Atmospheric air pollution. Air pollution

Any undesirable change in the composition of the earth's atmosphere as a result of the entry of various gases, water vapor and solid particles into it (under the influence of natural processes or as a result of human activity).

Approximately 10% of pollutants enter the atmosphere as a result of natural processes such as volcanic eruptions, which are accompanied by the release of ash, sprayed acids, including sulfuric acid, and a variety of toxic gases into the atmosphere. In addition, the main sources of sulfur in the atmosphere are seawater spray and decaying plant debris. Also worth noting are forest fires, which result in the formation of dense clouds of smoke that envelop large areas, and dust storms. Trees and shrubs emit a lot of volatile organic compounds (VOCs), creating a blue haze that obscures the

most of the Blue Ridge Mountains in the USA (translated as “blue ridge”). Microorganisms present in the air (pollen, molds, bacteria, viruses) cause allergy attacks in many people and infectious diseases.

The remaining 90% of pollutants are of anthropogenic origin. Their main sources are: combustion of fossil fuels in power plants (smoke emissions) and in car engines; production processes not related to fuel combustion, but leading to dust pollution, for example due to soil erosion, coal mining open method, blasting, and VOC leakage from valves, pipe joints in refineries, chemical plants, and reactors; solid waste storage; as well as a variety of mixed sources.

Pollutants entering the atmosphere are transported over long distances from the source and then return to the earth's surface in the form of solid particles, droplets or chemical compounds dissolved in precipitation.

Chemical compounds that originate at ground level quickly mix with the air in the lower atmosphere (troposphere). These are called primary pollutants. Some of them react chemically with other pollutants or with the main components of air (oxygen, nitrogen and water vapor), forming secondary pollutants. As a result, phenomena such as photochemical smog, acid rain and the formation of ozone in the ground layer of the atmosphere are observed. The energy source for these reactions is solar radiation. Secondary pollutants—photochemical oxidants and acids found in the atmosphere—pose a major threat to human health and global change. environment.

Hazardous Exposure

Air pollution has harmful effects on living organisms in several ways: 1) delivering aerosol particles and toxic gases into the respiratory system of humans and animals and into plant leaves; 2) increasing the acidity of atmospheric precipitation, which, in turn, affects changes in the chemical composition of soils and water; 3) stimulating such chemical reactions in the atmosphere that lead to an increase in the duration of exposure of living organisms to harmful solar rays; 4) changing the composition and temperature of the atmosphere on a global scale and thus creating conditions unfavorable for the survival of organisms.

Human respiratory system. Through the respiratory system, oxygen enters the human body, which is carried by hemoglobin (red pigments of red blood cells) to vital important bodies, and waste products, in particular carbon dioxide, are removed. The respiratory system consists of the nasal cavity, larynx, trachea, bronchi and lungs. In each healthy lung there are approximately 5 million alveoli (air sacs), in which gas exchange occurs. From the alveoli, oxygen enters the blood, and through them carbon dioxide is removed from the blood and released into the air.

The respiratory system has a number of protective mechanisms that protect against exposure to pollutants contained in the air. Nasal hairs filter out large particles. The mucous membrane of the nasal cavity, larynx and trachea retains and dissolves fine particles and some harmful gases. If pollutants enter the respiratory system, a person sneezes and coughs. In this way, polluted air and mucus are evacuated. In addition, the upper respiratory tract is lined with hundreds of thin cilia ciliated epithelium, which are in constant motion and move mucus up the larynx along with dirt that has entered the respiratory system, which are either swallowed or expelled.

Constant long-term exposure to by-products of tobacco smoke and air pollution leads to overload and overcrowding protective systems humans, as a result, diseases develop respiratory system: allergic asthma, lung cancer and emphysema, chronic bronchitis.

Acid precipitation. The entry into soil or water bodies of various acids, such as sulfuric (H2SO4) or nitric (HNO3), as a result of acid precipitation (abnormally acidic rain and snow) causes harm to living organisms and contributes to the destruction of various structures. Similar phenomena are quite often observed in areas with significant concentrations of industrial enterprises using fossil fuels.

The damage caused to biota by acid precipitation is most noticeable in forests and lakes. Certain types of trees, particularly pine trees, are especially sensitive to changes in soil acidity. Large areas of forests in New England, Canada and the Scandinavian countries have been severely damaged by acid rain. In some cases, plants serve as indicators of such effects: leaves become stained or discolored. Acid overload associated with spring runoff into lakes and rivers melt water, may have harmful effects on fish and other aquatic life.

Composition and structure of the atmosphere

The atmosphere, or "ocean of air", consists of gases necessary to support life on Earth. In height it can be divided into five layers, or shells, surrounding Earth: troposphere, stratosphere, mesosphere, thermosphere and exosphere. Their boundaries are determined by sudden changes in temperature caused by differences in the absorption of solar radiation. Air density also changes with altitude. IN upper layers The air in the atmosphere is cold and rarefied, but near the Earth’s surface, due to gravity, it is denser. It is mainly the two lower layers of the atmosphere that are polluted.

Troposphere. The composition and structure of the lower layer - the troposphere - is determined by the supply of gases from the earth's crust and the presence of life on earth's surface. Upper limit The troposphere is located at altitudes of approximately 17 km above sea level at the equator and approx. 8 km at the poles. This thin layer contains two important gaseous components: nitrogen (N2) and oxygen (O2), which account for 78 and 21% of the atmosphere's volume, respectively.

The nitrogen cycle in nature (nitrogen cycle) plays a very important role important role in plant nutrition. Atmospheric nitrogen is bound by nodule bacteria contained in the root thickenings of leguminous plants, with the formation of numerous organic compounds, especially proteins. Other specialized bacteria then decompose and convert the nitrogen-rich organic residues into simpler inorganic substances, such as ammonia (NH4), through a process of mineralization. Finally, nitrifying bacteria convert them back into nitrogen oxide (NO) and dioxide (NO2), which are returned to the atmosphere. Then the cycle resumes.

