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Air percentage. What is Air: Science for Adults

Air percentage. What is Air: Science for Adults

11.10.2019

The chemical composition of the air is of great hygienic importance.

It contains: 78% nitrogen, 21% oxygen, 0.03% carbon dioxide and small amounts of other inert gases (argon, neon, krypton, etc.), ozone and water vapor. In addition to permanent components, the atmospheric air may contain some impurities of natural origin, as well as a variety of pollution introduced into the atmosphere due to human production activities.

A huge influence on the gas composition and humidity of the indoor air is exerted by a variety of metabolic products emitted by animals in the course of their life.

So, when breathing, animals release a large amount of water vapor and carbon dioxide into the environment. As a result of the decomposition of urine and feces, ammonia, hydrogen sulfide and other gaseous products often accumulate in pigsties, most of which belong to the group of harmful and toxic gases.

Indoor air is significantly different from atmospheric air. The degree of this difference depends on the sanitary and hygienic regime of livestock premises (ventilation, sewerage, animal density, etc.). The concentration of oxygen and nitrogen in the air of livestock buildings under normal conditions remains unchanged. The concentration of carbon dioxide can increase significantly (by a factor of 10 or more), and ammonia, hydrogen sulfide, cesspool, and other gases often appear.

Oxygen (O 2) is a gas, without which the life of animals is impossible. Each cell of the body in the process of metabolism constantly uses oxygen to oxidize organic substances - proteins, fats, carbohydrates. The oxygen inhaled with air combines with the hemoglobin of red blood cells, and is carried to tissues and organs. The amount of oxygen consumed depends on the species, age, sex and physiological state of the animal.

The oxygen concentration in livestock buildings is usually constant, fluctuations in do not exceed 0.1-0.5%. A slight deviation from the norm does not cause changes in physiological functions in the body. In the premises for animals, the amount of oxygen remains almost constant and close to its content in the atmospheric air. A decrease in the amount of oxygen in the inhaled air up to 15% is accompanied by accelerated respiration of pigs and an increase in the pulse rate, as well as a weakening of oxidative processes. Animals are very sensitive to the lack of oxygen.

Under normal conditions, animals do not experience a lack of oxygen. In rooms for animals, the decrease in oxygen does not exceed 0.4-1%, which has no hygienic significance, since blood hemoglobin is saturated with oxygen at a lower partial pressure. Lack of oxygen can be observed in exceptional cases (long-term stay of animals in crowded conditions and on high mountain pastures).

Carbon dioxide (CO2) is a colorless, odorless gas with a sour taste. It is formed during the exhalation of animals, as the end product of metabolism. Exhaled air contains more of this gas (3.6%) than atmospheric air. For example, a lactating uterus weighing 150 kg releases 90 liters of carbon dioxide per hour. The maximum content of carbon dioxide in pigsties is allowed no more than 0.3%, i.e. 10 times more than in atmospheric air. Indoor air with a high content of carbon dioxide cannot be considered harmless to animal health from a hygienic point of view.

It is formed during the respiration of animals, as the end product of metabolism. Under natural conditions, continuous processes of emission and absorption of carbon dioxide occur. Carbon dioxide is released into the atmosphere as a result of the vital activity of living organisms, the processes of combustion, decay and fermentation.

Along with the processes of carbon dioxide in nature, there are processes of its assimilation. It is actively absorbed by plants during photosynthesis. Carbon dioxide is washed out of the air by precipitation. Recently, there has been an increase in the concentration of carbon dioxide in the air of industrial cities (up to 0.04% and higher) due to fuel combustion products.

Carbon dioxide plays an important role in the life of animals, as it is a physiological causative agent of the respiratory center. A decrease in the concentration of carbon dioxide in the inhaled air does not pose a significant danger to the body, since the necessary level of its partial pressure in the blood is provided by the regulation of acid-base balance. In contrast, an increase in the content of carbon dioxide in the air leads to a violation of the redox processes in the body. Under such conditions, oxidative processes are suppressed in the body, body temperature decreases, tissue acidity increases, which leads to pronounced acidotic edema and bone demineralization. An increase in the concentration of carbon dioxide in the air to 0.5% causes an increase in blood pressure, increased breathing and heart rate. In a room with an optimal hygienic regime, the content of carbon dioxide increases by no more than 2-3 times compared to atmospheric air. With unsatisfactory operation of ventilation and crowded keeping of animals, carbon dioxide can accumulate in quantities exceeding its content in the atmospheric air by 20-30 times, which is 0.5-1% and more. The main source of carbon dioxide accumulation in the premises are animals, which, depending on the species, age and productivity, emit it up to 16-225 l/h.

In the air of livestock buildings, carbon dioxide does not reach a concentration that causes an acute toxic effect on the body. However, long-term (in conditions of winter stall keeping) exposure of the body to air containing more than 1% carbon dioxide can cause chronic poisoning of animals. Such animals become lethargic, their appetite, productivity and resistance to diseases decrease.

Indicators of carbon dioxide concentration in indoor air have an indirect hygienic value. By the amount of carbon dioxide in indoor air, one can judge to a certain extent its sanitary and hygienic state as a whole. There is a direct relationship between the concentration of carbon dioxide and the content of water vapor, ammonia, hydrogen sulfide, and microflora in it.

The maximum allowable concentration of carbon dioxide in the indoor air for animals, depending on their species, age and physiological state, should not exceed 15-0.25%, and for birds - 0.15-0.20%.

Carbon monoxide (CO) - accumulates in indoor air during incomplete combustion of fuel or when internal combustion engines operate in them and insufficient ventilation.

When distributing feed using tractor or automobile traction, the content of carbon monoxide within 10 minutes is 3 mg / m 3, 15 minutes - 5-8 mg / m 3. The formation of carbon monoxide occurs when using electric heaters with open heating elements. At the same time, organic dust (compound feed, fluff, droppings, etc.), especially during air recirculation, in contact with heating elements, does not burn completely and saturates the air with carbon monoxide.

This gas is poisonous. The mechanism of technical action is that it displaces the oxygen of hemoglobin, forming a stable chemical compound with it - carboxyhemoglobin, which is 200-250 times more stable than oxyhemoglobin. As a result, oxygen supply to tissues is disrupted, hypoxemia occurs, oxidative processes decrease, and underoxidized metabolic products accumulate in the body. Poisoning is clinically characterized by nervous symptoms, rapid breathing, vomiting, convulsions, coma. Inhalation of carbon monoxide at concentrations of 0.4-0.5% in 5-10 minutes causes the death of animals. Birds are most sensitive to carbon monoxide.

The maximum allowable concentration of carbon monoxide in the air of livestock buildings is 2 mg/m 3 .

Ammonia (NH3) is a colorless poisonous gas with a pungent odor that strongly irritates the mucous membranes of the eyes and respiratory tract. It is formed during the decomposition of various organic nitrogen-forming substances (urine, manure). It is usually not present in the atmosphere. In the air of pigsties, high concentrations of ammonia occur, in the presence of permeable floors and improperly arranged sewers, as a result of which ammonia and other gases penetrate from the sump into the room.

