from photochemical reactions that occur in gaseous emissions under the action of solar radiation; persistent bluish haze of corrosive gases without fog. Photochemical smog - smog, the main cause of which is considered to be automobile exhaust. Automotive exhaust gases and pollutant emissions from enterprises under conditions of temperature inversion enter into a chemical reaction with solar radiation, forming ozone. Photochemical smog can cause respiratory damage, vomiting, eye irritation, and general lethargy. In some cases, photochemical smog may contain nitrogen compounds that increase the likelihood of cancer. Photochemical smog DETAILS: Photochemical fog is a multicomponent mixture of gases and aerosol particles of primary and secondary origin. The composition of the main components of smog includes ozone, nitrogen and sulfur oxides, numerous organic peroxide compounds, collectively called photooxidants. Photochemical smog occurs as a result of photochemical reactions under certain conditions: the presence of a high concentration of nitrogen oxides, hydrocarbons and other pollutants in the atmosphere, intense solar radiation and calm or very weak air exchange in the surface layer with a powerful and increased inversion for at least a day. Sustained calm weather, usually accompanied by inversions, is necessary to create a high concentration of reactants. Such conditions are created more often in June - September and less often in winter. In prolonged clear weather, solar radiation causes the breakdown of nitrogen dioxide molecules with the formation of nitric oxide and atomic oxygen. Atomic oxygen with molecular oxygen give ozone. It would seem that the latter, oxidizing nitric oxide, should again turn into molecular oxygen, and nitric oxide into dioxide. But that doesn't happen. The nitric oxide reacts with the olefins in the exhaust gases, which then split at the double bond and form fragments of molecules, and an excess of ozone. As a result of the ongoing dissociation, new masses of nitrogen dioxide are split and give additional amounts of ozone. A cyclic reaction occurs, as a result of which ozone gradually accumulates in the atmosphere. This process stops at night. In turn, ozone reacts with olefins. Various peroxides are concentrated in the atmosphere, which in total form oxidants characteristic of photochemical fog. The latter are the source of the so-called free radicals, which are characterized by a special reactivity. Such smog is a frequent phenomenon over London, Paris, Los Angeles, New York and other cities of Europe and America. According to their physiological effects on the human body, they are extremely dangerous for the respiratory and circulatory systems and often cause premature death of urban residents with poor health. Smog is usually observed with weak turbulence (swirling of air currents) of the air, and therefore, with a stable distribution of air temperature along the height, especially during temperature inversions, with light wind or calm. Temperature inversions in the atmosphere, an increase in air temperature with height instead of its usual decrease for the troposphere. Temperature inversions occur both near the earth's surface (surface temperature inversions.), And in the free atmosphere. Surface temperature inversions are most often formed on calm nights (in winter, sometimes during the day) as a result of intense heat radiation from the earth's surface, which leads to cooling of both itself and the adjacent air layer. The thickness of surface temperature inversions is tens to hundreds of meters. The increase in temperature in the inversion layer ranges from tenths of degrees to 15-20 °C and more. The most powerful winter surface temperature inversions are in Eastern Siberia and Antarctica. In the troposphere, above the surface layer, temperature inversions are more likely to form in an anticyclone

16question In the atmospheric air, the concentrations of substances determined by the priority list of harmful impurities established in accordance with the "Temporary recommendations for compiling a priority list of harmful impurities to be controlled in the atmosphere", Leningrad, 1983 were measured. The concentrations of 19 pollutants were measured: the main ones (suspended substances, sulfur dioxide, carbon monoxide, nitrogen dioxide), and specific (formaldehyde, fluorine compounds, benzo (a) pyrene, metals, mercury).

17 question There are 7 large rivers in Kazakhstan, the length of each of which exceeds 1000 km. Among them: the Ural River (its upper course is located on the territory of Russia), which flows into the Caspian Sea; Syr Darya (its upper course is located on the territory of Kyrgyzstan, Uzbekistan and Tajikistan) - to the Aral Sea; The Irtysh (its upper reaches in China; on the territory of Kazakhstan it has large tributaries Tobol and Ishim) crosses the republic, and already on the territory of Russia flows into the Ob, which flows into the Arctic Ocean; the Ili River (its upper reaches are located on the territory of China) flows into Lake Balkhash. There are many large and small lakes in Kazakhstan. The largest among them are the Caspian Sea, the Aral Sea, Balkhash, Alakol, Zaysan, Tengiz. Kazakhstan includes most of the northern and half of the eastern coast of the Caspian Sea. The length of the coast of the Caspian Sea in Kazakhstan is 2340 km. There are 13 reservoirs in Kazakhstan with a total area of ​​8816 km² and a total water volume of 87.326 km³. The countries of the world are provided with water resources extremely unevenly. The following countries are the most endowed with water resources: Brazil (8,233 km3), Russia (4,508 km3), USA (3,051 km3), Canada (2,902 km3), Indonesia (2,838 km3), China (2,830 km3), Colombia (2,132 km3), Peru (1,913 km3), India (1,880 km3), Congo (1,283 km3), Venezuela (1,233 km3), Bangladesh (1,211 km3), Burma (1,046 km3).

