The composition of the air on earth is one of the reasons for our life. Without air, a person will live only three minutes, and after 10 clinical death will occur.
As long as we breathe, we live. On no other planet in the solar system is there such a close connection between chemistry and biology. Our world is unique.
Depending on the territory, the volume of the main component of the vital gas ranges from 16 to 20 percent - this is oxygen, the formula of which is O 2. Its variation is felt in space as “freshness” after a thunderstorm - this is ozone O 3.
From this article you will learn all the secrets of the earth's air envelope. What will happen to the world without one component? What harm can it cause? How will a slight deterioration of the atmosphere affect life?
What is air
The ancient Greeks used two words to define air: calamus, which meant the lower layers of the atmosphere (Dim), and aether meaning the bright upper layers of the atmosphere (the space beyond the clouds).
In alchemy, the symbol for air is a triangle divided in two by a horizontal line.
In the modern world, this definition would suit it - a gas mixture surrounding the planet, which protects against the penetration of solar radiation and large doses of ultraviolet radiation.
Over a multimillion-year period of development, the planet transformed gaseous substances and created a unique protective shield, which is almost impossible to see. Their mass fraction is disproportionately small for space.
Nothing else has an impact on the formation of the world. If we remember that part of the air masses is oxygen, then what will happen on earth without it? Buildings and structures will collapse.
Metal bridges and other structures that fascinate millions of tourists will turn into a single lump due to the small number of oxygen molecules (in this situation, close to zero). The life of all living organisms on the planet will worsen, and some will lead to death.
The seas and oceans, evaporating in the form of hydrogen, will disappear. And when the planet becomes like the Moon, a radiation fire will reign, burning out the remains of the flora, since without oxygen the temperature will increase very much, but without an atmosphere there will be no protection from the sun.
What is air made of?
Almost the entire earth's atmosphere consists of only five gases: nitrogen, oxygen, water vapor, argon and carbon dioxide.
Other mixtures are also present in it, but for the sake of purity of presentation, the chemical composition of water vapor will not be considered. It is worth mentioning that it occupies no more than five percent of the air mass.
Air composition in percentage
Ideally, the air collected in a jar consists of:
- 78 percent from nitrogen;
- 16 - 20 percent oxygen;
- 1 percent argon;
- three hundredths of a percent carbon dioxide;
- one thousandth of one percent neon;
- 0.0002 percent methane.
Smaller components are:
- helium - 0.000524%;
- krypton - 0.000114%;
- hydrogen - H2 0.00005%;
- xenon - 0.0000087%;
- ozone O 3 - 0.000007%;
- nitrogen dioxide - 0.000002%;
- iodine - 0.000001%;
- carbon monoxide;
- ammonia.
Composition of inhaled and exhaled air
Breathing takes precedence over other human needs. From school courses, everyone knows that a person inhales oxygen and exhales carbon dioxide. Although in life there are other substances in the air besides pure O2.
Inhale - exhale. This cycle is repeated about 22,000 times a day, in the process consuming oxygen, which maintains the vitality of the human body. The problem is that delicate lung tissue is attacked by air pollution, cleaning solutions, fibers, fumes and dust.
The first half of the article talked about reducing oxygen, but what will happen with an increase. Doubling the concentration of the main gas would lead to a reduction in fuel consumption in cars.
By breathing in more oxygen, a person would become much more psychologically positive. However, a favorable climate would allow some insects to increase in size. There are a number of theories predicting this. It seems that no one would want to encounter a spider the size of a dog, and one can only fantasize about the growth of large representatives.
By inhaling fewer heavy metals, humanity could overcome a number of complex diseases, but such a project would require a lot of effort. There is a whole program aimed at creating a practical paradise on earth: in every home, room, city or country. Its goal is to make the atmosphere cleaner, to save people from dangerous work in mines and metallurgy. A place where jobs would be occupied by masters of their craft.