Oxygen is formed during the process of photosynthesis in plants and, in turn, is used by micro- and macroorganisms during respiration, the by-product of which is carbon dioxide.

In addition to nitrogen and oxygen, the atmosphere includes argon (Ar - 0.93%) and carbon dioxide (CO2 - 0.036%), as well as in small quantities neon (Ne), helium (He), methane (CH4), krypton (Kr ), hydrogen (H2), xenon (Xe) and chlorofluorocarbons (CFCs) of anthropogenic origin.

Source and necessary component life on Earth, which contributes, in particular, to maintaining the temperature of its surface, is water vapor (H2O), which enters the troposphere mainly as a result of the evaporation of water from the surface of the ocean. Its content in the atmosphere varies significantly depending on the time of year and geographical location. For living organisms, consisting mainly of organic compounds of carbon with hydrogen and oxygen, oxygen, water and carbon dioxide play a primary role. Water and carbon dioxide are critical to heating the earth's surface due to their ability to absorb solar radiation.

Stratosphere. Directly above the troposphere at altitudes from 18 to 48 km above the earth's surface is the stratosphere. Although these shells are very similar in composition, in the stratosphere the content of water vapor is approximately 1000 times less, and the content of ozone is approximately 1000 times greater than in the troposphere. Ozone is formed in the stratosphere by the interaction of oxygen molecules during lightning discharges and ultraviolet irradiation from the Sun.

The composition of air pollutants has changed significantly since World War II. In the 1950s, coal was replaced by diesel fuel, and soon natural gas. By 2000, most homes were heated by natural gas, the cleanest of all fossil fuels. On the other hand, the atmosphere increasingly began to be polluted by exhaust gases generated during the operation of internal combustion engines.

Main pollutants

Sulfur dioxide, or sulfur dioxide (sulfur dioxide). Sulfur enters the atmosphere through many natural processes, including the evaporation of seawater spray, the movement of sulfur-containing soils in arid regions, gas emissions from volcanic eruptions, and the release of biogenic hydrogen sulfide (H2S).

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If we consider environmental problems, one of the most pressing is air pollution. Environmentalists are sounding the alarm and calling on humanity to reconsider its attitude to life and consumption of natural resources, because only protection from air pollution will improve the situation and prevent serious consequences. Find out how to solve such a pressing issue, influence the environmental situation and preserve the atmosphere.

Natural sources of clogging

What is air pollution? This concept includes the introduction and entry into the atmosphere and all its layers of uncharacteristic elements of a physical, biological or chemical nature, as well as changes in their concentrations.

What pollutes our air? Air pollution is caused by many reasons, and all sources can be divided into natural or natural, as well as artificial, that is, anthropogenic.

It’s worth starting with the first group, which includes pollutants generated by nature itself:

The first source is volcanoes. When they erupt, they throw out huge amounts of tiny particles various breeds, ash, poisonous gases, sulfur oxides and other equally harmful substances. And although eruptions occur quite rarely, according to statistics, as a result of volcanic activity, the level of air pollution increases significantly, because up to 40 million tons of hazardous compounds are released into the atmosphere every year.
If we consider natural causes air pollution, it is worth noting such as peat bogs or forest fires. Most often, fires occur due to unintentional arson by a person who is negligent about the rules of safety and behavior in the forest. Even a small spark from a fire that is not completely extinguished can cause the fire to spread. Less often, fires are caused by very high solar activity, which is why the peak of danger occurs in the hot summer.
Considering the main types of natural pollutants, one cannot fail to mention dust storms that arise due to strong gusts of wind and mixing air flow. During a hurricane or other natural event, tons of dust rises, causing air pollution.

Artificial sources

Air pollution in Russia and other developed countries is often caused by the influence of anthropogenic factors caused by the activities carried out by people.

Let's list the main artificial sources causing air pollution:

Rapid development of industry. It’s worth starting with chemical air pollution caused by the activities of chemical plants. Toxic substances released into the air poison it. Also air pollution harmful substances cause metallurgical plants: metal recycling is a complex process involving huge emissions due to heating and combustion. In addition, small solid particles formed during the manufacture of building or finishing materials also pollute the air.
The problem of air pollution from motor vehicles is especially pressing. Although other types also provoke, it is machines that have the most significant negative impact on it, since there are many more of them than any other Vehicle. The exhaust emitted by motor vehicles and generated during engine operation contains a lot of substances, including hazardous ones. It's sad that emissions are increasing every year. An increasing number of people are acquiring an “iron horse”, which, of course, has a detrimental effect on the environment.
Operation of thermal and nuclear power plants, boiler plants. Life activity of mankind at this stage impossible without the use of such installations. They supply us with vital resources: heat, electricity, hot water. But when any type of fuel is burned, the atmosphere changes.
Household waste. Every year the purchasing power of people increases, and as a result, the volumes of waste generated also increase. Their disposal is not given due attention, but some types of waste are extremely dangerous, have a long decomposition period and emit fumes that have an extremely adverse effect on the atmosphere. Every person pollutes the air every day, but waste from industrial enterprises, which is taken to landfills and is not disposed of in any way, is much more dangerous.

What substances most often pollute the air?

There are an incredibly large number of air pollutants, and environmentalists are constantly discovering new ones, which is associated with the rapid pace of industrial development and the introduction of new production and processing technologies. But the most common compounds found in the atmosphere are:

Carbon monoxide, also called carbon monoxide. It is colorless and odorless and is formed during incomplete combustion of fuel with low volumes of oxygen and low temperatures. This compound is dangerous and causes death due to lack of oxygen.
Carbon dioxide is found in the atmosphere and has a slightly sour odor.
Sulfur dioxide is released during the combustion of some sulfur-containing fuels. This compound provokes acid rain and depresses human breathing.
Nitrogen dioxides and oxides characterize air pollution from industrial enterprises, since they are most often formed during their activities, especially during the production of certain fertilizers, dyes and acids. These substances can also be released as a result of fuel combustion or during operation of the machine, especially when it is malfunctioning.
Hydrocarbons are one of the most common substances and can be contained in solvents, detergents, and petroleum products.
Lead is also harmful and is used to make batteries, cartridges and ammunition.
Ozone is extremely toxic and is formed during photochemical processes or during the operation of transport and factories.