At high air humidity and low temperature, ammonia is strongly absorbed by walls, equipment, and bedding, and then ammonia is released back into the air. The concentration of ammonia near the floor (in the area where pigs live) is higher than near the ceiling. Its content in indoor air over 0.025% is harmful to animals. Prolonged inhalation of air containing even low concentrations of ammonia (0.1 mg/l) adversely affects the health and productivity of animals.

Prolonged inhalation of air containing low concentrations of ammonia adversely affects the health and productivity of animals. After a short inhalation of air with the presence of ammonia, the body is released from it, turning it into urea. Prolonged action of non-toxic doses of ammonia does not directly cause pathological processes, but weakens the body's resistance.

Ammonia dissolves well in water, as a result of which it is adsorbed by the mucous membranes of the eyes and upper respiratory tract, causing severe irritation. There is a cough, lacrimation, followed by inflammation of the mucous membranes of the nose, larynx, trachea, bronchi and conjunctiva of the eyes. With a high content of ammonia in the inhaled air (1000-3000 mg / m 3), spasms of the glottis, tracheal and bronchial muscles are observed in animals, death occurs from pulmonary edema or respiratory paralysis.

When ammonia enters the blood, it converts hemoglobin into alkaline hematin, as a result of which the amount of hemoglobin decreases and oxygen starvation occurs. With prolonged inhalation of air containing ammonia, the alkaline reserve of the blood, gas exchange and digestibility of nutrients decrease. The intake of large amounts of ammonia into the blood causes a strong excitation of the central nervous system, convulsions, coma, paralysis of the respiratory center and death. At higher concentrations, ammonia causes acute poisoning, accompanied by rapid death of animals.

The toxicity and aggressiveness of ammonia increases significantly at high humidity. Under such conditions, ammonia is oxidized and nitric acid is formed, which, combining with calcium in the plaster of walls and other enclosing structures (calcium nitrate is formed), causes their destruction.

The maximum allowable concentration of ammonia in indoor air for animals, depending on their type and age, is 10-20 mg/m 3 .

Hydrogen sulfide (H2S) is a colorless poisonous gas with a pronounced smell of rotten eggs. It is formed during the decay of protein substances and is excreted by animals with intestinal gases. It appears in pigsties as a result of poor ventilation and untimely manure cleaning. This gas can penetrate into the room and from the liquid collectors in the absence of hydraulic seals (flaps that block the return flow of gases).

In the winter-spring period, at a room temperature of up to 10 ° C, the amount of hydrogen sulfide is within acceptable limits. In summer, under the influence of higher air temperatures, the decomposition of organic matter increases and the release of hydrogen sulfide increases. The presence of hydrogen sulfide in the air indicates improper operation of the building's sanitary facilities.

Hydrogen sulfide has the ability to block iron-containing groups of enzymes. The mechanism of action of hydrogen sulfide is that it, in contact with the mucous membranes of the respiratory tract and gas, combining with tissue alkalis, forms sodium or potassium sulfide, which cause inflammation of the mucous membranes. Sulfides are absorbed into the blood, hydrolyzed and release hydrogen sulfide, which acts on the nervous system. Hydrogen sulfide combines with iron in hemoglobin to form iron sulfide. Deprived of catalytically acting iron, hemoglobin loses its ability to absorb oxygen and oxygen starvation of tissues occurs.

At a concentration of 20 mg / m 3 and above, symptoms of poisoning appear (weakness, irritation of the mucous membranes of the respiratory tract, dysfunction of the digestive system, headache, etc.). At a concentration of 1200 mg/m 3 and above, a severe form of poisoning develops, and as a result of inhibition of tissue respiration enzymes, death of animals occurs. Cases of fatal poisoning of people with hydrogen sulfide during the cleaning of slurry wells of pigsties are described.

The maximum allowable amount of hydrogen sulfide in the air of rooms for animals should be no more than 0.0026%. It is necessary to strive in every possible way for the complete absence of ammonia in indoor air.

The presence of elevated concentrations of carbon dioxide, ammonia and hydrogen sulfide indicates the unsanitary state of the pigsty. Maintaining good indoor air conditions, as a rule, is achieved by keeping animals of various age and production groups on daily dry bedding or insulated floors with a slope towards sewer trays. Proper placement of animals and regular cleaning of stalls, dens and feeding areas are of great importance.

The ambient air and rooms always contain water vapor, the amount of which varies greatly depending on climatic conditions, animal species and type of rooms. The air of livestock buildings almost always contains dust, consisting of the smallest particles of mineral substances, fragments of plants, insects, and living microorganisms. Pollution of the skin of animals with dust along with sweat, dead cells of the upper layer of the skin and microorganisms is accompanied by irritation, itching and inflammation. Dust trapped in the upper respiratory tract often leads to diseases of these organs.

The air of livestock buildings often contains intestinal gases: indole, skatol, mercaptan, amines (nitrosamines), which have a bad smell. As a rule, the smell, especially from pigsties, is so intense that a hygienic (protective) belt 0.5-1 km wide or more from settlements is insufficient. Some gases (nitrosamines) are strong chemical carcinogens and can be found in the air in relatively high concentrations.

It must be taken into account that the air quality of livestock buildings affects not only the animal, but also the personnel serving it. Prolonged stay of animals in rooms with a significant accumulation of harmful gases in the air has a toxic effect on the body, reduces their resistance and productivity. Thus, with an increased content of ammonia in indoor air, the increase in the mass of cattle is reduced by 25-28%. Harmful gases reduce the body's resistance and promote the spread of non-contagious (rhinitis, laryngitis, bronchitis, pneumonia, ammonia blindness in chickens, etc.) and infectious (tuberculosis, etc.). Improving the gas composition of the air is achieved through the proper construction and operation of ventilation and sewerage and compliance with the density of animals. An important condition is to ensure the impermeability of solid floors, which prevents the penetration of urine into the underground and its decomposition. With a hydraulic manure removal system, a significant amount of harmful gases is contained in the manure channels. The concentration of ammonia in them reaches more than 35 mg/m 3 , hydrogen sulfide - 23 mg/m 3 , which is 2-3 times higher than the permissible norms. In this regard, the removal of polluted air must be carried out directly from the manure channels of livestock buildings. Effective methods of air deodorization are ultraviolet irradiation, ozonization and ionization. For this purpose. Aerosols from pine needle extracts have been successfully tested. Deodorization in small rooms (opening room) is carried out with aromatic substances in aerosol cans or solutions of chemicals (potassium permanganate, iodine monochloride, bleach, etc.).

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The atmosphere is the air environment that surrounds the globe and one of the most important reasons for the emergence of life on earth. It was atmospheric air, its unique composition that gave living beings the opportunity to oxidize organic matter with oxygen and obtain energy for existence. Without it, the existence of man, as well as all representatives of the animal kingdom, most plants, fungi and bacteria, will be impossible.

Significance for a person

The air environment is not only a source of oxygen. It allows a person to see, perceive spatial signals, use the senses. Hearing, vision, smell - they all depend on the state of the air environment.

The second important point is protection from solar radiation. The atmosphere envelops the planet with a shell that traps part of the spectrum of sunlight. As a result, about 30% of solar radiation reaches the earth.

