Smoke is a serious environmental problem of modern society. A caustic fog covers many cities - from London to Beijing. We will talk about the reasons for the formation of Smog, about its species and influence on health, as well as what each of us can make to prevent smog.

Smog - This is a mixture of smoke, fog and some pollutants. This term of English origin ("SMOG") is a merger of two English words "smoke" and "fog" - "smoke" and "fog". For the first time, this word was used in London in the early 1900s to describe the environmental situation in the city.

According to several sources, the term was first used by Dr. Henry Antoine de V. The scientist described one of the types of smog - a combination of smoke and sulfur dioxide, the result of active use of coal for heating houses and enterprises in England.

It was now characteristic not only for Britain, but also for many industrialized countries. How does this dangerous phenomenon occur, what are its views and negative consequences? Let's find out.

How to form

Causes of smog formation may be as follows:

• natural and peat fires;
• car exhaust gases;
• activities of power plants and factories;
• coal burning;
• smoking;
• harmful evaporation from many consumer goods, including chemical solvents, paint or even hair polish.

When sunlight and heat react with harmful gases and particles in the atmosphere, then malicious fog arises.

The main cases of the appearance of smog are often associated with the intensive movement of vehicles, high air temperature, sunlight and windless weather. Thus, the low wind speed can be found in a certain area. The stagnation may contribute to the temperature inversion, in which the warm air at the surface of the earth and all pollutants are blocked by the "lid" from cold air.

In addition to other harmful substances and gases, carbon oxide, familiar to us as carbonated gas, is contained in the smog. It is not noticeable for us because there is no smell, nor the color, but his suffocating impact can significantly affect health and even lead to death.

I could from forest fires

Could, formed as a result of natural fires, are not distinguished in a separate appearance. But it is dangerous, since when burning into the atmosphere, a large amount of carbon monoxide is distinguished. This gas has no color and smell, but toxic for all living things.

Forest fires in the Krasnoyarsk Territory in 2019 provoked the formation of smog in large cities of neighboring regions. Because of the haze and windless weather, the citizens did not see the pure blue sky for 5 days. According to unofficial information, the cause of the fire of Siberian forests became dry thunderstorms resulting from high air temperature.

Views of Smog.

There are at least four varieties of smog: sulfur, photochemical, volcanic and icy.

Wet London type

This type is also called sulfur. It is the result of a high concentration of sulfur oxides in the air and is due to the use of sulfur-containing fuels, in particular coal. The danger of this type is exacerbated by the high concentration of suspended particles in the air.

One of the most serious incidents associated with this type occurred in London in 1952. Coal, which was actively used by the townspeople at that time for heating, contained a sulfur, which in the air increased the content of sulfur dioxide. Also increased the contamination of the exhaust gases of machines and the activities of coal power plants.

"The Great I was able, who hung over the city was so thick that Imbered the movement of cars. Conducted public transport and ambulance. Fog penetrated into the premises. In London, many cultural events and film images were canceled: due to the dense curtain there was no scene and screen. The formed urban smoked life of more than 12 thousand people; More than 100 thousand got sick with respiratory diseases.

Photochemical (dry) was able to Los Angeles

Photochemical, or white, was able - This is the most common type to date. It is formed when the interaction of several substances:

• Nitrogen oxides. They are formed when burning fuel due to the activities of TPP, CHP, metallurgy and other industrial production areas. Also on the appearance of nitrogen oxides affect exhaust gases. The minimum effects of these compounds are irritation of the eyes and nasopharynx and difficulty breathing.
• Ozone. Ozone is one of the main factors affecting the formation of a photochemical smog, and, although in the upper layers of the atmosphere, it is a beneficial chemical that protects us from solar radiation, in the lower layers it is a pollutant who can be harmful to people's health.
• Weighted particles PM2.5. These are the smallest dust particles, soot, ashes and other contaminants that we cannot see the naked eye. PM2.5 is very dangerous to human health: they reduce life expectancy, they are associated with lung cancer and diseases of respiratory and cardiovascular systems. Fortunately, now there are blocking the receipt of these particles into the room.
• Volatile organic compounds. These are pairs of paints, solvents, gasoline and other toxic substances.

Photochemical was able to aerosol arising from the effects of sunlight on nitrogen oxides, hydrocarbons and volatile organic compounds that can be found in exhaust gases and emissions of plants and power plants. As a result, he could have a light brown color.