It is important that you can breathe clean air, untouched by industry, but this requires political, or better yet, global will. And while people are busy looking for money and cheap (dirty) technologies, all that remains is to inhale city smog. How long this will last is unknown.
The map will allow you to clearly evaluate the atmospheric air of the capital of our homeland, which is inhaled by more than a dozen people.
Hygienic value of atmospheric air
Officially, air pollution can be defined as the content of harmful substances in the air, either particles or microscopic biological molecules that pose a danger to the health of living organisms: humans, animals or plants.
The level of air pollution in a particular location depends primarily on the source or sources of the pollution. This includes:
- car exhaust gases;
- coal power plants;
- industrial plants and other sources of pollution.
All of the above spews various types of hazardous substances and toxins into the air, exceeding the norm by tens and sometimes hundreds of times. In combination with natural sources - volcanoes, geysers, etc. - a deadly cocktail of toxic air masses is created, which is usually called “smog”.
The evidence of each person's guilt is clear. Our personal choices and industry can have a detrimental effect on much-needed gas. Over the century of technological breakthrough, nature has suffered, which means revenge is inevitable.
By increasing emissions, humanity is approaching an abyss from which there is no return and cannot be. Before it's too late, at least something should be fixed. It has been proven that alternative industrial technologies can help clean the air in Moscow, St. Petersburg, Tokyo, Berlin and any other major city.
Here are some solutions:
- Replace gasoline with electricity in cars, and the sky over the city will become a little more beautiful.
- Remove coal plants from cities, let them go down in the history of the country, start using the energy of the sun, water, and wind. Then, after the rain, soot will not fly out of the chimney of the next plant, but only the smell of “freshness.”
- Plant a tree in the park. If thousands do this, then asthmatics and depressed people will stop visiting hospitals in search of a unique recipe from a psychologist.
Air- a mixture of gases, mainly nitrogen and oxygen, that make up the atmosphere of the globe. The total mass of air is 5.13 × 10 15 T and exerts on the Earth's surface a pressure equal to an average of 1.0333 at sea level kg by 1 cm 3. Mass 1 l dry air free from water vapor and carbon dioxide, under normal conditions is equal to 1.2928 G, specific heat capacity - 0.24, thermal conductivity coefficient at 0° - 0.000058, viscosity - 0.000171, refractive index - 1.00029, solubility in water 29.18 ml by 1 l water. Composition of atmospheric air - see table . Atmospheric air also contains water vapor and impurities (solid particles, ammonia, hydrogen sulfide, etc.) in varying quantities.
Composition of atmospheric air
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Percentage |
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by volume |
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Oxygen |
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Carbon dioxide (carbon dioxide) |
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Nitrous oxide |
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6× 10 -18 |
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For humans, a vital component of B is oxygen, the total mass of which is 3.5 × 10 15 T. In the process of restoring normal oxygen levels, the main role is played by photosynthesis by green plants, the starting materials for which are carbon dioxide and water. The transition of oxygen from atmospheric air to blood and from blood to tissue depends on the difference in its partial pressure, therefore the partial pressure of oxygen is biologically significant, and not its percentage in V. At sea level, the partial pressure of oxygen is 160 mm. When it is reduced to 140 mm the person shows the first signs hypoxia. Reducing partial pressure to 50-60 mm life-threatening (see Altitude sickness, Mountain sickness).
Bibliography: Atmosphere of the Earth and Planets, ed. D.P. Kuiper. lane from English, M., 1951; Gubernsky Yu.D. and Korenevskaya E.I. Hygienic principles of microclimate conditioning in residential and public buildings, M., 1978; Minkh A.A. Air ionization and its hygienic significance, M., 1963; Guide to Atmospheric Air Hygiene, ed. K.A. Bushtueva, M., 1976; Guide to Municipal Hygiene, ed. F.G. Krotkova, vol. 1, p. 137, M., 1961.