Now you know which substances pollute the air most often. But this is only a small part of them; the atmosphere contains a lot of different compounds, and some of them are even unknown to scientists.

Sad consequences

The scale of the impact of air pollution on human health and the entire ecosystem as a whole is simply enormous, and many people underestimate it. Let's start with the environment.

Firstly, due to polluted air, a greenhouse effect has developed, which gradually but globally changes the climate, leads to warming and provokes natural disasters. It can be said that it leads to irreversible consequences in the state of the environment.
Secondly, acid rain is becoming more and more frequent, which has a negative impact on all life on Earth. Through their fault, entire populations of fish die, unable to live in such an acidic environment. A negative impact is observed when examining historical monuments and architectural monuments.
Thirdly, fauna and flora suffer, since dangerous fumes are inhaled by animals, they also enter plants and gradually destroy them.

A polluted atmosphere has an extremely negative impact on human health. The emissions enter the lungs and cause disruptions in the respiratory system and severe allergic reactions. Together with the blood, dangerous compounds are carried throughout the body and greatly wear it out. And some elements can provoke mutation and degeneration of cells.

How to solve the problem and save the environment

The problem of air pollution is very relevant, especially considering that the environment has deteriorated greatly over the past few decades. And it needs to be solved comprehensively and in several ways.

Let's consider several effective measures to prevent air pollution:

To combat air pollution at individual enterprises, it is necessary to mandatory install treatment and filtering facilities and systems. And at particularly large industrial plants it is necessary to begin introducing stationary monitoring posts for monitoring air pollution.
To avoid air pollution from cars, you should switch to alternative and less harmful energy sources, such as solar panels or electricity.
Replacing combustible fuels with more accessible and less dangerous ones, such as water, wind, sunlight and others that do not require combustion, will help protect atmospheric air from pollution.
The protection of atmospheric air from pollution must be supported at the state level, and there are already laws aimed at protecting it. But it is also necessary to act and exercise control in individual constituent entities of the Russian Federation.
One of effective ways, which should include the protection of air from pollution, is the establishment of a system for the disposal of all waste or its recycling.
To solve the problem of air pollution, plants should be used. Widespread landscaping will improve the atmosphere and increase the amount of oxygen in it.

How to protect atmospheric air from pollution? If all of humanity fights it, then there is a chance of improving the environment. Knowing the essence of the problem of air pollution, its relevance and the main solutions, we need to jointly and comprehensively combat pollution.