In contrast to London, this type is called Los Angeles - after all, in the city of Angels, millions of cars throw out more than a thousand tons of nitrogen oxides per day.

Volcanic

Volcanic - This is a kind that is formed in the atmosphere as a result of the volcanic eruption. Harmful gases and particles are released from the jar and react with sunlight and oxygen. Some chemicals in volcanic smog can cause damage to people and animals, and plants. People can experience breathing problems, irritation of mucous membranes and sore throat. This type is peculiar to countries in which there are current volcanoes, for example, for the Hawaiian Islands.

This type is found in nature much less often.

Weather conditions that contribute to the formation of ice smug are as follows:

• very low air temperature;
• lack of wind;
• high humidity.

When with such weather in the air, small crystals of ice are formed, all pollutants are attached to them. The combination of ice crystals and particles of harmful substances forms a thick fog that adversely affects the blood circulation and human respiratory organs.

Unde, including forest fires, in addition to carbon monoxide, is dangerous with a high content of ultrafine particles PM2.5 and PM10.

These particles are so small and light, which is not settled under the influence of gravity for the surface, and twist in the air, inhale alive creatures, it is freely reaching the lungs and fall into the blood. According to the World Health Organization (WHO), the impact of hazardous particles in the long run can cause the development of respiratory, cardiovascular diseases and lung cancer.

Environmental consequences Smog

Not only can impass visibility, it also has a negative impact on health. The consequences of its impact on human health range from small eye irritation and nasopharynx to potentially fatal diseases such as lung cancer. The strength of these consequences depends on the duration of the existence of the fog, its density, concentration and the level of danger of the substances that are contained in it. Could could cause or exacerbate diseases such as emphysema, chronic bronchitis, etc. In addition, it reduces sustainability to colds and pulmonary infections.

Especially sensitive to be able to four groups of people:

• Children. Active children spent a lot of time on the street are most at risk from the effects of a mixture of smoke and fog. Also, studies conducted in London showed that infants who survived could be more prone to the development of asthma and other respiratory diseases.
• Adults spent a lot of time outdoors. Healthy adults of any age who walk a lot, play sports or work on the street, are considered more susceptible to health problems from Smog.
• People with respiratory diseases. People with asthma or other chronic respiratory diseases are more sensitive and vulnerable to the effects of pollutants. As a rule, they begin to experience adverse effects earlier and at a lower level of impact than the rest.
• People with increased susceptibility. We are all individual, so some healthy people are simply more sensitive to ozone and other gases and particles in Smith than others, and may be subject to more unfavorable health consequences.

However, the consequences of smog are not limited to the impact on the health of people. Scientists argue that it also affects plants and animals. It is also known that fog causes corrosion damage to buildings and vehicles. Ozone in smith has a negative effect: it prevents plant growth and damage agricultural crops and forests.

How to deal with I could?

He was able to one of the most significant in many countries, therefore states create laws and monitoring systems aimed at tracking and reducing the ill-fated fog. Some of the laws include restrictions on which chemicals can throw an enterprise into the atmosphere, some - determine the substances in the air.

Everyone can contribute to prevent the emergence of Smog:

• You should walk more on foot, ride a bike or use public transport services when possible.
• Also refuel the car is better early in the morning or at night, when the street is still cool: it prevents the heating of gasoline evaporation and ozone formation.
• If you are going to be outdoors, stay away from areas that are large sources of pollution, such as motorways and plants.
• To protect yourself and your family from exposure to pollutants, pay attention to air filtration climate technique. For example, it serves from the street to the room already purified air, and destroys harmful substances and microorganisms from the air, which is already in the room.
• Avoid products (colors, solvents, etc.) with a high content of volatile organic compounds.
• Instead of gas appliances it is worth using electrical.

Be careful to your health and environment!

SMOG- aerosol consisting of smoke, fog and dust. The English word "SMOG" is derived from "Smoke" - smoke and "fog" - fog. It was the inhabitants of the English capital that were first faced with problems associated with the pollution of urban air.

In London, coal burned from the 13th century. The townspeople experienced concern because of a tangible smell - they believed that he could cause various diseases.

With full combustion of fossil fuels (coal or hydrocarbons), there are quite harmless products - carbon dioxide and water, however, in conditions of lack of oxygen, a toxic carbon monoxide is formed. If oxygen is even less, carbon (in the form of soot) appears among the combustion products. At low temperatures and a small amount of oxygen, the destruction of hydrocarbons may be accompanied by their isomerization and polycondensation, leading to the formation of polycyclic aromatic hydrocarbons, including a chainsopyrin with carcinogenic properties.