The air environment is the shell in which precipitation forms and evaporation rises. It is she who is responsible for half of the moisture exchange cycle. Precipitation formed in the atmosphere affects the work of the World Ocean, contributes to the accumulation of moisture on the continents, and determines the destruction of open rocks. She takes part in the formation of the climate. The circulation of air masses is the most important factor in the formation of specific climatic zones and natural zones. The winds that occur over the Earth determine the temperature, humidity, precipitation, pressure, and weather stability in the region.

Currently, chemicals are extracted from the air: oxygen, helium, argon, nitrogen. The technology is still at the testing stage, but in the future it can be considered a promising direction in the chemical industry.

The above is the obvious. But the air environment is also important for industry and human activities:

It is the most important chemical agent for the reactions of combustion and oxidation.
Transfers heat.

Thus, atmospheric air is a unique air environment that allows living things to exist, and man to develop industry. Close interaction has been established between the human body and the air environment. If you violate it, serious consequences will not keep you waiting.

Hygienic characteristic of air

Pollution is the process of impurities entering the atmospheric air, which should not normally be present. Pollution can be natural or artificial. Impurities that come from natural sources are neutralized in the planetary circulation of matter. With artificial pollution, the situation is more complicated.

Natural contaminants include:

Cosmic dust.
Impurities formed during volcanic eruptions, weathering, fires.

Artificial pollution is anthropogenic in nature. Distinguish between global and local pollution. Global is all emissions that can affect the composition or structure of the atmosphere. Local is a change in indicators in a specific area or in a room used for living, working or public events.

Atmospheric air hygiene is an important branch of hygiene that deals with the assessment and control of indoor air. This section appeared in connection with the need for sanitary protection. It is difficult to overestimate the hygienic value of atmospheric air - along with breathing, all the impurities and particles contained in the air enter the human body.

The hygienic assessment includes the following indicators:

Physical properties of atmospheric air. This includes temperature (the most common violation of SanPiN at workplaces is that the air heats up too much), pressure, wind speed (in open areas), radioactivity, humidity and other indicators.
The presence of impurities and deviation from the standard chemical composition. Atmospheric air is characterized by its suitability for breathing.
The presence of solid impurities - dust, other microparticles.
The presence of bacterial contamination - pathogenic and conditionally pathogenic microorganisms.

To compile a hygienic characteristic, the indications obtained for four points are compared with the established standards.

environmental protection

Recently, the state of atmospheric air has been a concern for environmentalists. Along with the development of industry, environmental risks also grow. Factories and industrial zones not only destroy the ozone layer, heating the atmosphere and saturating it with carbon impurities, but also reduce hygiene. Therefore, in developed countries it is customary to carry out comprehensive measures to protect the air environment.

The main areas of protection:

Legislative regulation.
Development of recommendations for the location of industrial zones, taking into account climatic and geographical factors.
Carrying out measures to reduce emissions.
Sanitary and hygienic control at enterprises.
Regular composition monitoring.

Protection measures also include the planting of green spaces, the creation of artificial reservoirs, the creation of barrier zones between industrial and residential areas. Recommendations for the implementation of protective measures have been developed in organizations such as WHO and UNESCO. State and regional recommendations are developed on the basis of international ones.

Currently, the problem of air hygiene is receiving more and more attention. Unfortunately, at the moment the measures taken are not enough to completely minimize anthropogenic harm. But one can hope that in the future, together with the development of more environmentally friendly industries, it will be possible to reduce the burden on the atmosphere.

Air is an essential condition for the life of the overwhelming number of organisms on our planet.

A person can live for a month without food. Three days without water. Without air - just a few minutes.

Research History

Not everyone knows that the main component of our life is an extremely heterogeneous substance. Air is a mixture of gases. Which ones?

For a long time it was believed that air is a single substance, not a mixture of gases. The heterogeneity hypothesis appeared in the scientific works of many scientists at different times. But no one has gone further than theoretical conjectures. Only in the eighteenth century, the Scottish chemist Joseph Black experimentally proved that the gas composition of air is not uniform. The discovery was made in the course of regular experiments.

Modern scientists have proven that air is a mixture of gases, consisting of ten basic elements.

The composition differs depending on the place of concentration. Determination of the composition of the air occurs constantly. The health of the people depends on it. Air is a mixture of what gases?

At higher elevations (especially in the mountains) there is a low oxygen content. This concentration is called "rarefied air". In forests, on the contrary, the oxygen content is maximum. In megacities, the content of carbon dioxide is increased. Determining the composition of the air is one of the most important responsibilities of environmental services.

Where can air be used?

The compressed mass is used when pumping air under pressure. Installation up to ten bar is installed at any tire fitting station. Tires are inflated with air.
Workers use jackhammers, pneumatic guns to quickly remove / install nuts and bolts. Such equipment is characterized by low weight and high efficiency.
In industries using varnishes and paints, it is used to speed up the drying process.
In car washes, the compressed air mass helps in quick drying of cars;
Manufacturing plants use compressed air to clean tools from any kind of contamination. In this way, whole hangars can be cleaned of chips and sawdust.
The petrochemical industry can no longer imagine itself without equipment for purging pipelines before the first start-up.
In the production of oxides and acids.
To increase the temperature of technological processes;
Extracted from the air;

Why do living beings need air?

The main task of air, or rather, one of the main components - oxygen - is to penetrate into cells, thereby promoting oxidation processes. Thanks to this, the body receives the most important energy for life.

Air enters the body through the lungs, after which it is distributed throughout the body through the circulatory system.

Air is a mixture of what gases? Let's consider them in more detail.

Nitrogen

Air is a mixture of gases, the first of which is nitrogen. The seventh element of the periodic system of Dmitri Mendeleev. The Scottish chemist Daniel Rutherford in 1772 is considered the discoverer.

It is part of the proteins and nucleic acids of the human body. Although its proportion in cells is small - no more than three percent, gas is essential for normal life.

In the composition of the air, its content is more than seventy-eight percent.

Under normal conditions, it is colorless and odorless. Does not enter into compounds with other chemical elements.

The largest amount of nitrogen is used in the chemical industry, primarily in the manufacture of fertilizers.

Nitrogen is used in the medical industry, in the production of dyes,

In cosmetology, gas is used to treat acne, scars, warts, and the body's thermoregulation system.

With the use of nitrogen, ammonia is synthesized, nitric acid is produced.

In the chemical industry, oxygen is used to oxidize hydrocarbons to alcohols, acids, aldehydes, and to produce nitric acid.

Fishing industry - oxygenation of reservoirs.

But the most important gas is for living beings. With the help of oxygen, the body can utilize (oxidize) the necessary proteins, fats and carbohydrates, turning them into the necessary energy.

Argon

The gas that is part of the air is in third place in importance - argon. The content does not exceed one percent. It is an inert gas without color, taste and smell. The eighteenth element of the periodic system.

The first mention is attributed to an English chemist in 1785. And Lord Laray and William Ramsay received Nobel Prizes for proving the existence of gas and experiments with it.

Areas of application of argon:

incandescent lamps;
filling the space between the panes in plastic windows;
protective environment during welding;
fire extinguishing agent;
for air purification;
chemical synthesis.

It doesn't do much good for the human body. At high concentrations of gas leads to asphyxiation.

Cylinders with argon gray or black.

The remaining seven elements make up 0.03% in air.

Carbon dioxide

Carbon dioxide in air is colorless and odorless.

It is formed as a result of decay or combustion of organic materials, it is released during breathing and the operation of cars and other vehicles.

