Pure air is one of the main wealth of nature: arguments for the lesson "The World". Why is the air polluted? Using air by man

Air is something without which it is impossible for a person to live. Therefore, you need to know about the meaning that it has for nature, about its composition and, of course, about how human activity affects the purity of air.

Content

It is also important to understand what measures can be taken to protect the air in order to prevent or at least reduce the harmful influence of the sources of its pollution. The air is a mixture of gases that does not have the shape, taste and smell, in which nitrogen is predominant (78%). The air also includes 21% oxygen and 1% - carbon dioxide, inert gases and other substances.

People receive oxygen directly from the air

Oxygen enters the human body during inhalation - the respiratory system is involved in this process. It also provides carbon dioxide removal from the body. In this case, processes are carried out:

Pulmonary ventilation (direct exchange of gases, which occurs between light and environment).
Pulmonary breathing (when the alveoli of the lungs and blood exchange with gases).
Tissue (or internal) breathing, in which gases are carried by blood to the tissues of the body.

Thus, in addition to the respiratory system, the circulatory system is also involved in the transportation of gases to all organs and tissues.

The person’s respiratory system, which provides air from the environment, includes the light and air paths themselves, starting from the nasal cavity. There are there hairsdelaying a certain number of dust particles, and smell receptors that contribute to the determination of odors. The air cleaned of dust passes to the nasopharynx, the mucous membrane of which, filled with blood vessels, moisturizes and heats the air.
On the trachea from the larynx The air passes to the bronchi, who, at the entrance to the lungs, begin to divide into bronchioles, gradually becoming less and ending with a slice, which, together with an alveolar bag, forms an alveoli. In them, gas exchange occurs when alveolar air gives oxygen into venous blood and takes carbon dioxide from it. Further, blood, enriched with oxygen, carries it to tissues and cells, enriching them.
The most deep breath showing how much air a person is able to breathe after it exhausts deeply, determines such an indicator as the life capacity of the lungs. It is measured by a Spirometer with a special device. The average value for a healthy person is about 3.5 liters.
There is also such a parameter as a residual volume - it is air that is never removed from the lungs, even with the deepest exhalation (about 1.5 l). With ordinary exhalation in the lungs, and more - up to 3 liters remains. It is these half a liter of the difference between the volume of a deep and ordinary breath that is called the breathing air.
There are also concepts of additional air (about 1.5 liters, which a person may breathe, extending a calm breath) and a spare (the same 1.5 liters that can exhale a few seconds after a calm exhalation). Also, speaking of the receipt of oxygen from the air, terms such as "Pulmonary ventilation" - the number of liters of air that a person inhales for 1 min; "breathing rate" - The number of breaths and exhalations for a minute. With age, the last indicator is becoming less. The more often breathing, the less the lung capacity is filled.
The amount of oxygen, which a person receives from the air in a conditional time, is indicated by such a parameter as the dose of oxygen consumption. It is also associated with the frequency of breathing and pulmonary ventilation. In addition, when a person breathes with his nose, he receives a quarter more oxygen than with his mouth.

What is the importance of air for plants, animals?

The value of air is vital not only for humans, but also for all living things on Earth, including animals and plants.

Plants get air thanks to the roots and leaves that act as an air supply organs. The resulting air is necessary for plant growth and the process of photosynthesis, in which they consume carbon dioxide, releasing oxygen into the atmosphere.
In the process of breathing, the reverse process occurs. Sunlight contributes to more release, and at night oxygen is absorbed from the soil with the help of roots. Also, thanks to the air, the soil is saturated with useful substances (for example, nitrogen, potassium, phosphorus) that are favorable for the root of the plant to develop well.
Gusts of wind help to scatter seeds, drain excess moisture and regulate thermal regime.
The air is no less important for animals that also need to breathe. Mammals do this with the help of lungs, the inhabitants of reservoirs are used for breathing gills, amphibians breathe with the help of pores on the skin, and trachea help with insects. The respiratory process in animals is similar to human, air also enters all organs using a circulatory system.
Oxygen oxidizes squirrels, fats and carbohydrates, which leads to the production of energy that goes to the functioning of each organs. Oxygen starvation leads to a decrease in temperature, a change in oxidative processes, as a result of which the animal dies.