Air pollution can be caused and included in the fuel of impurities, first of all, sulfur compounds. Its content in some coals can reach 6%. When burning such a fuel, sulfur dioxide is formed. Dissolving in water droplets, which condensed around smoke particles, sulfur dioxide significantly reduces its pH. "Acid fog" is dangerous for health; It has a harmful effect on plants and animals, causes the destruction of metals and building materials.

Sale and sulfur dioxide generated directly when burning fuel are primary air pollutants. Under conditions of dampness and fog characteristic of winter London, they became the causes of long-term samples leading to the growth of pulmonary diseases. Over time, he was able to become the usual phenomenon and in other major cities and industrial centers.

The distribution of pollution in the air to a large extent depends on the weather and climatic phenomena. Winds increase the scattering rate and stirring, and the air flows directed from the ground are contaminated into the upper layers of the atmosphere. However, conditions may occur in which the atmospheric layers become very stable. Then contamination, instead of moving into the upper layers of the atmosphere, remain near the surface of the Earth. The unusual state of the atmosphere, at which the air temperature in the troposphere does not decrease with a height, are called inversion. This leads to the fact that colder air is located below the warmer, and cannot rise up and dispel in the atmosphere. Under the "roof" of warm air pollution accumulates in such large quantities that are becoming dangerous to health.

The very first of officially registered cases of pollution of the atmosphere, who had serious consequences, was able to in the city of Donor (USA) in 1948. For 36 hours, two dozen deaths were registered, hundreds of residents felt very bad. Four years later, in December 1952, an even more tragic case occurred in London. Due to pollution accumulated in the air, more than 4,000 people died in five days. Although in subsequent years he could have been strong in London and other cities repeatedly, such catastrophic consequences, fortunately, was no longer.

The transition from coal to hydrocarbon fuels reduced the danger of air pollution by particles of soot. However, new types of pollution, both the primary and secondary, resulting in the reactions of primary pollutants with unburned fuel and air oxygen appeared. Chemical reactions leading to the formation of secondary pollutants are most effectively flowing at sunlight, so the emerging air pollution received the name of the photochemical smog. He was first noted in Los Angeles (USA) during World War II. The appearance of photochemical smog is associated with the rapid development of road transport.

In terms of high temperature at which fuel combustion in the car engine, the interaction begins between oxygen and nitrogen, which is part of atmospheric air. Atomic oxygen molecules formed during dissociation, atomic oxygen is capable of splitting the molecule of relatively inert nitrogen, initiating a chain reaction:

O + N 2 \u003d NO + N

N + O 2 \u003d NO + O

As a result, nitrogen monoxide appears in the exhaust gases, which, occur in the atmosphere, is oxidized by air oxygen, turning into nitrogen dioxide. Brown nitrogen dioxide is photochemically active. Absorbing light, it dissociates:

Thus, a reactive oxygen atom appears in the air, which can react with ozone formation:

The presence of ozone is the most characteristic sign of photochemical smog. It is not formed when combustion of fuel, but is a secondary pollutant. Possessing the strongest oxidative properties, ozone has a harmful effect on people's health and destroys many materials, first of all, rubber.

In addition, the reaction between nitrogen oxides and unburned organic compounds proceed in the photochemical smog. Among the products of such reactions have many carcinogenic substances.

The differences between the "wet can" caused by the burning of coal in London, and "dryly", due to road exhausts in Los Angeles, are shown in the table.

In the big cities of our country, three ten years ago cars were not the main source of air pollution. Now the environmental problems of vehicles in large Russian cities have become a serious problem. Thus, automobile exhausts in Moscow and St. Petersburg are calculated hundreds of thousands of tons per year. Motor transport confidently went to first place among all other sources of air pollution. Therefore, in Moscow, St. Petersburg and other major cities, it was becoming a frequent guest, especially in a glad weather.

To prevent smog, it is necessary to improve the engines of cars and effectively purify exhaust gases. The amount of carbon monoxide generated in car motors can be reduced by surviving it to less hazardous carbon dioxide. Increasing the proportion of air in a combustible mixture helps to reduce emissions not only with, but also unburned hydrocarbons. Catalytic transducers were most effective, in which carbon monoxide and unburned hydrocarbons are oxidized to carbon dioxide and water, and nitrogen oxides are restored to molecular nitrogen. Unfortunately, catalytic survivors cannot be used in case of refueling the vehicle with ethyl gasoline. Such gasoline contains lead compounds, irreversibly poisoning catalyst. Alas, in our country, the ethyl gasoline is still widely used.