AIR POLLUTION
any undesirable change in the composition of the earth's atmosphere as a result of the entry of various gases, water vapor and solid particles into it (under the influence of natural processes or as a result of human activity). Approximately 10% of pollutants enter the atmosphere as a result of natural processes such as volcanic eruptions, which are accompanied by the release of ash, sprayed acids, including sulfuric acid, and a variety of toxic gases into the atmosphere. In addition, the main sources of sulfur in the atmosphere are seawater spray and decaying plant debris. Also worth noting are forest fires, which result in the formation of dense clouds of smoke that envelop large areas, and dust storms. Trees and shrubs emit high levels of volatile organic compounds (VOCs) that create the blue haze that obscures much of the Blue Ridge Mountains in the United States. Microorganisms present in the air (pollen, molds, bacteria, viruses) cause allergy attacks and infectious diseases in many people. The remaining 90% of pollutants are of anthropogenic origin. Their main sources are: combustion of fossil fuels in power plants (smoke emissions) and in car engines; industrial processes that do not involve combustion of fuel, but lead to dust pollution, for example due to soil erosion, open-pit coal mining, blasting and the release of VOCs from valves, pipe joints in refineries and chemical plants and from reactors; solid waste storage; as well as a variety of mixed sources. Pollutants entering the atmosphere are transported over long distances from the source and then return to the earth's surface in the form of solid particles, droplets or chemical compounds dissolved in precipitation. Chemical compounds that originate at ground level quickly mix with the air in the lower atmosphere (troposphere). These are called primary pollutants. Some of them react chemically with other pollutants or with the main components of air (oxygen, nitrogen and water vapor), forming secondary pollutants. As a result, phenomena such as photochemical smog, acid rain and the formation of ozone in the ground layer of the atmosphere are observed. The energy source for these reactions is solar radiation. Secondary pollutants - photochemical oxidants and acids contained in the atmosphere - pose a major threat to human health and global environmental changes.
HAZARDOUS EXPOSURE
Air pollution has harmful effects on living organisms in several ways: 1) by delivering aerosol particles and toxic gases into the respiratory system of humans and animals and into plant leaves; 2) increasing the acidity of atmospheric precipitation, which, in turn, affects changes in the chemical composition of soils and water; 3) stimulating such chemical reactions in the atmosphere that lead to an increase in the duration of exposure of living organisms to harmful solar rays; 4) changing the composition and temperature of the atmosphere on a global scale and thus creating conditions unfavorable for the survival of organisms.
Human respiratory system. Through the respiratory system, oxygen enters the human body, which is carried by hemoglobin (red pigments of red blood cells) to vital organs, and waste products, in particular carbon dioxide, are eliminated. The respiratory system consists of the nasal cavity, larynx, trachea, bronchi and lungs. In each healthy lung there are approximately 5 million alveoli (air sacs), in which gas exchange occurs. From the alveoli, oxygen enters the blood, and through them carbon dioxide is removed from the blood and released into the air. The respiratory system has a number of protective mechanisms that protect against exposure to pollutants contained in the air. Nasal hairs filter out large particles. The mucous membrane of the nasal cavity, larynx and trachea traps and dissolves small particles and some harmful gases. If pollutants enter the respiratory system, a person sneezes and coughs. In this way, polluted air and mucus are evacuated. In addition, the upper respiratory tract is lined with hundreds of thin cilia of the ciliated epithelium, which are in constant motion and move mucus up the larynx along with dirt that has entered the respiratory system, which are either swallowed or removed out. Constant long-term exposure to by-products of tobacco smoke and polluted air leads to overload and overwhelm of human defense systems, resulting in the development of diseases of the respiratory system: allergic asthma, cancer and emphysema, chronic bronchitis. See also RESPIRATORY ORGANS.
Acid precipitation. The entry into soil or water bodies of various acids, such as sulfuric (H2SO4) or nitric (HNO3), as a result of acid precipitation (abnormally acidic rain and snow) causes harm to living organisms and contributes to the destruction of various structures. Similar phenomena are quite often observed in areas with significant concentrations of industrial enterprises using fossil fuels. The damage caused to biota by acid precipitation is most noticeable in forests and lakes. Certain types of trees, particularly pine trees, are especially sensitive to changes in soil acidity. Large areas of forests in New England, Canada and the Scandinavian countries have been severely damaged by acid rain. In some cases, plants serve as indicators of such effects: leaves become stained or discolored. Acid overload associated with spring meltwater runoff into lakes and rivers can have detrimental effects on fish and other aquatic organisms. see also
ACID PRECIPITATION;
ENVIRONMENTAL DEGRADATION.
COMPOSITION AND STRUCTURE OF THE ATMOSPHERE
The atmosphere, or "ocean of air", consists of gases necessary to support life on Earth. Based on its height, it can be divided into five layers, or shells, surrounding the globe: the troposphere, stratosphere, mesosphere, thermosphere and exosphere. Their boundaries are determined by sudden changes in temperature caused by differences in the absorption of solar radiation. Air density also changes with altitude. In the upper layers of the atmosphere, the air is cold and rarefied, but near the Earth's surface, due to gravity, it is denser. It is mainly the two lower layers of the atmosphere that are polluted. See also ATMOSPHERE.
Troposphere. The composition and structure of the lower layer - the troposphere - is determined by the supply of gases from the earth's crust and the presence of life on the earth's surface. The upper boundary of the troposphere is located at altitudes of approximately 17 km above sea level at the equator and approx. 8 km at the poles. This thin layer contains two important gaseous components: nitrogen (N2) and oxygen (O2), which account for 78 and 21% of the atmosphere's volume, respectively. The nitrogen cycle in nature (nitrogen cycle) plays a very important role in plant nutrition. Atmospheric nitrogen is bound by nodule bacteria contained in the root thickenings of leguminous plants, with the formation of numerous organic compounds, especially proteins. Other specialized bacteria then decompose and convert the nitrogen-rich organic residues into simpler inorganic substances, such as ammonia (NH4), through a process of mineralization. Finally, nitrifying bacteria convert them back into nitrogen oxide (NO) and dioxide (NO2), which are returned to the atmosphere. Then the cycle resumes.
See also NITROGEN. Oxygen is formed during the process of photosynthesis in plants and, in turn, is used by micro- and macroorganisms during respiration, the by-product of which is carbon dioxide.
see also
CARBON CYCLE ;
PHOTOSYNTHESIS. In addition to nitrogen and oxygen, the atmosphere includes argon (Ar - 0.93%) and carbon dioxide (CO2 - 0.036%), as well as in small quantities neon (Ne), helium (He), methane (CH4), krypton (Kr ), hydrogen (H2), xenon (Xe) and chlorofluorocarbons (CFCs) of anthropogenic origin. The source and necessary component of life on Earth, which contributes, in particular, to maintaining the temperature of its surface, is water vapor (H2O), which enters the troposphere mainly as a result of the evaporation of water from the surface of the ocean. Its content in the atmosphere varies significantly depending on the time of year and geographical location. For living organisms, consisting mainly of organic compounds of carbon with hydrogen and oxygen, oxygen, water and carbon dioxide play a primary role. Water and carbon dioxide are critical to heating the earth's surface due to their ability to absorb solar radiation.