Will a person live without air?

On average without air, a person is able to remain up to 5 minutes. Trained people can do without oxygen up to 9 minutes. After that, the brain, which enters the fifth of all oxygen, which spreads with blood through the body, begins to experience oxygen starvation, leading to loss of consciousness and subsequent death.
It is estimated that, inhaling about 0.5 liters of air at every inspiration, a person consumes up to 15 thousand liters per day. With such a huge need of the body, of course, you cannot live without air.
If the oxygen level decreases slightly, then the human body is able to turn on the protective mechanism of self -regulation: for example, to make more frequent breaths.

The lack of oxygen does not pass for a person for nothing: the consequences

When the body experiences oxygen starvation, begins hypoxia. It can be caused by various reasons:

Exogenous, when the level of oxygen decreases directly in the air that a person breathes. This can happen in a stuffy room or, for example, high in the mountains.
Respiratory, When the movement of air in the lungs is disturbed. An example is pneumonia, swelling in lungs or bronchi, drowning or strangulation.
BloodWhen the blood property is disturbed to deliver oxygen to interact with hemoglobin, as in the case of carbon monoxide or anemia poisoning.
Circulatory It is a consequence of cardiovascular failure, when a blood flow is difficult and, as a result, the saturation of organs with oxygen. This happens with heart attacks or diabetes if blood vessels are affected.
Fabric, When the ability to absorb oxygen by tissues is disturbed. A similar situation may arise, for example, with poisoning.
Overloadi hypoxia occurs after excessive physical exertion on a particular organ.
Mixedcombining various options.

Hypoxia can be acute, developing for several hours or minutes, or chronic, flowing over years or months. With significant hypoxia, consciousness is impaired, disorientation in space begins, brain edema is possible.
Headache, increased fatigue, drowsiness - Signs of minor hypoxia. In the first case, the consequences are much harder and occur faster, in the second - the body has time to adapt. But ultimately the consequences are irreversible in both cases.

How do harmful substances fall into the air?

There are two methods of air pollution:

Natural, natural origin. This is primarily the dust formed from the exposure of the wind. The smaller the vegetation on the soil (for example, in deserts or steppes), the more its particles can raise and carry the wind into the atmosphere. Another natural source of air pollution is volcanoes, which, erupting, fill the air in tons of not only ash, but also harmful gases. Natural fires, destruction of rocks, salt evaporating from the seas and oceans, cosmic dust, pollen of plants, discharge that animals or birds leave - all these are natural air pollution.
Anthropogenic, as a result of human activity. The air is largely polluted various modes of transport - automobile, railway, aircraft, navigable. Any means of transportation throws harmful substances into the atmosphere. The source of air pollution is also metallurgical enterprises, since in the process of rendering the ore is released into the atmosphere of solid particles, heavy metals, oxides. A person actively uses boiler rooms and power plants, which, regardless of whether they are atomic or thermal, pollute the air with oxides and dioxides, solid particles, etc.

Great harm is caused to nature and atmospheric layer of garbage dumps in waste processing, fuel that we use in the process of cooking. The agricultural industry also acts as an atmosphere pollutant, since chemicals and pesticides are actively used here, which destroy weeds, and there are many harmful emissions from the work of poultry and livestock complexes.
The situation is aggravated by the fact that when the air of harmful substances formed in the anthropogenic way enters the air, they can also pollute the soil on which they fall along with atmospheric precipitation.

How is the air guarded from pollution?