To reduce sulfur dioxide emissions, sulfur compounds are pre-removed from oil, and the exhaust flue gases are additionally cleaned. Sulfur compounds in the atmosphere can be reduced due to burning solid fuel in a boiling layer. Emissions of solid particles with thermal power plants reduce, using electrostilifers or vacuum air filters.

In some cities, including in Moscow, a large role in the prevention of smog is the struggle against forest and peat fires in the surrounding forests, also provoking the emergence of sustainable urban air pollution.

Unfortunately, progress in the fight against individual types of air pollution has not yet led to the disappearance of the SMOV. Thus, the reduction of harmful emissions in the exhaust gases of cars per unit of run is compensated by a rapid increase in the number of vehicles, so the overall level of pollution is not reduced. Apparently, it was able to remain a serious problem for residents of many major cities for a long time.

Elena Savinkina

- aerosol consisting of smoke, fog and dust. The English word "SMOG" is derived from "Smoke" - smoke and "fog" - fog. It was the inhabitants of the English capital that were first faced with problems associated with the pollution of urban air.

In London, coal burned from the 13th century. The townspeople experienced concern because of a tangible smell - they believed that he could cause various diseases.

With full combustion of fossil fuels (coal or hydrocarbons), there are quite harmless products - carbon dioxide and water, however, in conditions of lack of oxygen, a toxic carbon monoxide is formed. If oxygen is even less, carbon (in the form of soot) appears among the combustion products. At low temperatures and a small amount of oxygen, the destruction of hydrocarbons may be accompanied by their isomerization and polycondensation, leading to the formation of polycyclic aromatic hydrocarbons, including a chainsopyrin with carcinogenic properties.

Air pollution can be caused and included in the fuel of impurities, first of all, sulfur compounds. Its content in some coals can reach 6%. When burning such a fuel, sulfur dioxide is formed. Dissolving in water droplets, which condensed around smoke particles, sulfur dioxide significantly reduces its pH. "Acid fog" is dangerous for health; It has a harmful effect on plants and animals, causes the destruction of metals and building materials.

Sale and sulfur dioxide generated directly when burning fuel are primary air pollutants. Under conditions of dampness and fog characteristic of winter London, they became the causes of long-term samples leading to the growth of pulmonary diseases. Over time, he was able to become the usual phenomenon and in other major cities and industrial centers.

The distribution of pollution in the air to a large extent depends on the weather and climatic phenomena. Winds increase the scattering rate and stirring, and the air flows directed from the ground are contaminated into the upper layers of the atmosphere. However, conditions may occur in which the atmospheric layers become very stable. Then contamination, instead of moving into the upper layers of the atmosphere, remain near the surface of the Earth. The unusual state of the atmosphere, at which the air temperature in the troposphere does not decrease with a height, are called inversion. This leads to the fact that colder air is located below the warmer, and cannot rise up and dispel in the atmosphere. Under the "roof" of warm air pollution accumulates in such large quantities that are becoming dangerous to health.

The very first of officially registered cases of pollution of the atmosphere, who had serious consequences, was able to in the city of Donor (USA) in 1948. For 36 hours, two dozen deaths were registered, hundreds of residents felt very bad. Four years later, in December 1952, an even more tragic case occurred in London. Due to pollution accumulated in the air, more than 4,000 people died in five days. Although in subsequent years he could have been strong in London and other cities repeatedly, such catastrophic consequences, fortunately, was no longer.

The transition from coal to hydrocarbon fuels reduced the danger of air pollution by particles of soot. However, new types of pollution, both the primary and secondary, resulting in the reactions of primary pollutants with unburned fuel and air oxygen appeared. Chemical reactions leading to the formation of secondary pollutants are most effectively flowing at sunlight, so the emerging air pollution received the name of the photochemical smog. He was first noted in Los Angeles (USA) during World War II. The appearance of photochemical smog is associated with the rapid development of road transport.