In the human body, it is formed in tissues due to vital processes and is transferred through the venous system to the lungs.

It has a positive meaning, because under load, it expands the capillaries, which provides the possibility of greater transport of substances. Positive effect on the myocardium. It helps to increase the frequency and strength of the load. Used in the correction of hypoxia. Participates in the regulation of respiration.

In industry, carbon dioxide is obtained from combustion products, as a by-product of chemical processes or in the separation of air.

The application is extremely wide:

preservative in the food industry;
saturation of drinks;
fire extinguishers and fire extinguishing systems;
feeding aquarium plants;
protective environment during welding;
use in cartridges for gas weapons;
coolant.

Neon

Air is a mixture of gases, the fifth of which is neon. It was opened much later - in 1898. The name is translated from Greek as "new".

A monatomic gas that is colorless and odorless.

It has high electrical conductivity. It has a complete electron shell. Inert.

Gas is obtained by separation of air.

Application:

Inert environment in industry;
Refrigerant in cryogenic installations;
Filler for gas discharge lamps. Has found wide application thanks to advertising. Most of the colored signs are made with neon. When an electric discharge is passed, the lamps give a bright colored glow.
Signal lights at beacons and airfields. Worked well in heavy fog.
Air mixture element for people working with high pressure.

Helium

Helium is a monatomic gas, colorless and odorless.

Application:

Like neon, when an electric discharge is passed through, it gives a bright light.
In industry - to remove impurities from steel during smelting;
Coolant.
Filling airships and balloons;
Partially in breathing mixes for deep dives.
Coolant in nuclear reactors.
The main children's joy is flying balloons.

For living organisms, it is of no particular benefit. In high concentrations, it can cause poisoning.

Methane

Air is a mixture of gases, the seventh of which is methane. The gas is colorless and odorless. Explosive in high concentrations. Therefore, for indication, odorants are added to it.

It is used most often as a fuel and raw material in organic synthesis.

Home stoves, boilers, gas water heaters work mainly on methane.

The product of the vital activity of microorganisms.

Krypton

Krypton is an inert monatomic gas, colorless and odorless.

Application:

in the production of lasers;
propellant oxidizer;
filling incandescent lamps.

The effect on the human body has been studied little. Applications for deep-sea diving are being studied.

Hydrogen

Hydrogen is a colorless combustible gas.

Application:

Chemical industry - production of ammonia, soap, plastics.
Filling of spherical shells in meteorology.
Rocket fuel.
Cooling of electrical generators.

Xenon

Xenon is a monatomic colorless gas.

Application:

filling incandescent lamps;
in spacecraft engines;
as an anesthetic.

Harmless to the human body. Doesn't offer much benefit.

The chemical composition of the air is of great hygienic importance, since it plays a decisive role in the implementation of the respiratory function of the body. Atmospheric air is a mixture of oxygen, carbon dioxide, argon and other gases in the ratios given in Table. one.

Oxygen(O2) - the most important component of air for humans. At rest, a person usually absorbs an average of 0.3 liters of oxygen per minute.

During physical activity, oxygen consumption increases dramatically and can reach 4.5/5 liters or more in 1 minute. Fluctuations in the oxygen content in the atmospheric air are small and do not exceed, as a rule, 0.5%.

In residential, public and sports premises, significant changes in the oxygen content are not observed, since outside air penetrates into them. Under the most unfavorable hygienic conditions in the room, a decrease in the oxygen content by 1% was noted. Such fluctuations do not have a noticeable effect on the body.

Usually, physiological changes are observed when the oxygen content decreases to 16-17%. If its content decreases to 11-13% (when climbing to a height), a pronounced oxygen deficiency appears, a sharp deterioration in well-being and a decrease in working capacity. An oxygen content of up to 7-8% can be fatal.

In sports practice, in order to increase the efficiency and intensity of recovery processes, oxygen inhalation is used.

Carbon dioxide(CO2), or carbon dioxide, is a colorless, odorless gas formed during the breathing of people and animals, decay and decomposition of organic substances, fuel combustion, etc. In the atmospheric air outside settlements, the carbon dioxide content averages 0.04%, and in industrial centers, its concentration rises to 0.05-0.06%. In residential and public buildings, when there are a large number of people in them, the content of carbon dioxide can increase up to 0.6-0.8%. Under the worst hygienic conditions in the room (large crowds, poor ventilation, etc.), its concentration usually does not exceed 1% due to the penetration of outside air. Such concentrations do not cause negative effects in the body.

With prolonged inhalation of air with a content of 1 - 1.5% carbon dioxide, a deterioration in health is noted, and at 2-2.5%, pathological changes are detected. Significant disturbances in body functions and a decrease in efficiency occur when the carbon dioxide content is 4-5%. At a content of 8-10%, loss of consciousness and death occurs. A significant increase in the content of carbon dioxide in the air can occur in emergency situations in confined spaces (mines, mines, submarines, bomb shelters, etc.) or in places where there is an intensive decomposition of organic matter.

Determination of carbon dioxide content in residential, public and sports facilities can serve as an indirect indicator of air pollution by human waste products. As already noted, carbon dioxide itself in these cases does not harm the body, however, along with an increase in its content, a deterioration in the physical and chemical properties of the air is observed (temperature and humidity increase, the ionic composition is disturbed, foul-smelling gases appear). Indoor air is considered poor quality if the carbon dioxide content in it exceeds 0.1%. This value is taken as a calculated one when designing and installing ventilation in rooms.

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The chemical composition of the air plays an important role in the implementation of the respiratory function. Atmospheric air is a mixture of gases: oxygen, carbon dioxide, argon, nitrogen, neon, krypton, xenon, hydrogen, ozone, etc. Oxygen is the most important. At rest, a person absorbs 0.3 l / min. During physical activity, oxygen consumption increases and can reach 4.5–8 l/min. Fluctuations in the oxygen content in the atmosphere are small and do not exceed 0.5%. If the oxygen content decreases to 11-13%, there are phenomena of oxygen deficiency.

An oxygen content of 7-8% can lead to death. Carbon dioxide - colorless and odorless, is formed during respiration and decay, combustion of fuel. In the atmosphere it is 0.04%, and in industrial areas - 0.05-0.06%. With a large crowd of people, it can increase to 0.6 - 0.8%. With prolonged inhalation of air with a content of 1-1.5% carbon dioxide, a deterioration in well-being is noted, and with 2-2.5% - pathological changes. At 8-10% loss of consciousness and death, the air has a pressure called atmospheric or barometric. It is measured in millimeters of mercury (mm Hg), hectopascals (hPa), millibars (mb). Normal pressure is considered to be atmospheric pressure at sea level at a latitude of 45˚ at an air temperature of 0˚С. It is equal to 760 mm Hg. (Indoor air is considered to be of poor quality if it contains 1% carbon dioxide. This value is taken as a calculated value when designing and installing ventilation in rooms.