Stratosphere. Directly above the troposphere at altitudes from 18 to 48 km above the earth's surface is the stratosphere. Although these shells are very similar in composition, in the stratosphere the water vapor content is approximately 1000 times less, and the ozone content is approximately 1000 times greater than in the troposphere. Ozone is formed in the stratosphere by the interaction of oxygen molecules during lightning discharges and ultraviolet irradiation from the Sun. The composition of air pollutants has changed significantly since World War II. In the 1950s, coal was replaced by diesel fuel, and soon natural gas. By 2000, most homes were heated by natural gas, the cleanest of all fossil fuels. On the other hand, the atmosphere increasingly began to be polluted by exhaust gases generated during the operation of internal combustion engines.
MAJOR POLLUTANTS
Sulfur dioxide, or sulfur dioxide (sulfur dioxide). Sulfur enters the atmosphere through many natural processes, including the evaporation of seawater spray, the movement of sulfur-containing soils in arid regions, gas emissions from volcanic eruptions, and the release of biogenic hydrogen sulfide (H2S).
See also SULFUR. The most widespread sulfur compound is sulfur dioxide (SO2), a colorless gas produced during the combustion of sulfur-containing fuels (primarily coal and heavy petroleum), as well as during various production processes, such as the smelting of sulfide ores. Sulfur dioxide is especially harmful to trees, causing chlorosis (yellowing or discoloration of leaves) and dwarfism. In humans, this gas irritates the upper respiratory tract, as it easily dissolves in the mucus of the larynx and trachea. Chronic exposure to sulfur dioxide can cause a respiratory disease similar to bronchitis. This gas itself does not cause significant harm to public health, but in the atmosphere it reacts with water vapor to form a secondary pollutant - sulfuric acid (H2SO4). Drops of acid are transported over considerable distances and, when they enter the lungs, severely destroy them. The most dangerous form of air pollution occurs when sulfur dioxide reacts with suspended particles, accompanied by the formation of sulfuric acid salts, which penetrate into the lungs during breathing and settle there.
Carbon monoxide, or carbon monoxide, is a very poisonous gas without color, smell or taste. It is formed during incomplete combustion of wood, fossil fuels and tobacco, during the combustion of solid waste and partial anaerobic decomposition of organic matter. Approximately 50% of carbon monoxide is produced due to human activities, mainly from the internal combustion engines of automobiles. IN indoors(for example, in a garage) filled with carbon monoxide, the ability of red blood cell hemoglobin to carry oxygen decreases, which causes a person’s reactions to slow down, perception to weaken, headaches, drowsiness, and nausea to appear. Under the influence of large amounts of carbon monoxide, fainting, coma, and even death can occur. See also CARBON. Suspended particles, including dust, soot, pollen and plant spores, etc., vary greatly in size and composition. They can either be directly contained in the air, or be contained in droplets suspended in the air (so-called aerosols). In general, approx. 100 million tons of aerosols of anthropogenic origin. This is about 100 times less than the amount of aerosols of natural origin - volcanic ash, wind-blown dust and sea water spray. Approximately 50% of anthropogenic particles are released into the air due to incomplete combustion of fuel in transport, factories, factories and thermal power plants. According to World Organization health care, 70% of the population living in cities in developing countries breathes highly polluted air containing a lot of aerosols. Aerosols are often the most obvious form of air pollution, as they reduce visibility and leave dirty marks on painted surfaces, fabrics, vegetation and other objects. Larger particles are mainly captured by the hairs and mucous membranes of the nose and larynx and then expelled. It is assumed that particles smaller than 10 microns are most dangerous to human health; they are so small that they penetrate the body's protective barriers into the lungs, damaging tissue respiratory organs and promoting development chronic diseases respiratory system and cancer. The most carcinogenic and therefore very dangerous to health are also considered tobacco smoke and asbestos fibers contained in urban air and indoors. Other types of aerosol pollution complicate bronchitis and asthma and cause allergic reactions. The accumulation of a certain amount of small particles in the body makes breathing difficult due to blockage of capillaries and constant irritation of the respiratory system. Volatile organic compounds (VOCs) are toxic vapors in the atmosphere. They are the source of many problems, including mutations, respiratory disorders and cancer, and also play a major role in the formation of photochemical oxidants.
The largest natural source of VOCs are
plants that annually release approximately 350 million tons of isoprene (C5H8) and 450 million tons of terpenes (C10H16). Another VOC is methane gas (CH4), which is produced in wet areas (such as swamps or rice fields) and is also produced by bacteria in the stomachs of termites and ruminants. In the atmosphere, VOCs are usually oxidized to carbon oxides - carbon monoxide (CO) and carbon dioxide (CO2). In addition, anthropogenic sources emit many toxic synthetic substances into the atmosphere. organic matter, such as benzene, chloroform, formaldehyde, phenols, toluene, trichloroethane and vinyl chloride. The main part of these compounds enters the air during incomplete combustion of hydrocarbons from automobile fuel, at thermal power plants, chemical and oil refineries.
Nitrogen dioxide. Nitrogen oxide (NO) and dioxide (NO2) are formed during the combustion of fuel at very high high temperatures(above 650o C) and excess oxygen. In addition, these substances are released when bacteria oxidize nitrogen-containing compounds in water or soil. Subsequently, in the atmosphere, nitrogen oxide is oxidized to gaseous dioxide of a red-brown color, which is clearly visible in the atmosphere of most major cities. The main sources of nitrogen dioxide in cities are car exhaust gases and emissions from thermal power plants (which use not only fossil fuels). In addition, nitrogen dioxide is formed during the combustion of solid waste, as this process occurs at high combustion temperatures. NO2 also plays an important role in the formation of photochemical smog in the surface layer of the atmosphere. In significant concentrations, nitrogen dioxide has a pungent, sweetish odor. Unlike sulfur dioxide, it is irritating lower section respiratory system, especially lung tissue, thereby worsening the condition of people suffering from asthma, chronic bronchitis and pulmonary emphysema. Nitrogen dioxide increases susceptibility to acute respiratory diseases, such as pneumonia. Photochemical oxidizers ozone (O3), peroxoacetyl nitrate (PAN) and formaldehyde are products of secondary atmospheric pollution as a result of chemical reactions under the influence of solar radiation. Ozone is formed when either an oxygen molecule (O2) or nitrogen dioxide (NO2) breaks down to form atomic oxygen (O), which then combines with another oxygen molecule. This process involves hydrocarbons that bind the nitric oxide molecule to other substances. Thus, for example, PAN is formed. Although ozone plays an important role in the stratosphere as a protective shield that absorbs short-wave ultraviolet radiation (see below), in the troposphere it is a strong oxidizing agent that destroys plants, building materials, rubber and plastics. Ozone has a characteristic odor that is a sign of photochemical smog. Inhalation by humans causes coughing, chest pain, rapid breathing, and irritation of the eyes, nasal cavity, and larynx. Exposure to ozone also leads to a deterioration in the condition of patients chronic asthma, bronchitis, emphysema and those suffering from cardiovascular diseases.
GLOBAL AIR POLLUTION PROBLEMS