In terms of high temperature at which fuel combustion in the car engine, the interaction begins between oxygen and nitrogen, which is part of atmospheric air. Atomic oxygen molecules formed during dissociation, atomic oxygen is capable of splitting the molecule of relatively inert nitrogen, initiating a chain reaction:

O + N 2 \u003d NO + N

N + O 2 \u003d NO + O

As a result, nitrogen monoxide appears in the exhaust gases, which, occur in the atmosphere, is oxidized by air oxygen, turning into nitrogen dioxide. Brown nitrogen dioxide is photochemically active. Absorbing light, it dissociates:

Thus, a reactive oxygen atom appears in the air, which can react with ozone formation:

The presence of ozone is the most characteristic sign of photochemical smog. It is not formed when combustion of fuel, but is a secondary pollutant. Possessing the strongest oxidative properties, ozone has a harmful effect on people's health and destroys many materials, first of all, rubber.

In addition, the reaction between nitrogen oxides and unburned organic compounds proceed in the photochemical smog. Among the products of such reactions have many carcinogenic substances.

The differences between the "wet can" caused by the burning of coal in London, and "dryly", due to road exhausts in Los Angeles, are shown in the table.

In the big cities of our country, three ten years ago cars were not the main source of air pollution. Now the environmental problems of vehicles in large Russian cities have become a serious problem. Thus, automobile exhausts in Moscow and St. Petersburg are calculated hundreds of thousands of tons per year. Motor transport confidently went to first place among all other sources of air pollution. Therefore, in Moscow, St. Petersburg and other major cities, it was becoming a frequent guest, especially in a glad weather.

To prevent smog, it is necessary to improve the engines of cars and effectively purify exhaust gases. The amount of carbon monoxide generated in car motors can be reduced by surviving it to less hazardous carbon dioxide. Increasing the proportion of air in a combustible mixture helps to reduce emissions not only with, but also unburned hydrocarbons. Catalytic transducers were most effective, in which carbon monoxide and unburned hydrocarbons are oxidized to carbon dioxide and water, and nitrogen oxides are restored to molecular nitrogen. Unfortunately, catalytic survivors cannot be used in case of refueling the vehicle with ethyl gasoline. Such gasoline contains lead compounds, irreversibly poisoning catalyst. Alas, in our country, the ethyl gasoline is still widely used.

To reduce sulfur dioxide emissions, sulfur compounds are pre-removed from oil, and the exhaust flue gases are additionally cleaned. Sulfur compounds in the atmosphere can be reduced due to burning solid fuel in a boiling layer. Emissions of solid particles with thermal power plants reduce, using electrostilifers or vacuum air filters.

In some cities, including in Moscow, a large role in the prevention of smog is the struggle against forest and peat fires in the surrounding forests, also provoking the emergence of sustainable urban air pollution.

Unfortunately, progress in the fight against individual types of air pollution has not yet led to the disappearance of the SMOV. Thus, the reduction of harmful emissions in the exhaust gases of cars per unit of run is compensated by a rapid increase in the number of vehicles, so the overall level of pollution is not reduced. Apparently, it was able to remain a serious problem for residents of many major cities for a long time.

Elena Savinkina

Opalovsky A.A. Planet Earth Eyes Chemist. M., Science, 1990
Revel P., Revel C. Wednesday of our habitat. In four books (translation from English). M., Mir, 1995
Chemistry and society (Translation from English). M., Mir, 1995
Dobrovolsky V.V. Basics of biogeochemistry. Studies. Manual for geogr., biol., Geol., S.-H. specialist. universities. M., Higher. Shk., 1998
Andruz J., Brimbrilembumb P., Jikelz T., Liss P. Environmental Introduction (Translation from English) M., World, 1999

Smog

intensive chemical air pollution by emissions from industrial activity. Observed in large cities and industrial areas. Lovely was able to two types: smoky fog, or sulfur class (London-type smog), and photochemical models (Los Angeles type). The resulting was able to any of two types are much more harmful to health than the set of all its components separately. Especially serious consequences are observed when he could not disappear for a long time. This is facilitated by temperature inversion, weak winds, the absence of precipitation, the accumulation of pollution in the valleys and the basins.
Smoky fogwho gave the name to the whole phenomenon (from the English words "smoke" - smoke and "fog" - fog), is formed as a result of the reaction of the products of incomplete combustion or waste of chemical production with water drops in the fog. As a rule, among pollutants there are oxides of sulfur, nitrogen and other elements, and with their reaction with drops of water in the fog, caustic acids are formed. As a result, when inhalation of the smoot, a sensation of suffocation and a throat, drops of acids energize the mucous membrane of the respiratory tract, which can lead to a serious disease, up to a deadly outcome. In December 1952, 4,000 people died in London from smoky fog.