Air pollution. Carbon monoxide is a colorless and odorless gas, formed during incomplete combustion of fuel and enters the atmosphere with industrial emissions and exhaust gases of internal combustion engines. In megacities, its concentration can reach up to 50-200 mg/m3. When smoking tobacco, carbon monoxide enters the body. Carbon monoxide is a blood and general toxic poison. It blocks hemoglobin, it loses the ability to carry oxygen to the tissues. Acute poisoning occurs when the concentration of carbon monoxide in the air is 200-500 mg/m3. In this case, there is a headache, general weakness, nausea, vomiting. The maximum allowable concentration is average daily 0 1 mg/m3, single - 6 mg/m3. The air can be polluted with sulfur dioxide, soot, resinous substances, nitrogen oxides, carbon disulfide.

Microorganisms. In small quantities, they are always in the air, where they are carried with soil dust. Microbes of infectious diseases that enter the atmosphere quickly die. Of particular danger in the epidemiological relationship is the air of residential premises and sports facilities. For example, in wrestling halls, the content of microbes up to 26,000 in 1 m3 of air is observed. Aerogenic infections in such air spread very quickly.

Dust It is a light dense particles of mineral or organic origin, getting into the lungs of dust, it lingers there and causes various diseases. Industrial dust (lead, chromium) can cause poisoning. In cities, dust should not exceed 0.15 mg/m3. Sports grounds must be watered regularly, have a green area, and carry out wet cleaning. Sanitary protection zones have been established for all enterprises polluting the atmosphere. In accordance with the hazard class, they have different sizes: for enterprises of the 1st class - 1000 m, 2 - 500 m, 3 - 300 m, 4 -100 m, 5 - 50 m. When placing sports facilities near enterprises, it is necessary to take into account the wind rose, sanitary protective zones, the degree of air pollution, etc.

One of the important measures for the protection of the air environment is preventive and current sanitary supervision and systematic monitoring of the state of atmospheric air. It is produced using an automated monitoring system.

Clean atmospheric air near the Earth's surface has the following chemical composition: oxygen - 20.93%, carbon dioxide - 0.03-0.04%, nitrogen - 78.1%, argon, helium, krypton 1%.

Exhaled air contains 25% less oxygen and 100 times more carbon dioxide.
Oxygen. The most important constituent of air. It ensures the course of redox processes in the body. An adult at rest consumes 12 liters of oxygen, during physical work 10 times more. In the blood, oxygen is bound to hemoglobin.

Ozone. Chemically unstable gas, capable of absorbing solar short-wave ultraviolet radiation, which has a detrimental effect on all living things. Ozone absorbs long-wave infrared radiation coming from the Earth and thus prevents its excessive cooling (Earth's ozone layer). Under the influence of UV radiation, ozone decomposes into a molecule and an oxygen atom. Ozone is a bactericidal agent for water disinfection. In nature, it is formed during electrical discharges, during the evaporation of water, during ultraviolet radiation, during thunderstorms, in the mountains and in coniferous forests.

Carbon dioxide. It is formed as a result of redox processes occurring in the body of people and animals, fuel combustion, decay of organic substances. In the air of cities, the concentration of carbon dioxide is increased due to industrial emissions - up to 0.045%, in residential premises - up to 0.6-0.85. An adult at rest emits 22 liters of carbon dioxide per hour, and during physical work - 2-3 times more. Signs of deterioration in a person's well-being appear only with prolonged inhalation of air containing 1-1.5% carbon dioxide, pronounced functional changes - at a concentration of 2-2.5% and pronounced symptoms (headache, general weakness, shortness of breath, palpitations, lowering performance) - at 3-4%. The hygienic significance of carbon dioxide lies in the fact that it serves as an indirect indicator of general air pollution. The norm of carbon dioxide in gyms is 0.1%.

Nitrogen. An indifferent gas serves as a diluent for other gases. Increased inhalation of nitrogen can have a narcotic effect.

Carbon monoxide. It is formed during the incomplete combustion of organic substances. Has no color or smell. The concentration in the atmosphere depends on the intensity of vehicular traffic. Penetrating through the pulmonary alveoli into the blood, it forms carboxyhemoglobin, as a result, hemoglobin loses its ability to carry oxygen. The maximum allowable average daily concentration of carbon monoxide is 1 mg/m3. Toxic doses of carbon monoxide in the air are 0.25-0.5 mg/l. With prolonged exposure, headache, fainting, palpitations.

Sulphur dioxide. It enters the atmosphere as a result of burning fuels rich in sulfur (coal). It is formed during roasting and melting of sulfur ores, during dyeing of fabrics. It irritates the mucous membranes of the eyes and the upper respiratory tract. The threshold of sensation is 0.002-0.003 mg / l. Gas has a harmful effect on vegetation, especially coniferous trees.
Mechanical impurities of air come in the form of smoke, soot, soot, crushed soil particles and other solids. The dust content of the air depends on the nature of the soil (sand, clay, asphalt), its sanitary condition (watering, cleaning), air pollution by industrial emissions, and the sanitary condition of the premises.

Dust mechanically irritates the mucous membranes of the upper respiratory tract and eyes. Systematic inhalation of dust causes respiratory diseases. When breathing through the nose, up to 40-50% of dust is retained. Microscopic dust, which is in a suspended state for a long time, is the most unfavorable in terms of hygiene. The electric charge of the dust enhances its ability to penetrate the lungs and linger in them. Dust. containing lead, arsenic, chromium, and other toxic substances, causes typical poisoning phenomena, and when penetrated not only by inhalation, but also through the skin and gastrointestinal tract. In dusty air, the intensity of solar radiation and air ionization are significantly reduced. To prevent the adverse effects of dust on the body, residential buildings are disposed to air pollutants from the windward side. Sanitary protection zones 50-1000 m wide and more are arranged between them. In residential premises, systematic wet cleaning, ventilation of premises, change of shoes and outerwear, use of non-dusty soils and watering in open areas.

air microorganisms. Bacterial air pollution, as well as other environmental objects (water, soil), is dangerous in epidemiological terms. There are various microorganisms in the air: bacteria, viruses, mold fungi, yeast cells. The most common is the airborne method of transmission of infections: a large number of microbes enter the air, and when breathing, they enter the respiratory tract of healthy people. For example, when talking loudly, and even more so when coughing and sneezing, the smallest droplets are sprayed at a distance of 1-1.5 m and spread with air to 8-9 m. These droplets can be in suspension for 4-5 hours, but in most cases settle in 40-60 minutes. In dust, the influenza virus and diphtheria bacilli remain viable for 120-150 days. There is a well-known relationship: the more dust in the indoor air, the more abundant the content of microflora in it.

The chemical composition of the air

Air is a mixture of gases that form a protective layer around the Earth - the atmosphere. Air is necessary for all living organisms: animals for breathing, and plants for food. In addition, the air protects the Earth from the destructive ultraviolet radiation of the Sun. The main constituents of air are nitrogen and oxygen. In the air there are also small impurities of noble gases, carbon dioxide and a certain amount of solid particles - soot, dust. All animals need air to breathe. About 21% of air is oxygen. An oxygen molecule (O2) consists of two bonded oxygen atoms.

Composition of air

The percentage of various gases in the air varies slightly depending on the place, time of year and day. Nitrogen and oxygen are the main components of air. One percent of the air is made up of noble gases, carbon dioxide, water vapor, and pollutants such as nitrogen dioxide. The gases in air can be separated by fractional distillation. The air is cooled until the gases become liquid (see the article "Solids, Liquids and Gases"). After this, the liquid mixture is heated. Each liquid has its own boiling point, and the gases formed during boiling can be collected separately. Oxygen, nitrogen and carbon dioxide constantly fall from the air into living organisms and return to the air, i.e. a cycle takes place. Animals breathe in oxygen and breathe out carbon dioxide.