Two global environmental problems associated with air pollution pose a serious threat to the health and prosperity of humanity and other life forms: abnormally high levels of solar ultraviolet radiation reaching the earth's surface, caused by a decrease in ozone levels in the stratosphere, and climate change (global warming), caused by the entry of into the atmosphere of a large number of so-called greenhouse gases. Both problems are closely interrelated, since they depend on the entry into the atmosphere of almost the same gases of anthropogenic origin. For example, fluorochlorine-containing refrigerants (chlorofluorocarbons) contribute to the destruction of the ozone layer and play an important role in the occurrence of the greenhouse effect. See also METEOROLOGY AND CLIMATOLOGY. Depletion of the ozone layer. Stratospheric ozone is concentrated mainly at altitudes from 20 to 25 km. Absorbing 99% shortwave radiation The sun, dangerous for all living things, ozone protects the earth's surface and troposphere from it, protecting people from sunburn, skin and eye cancer, cataracts, etc. In addition, it prevents most of the tropospheric oxygen from being converted into ozone. Along with the process of ozone formation in the atmosphere, the reverse process of its decay occurs, which also occurs during the absorption of solar ultraviolet radiation. Atmospheric hydrogen oxides (HOx), methane (CH4), hydrogen gas (H2) and nitrogen oxides (NOx) can also destroy stratospheric ozone. If there is no anthropogenic impact, there is a certain balance between the formation and decay of ozone molecules. The global chemical time bomb is artificial chlorofluorocarbons, which contribute to a decrease in the average concentration of ozone in the troposphere. First synthesized in 1928 and known as freons, chlorofluorocarbons became chemical marvels in the 1940s. Chemically inert, non-toxic, odorless, non-flammable, non-destructive of metals and alloys and inexpensive to produce, they quickly gained popularity and were widely used as refrigerants. Sources of chlorofluorocarbons in the atmosphere include aerosol cans, damaged refrigerators, and air conditioners. It is obvious that freon molecules are too inert and do not disintegrate in the troposphere, but slowly rise upward and after 10-20 years enter the stratosphere. There, ultraviolet radiation from the Sun destroys the molecules of these substances (the so-called photolytic decomposition process), resulting in the release of a chlorine atom. It reacts with ozone to form atomic oxygen (O) and an oxygen molecule (O2). Chlorine oxide (Cl2O) is unstable and reacts with a free oxygen atom, resulting in the formation of an oxygen molecule and a free chlorine atom. Therefore, a single chlorine atom, once formed from the breakdown of a chlorofluorocarbon, can destroy thousands of ozone molecules. Short-wave ultraviolet radiation from the Sun, which is dangerous for living cells, can penetrate to the earth's surface due to seasonal decreases in ozone concentration (so-called ozone holes), which were observed, in particular, over Antarctica and to a lesser extent over other regions. According to forecasts, increased doses of ultraviolet radiation will lead to an increase in the number of victims of sunburn, as well as an increase in the incidence of skin cancer (this trend is already visible in Australia, New Zealand, South Africa, Argentina and Chile), eye cataracts, etc.
See also ENVIRONMENTAL DEGRADATION. In 1978, the US government banned the use of CFCs as aerosol sprays. In 1987, government representatives from 36 countries held a special meeting in Montreal and agreed on a plan (the Montreal Protocol) to reduce emissions of chlorofluorocarbons into the atmosphere by about 35% between 1989 and 2000. At a second meeting in Copenhagen in 1992, held amid growing concerns about the destruction ozone screen, representatives of a number of countries agreed that in the future it is necessary: to abandon the production of halons (a class of fluorocarbons containing bromine atoms) by January 1, 1994, and chlorofluorocarbons and hydrobromofluorocarbons (halon substitutes) - by January 1, 1996; for the period until 1996, freeze the consumption of hydrochlorofluorocarbons at the 1991 level and completely eliminate their use by 2030. It was also noted that most of the previously set goals have been achieved.
Greenhouse effect. In 1896, Swedish chemist Svante Arrhenius first suggested the heating of the atmosphere and earth's surface as a result of the greenhouse effect. Solar energy enters the Earth's atmosphere in the form of short-wave radiation. Some of it is reflected into outer space, the other is absorbed by air molecules and heats it, and about half reaches the earth's surface. The Earth's surface heats up and emits long-wave radiation, which has less energy than short-wave radiation. The radiation then passes through the atmosphere and is partially lost into space, and most of it is absorbed by the atmosphere and reflected again to the Earth's surface. This process of secondary reflection of radiation is possible due to the presence in the air, albeit in small concentrations, of impurities of many gases (the so-called greenhouse gases), which have both natural and anthropogenic origin. They transmit short-wave radiation but absorb or reflect long-wave radiation. The amount of thermal energy retained depends on the concentration of greenhouse gases and the length of time they remain in the atmosphere. The main greenhouse gases are water vapor, carbon dioxide, ozone, methane, nitrous oxide and chlorofluorocarbons. Undoubtedly, the most important among them is water vapor, and the contribution of carbon dioxide is also significant. 90% of the carbon dioxide that enters the atmosphere annually is formed during respiration (the oxidation of organic compounds by plant and animal cells). However, this intake is compensated by its consumption by green plants during photosynthesis. See also PHOTOSYNTHESIS. The average concentration of carbon dioxide in the troposphere due to human activity increases annually by approximately 0.4%. Based on computer modeling, a forecast was made according to which global warming will inevitably occur as a result of an increase in the content of carbon dioxide and other greenhouse gases in the troposphere. If it comes true and the average air temperature on Earth rises by just a few degrees, the consequences could be catastrophic: the climate and weather will change, the growing conditions of plants, including agricultural crops, will be significantly disrupted, droughts will become more frequent, glaciers and ice sheets will begin to melt, which, in in turn, will lead to rising sea levels and flooding of coastal lowlands. Scientists have calculated that to stabilize the planet's climate, a 60% (relative to 1990 level) reduction in greenhouse gas emissions is necessary. In June 1992, at the UN Conference on Environment and Development in Rio de Janeiro, delegates from 160 countries signed the Climate Change Convention, which encouraged further efforts to reduce greenhouse gas emissions and set a goal of stabilizing their release into the atmosphere at 1990 levels by 2000.
see also
CLIMATE ;
ENVIRONMENTAL DEGRADATION.
INDOOR AIR POLLUTION
Indoor air pollution is the main cause oncological diseases. The main sources of this pollution are radon, products of incomplete combustion, and evaporation of chemicals.
Radon. Radon exposure is considered to be the second leading cause of lung cancer. This mainly occurs in houses that were built on loose sediments or bedrock enriched with uranium-containing minerals. Radon gas, a product of the radioactive decay of uranium, enters houses by seeping from the soil. The solution to this problem largely depends on the type of building structures. In addition, ventilation of buildings, for example ventilation windows in foundations, helps improve the environmental situation. Ventilation pipes inserted into the base of the foundation can remove radon directly from the soil to the atmosphere.
Products of incomplete combustion. When fuel is incompletely burned in stoves, fireplaces and other heating devices, as well as when smoking, carcinogenic substances are formed. chemical substances, such as hydrocarbons. In homes, carbon monoxide is a major concern because it is colorless, odorless, and tasteless, making it very difficult to detect. Undoubtedly, the main and very insidious pollutant of indoor air, and therefore very dangerous to human health, is cigarette smoke, which can cause lung cancer and many other diseases of the respiratory and heart organs. Even non-smokers, being in the same room with smokers (so-called passive smokers), expose themselves to great risk.
Release of chemicals. Mothballs, bleaches, paints, shoe polish, various cleaning products, deodorants are just a few wide range chemicals that everyone (especially industrial workers) are exposed to almost every day and that emit carcinogens. For example, plastics, synthetic fibers and cleaners evaporate benzene, while foam insulation, plywood, and particleboard are sources of formaldehyde. Such emissions can cause headache, dizziness and nausea.
Asbestos. Inhalation of asbestos fibers causes a progressive, incurable lung disease, asbestosis. This problem is especially true for owners of houses built before 1972. The fact that asbestos is used as a fireproofing or thermal insulation material in such buildings does not necessarily pose a health risk. The condition of structures containing asbestos is extremely important.
LITERATURE
Datsenko I.I. Air environment and health. Lvov, 1981 Budyko M.I., Golitsyn G.S., Israel Yu.A. Global climate disasters. M., 1986 Pinigin M.A. Atmospheric air protection. M., 1989 Bezuglaya E.Yu. What does an industrial city breathe? L., 1991 Alexandrov E.L., Israel Yu.A., Karol I.L., Khrgian L.H. The Earth's ozone shield and its changes. St. Petersburg, 1992 Climate, weather, ecology of Moscow. St. Petersburg, 1995