Geography. Modern illustrated encyclopedia. - M.: Rosman. Edited by prof. A. P. Gorkina. 2006 .

Watch what was "able" in other dictionaries:

I could, and ... Russian verbal emphasis

Cassed, a thick mixture of smoke with fog and chemical couples formed in an atmosphere over urbanized or industrial areas. Smoke arises, as a rule, where there is a radiation fog. In the windless weather, the fog becomes curly, and in ... ... Scientific and Technical Encyclopedic Dictionary

BUT; m. [English SMOG] Polluted air (a mixture of smoke, fog and dust), characteristic of industrial cities. Over the city picked with. C. may be the cause of the exacerbation of diseases of blood circulation and respiratory organs. * * * Smog Smog, from smoke smoke and ... encyclopedic Dictionary

Modern encyclopedia

- [English. SMOG Russian Language Foreign Words

Smog - (English Smog, from smoke smoke and fog fog), toxic fog, dangerous contamination of atmospheric air, characterized by a combination of dust particles and fog droplets. It is formed mainly when inversions of temperature. Ecological ... ... Ecological Dictionary

- (SMOG) Pollution of the atmosphere associated with photochemical processes arising from emissions of hydrocarbon emissions and nitrogen oxides (NOX) is a mixture of smoke and fog. Smoke is harmful to health. It appears mainly as a result ... Economic Dictionary

smog - Smoke and fog English: SMOG, Smoke + Fog Eng. Union of young geniuses The group of young writers of dissidents in Moscow in early 1960s was able to monitor dangerous goods monitoring system: http: // www ... Dictionary of contractions and abbreviation

Smog - I could, aerosol arising in an atmosphere of industrial cities from particles of industrial and construction dust, emissions of thermal power plants, vehicles, etc. In a wet atmosphere on solid particles, droplets of moisture, evaporation acids ... Illustrated Encyclopedic Dictionary

Smagted, was able. POST. BP. from Moch. Explanatory dictionary of Ushakov. D.N. Ushakov. 1935 1940 ... Explanatory Dictionary Ushakov

Books

• Smog. Volume 1, Ray Catherine. The largest cities one by one disappear from the cards, hiding under the veil smog - a dark curtain provokes desertification, the city is slow and painfully dying. Main characters: Ed and Marie, ...

Introduction

Types Smog.

The consequences of smog

Methods of combating CO could

Conclusion

BIBLIOGRAPHY

Introduction

Great smoked (eng. Great Smog) London enveloped on December 5, 1952 and dissipated only by December 9 of the same year. The happening has become a real catastrophe, as a result of which 12,000 people died, which served as it is considered that the starting point of modern environmental protection (environmental) movement.

In early December 1952, the cold fog dropped to London. Because of the cold, the citizens began to use coal for heating in more quantities than usual. Approximately the same time the process of replacing urban electric transport (trams) was completed for buses with a diesel engine. Locked with a more severe layer of cold air, combustion products in the air in a matter of days have reached an emergency concentration. The fog was so thick, which prevented the movement of cars. Concerts were canceled, the demonstration of movies was stopped, because he could easily penetrate the premises. Spectators sometimes simply did not see the scene or screen due to a dense curtain.

At first, the reaction of the citizens was calm, because in London fogs are not uncommon. In the following weeks, however, the statistical data collected by the medical services of the city revealed the deadly nature of the disaster - the number of deaths among babies, the elderly and respiratory diseases reached four thousand people. About eight thousand people died in the following weeks and months.

Shock caused by this cruel lesson, made people change their attitude towards air pollution. Disaster clearly demonstrated people all over the world that this problem is a direct threat to people's lives. New environmental standards were adopted, aimed at limiting the use of dirty fuels in the industry and for the prohibition of sage-containing exhaust gases. Among the measures taken is the introduction of the Law "On Clean Air" (revised from 1956 and 1968) and a similar law of the city of London (1954).