Oxygen

Oxygen is essential for life. Animals breathe it, use it to digest food and get energy. During the day, a process occurs in plants photosynthesis and plants release oxygen. Oxygen is also required for combustion; without oxygen, nothing can burn. Almost 50% of the compounds in the earth's crust and the world's oceans contain oxygen. Ordinary sand is a combination of silicon and oxygen. Oxygen is used in breathing apparatus for divers and in hospitals. Oxygen is also used in steel production (see Iron, Steel and Other Materials) and rocketry (see Rockets and Spacecraft).

In the upper atmosphere, oxygen atoms combine in threes to form the ozone (O3) molecule. Ozone is an allotropic modification of oxygen. Ozone is a poisonous gas, but in the atmosphere, the ozone layer protects our planet by absorbing most of the Sun's harmful ultraviolet radiation (for more details, see the article "The Sun's Impact on Earth").

Nitrogen

More than 78% of the air is nitrogen. The proteins from which living organisms are built also contain nitrogen. The main industrial application of nitrogen is ammonia production needed for fertilizer. For this, nitrogen is combined with hydrogen. Nitrogen is pumped into packages for meat or fish, because. when exposed to ordinary air, the products oxidize and deteriorate. Human organs intended for transplantation are stored in liquid nitrogen because it is cold and chemically inert. The nitrogen (N2) molecule consists of two linked nitrogen atoms.

Plants obtain nitrogen from the soil in the form of nitrates and use it for protein synthesis. Animals eat plants, and nitrogen compounds are returned to the soil with animal excretions, as well as when their dead bodies decompose. In the soil, nitrogen compounds are decomposed by bacteria with the release of ammonia, and then free nitrogen. Other bacteria take up nitrogen from the air and convert it into plant-available nitrates.

Carbon dioxide

Carbon dioxide is a compound of carbon and oxygen. The air contains about 0.003% carbon dioxide. A carbon dioxide (CO2) molecule consists of two oxygen atoms and one carbon atom. Carbon dioxide is one of the elements of the carbon cycle. Plants take it in during photosynthesis and animals breathe it out. Carbon dioxide is also formed during the combustion of substances containing carbon, such as wood or gasoline. Since our cars and factories burn so much fuel, the proportion of carbon dioxide in the atmosphere is growing. Most substances cannot burn in carbon dioxide, which is why it is used in fire extinguishers. Carbon dioxide is denser than air. It "suffocates" the flame, blocking the access of oxygen. Carbon dioxide dissolves slightly in water, forming a weak solution of carbonic acid. Solid carbon dioxide is called dry ice. When dry ice melts, it turns into gas; it is used to create artificial clouds in the theater.

Air pollution

Soot and poisonous gases - carbon monoxide, nitrogen dioxide, sulfur dioxide - pollute the atmosphere. Carbon monoxide is formed during combustion. Many substances burn out so quickly that they do not have time to attach enough oxygen and carbon monoxide (CO) is formed instead of carbon dioxide (CO2). Carbon monoxide is highly toxic; it prevents the blood of animals from carrying oxygen. There is only one oxygen atom in a carbon monoxide molecule. Car exhaust contains carbon monoxide and nitrogen dioxide, which causes acid rain. Sulfur dioxide is released when fossil fuels, especially coal, are burned. It is poisonous and makes breathing difficult. In addition, it dissolves in water and causes acid rain. Particles of dust and co-sweat emitted into the atmosphere by enterprises also pollute the air; we breathe them in, they settle on the plants. Lead is added to gasoline for better combustion (however, many cars now run on lead-free gasoline). Lead compounds accumulate in the body and adversely affect the nervous system. In children, they can cause brain damage.

acid rain

Rainwater always contains a little acidity due to dissolved carbon dioxide, but pollutants (sulphur and nitrogen dioxide) increase the acidity of the rain. Acid rain corrodes metals, corrodes stone structures and increases the acidity of fresh water.

noble gases

Noble gases are 6 elements of the 8th group of the periodic table. They are extremely inert chemically. Only they exist in the form of separate atoms that do not form molecules. Because of their passivity, lamps are filled with some of them. Xenon is practically not used by humans, but argon is pumped into light bulbs, and fluorescent lamps are filled with creep-tone. Neon flashes red-orange light when an electrical discharge passes. It is used in sodium street lamps and neon lamps. Radon is radioactive. It is formed as a result of the decay of radium metal. No helium compounds are known to science, and helium is considered absolutely inert. Its density is 7 times less than the density of air, so airships are filled with it. Helium-filled balloons are equipped with scientific instruments and launched into the upper atmosphere.

Greenhouse effect

This is the name of the currently observed increase in the content of carbon dioxide in the atmosphere and the resulting global warming, i.e. an increase in average annual temperatures around the world. Carbon dioxide keeps heat from leaving the Earth, just like glass keeps heat inside a greenhouse. As there is more and more carbon dioxide in the air, more and more heat is trapped in the atmosphere. Even a slight warming causes an increase in the level of the World Ocean, a change in winds and the melting of some ice near the poles. Scientists believe that if the carbon dioxide content continues to grow as rapidly, then in 50 years the average temperature could increase by 1.5°C to 4°C.

air is a mixture of gases, and therefore elements. . Nitrogen, oxygen, carbon dioxide. In cities and other gases ...

percentage of gases.

Do you need a graphic representation of an air molecule?

Air in chemistry-NO2

zit hein. Allah Akbar. takbir. foreign words that are forbidden to be spoken. what is it for - lol

If you think that air has its own separate formula, you are mistaken, in chemistry it is not designated in any way.

Air is a natural mixture of gases, mainly nitrogen and oxygen, that makes up the earth's atmosphere. Composition of air: Nitrogen N2 Oxygen O2 Argon Ar Carbon dioxide CO2 Neon Ne Methane CH4 Helium He Krypton Kr Hydrogen H2 Xenon Xe Water H2O In addition, air always contains water vapor. So, at a temperature of 0 °C, 1 m³ of air can hold a maximum of 5 grams of water, and at a temperature of +10 °C - already 10 grams. In alchemy, air is represented by a triangle with a horizontal line.

nitrogen

the main component is inhaled. air

Alternative descriptions

Gas that makes metal brittle

The gas that makes up 78% of air

Main "air filler"

The main component of the air you inhale, which cannot be breathed in its pure form

Air component

Fertilizer in the air

Chemical element - the basis of a number of fertilizers

Chemical element, one of the main plant nutrients

Chemical element, constituent of air

Nitrogenium

Liquid refrigerant

Chemical element, gas

Magic sword of Paracelsus

In Latin, this gas is called "nitrogenium", that is, "giving birth to saltpeter"

The name of this gas comes from the Latin word "lifeless"

This gas - a component of air - was practically absent in the Earth's primary atmosphere 4.5 billion years ago

A gas whose liquid is used to cool ultra-precise instruments

What gas is stored in a liquid state in a Dewar vessel?

The gas that froze Terminator II

gas cooler

What gas extinguishes fire?