Collier's Encyclopedia. - Open Society. 2000 .

It has been going on for more than a millennium, but never before has it been as intense as in the last tens of years. The only influence that man ever had on the atmosphere was to cause air pollution, is the use of fire. Because of this, the walls of the home suffered and it became difficult to breathe in the room, but the warmth that the flame gave people was much more important. Even when ancient people concentrated in large enough groups, this did not pose a threat to the atmosphere. This was the case until the nineteenth century. And in the last hundred years, technological processes that once could not even be imagined have become widespread. And what about the uncontrolled growth of millionaire cities, which is no longer possible to stop. Ambient air pollution- this is, of course, the result of human activity.

There are three categories of sources of air pollution: industrial, domestic, and transport. In different parts of the world, the proportion of each species varies greatly. Generally greatest harm brings industry.

Thermal power plants, along with smoke, emit carbon dioxide and sulfur dioxide into the atmosphere, enterprises processing ferrous and especially non-ferrous metals emit chlorine, ammonia, fluorine, hydrogen sulfide, phosphorus, and mercury particles. Cement and chemical factories are also sources of pollution. Harmful gases resulting from the combustion of various fuels for the needs of industry, home heating, transport, and waste processing are also causes of air pollution.

Pollution itself can be primary or secondary. The former immediately enter the atmosphere, while the latter are formed as a result of the transformation and breakdown of primary pollutants. For example, it turns into sulfuric anhydride, which interacts with water vapor and forms drops. If sulfuric anhydride enters into a chemical reaction with ammonia, it is released in the form of crystals.

The danger to the atmosphere is represented by pyrogenic sources that cause air pollution- enterprises of the chemical and metallurgical industries, thermal power plants, boiler plants. As a result of their activities, the following stand out:

Carbon monoxide. It is formed when its compounds do not burn completely. It goes into the air after the combustion of solid waste, with exhaust and emissions from enterprises. Carbon monoxide actively reacts with many elements of the atmosphere and gradually contributes to an increase in temperature throughout the planet.

Sulfur dioxide. This substance is the result of burning fuel, which contains sulfur, as well as its processing in the form of ore.

Sulfuric anhydride is the result of the oxidation of the above substance. It is absorbed into the soil with rainwater, acidifying it.

Air pollution Causes cosmic dust, which is released after the combustion of meteorites passing through the atmosphere. Every year, a huge amount of “garbage” from space settles on earth - up to five million tons. Dust from the Earth is part of the atmosphere; its main sources are steppes and deserts, volcanoes, products of decay and decomposition of plants and animals.

The air above the surface of the oceans contains small particles of sodium, magnesium, calcium, and potassium salts, which appear after the water splashes dry.

It should be noted that natural air pollution does not threaten negative consequences for any biocenosis and living organisms, however, a short-term negative impact cannot be excluded.

Dust in the atmosphere provokes rapid accumulation of condensation and, as a result, precipitation forms faster. It also significantly reduces the penetration of solar radiation, protecting living organisms.

Sources and causes of air pollution.

Air pollution is a gas (or a liquid or solid dispersed through ordinary air) released in sufficiently large quantities that it can harm or kill the health of people, animals, or plants, stunt their growth, cause damage or disruption to other aspects of the environment (eg , destruction of buildings), or cause some other adverse effects (restricted visibility, unpleasant odor).

All types of air pollution can be divided into natural and artificial (anthropogenic).

Natural pollution can occur as a result of forest fires (huge areas of smoke that spread for many kilometers over neighboring cities, countries and continents); volcanic eruptions (gas emissions change the chemical composition of the air, and huge amounts of volcanic dust block significant amounts of sunlight and cause the planet to cool), and gases released as a result of radioactive decay of rocks inside the Earth are just three examples of natural air pollution (can be a source of gas radon), which have extremely destructive consequences for people and the planet.

Artificial (anthropogenic sources of pollution are tens of thousands of chemical compounds, including special concern cause the following:

There are gaseous and mechanical impurities in the air.

Gaseous impurities. Sulphur dioxide is the most common air pollutant, enters the air during oil refining, combustion of solid and liquid fuels, and with vehicle exhaust gases. Increased quantity This gas in the air leads to “acid rain”, the death of vegetation and is a serious problem for all industrial regions and large cities. Sulfur dioxide poses a significant danger to human health - it is irritating and toxic effect, affects the respiratory system, contributes to the disease of people with bronchial asthma.