Less than 200 years ago, the earth's atmosphere contained 40% oxygen. Today there is only 21% oxygen in the air
In the city park 20,8%
In the forest 21,6%
By the sea 21,9%
In the apartment and office less 20%
Scientists have proven that a 1% decrease in oxygen leads to a 30% decrease in performance.
Oxygen deficiency is a result of automobiles, industrial emissions and pollution. There is 1% less oxygen in the city than in the forest.
But the biggest culprit for the lack of oxygen is ourselves. By building warm and airtight houses, living in apartments with plastic windows, we protected ourselves from the flow of fresh air. With each exhalation, reducing the concentration of oxygen and increasing the amount of carbon dioxide. Often the oxygen content in the office is 18%, in the apartment 19%.
The quality of air necessary to support the life processes of all living organisms on Earth,
determined by its oxygen content.
The dependence of air quality on the percentage of oxygen in it.
Level of comfortable oxygen content in the air
Zone 3-4: limited by the legally approved standard for the minimum oxygen content in indoor air (20.5%) and the fresh air “standard” (21%). For urban air, an oxygen content of 20.8% is considered normal.
Favorable level of oxygen in the air
Zone 1-2: This level of oxygen content is typical for ecologically clean areas and forests. The oxygen content in the air on the ocean shore can reach 21.9%
Insufficient oxygen levels in the air
Zano 5-6: limited to the minimum permissible oxygen level when a person can be without a breathing apparatus (18%).
Staying in rooms with such air is accompanied by rapid fatigue, drowsiness, decreased mental activity, and headaches.
Prolonged stay in rooms with such an atmosphere is dangerous to health.
Dangerously low levels of oxygen in the air
Zone 7 onwards: at oxygen content16% dizziness, rapid breathing,13% - loss of consciousness,12% - irreversible changes in the functioning of the body, 7% - death.
External signs of oxygen starvation (hypoxia)
- deterioration of skin color
- fatigue, decreased mental, physical and sexual activity
- depression, irritability, sleep disturbance
- headache
Spending a long time indoors with insufficient oxygen levels can lead to more serious health problems because... Since oxygen is responsible for all metabolic processes in the body, the consequences of its deficiency are:
Metabolic disease
Decreased immunity
A properly organized ventilation system for living and working spaces can be the key to good health.
The role of oxygen for human health. Oxygen:
Increases mental performance;
Increases the body's resistance to stress and increased nervous stress;
Maintains oxygen levels in the blood;
Improves the coordination of internal organs;
Increases immunity;
Promotes weight loss. Regular oxygen consumption in combination with physical activity leads to active breakdown of fats;
Sleep is normalized: it becomes deeper and longer, the period of falling asleep and physical activity decreases
Conclusions:
Oxygen influences our lives, and the more of it, the more colorful and diverse our lives are.
You can buy an oxygen tank or give up everything and go live in the forest. If this is not available to you, ventilate your apartment or office every hour. If drafts, dust, or noise interfere, install ventilation that will supply you with fresh air and cleanse you of exhaust gases.
Do everything to bring fresh air into your home and you will see changes in your life.
Unlike the hot and cold planets of our solar system, conditions exist on planet Earth that allow life in some form. One of the main conditions is the composition of the atmosphere, which gives all living things the opportunity to breathe freely and protects them from the deadly radiation that reigns in space.
What does the atmosphere consist of?
The Earth's atmosphere consists of many gases. Basically which occupies 77%. Gas, without which life on Earth is unthinkable, occupies a much smaller volume; the oxygen content in the air is equal to 21% of the total volume of the atmosphere. The last 2% is a mixture of various gases, including argon, helium, neon, krypton and others.
The Earth's atmosphere rises to a height of 8 thousand km. Air suitable for breathing is found only in the lower layer of the atmosphere, in the troposphere, which reaches 8 km up at the poles, and 16 km above the equator. As altitude increases, the air becomes thinner and the greater the lack of oxygen. To consider what the oxygen content in the air is at different altitudes, let's give an example. At the peak of Everest (height 8848 m), the air holds 3 times less of this gas than above sea level. Therefore, conquerors of high mountain peaks - climbers - can climb to its peak only in oxygen masks.