Most common element in the atmosphere

The basis of all nitrates

Chemical element, N

freezing gas

Air three quarters

In the composition of ammonia

Gas from air

Gas number 7

Saltpeter element

The main gas in the air

The most popular gas

Element from nitrates

Liquid gas from a vessel

Gas #1 in the atmosphere

Fertilizer in the air

78% air

gas for cryostat

Almost 80% air

Natural chemical composition of atmospheric air

According to the chemical composition, clean atmospheric air is a mixture of gases: oxygen, carbon dioxide, nitrogen, as well as a number of inert gases (argon, helium, krypton, etc.). Since air is a physical mixture, and not a chemical compound of its constituent gases, when rising even for tens of kilometers, the percentage of these gases practically does not change.

However, with height, as a result of a decrease in the density of the atmosphere, the concentrations and partial pressures of all gases in the air decrease.

At the Earth's surface, atmospheric air contains:

oxygen - 20.93%;

nitrogen - 78.1%;

carbon dioxide - 0.03-0.04%;

inert gases - from 10-3 to 10-6%.

Oxygen (O2) is the most important part of air for life. It is necessary for oxidative processes and is found in the blood, mainly in a bound state - in the form of oxyhemoglobin, which is carried by red blood cells to the cells of the body.

The transfer of oxygen from the alveolar air to the blood occurs due to the difference in partial pressure in the alveolar air and venous blood. For the same reason, oxygen is supplied from the arterial blood to the interstitial fluid, and then to the cells.

In nature, oxygen is consumed mainly for the oxidation of organic substances contained in air, water, soil and for combustion processes. The decrease in oxygen is replenished due to its large reserves in the atmosphere, as well as as a result of the activity of phytoplankton in the oceans and land plants. Continuous turbulent currents of air masses equalize the oxygen content in the surface layer of the atmosphere. Therefore, the level of oxygen at the Earth's surface fluctuates slightly: from 20.7 to 20.95%. In residential premises, public buildings, the oxygen content also remains practically unchanged due to its easy diffusion through the pores of building materials, gaps in windows, etc.

In sealed rooms (shelters, submarines, etc.), the oxygen content can significantly decrease. However, a pronounced deterioration in well-being, a decrease in working capacity in people are observed with a very significant drop in the oxygen content - up to 15-17% (at the norm - almost 21%). It should be emphasized that in this case we are talking about a reduced oxygen content at normal atmospheric pressure.

With an increase in air temperature to 35-40 ° C and high humidity, the partial pressure of oxygen decreases, which can have a negative effect on patients with hypoxia.

In healthy people, oxygen starvation due to a decrease in the partial pressure of oxygen can be observed during flights (altitude sickness) and when climbing mountains (mountain sickness, starting at an altitude of about 3 km).

Altitudes of 7-8 km correspond to 8.5-7.5% oxygen in the air at sea level and for untrained people are considered incompatible with life without the use of oxygen devices.

A dosed increase in the partial pressure of oxygen in the air in pressure chambers is used in surgery, therapy and emergency care.

Oxygen in its pure form is toxic. So, in experiments on animals it was shown that when breathing pure oxygen in animals, atelectases in the lungs are detected after 1-2 hours, after 3-6 hours - a violation of the permeability of capillaries in the lungs, after 24 hours - the phenomena of pulmonary edema.

Hyperoxia develops even faster in an oxygen environment with increased pressure - both lung tissue damage and damage to the central nervous system are observed.

Carbon dioxide or carbon dioxide, in nature is in free and bound states. Up to 70% of carbon dioxide is dissolved in the water of the seas and oceans; some mineral compounds (limestones and dolomites) contain about 22% of the total amount of carbon dioxide. The rest of the amount falls on the animal and plant world. In nature, there are continuous processes of release and absorption of carbon dioxide. It is released into the atmosphere as a result of human and animal respiration, as well as combustion, decay, and fermentation. In addition, carbon dioxide is formed during the industrial firing of limestones and dolomites, and its release with volcanic gases is possible. Along with the processes of formation in nature, there are processes of assimilation of carbon dioxide - active absorption by plants in the process of photosynthesis. Carbon dioxide is washed out of the air by precipitation.

An important role in maintaining a constant concentration of carbon dioxide in the atmospheric air is played by its release from the surface of the seas and oceans. The carbon dioxide dissolved in the water of the seas and oceans is in dynamic equilibrium with the carbon dioxide of the air, and with an increase in the partial pressure in the air it dissolves in water, and with a decrease in the partial pressure it is released into the atmosphere. The processes of formation and assimilation are interconnected, due to this the content of carbon dioxide in the atmospheric air is relatively constant and amounts to 0.03-0.04%. Recently, the concentration of carbon dioxide in the air of industrial cities has been increasing as a result of intense air pollution by fuel combustion products. The content of carbon dioxide in urban air can be higher than in a clean atmosphere, and be up to 0.05% or more. The role of carbon dioxide in creating a "greenhouse effect" is known, leading to an increase in the temperature of the surface air layer.

Carbon dioxide is a physiological stimulant of the respiratory center. Its partial pressure in the blood is provided by the regulation of acid-base balance. In the body, it is in a bound state in the form of sodium carbonate salts in plasma and red blood cells. When high concentrations of carbon dioxide are inhaled, redox processes are disturbed. The more carbon dioxide in the air we breathe, the less it can be excreted by the body. The accumulation of carbon dioxide in the blood and tissues leads to the development of tissue anoxia. With an increase in the content of carbon dioxide in the inhaled air up to 3-4%, symptoms of intoxication are noted, at 8% severe poisoning occurs and death occurs. The content of carbon dioxide is used to judge the purity of the air in residential and public buildings. A significant accumulation of this compound in the indoor air indicates the sanitary problems of the premises (crowded people, poor ventilation). MPC of carbon dioxide in the air of medical institutions is 0.07%, in the air of residential and public buildings - 0.1%. The latter value is taken as a calculated one when determining the ventilation efficiency of residential and public buildings.

Nitrogen. Along with oxygen and carbon dioxide, atmospheric air includes nitrogen, which, in terms of quantitative content, is the most significant part of atmospheric air.

Nitrogen belongs to inert gases, it does not support respiration and combustion. In a nitrogen atmosphere, life is impossible. In nature, there is a cycle. Nitrogen from the air is absorbed by some types of soil bacteria, as well as blue-green algae. Nitrogen in the air under the influence of electrical discharges turns into oxides, which, being washed out of the atmosphere by precipitation, enrich the soil with salts of nitrous and nitric acids. Under the influence of soil bacteria, nitrous acid salts are converted into nitric acid salts, which in turn are absorbed by plants and serve for protein synthesis. It has been established that 95% of atmospheric air is assimilated by living organisms and only 5% is bound as a result of physical processes in nature. Consequently, the bulk of the bound nitrogen is of biogenic origin. Along with the assimilation of nitrogen, it is released into the atmosphere. Free nitrogen is formed during the combustion of wood, coal, oil, a small amount of free nitrogen is released during the decomposition of organic compounds by denitrophicating microorganisms. Thus, in nature there is a continuous cycle of nitrogen, as a result of which the nitrogen of the atmosphere is converted into organic compounds. When these compounds decompose, nitrogen is restored and enters the atmosphere, and then it is again bound by biological objects.