Of decisive importance for the development of measures to improve the environmental situation in cities is the availability of complete, objective, specific information on this problem. Since 1992, such information has been published in the annual State reports of the Ministry natural resources of the Russian Federation "On the state and protection of the natural environment of the Russian Federation", reports of the Department of Nature Management and Environmental Protection of the Government of Moscow "On the state of the environment in Moscow", and other similar documents.

According to these documents, "environmental pollution remains the most acute environmental problem which has priority social and economic importance for the Russian Federation".

A constant environmental problem of urban areas is air pollution. Its paramount importance is determined by the fact that air purity is a factor that directly affects the health of the population. The atmosphere has an intense impact on the hydrosphere, soil and vegetation cover, geological environment, buildings, structures and other man-made objects.

Among the anthropogenic sources of pollution of the surface atmosphere, the most dangerous include the combustion of various types of fuel, domestic and industrial waste, nuclear reactions in the production of atomic energy, metallurgy and hot metal working, various chemical industries, including gas, oil and coal processing. Building objects, transport and motor transport facilities contribute to urban air pollution.

So, for example, in Moscow, according to data for 1997, sources of air pollution were about 31 thousand industrial and construction facilities (including 2.7 thousand motor transport facilities), 13 heat and power plants and their branches, 63 regional and quarterly thermal stations, more than 1 thousand small boiler houses, as well as over 3 million vehicles. As a result, about 1 million tons of pollutants were emitted into the atmosphere every year. At the same time, their total increased every year.

It should also be taken into account that in major cities negative impact general condition The atmosphere is exacerbated by the fact that most of the population spends up to 20-23 hours a day indoors, while the level of pollution inside the building exceeds the level of outdoor air pollution by 1.5-4 times.

The main air pollutants are nitrogen dioxide, carbon monoxide, suspended solids, sulfur dioxide, formaldehyde, phenol, hydrogen sulfide, lead, chromium, nickel, 3,4-benzapyrene.

According to Rosstat data for 2007, more than 30,000 enterprises emit pollutants with exhaust gases from stationary sources into the atmosphere. The amount of pollutants emitted from them - 81.98 million tons; 18.11 million tons were released into the atmosphere without treatment. Of the emissions received at the treatment facilities, 74.8% was captured and neutralized.

About 58 million people live in cities with a high level of air pollution, including 100% in Moscow and St. Petersburg, and more than 70% of the population in Kamchatka, Novosibirsk, Orenburg and Omsk regions. In cities, the atmosphere of which contains high concentrations of nitrogen dioxide, 51.5 million people live, suspended solids - 23.5, formaldehyde and phenol - more than 20, gasoline and benzene - more than 19 million people. However, since the late 1990s the number of cities with high and very high levels of air pollution is increasing.

Until the early 1990s, industrial enterprises made the main contribution to atmospheric air pollution. During this period, the settlements with the highest level of air pollution included such "factory cities" as Bratsk, Yekaterinburg, Kemerovo, Krasnoyarsk, Lipetsk, Magnitogorsk, Nizhny Tagil, Novokuznetsk, Novosibirsk, Rostov-on-Don, Tolyatti, Norilsk etc. However, as the decline, and then some rise and re-profiling industrial production, on the one hand, and the accelerated growth of the car park, which is taking place in line with global trends, on the other hand, there have been changes in the list of priority factors affecting the state of the atmosphere in settlements.

First of all, this affected the ecology of large cities. So, in Moscow in 1994-1998. the main trends in the state of the environment were characterized by "... a decrease in the influence of industry on the state of all natural environments. The share of air pollution from industrial facilities has decreased to 2-3% of the total emissions of pollutants. The share of public utilities (energy, water supply, waste incineration, etc.) also decreased sharply and is about 6-8%. The determining factor in the state of the air basin of Moscow at the present time and for the next 15-20 years has become motor transport.

Six years later, in 2004, in Moscow, the intake of pollutants from industrial enterprises increased to 8%, the contribution of thermal power facilities remained almost unchanged - 5%, and the share of road transport increased even more - 87%. (During the same period, the average for Russia was different: emissions from motor vehicles amounted to 43%.) To date, the capital's car park is over 3 million units. The total emission of pollutants into the atmosphere of the city is 1830 tons/year or 120 kg per inhabitant.

In St. Petersburg, the contribution of motor transport to the gross emission of pollutants in 2002 was about 77%. During the period of the 90s, the car park in the city increased 3 times. In 2001, their number was 1.4 million units.

The accelerated growth of motor transport has a sharply negative impact on the state of the environment in cities, which is not limited to air pollution with compounds such as nitrogen dioxide, formaldehyde, benzapyrene, suspended particles, carbon monoxide, phenol, lead compounds, etc. This factor leads to soil pollution , noise discomfort, inhibition of vegetation near highways, etc.

In Russia, the uncontrolled growth of the motor transport fleet is accompanied by a decrease in the number of environmentally friendly public transport units - trolleybuses and trams. In addition, motorization of the population affects the state of the environment more than in other industrial countries, since it occurs in conditions of lagging environmental performance of domestic vehicles and used motor fuels from the world level, as well as lagging behind in the development and technical condition of the road network. In this regard, the main issue of environmental policy in large cities of Russia is the "greening" of the motor transport complex, which means not only the cars themselves, but also the strategy for the development of public transport, urban planning policy, the strategy for preserving the natural complex, the system of regulatory legal acts, economic mechanisms "displacement" of hydrocarbon fuels (with the exception of natural gas), etc.