Oxygen is the main condition for survival on the planet
At the beginning of the Earth's existence, the air that surrounded it did not have this gas in its composition. This was quite suitable for the life of protozoa - single-celled molecules that swam in the ocean. They didn't need oxygen. The process began approximately 2 million years ago, when the first living organisms, as a result of the reaction of photosynthesis, began to release small doses of this gas, obtained as a result of chemical reactions, first into the ocean, then into the atmosphere. Life evolved on the planet and took on a variety of forms, most of which have not survived into modern times. Some organisms eventually adapted to living with the new gas.
They learned to harness its power safely inside a cell, where it acted as a powerhouse to extract energy from food. This way of using oxygen is called breathing, and we do it every second. It was breathing that made it possible for the emergence of more complex organisms and people. Over millions of years, the oxygen content in the air has soared to modern levels - about 21%. The accumulation of this gas in the atmosphere contributed to the creation of the ozone layer at an altitude of 8-30 km from the earth's surface. At the same time, the planet received protection from the harmful effects of ultraviolet rays. The further evolution of life forms on water and land increased rapidly as a result of increased photosynthesis.
Anaerobic life
Although some organisms adapted to the increasing levels of gas released, many of the simplest forms of life that existed on Earth disappeared. Other organisms survived by hiding from oxygen. Some of them today live in the roots of legumes, using nitrogen from the air to build amino acids for plants. The deadly organism botulism is another refugee from oxygen. It easily survives in vacuum-packed canned foods.
What oxygen level is optimal for life?
Prematurely born babies, whose lungs are not yet fully open for breathing, end up in special incubators. In them, the oxygen content in the air is higher by volume, and instead of the usual 21%, its level is set at 30-40%. Babies with severe breathing problems are surrounded by air with 100 percent oxygen levels to prevent damage to the child's brain. Being in such circumstances improves the oxygen regime of tissues that are in a state of hypoxia and normalizes their vital functions. But too much of it in the air is just as dangerous as too little. Excessive oxygen in a child's blood can damage the blood vessels in the eyes and cause vision loss. This shows the duality of gas properties. We need to breathe it in order to live, but its excess can sometimes become poison for the body.
Oxidation process
When oxygen combines with hydrogen or carbon, a reaction called oxidation occurs. This process causes the organic molecules that are the basis of life to disintegrate. In the human body, oxidation occurs as follows. Red blood cells collect oxygen from the lungs and carry it throughout the body. There is a process of destruction of the molecules of the food we eat. This process releases energy, water and leaves behind carbon dioxide. The latter is excreted by blood cells back into the lungs, and we exhale it into the air. A person may suffocate if they are prevented from breathing for more than 5 minutes.
Breath
Let's consider the oxygen content in the inhaled air. Atmospheric air that enters the lungs from outside during inhalation is called inhaled air, and air that comes out through the respiratory system during exhalation is called exhaled air.
It is a mixture of the air that filled the alveoli with that in the respiratory tract. The chemical composition of the air that a healthy person inhales and exhales under natural conditions practically does not change and is expressed in the following numbers.
Oxygen is the main component of air for life. Changes in the amount of this gas in the atmosphere are small. If the oxygen content in the air near the sea reaches up to 20.99%, then even in the very polluted air of industrial cities its level does not fall below 20.5%. Such changes do not reveal effects on the human body. Physiological disturbances appear when the percentage of oxygen in the air drops to 16-17%. In this case, there is an obvious one that leads to a sharp decline in vital activity, and when the oxygen content in the air is 7-8%, death is possible.