Sulfur dioxide. Coal, oil and other fuels often contain sulfur as well as organic (carbon) compounds. When sulfur burns, sulfur dioxide is formed. Coal-fired power plants are the world's largest source of sulfur dioxide, which contributes to smog, acid rain, and health problems including lung disease.

Carbon monoxide (carbon monoxide)- one of the most common air pollutants, a product of incomplete combustion of fuel, is part of car exhaust gases. Carbon monoxide is odorless, non-irritating and can therefore accumulate to significant concentrations unnoticed. Human poisoning occurs due to the ability of carbon monoxide to convert hemoglobin into carboxyhemoglobin, which does not have the ability to carry oxygen, which leads to oxygen deficiency.

Carbon dioxide. This gas occupies a central place in Everyday life. It is generally not considered a pollutant: we all produce it when we breathe. Plants and trees need it to grow. However, too much energy is emitted into the atmosphere by power plants and engines. a large number of carbon dioxide, and therefore, since the beginning of the industrial revolution, this factor has created and aggravated the problem global warming and climate change.

Nitrogen oxides. Nitrogen dioxide (NO2) and nitric oxide (NO) are an indirect result of combustion when nitrogen and oxygen from the air react with each other. Atmospheric air pollution with nitrogen oxides occurs during the operation of automobile engines and power plants. Like carbon dioxide, nitrogen oxides are also greenhouse gases (i.e., they contribute to global warming). The most dangerous is nitrogen dioxide, which takes part in reactions with the formation of “acid rain”, “photochemical smog”, has an irritating effect on the human respiratory system, and has a pronounced toxic effect.

Volatile organic compounds(VOC). These carbonaceous (organic) chemicals evaporate easily at normal temperature and pressure, so they easily become gases. That is why they are used as solvents in household chemicals (paint, wax and varnish). They are air pollutants: long-term (chronic) exposure to VOCs is believed to have negative effects on human health, and VOCs also play a role in the formation of smog.

Mechanical impurities. Mechanical impurities are solid particles varying degrees dispersion ( different types dust, ash, etc.) and aerosols - small particles suspended in the air (smoke, fog, etc.). Air dust can lead to climate change, deterioration of sanitary conditions and the development of chronic human diseases. Toxic types of dust and aerosols are especially dangerous. Combustion of fuel and waste, exhausts road transport pollute the air with ash, soot, as well as toxic substances of the first hazard class, benzo(a)pyrene and dioxins. Lead aerosols that enter the air with exhaust gases from vehicles using leaded gasoline pose a danger to the biosphere and humans.

Ozone (trioxygen). Ozone molecules are made up of three oxygen atoms joined together ( chemical formula O 3). In the stratosphere (the upper layers of the atmosphere), a layer of ozone (the "ozone layer") protects us by filtering out harmful ultraviolet radiation(high energy blue light) shining down from the Sun. At ground level, this toxic pollutant can be harmful to health. It is formed when sunlight hits compounds of other environmental pollutants and is a key ingredient in smog.

Chlorofluorocarbons (CFCs). Previously, when these substances were considered harmless, they were widely used in the production of refrigerators and aerosol cans, but then they were discovered to damage the Earth's ozone layer.

Unburnt hydrocarbons. Petroleum is another fuel made up of a chain of carbon and hydrogen atoms. When they burn with enough oxygen, they are completely converted into harmless carbon dioxide and water; when they do not burn completely, they can release carbon monoxide or particulate matter, which contributes to the formation of smog.

Lead and heavy metals. Lead and other toxic heavy metals can become airborne either as toxic compounds or aerosols.

Causes of air pollution

Motor transport. Almost all of their cars run on gasoline and diesel engines, which burn oil to release energy. Oil is made up of hydrocarbons (large molecules made from hydrogen and carbon), and theoretically, when burned with enough oxygen, they should produce harmless substances such as carbon dioxide and water. But in practice, fuels are not pure hydrocarbons. As a result, engine emissions contain a large number of pollutants, in particular solid particles (soot different sizes), carbon monoxide (CO, a poisonous gas), nitrogen oxides (NOx), volatile organic compounds (VOCs), and lead and indirectly produce ozone . Mix this harmful mixture and activate it with sunlight, and you get a sometimes brownish, sometimes bluish fog (smog) that can exist over cities for several days in a row.

Smog(a combination of the words "smoke" and "fog") is created when sunlight acts on a mixture of polluting gases such as sulfur and nitrogen oxides, unburned hydrocarbons and carbon monoxide, which is why it is sometimes called photochemical smog (because chemical reactions are caused by light energy). One of the most harmful components of smog is ozone, which can cause severe breathing difficulties and even death.

The formation of smog is most relevant for areas with regular temperature inversions . Typically, the air gets colder the higher it rises, but with a temperature inversion the opposite happens: a layer of warm air is at the top, and a layer of cold air is closer to the ground.

Power plants. Renewable energy sources such as solar panels and wind turbines help us get some of our energy every year, but the vast majority of electricity (about 70 percent) is still produced by burning fossil fuels such as coal, gas, and oil, mostly in conventional power plants. Just like car engines, power plants should theoretically produce carbon dioxide and water, but in practice, power plants produce a range of pollutants, e.g. sulfur dioxide, nitrogen oxides, particulate matter . They also release huge amounts of carbon dioxide, which is a major cause of global warming and climate change.

Industrial pollution. Sources of industrial air pollution include energy, metallurgy, building materials, chemical and oil refining industries, and fertilizer production.

The air is considered clean if none of the microcomponents are present in concentrations that can harm human health, animals, vegetation or cause deterioration in the aesthetic perception of the environment (for example, in the presence of dust, dirt, unpleasant odors or when there is a lack of sunlight as a result of smoke in the air). Since all living things very slowly adapt to these new microcomponents, chemicals serve as an objective factor of adverse effects on the natural environment and human health.