What was the causes of its occurrence

For the first time, the term "smoke" was introduced by Dr. Henry Antoine de in 1905.<#"703523.files/image001.gif">

The distribution of pollution in the air to a large extent depends on the weather and climatic phenomena. Winds increase the scattering rate and stirring, and the air flows directed from the ground are contaminated into the upper layers of the atmosphere. However, conditions may occur in which the atmospheric layers become very stable. This, in particular, occurs during anticyclones (areas with high atmospheric pressure), with cylinder weather in general, and when heating the lowest air layer, when the air is warmer in the upper layers at some height, than in the lower (that is, the temperature inversion is observed). Then contamination, instead of moving into the upper layers of the atmosphere, remain near the surface of the Earth. This leads to the fact that colder air is located below the warmer, and cannot rise up and dispel in the atmosphere. Under the "roof" of warm air pollution accumulates in such large quantities that are becoming dangerous to health.

Cities located in the depths of the area are distinguished by increased repeatability of temperature inversions, and, therefore, with a high level of industrial air pollution, they are predisposed to the formation of smog.

Types Smog.

Three types of smog are distinguished:

ice could (Alaskan type);

humid mod (London type);

dry, or photochemical smoked (Los Angeles type).

Ice smoked (Alaskan type) - characteristic of high latitudes in winter at a temperature of -30-35 ° C and full of ulothels. Air steam, located in the atmosphere freezes, is absorbed on these crystals soot<#"703523.files/image002.gif">

This transformation is experiencing and no in the air.

On the sunlight NO2 is exposed to photodissociation:

Forming atomic oxygen is very active and can enter into a variety of reactions, in particular, to form ozone O3 with molecular oxygen

Where m - air molecules absorbing the released energy

The presence of ozone is the most characteristic sign of photochemical smog. It is not formed when combustion of fuel, but is a secondary pollutant.

In the daytime, ozone slowly reacts with NO2, forming a radical NO3, which in turn enters into further reactions with NO and NO2. One of the finite products of these reactions is N2O5. If there is water vapor in the atmosphere, then N2O5 can enter the reaction with water vapor and the product of this reaction is nitric acid - HNO3.

Considering all these transformations, we did not take into account the influence of hydrocarbons, but it is their presence in the troposphere that causes a deterioration in visibility and as a result of their partial destruction, many harmful substances are formed, among which: pan (peroxiaacetylthitrate), aldehydes, carbon monoxide (carbon black), carbon dioxide Gas, carboxylic acids, ketones, olefin oxide, paraffins, etc.

From the chart of the daily stroke of pollutants presented in Fig. 3, it can be seen that the maximum concentration of aldehydes and ozone has to immediately after the maximum of the concentration of hydrocarbons and NO2 (after 4 - 5 hours). From here, it can be concluded that an increase in emissions into the atmosphere of unburned fuel leads to a deterioration in the environmental situation and thereby causes the additional accumulation of the tropospheric ozone.

The consequences of smog

People and plants, and buildings, and various materials suffer from photochemical smog. Domestic animals die, mainly dogs and birds.

High concentrations of oxydants - ozone, pan, nitrogen oxides contained in the photochemical smog, give it extremely unpleasant properties. People who are under the influence of smog are experiencing a strong irritation of the mucous membranes of the eyes and respiratory tract due to the presence of substances like that pan. They cause tear at concentrations of 0.1 ppm. If the content of such oxidants exceeds 0.25 ppm, asthma attacks are observed, cough, unpleasant feelings in the chest, headache. Ozone concentrations achieved in the photochemical smog are also very harmful to health. Thus, already 0.1 ppm ozone in the air causes dryness in the throat, irritation of the respiratory tract, reduce resistance to bacteria. Ozone concentrations of 0.3 ppm cause respiratory disorders, chest spasm, dizziness. Long-term contact with such air leads to an increase in morbidity and mortality of people. Especially strongly susceptible to smog children and elderly people

Photochemical could adversely affect vegetation. Especially poorly photochemical was able to affect beans, beets, cereals, grapes, as well as decorative plants. A sign that the plant was harmful to the photochemical fog, is the swelling of the leaves, which then goes into the appearance on the upper leaves of spots and white plaque, and on the lower leads to the appearance of a bronze or silver shade. Then the plant begins to quickly stick.

Among other things, the photochemical fog leads to an accelerated corrosion of materials and elements of buildings, cracking of paints, rubber and synthetic products, and even damage.

Methods of combating CO could

He was able to carry a greater danger to the entire biosphere. The fight against it is one of the most important tasks in solving an environmental issue.

At the urban level, the struggle of CO was able to adopt various legislative measures that undertake industrial enterprises to strictly control the substances emitted by them into the atmosphere, reduce the total emissions from cars by restricting them in the city, calls to abandon personal vehicles. The main methods of reducing the pollution of the atmosphere, including acid-forming emissions, are the development and implementation of various treatment facilities and legal protection of the atmosphere.