Atmosphere in different eras
The composition of the atmosphere has always influenced evolution. At different geological times, due to natural disasters, rises or falls in oxygen levels were observed, and this entailed changes in the biosystem. About 300 million years ago, its content in the atmosphere rose to 35%, and the planet was colonized by insects of gigantic size. The greatest extinction of living things in Earth's history occurred about 250 million years ago. During it, more than 90% of the inhabitants of the ocean and 75% of the inhabitants of the land died. One version of the mass extinction says that the culprit was low oxygen levels in the air. The amount of this gas dropped to 12%, and this is in the lower layer of the atmosphere up to an altitude of 5300 meters. In our era, the oxygen content in atmospheric air reaches 20.9%, which is 0.7% lower than 800 thousand years ago. These figures were confirmed by scientists from Princeton University, who examined samples of Greenland and Atlantic ice that formed at that time. The frozen water preserved air bubbles, and this fact helps calculate the level of oxygen in the atmosphere.
What determines its level in the air?
Its active absorption from the atmosphere can be caused by the movement of glaciers. As they move away, they reveal gigantic areas of organic layers that consume oxygen. Another reason may be the cooling of the waters of the World Ocean: its bacteria at lower temperatures absorb oxygen more actively. Researchers argue that the industrial leap and, with it, the burning of huge amounts of fuel do not have a particular impact. The world's oceans have been cooling for 15 million years, and the amount of vital nutrients in the atmosphere has decreased regardless of human impact. There are probably some natural processes taking place on Earth that lead to oxygen consumption being higher than its production.
Human impact on the composition of the atmosphere
Let's talk about the human influence on the composition of air. The level we have today is ideal for living beings; the oxygen content in the air is 21%. The balance of it and other gases is determined by the life cycle in nature: animals exhale carbon dioxide, plants use it and release oxygen.
But there is no guarantee that this level will always be constant. The amount of carbon dioxide released into the atmosphere is increasing. This is due to humankind's use of fuel. And, as you know, it was formed from fossils of organic origin and carbon dioxide enters the air. Meanwhile, the largest plants on our planet, trees, are being destroyed at an increasing rate. In a minute, kilometers of forest disappear. This means that some of the oxygen in the air is gradually falling and scientists are already sounding the alarm. The earth's atmosphere is not a limitless storehouse and oxygen does not enter it from the outside. It was constantly being developed along with the development of the Earth. We must always remember that this gas is produced by vegetation during the process of photosynthesis through the consumption of carbon dioxide. And any significant decrease in vegetation in the form of destruction of forests inevitably reduces the entry of oxygen into the atmosphere, thereby disturbing its balance.
The quality of air necessary to support the life processes of all living organisms on Earth is determined by its oxygen content.
Let us consider the dependence of air quality on the percentage of oxygen in it using the example of Figure 1.
Rice. 1 Percentage of oxygen in air
Favorable level of oxygen in the air
Zone 1-2: This level of oxygen content is typical for ecologically clean areas and forests. The oxygen content in the air on the ocean shore can reach 21.9%
Level of comfortable oxygen content in the air
Zone 3-4: limited by the legally approved standard for the minimum oxygen content in indoor air (20.5%) and the fresh air “standard” (21%). For urban air, an oxygen content of 20.8% is considered normal.
Insufficient oxygen levels in the air
Zone 5-6: limited to the minimum permissible oxygen level when a person can be without a breathing apparatus (18%).
Staying in rooms with such air is accompanied by rapid fatigue, drowsiness, decreased mental activity, and headaches.
Prolonged stay in rooms with such an atmosphere is dangerous to health
Dangerously low levels of oxygen in the air
Zone 7 onwards: when the oxygen content is 16%, dizziness and rapid breathing are observed, 13% - loss of consciousness, 12% - irreversible changes in the functioning of the body, 7% - death.
An unbreathable atmosphere is also characterized not only by exceeding the maximum permissible concentrations of harmful substances in the air, but also by insufficient oxygen content.
Due to the various definitions given to the concept of “insufficient oxygen content,” gas rescuers very often make mistakes when describing gas rescue work. This occurs, among other things, as a result of studying charters, instructions, standards and other documents containing an indication of the oxygen content in the atmosphere.