Nitrogen is a diluent of oxygen, thus performing a vital function, since breathing pure oxygen leads to irreversible changes in the body. When studying the effect of various concentrations of nitrogen on the body, it was noted that its increased content in the inhaled air contributes to the onset of hypoxia and asphyxia due to a decrease in the partial pressure of oxygen. With an increase in the nitrogen content to 93%, death occurs. Nitrogen shows the most pronounced unfavorable properties under conditions of high pressure, which is associated with its narcotic effect. The role of nitrogen in the origin of decompression sickness is also known.

inert gases. Inert gases include argon, neon, helium, krypton, xenon, etc. Chemically, these gases are inert, they dissolve in body fluids depending on the partial pressure. The absolute amount of these gases in the blood and body tissues is negligible. Among the inert gases, a special place is occupied by radon, actinon and thoron - decay products of natural radioactive elements radium, thorium, actinium.

Chemically, these gases are inert, as already noted above, and their dangerous effect on the body is associated with their radioactivity. Under natural conditions, they determine the natural radioactivity of the atmosphere.

Air temperature

Atmospheric air is heated mainly from the earth's surface due to the heat received by it from the sun. About 47% of solar energy reaching the earth is absorbed by the earth's surface and converted into heat. Approximately 34% of solar energy is reflected back into outer space from the tops of clouds and the earth's surface, and only a fifth (19%) of solar energy directly heats the atmosphere. In this regard, the maximum air temperature occurs between 13 and 14 hours, when the earth's surface is heated to the greatest extent. The heated surface layers of air rise upwards, gradually cooling down. Therefore, with an increase in altitude above sea level, the air temperature decreases by an average of 0.6 ° C for every 100 meters of elevation.

The heating of the atmosphere occurs unevenly and depends primarily on geographic latitude: the greater the distance from the equator to the pole, the greater the angle of inclination of the sun's rays to the plane of the earth's surface, the less energy enters per unit area and heats it less.

The difference in air temperatures depending on the latitude of the area can be very significant and amount to more than 100 ° C. Thus, the highest air temperatures (up to +60°C) were recorded in equatorial Africa, the minimum (up to –90°C) - in Antarctica.

Daily fluctuations in air temperature are also very significant in a number of equatorial countries, constantly decreasing towards the poles.

A number of natural factors influence daily and annual fluctuations in air temperature: the intensity of solar radiation, the nature and topography of the terrain, altitude, proximity to the seas, the nature of sea currents, vegetation cover, etc.

The effect of unfavorable air temperature on the body is most pronounced in the conditions of stay or work of people in the open air, as well as in some industrial premises where very high or very low air temperatures are possible. This applies to agricultural workers, builders, oil workers, fishermen, etc., as well as those working in hot shops, in ultra-deep mines (1-2 km), specialists servicing refrigeration units, etc.

In residential and public premises, there are opportunities to ensure the most favorable air temperature (due to heating, ventilation of premises, use of air conditioners, etc.).

Atmosphere pressure

On the surface of the globe, fluctuations in atmospheric pressure are associated with weather conditions and during the day, as a rule, do not exceed 4-5 mm Hg.

However, there are special conditions of life and work of a person in which there are significant deviations from normal atmospheric pressure that can have a pathological effect.

Young children often ask their parents what air is and what it usually consists of. But not every adult can answer correctly. Of course, everyone studied the structure of air at school in nature studies, but over the years this knowledge could be forgotten. Let's try to fill them up.

What is Air?

Air is a unique "substance". You can't see it, touch it, it's tasteless. That is why it is so difficult to give a clear definition of what it is. Usually they just say - air is what we breathe. It is all around us, although we do not notice it at all. You can feel it only when a strong wind blows or an unpleasant smell appears.

What happens if the air disappears? Without it, not a single living organism can live and work, which means that all people and animals will die. It is not bypassed for the process of respiration. What matters is how clean and wholesome the air everyone breathes is.

Where can you find fresh air?

The most useful air is located:

In forests, especially pine.
In the mountains.
Near the sea.

The air in these places has a pleasant aroma and has beneficial properties for the body. This explains why children's health camps and various sanatoriums are located near forests, in the mountains or on the sea coast.

You can enjoy fresh air only away from the city. For this reason, many people buy summer cottages outside the village. Some move to a temporary or permanent place of residence in the village, build houses there. This is especially true for families with small children. People are leaving because the air in the city is heavily polluted.

Fresh air pollution problem

In the modern world, the problem of environmental pollution is especially relevant. The work of modern factories, enterprises, nuclear power plants, cars has a negative impact on nature. They emit harmful substances into the atmosphere that pollute the atmosphere. Therefore, very often people in urban areas experience a lack of fresh air, which is very dangerous.

A serious problem is heavy air inside a poorly ventilated room, especially if there are computers and other equipment in it. Being present in such a place, a person can begin to suffocate from a lack of air, he has pain in his head, weakness occurs.

According to statistics compiled by the World Health Organization, about 7 million human deaths per year are associated with the absorption of polluted air in the street and indoors.

Harmful air is considered one of the main causes of such a terrible disease as cancer. So say organizations involved in the study of cancer.

Therefore, it is necessary to take preventive measures.

How to get fresh air?

A person will be healthy if he can breathe fresh air every day. If it is not possible to move out of town due to important work, lack of money or for other reasons, then it is necessary to look for a way out of the situation on the spot. In order for the body to receive the necessary norm of fresh air, the following rules should be followed:

To be on the street more often, for example, to walk in the evenings in parks, gardens.
Go for a walk in the woods on weekends.
Constantly ventilate living and working areas.
Plant more green plants, especially in offices where there are computers.
It is advisable to visit resorts located on the sea or in the mountains once a year.

What gases does air consist of?

Every day, every second, people breathe in and out, completely without thinking about the air. People do not react to him in any way, despite the fact that he surrounds them everywhere. Despite its weightlessness and invisibility to the human eye, the air has a rather complex structure. It includes the interrelationship of several gases:

Nitrogen.
Oxygen.
Argon.
Carbon dioxide.
Neon.
Methane.
Helium.
Krypton.
Hydrogen.
Xenon.

The main part of the air is nitrogen , the mass fraction of which is 78 percent. 21 percent of the total is oxygen, the most essential gas for human life. The remaining percentages are occupied by other gases and water vapor, from which clouds are formed.

The question may arise, why is there so little oxygen, just a little more than 20%? This gas is reactive. Therefore, with an increase in its share in the atmosphere, the likelihood of fires in the world will increase significantly.

What is the air we breathe made of?

The two main gases that make up the basis of the air we breathe every day are:

Oxygen.
Carbon dioxide.

We inhale oxygen, we exhale carbon dioxide. Every student knows this information. But where does oxygen come from? The main source of oxygen production is green plants. They are also consumers of carbon dioxide.

The world is interesting. In all ongoing life processes, the rule of maintaining balance is observed. If something has gone from somewhere, then something has come somewhere. So it is with air. Green spaces produce the oxygen that humanity needs to breathe. Humans take in oxygen and give off carbon dioxide, which in turn is used by plants. Thanks to this system of interaction, life exists on planet Earth.

Knowing what the air we breathe consists of and how much it is polluted in modern times, it is necessary to protect the plant world of the planet and do everything possible to increase the representatives of green plants.