Studies are underway to reduce contaminants from car exhaust gases. Perspective replacement of gasoline in cars by other types of fuel (for example, a mixture of alcohols), the use of gas-ballon vehicles using natural gas, and electric vehicles;

Reduce the fraction of the smog created by the industry, it is possible with the help of dust collectors, if equipping enterprises. Effectively use special filters. Advantages of filters: high efficiency for recoverable components (90-98%); simplicity and compactness; the minimum level of energy consumption for cleaning (from 1.5 to 4.5 kW / day); reliability in operation, high degree of maintainability; Small sensitivity to concentration oscillations.

For medium and small energy enterprises, use the fuel combustion method in a boiling layer, at which up to 95% sulfur dioxide is removed and from 50 to 75% nitrogen oxides. The technology for reducing the content of nitrogen oxides (by 50-60%) by reducing the combustion temperature is well developed. Use on power plants as a fuel of natural gas. It is really replaced by combustible fossils can be renewable environmentally friendly energy resources, such as solar energy, wind, sea tides, thermal sprouts of the earth.

Local protection from Smog is a personal contribution of man to air purification and, accordingly, in its own health. This is achieved in principle use of environmentally friendly equipment and fuel, buying safe to the environment and its health of economic funds. A certain role can also play a decrease in energy consumption.

There are quite a lot of methods of struggle, but almost each of them has its drawbacks, and some methods are ineffective at all.

We will not be able to completely get rid of Smog, because for this you need to translate all the transport to environmentally friendly fuel, to establish treatment facilities at all factories and factories, significantly reduce the amount of evaporation of harmful gases, but to take less radical measures to clean the biosphere from its harmful effects are quite real .

The greatest difficulties in studies to reduce contamination from exhaust gases cause a decrease in nitrogen oxide emissions, which, in addition to the formation of acid precipitation, are responsible for the emergence of photochemical pollutants (photochemical and the destruction of the ozone layer in the stratosphere. To solve this problem, work is underway to create various catalytic converters that convert nitrogen oxides into molecular nitrogen.

The creation of waste-free production in all industries requires a solution to a number of complex engineering and technological tasks, huge investments.

The sulfur content in emissions can be reduced using low-grade coal, as well as by physical or chemical flushing it. But physical cleaning methods are minorhable. Chemical Purification Method: In various filters and cleaners, gaseous combustion products are passed through an aqueous solution of lime, as a result, an insoluble sulfate calcium calcium is formed. This method allows you to remove up to 95% SO2, but is expensive (decrease in the temperature of the flue gases and lowering the thrust requires additional energy costs for their heating; in addition, the problem of recycling SSO4) and is economically effective only during the construction of new large enterprises.

i was able to pollution photochemical

Conclusion

It turns out that living in large cities was mortally dangerous in the 13th century, when coal was used for heating housing. It is not difficult to imagine what is happening in our time and speeds.

Pollution of the atmosphere of automotive exhaust emissions increases with an increase in the number of cars themselves. And in the near future, a complete replacement of gasoline on other types of fuel is not foreseen. So, it is not possible to avoid photochemical smog in the summer.

I would like to believe that with the onset of autumn and winter the air will be cleaner, but no, the heating season comes. And although in the current times, coal is not used everywhere, but hydrocarbons came to shift, the burning of which, also becomes the cause of Smog.

And people suffer from smog, most often the most defenseless - children and old men. When preparing the material to the abstract, I found data that the caprizis of children and attacks of aggression in domestic animals are also the consequences of Smog.

To reduce the consequences of Smog, try not to go out during it outside, drink green tea or herbal fees, eating more fresh vegetables and fruits.

If it is possible to leave the city better while smog.

BIBLIOGRAPHY

Opalovsky A.A. Planet Earth through the eyes of a chemist. M., Science, 1990

Revel P., Revel C. Wednesday of our habitat. In four books (translation from English). M., Mir, 1995

Chemistry and society (translation from English). M., Mir, 1995

Dobrovolsky V.V. Basics of biogeochemistry. Studies. Manual for geogr., biol., Geol., S.-H. specialist. universities. M., Higher. Shk., 1998

Andruz J., Brimplekumb P., Jikelz T., Liss P. Introduction to the chemistry of the environment (translation from English) M., Mir, 1999