Let's look at the differences in the percentage of oxygen in the main regulatory documents.
1.Oxygen content less than 20%.
Gas hazardous work carried out when there is oxygen content in the air of the working area less than 20%.
- Standard instructions for organizing the safe conduct of gas-hazardous work (approved by the USSR State Mining and Technical Supervision on February 20, 1985):
1.5. Gas hazardous work includes work... with insufficient oxygen content (volume fraction below 20%).
- Standard instructions for organizing the safe conduct of gas-hazardous work at oil product supply enterprises TOI R-112-17-95 (approved by order of the Ministry of Fuel and Energy of the Russian Federation dated July 4, 1995 N 144):
1.3. Gas hazardous work includes work... when the oxygen content in the air is less than 20% by volume.
- National standard of the Russian Federation GOST R 55892-2013 "Facilities of small-scale production and consumption of liquefied natural gas. General technical requirements" (approved by order of the Federal Agency for Technical Regulation and Metrology dated December 17, 2013 N 2278-st):
K.1 Gas hazardous work includes work... when the oxygen content in the air of the working area is less than 20%.
2. Oxygen content less than 18%.
Gas rescue work carried out at oxygen levels less than 18%.
- Regulations on gas rescue formation (approved and put into effect by the First Deputy Minister of Industry, Science and Technology A.G. Svinarenko on 06/05/2003; approved by: Federal Mining and Industrial Supervision of the Russian Federation on 05/16/2003 N AS 04-35/ 373).
3. Gas rescue operations ... in conditions of reducing the oxygen content in the atmosphere to a level of less than 18 vol.% ...
- Guidelines for organizing and conducting emergency rescue operations at chemical enterprises (approved by UAC No. 5/6 Protocol No. 2 dated July 11, 2015).
2. Gas rescue operations... in conditions of insufficient (less than 18%) oxygen content...
- GOST R 22.9.02-95 Safety in emergency situations. Modes of activity of rescuers using personal protective equipment when eliminating the consequences of accidents at chemically hazardous facilities. General requirements (adopted as an interstate standard GOST 22.9.02-97)
6.5 At high concentrations of chemical substances and insufficient oxygen content (less than 18%) in the source of chemical contamination, use only insulating respiratory protective equipment.
3. Oxygen content less than 17%.
The use of filters is prohibited RPE at oxygen content less than 17%.
- GOST R 12.4.233-2012 (EN 132:1998) System of occupational safety standards. Personal respiratory protection. Terms, definitions and designations (approved and put into effect by order of the Federal Agency for Technical Regulation and Metrology dated November 29, 2012 N 1824-st)
2.87...oxygen-deficient atmosphere: Ambient air containing less than 17% oxygen by volume in which filtering RPE cannot be used.
- Interstate standard GOST 12.4.299-2015 System of occupational safety standards. Personal respiratory protection. Recommendations for selection, application and maintenance (put into effect by order of the Federal Agency for Technical Regulation and Metrology dated June 24, 2015 N 792-st)
B.2.1 Oxygen deficiency. If an analysis of environmental conditions indicates the presence or possibility of oxygen deficiency (volume fraction less than 17%), then filter-type RPE is not used...
- Decision of the Customs Union Commission of December 9, 2011 N 878 On the adoption of the technical regulations of the Customs Union "On the safety of personal protective equipment"
7) ...the use of filtering personal respiratory protection equipment is not allowed if the oxygen content in the inhaled air is less than 17 percent
- Interstate standard GOST 12.4.041-2001 System of occupational safety standards. Filtering personal respiratory protection equipment. General technical requirements (put into effect by Decree of the State Standard of the Russian Federation dated September 19, 2001 N 386-st)
1 ...filtering personal protective equipment for the respiratory system designed to protect against harmful aerosols, gases and vapors and their combinations in the ambient air, provided that it contains at least 17 vol oxygen. %.