To protect the air from pollution, a set of protective measures has been developed, the main of which are the following:

Technological processes strive to make the most environmentally friendly. For this, closed technological cycles are created, low -waste technologies are developed, which minimize or completely exclude the possibility of harmful emissions. Pre -cleaning fuel, reduce emissions created by thermal installations, seek to use alternative energy sources or switch to better fuel, replacing, for example, coal with natural gas. Speaking about the emissions made by vehicles, it should be noted such measures as the transition to electric vehicles, the purification of exhaust gases. The main traffic flows are now translated beyond the city. In addition, hydrogen transport is being developed.
Special installations clean technological gas emissions from the impurities that are harmful to human health.
Since it is not always possible to completely clean the emissions, they are striving to scatter in the air, for which smoke pipes exceeding 300 m are installed at the enterprises.
Sanitary protection zones are arranged in settlementsthat separate houses from enterprises with harmful production. Their width depends on what degree of harmfulness this or that production has, and varies from 50 m to a kilometer. When planning buildings, architects develop solutions in such a way that residential buildings are placed far from the sources of harmful emissions, taking into account the predominant direction of the wind in the area. Roads are also planned in such a way that they bypass settlements.

To cleanse emissions, use Dry and wet dust quilting, filters, electr) and other devices.

What needs to be done so that the air in the city is clean?

Each of us can help the environment. To do this, you need to adhere to simple rules:

If possible, use public transport, since in this way less combustion products enter the air. The principle is simple: the fewer cars in the city, the cleaner the air in it. And traffic jams, by the way, are much less.
If you still need to use the car, you should ensure that its tires are always well pumped. So the fuel consumption is reduced, and therefore, less exhausts enter the air.
The more trees in the city, the cleaner the air in it. Therefore, each planted tree will help to breathe in the village easier.
Electricity saving is not only a decrease in utility bills, but also a decrease in power power plants, and hence their harmful emissions.
The same applies to the use of paper. If you write or print on both sides of the sheet, then its consumption is halved. So saves forest stands used for paper production. Yes, and less harmful emissions.
Buy goods whose packaging is minimal or made of material that is suitable for re -use. And the things themselves, for the production of which processed materials were used, is preferable: so less raw materials are consumed.
Do not turn on hot water, if you can do with cold - thus saving fuel and the number of harmful substances thrown into the atmosphere is reduced.
Transportation of products is the use of vehicles, which is far from always environmentally friendly. Therefore, if the majority of the population begins to buy products produced on the spot, then the amount of auto flow will decrease.
When drawing with paints, give preference to those for the production of which the water base is used, so you will reduce the consumption of oil products.
Refuse polyethylene packages-they decompose over 60 years, all this time polluting the environment toxic substances that are contained in them.

Do not turn on the heating at the slightest decrease in temperature. While the atmosphere in the apartment allows, it is better to get on the wardly or cover yourself with a blanket. This will reduce the consumption of valuable resources and harmful emissions from their use.
Replace batteries with batteries. Batteries cause great harm to the environment, polluting it with heavy metals, and when burning or decomposition, poisonous substances are released into the atmosphere.

Using air by man

There are many examples of how air properties are used by a person. And the most important thing is our breathing in which we inhale oxygen in the air. Another example is that we hear precisely thanks to the air through which sound vibrations spread.
One of the properties of air is its compressionWhat is used in pneumatic equipment. Aviators fly through the air using the possibility of creating a support on it. The balloon or, for example, the balloon takes off precisely because experts calculate the mass so that it is less than the mass of air. The air flows that we call the wind are used in the operation of chickenpox and mills, contribute to the movement of sails, and make possible jumping with a parachute.
An important component of the air oxygen It is necessary in order to make the process of combustion possible. Pure oxygen is supported by the breath of sick people, it is also used by scuba divers under water. The fuel of the spaceship is oxidized using liquid oxygen. Another component of air - nitrogen - is used to produce fertilizers for agriculture, and liquid nitrogen is used in medicine.
The air can be healing: for example, sea, which contains iodine, bromine, ozone, sodium chloride, is used in the treatment of bronchitis and rhinitis. Mountain air is more rarefied, it has less oxygen, but this increases the reserves of our respiratory and circulatory systems and improves metabolic processes in the body.
Low air density Makes it with a poor conductor of heat, and people use this property in wearing warm things, fur coats, which seem to create an air shell around a person, which does not allow the heat to disappear. People use the ease of air compared to water while while relaxing on the water, floating on inflatable mattresses, rescue circles or sleeves, or in rubber boats.

Useful articles on the site: