, carbon dioxide, properties of carbon dioxide, production of carbon dioxide

It is not suitable for supporting life. However, this is what plants “feed” on, turning it into organic substances. In addition, it is a kind of “blanket” for the Earth. If this gas suddenly disappeared from the atmosphere, the Earth would become much cooler and rain would virtually disappear.

"Blanket of the Earth"

(carbon dioxide, carbon dioxide, CO 2) is formed when two elements combine: carbon and oxygen. It is formed during the combustion of coal or hydrocarbon compounds, during the fermentation of liquids, and also as a product of the respiration of people and animals. It is also found in small quantities in the atmosphere, from where it is assimilated by plants, which, in turn, produce oxygen.

Carbon dioxide is colorless and heavier than air. Freezes at −78.5°C to form snow consisting of carbon dioxide. In aqueous solution it forms carbonic acid, but it is not stable enough to be easily isolated.

Carbon dioxide is the Earth's blanket. It easily transmits ultraviolet rays that heat our planet and reflects infrared rays emitted from its surface into outer space. And if carbon dioxide suddenly disappears from the atmosphere, this will primarily affect the climate. It will become much cooler on Earth, and rain will fall very rarely. It’s not hard to guess where this will ultimately lead.

True, such a catastrophe does not yet threaten us. Quite the contrary. The combustion of organic substances: oil, coal, natural gas, wood - gradually increases the carbon dioxide content in the atmosphere. This means that over time we must expect significant warming and humidification of the earth’s climate. By the way, old-timers believe that it is already noticeably warmer than it was in the days of their youth...

Carbon dioxide is released liquid low temperature, high pressure liquid And gaseous. It is obtained from waste gases from ammonia and alcohol production, as well as from special fuel combustion and other industries. Gaseous carbon dioxide is a colorless and odorless gas at a temperature of 20 ° C and a pressure of 101.3 kPa (760 mm Hg), density - 1.839 kg / m 3. Liquid carbon dioxide is simply a colorless, odorless liquid.

Non-toxic and non-explosive. At concentrations of more than 5% (92 g/m3), carbon dioxide has a harmful effect on human health - it is heavier than air and can accumulate in poorly ventilated areas near the floor. This reduces the volume fraction of oxygen in the air, which can cause oxygen deficiency and suffocation.

Producing carbon dioxide

In industry, carbon dioxide is obtained from furnace gases, from decomposition products of natural carbonates(limestone, dolomite). The mixture of gases is washed with a solution of potassium carbonate, which absorbs carbon dioxide, turning into bicarbonate. When heated, the bicarbonate solution decomposes, releasing carbon dioxide. During industrial production, gas is pumped into cylinders.

In laboratory conditions small amounts are obtained interaction of carbonates and bicarbonates with acids, for example, marble with hydrochloric acid.

"Dry ice" and other beneficial properties of carbon dioxide

Carbon dioxide is used quite widely in everyday practice. For example, sparkling water with the addition of aromatic essences - a wonderful refreshing drink. IN Food Industry carbon dioxide is also used as a preservative - it is indicated on the packaging under the code E290, and also as a dough leavening agent.

Carbon dioxide fire extinguishers used in fires. Biochemists have found that fertilization... of the air with carbon dioxide a very effective means for increasing the yield of various crops. Perhaps this fertilizer has a single, but significant drawback: it can only be used in greenhouses. At plants that produce carbon dioxide, liquefied gas is packaged in steel cylinders and sent to consumers. If you open the valve, snow comes out with a hiss. What kind of miracle?

Everything is explained simply. The work expended on compressing the gas is significantly less than that required to expand it. And in order to somehow compensate for the resulting deficit, carbon dioxide cools sharply, turning into "dry ice". It is widely used to preserve food and has significant advantages over ordinary ice: firstly, its “cooling capacity” is twice as high per unit weight; secondly, it evaporates without a trace.

Carbon dioxide is used as an active medium in wire welding, since at arc temperature, carbon dioxide decomposes into carbon monoxide CO and oxygen, which, in turn, interacts with the liquid metal, oxidizing it.

Carbon dioxide in cans is used in air guns and as energy source for engines in aircraft modeling.

Loss of strength, weakness, headache, depression - is this condition familiar? Most often this happens in autumn and winter, and poor health is attributed to a lack of sunlight. But it’s not that, it’s the excess carbon dioxide in the air you breathe. The situation with CO₂ levels in residential premises and transport in our country is truly catastrophic. Stuffiness, high humidity and mold are also a consequence of lack of ventilation. Sealed plastic windows and air conditioners only make the situation worse. Do you know that when the level of carbon dioxide in the air is twice as high (relative to the street background), brain activity decreases by 2 times? By the way, students yawning during lectures are an indicator of increased CO₂ content in the classroom. And very often there is no ventilation in office buildings. What kind of productivity can we talk about if a person’s brain simply doesn’t work?

So let's start with the basics. When a person breathes, it absorbs oxygen and releases carbon dioxide. Carbon dioxide is also released when hydrocarbons are burned. The average CO₂ level on our planet is currently about 400 PPM (Parts per million - parts per million, or 0.04%) and is constantly growing due to the constant increase in consumption of petroleum products. At the same time, it is worth knowing that trees absorb carbon dioxide and this is precisely their main function (and not, as they mistakenly believe, that they only produce oxygen).

While a person is outdoors, there are no problems, but they begin when he is indoors. If a person is locked in a sealed room without an influx of fresh air, then he will die not from a lack of oxygen, as most people mistakenly believe, but from a multiple excess of the level of carbon dioxide that this person himself produced in the lungs. Let's put aside the problems of ventilation of public transport (I will write about this separately) and turn our attention to city apartments/country houses, in which there is a massive lack of ventilation.

At the same time, a person spends at least a third of his life in his house/apartment, and in reality half of it - you cannot save on your own health!

2. The problem of high CO₂ content in the air is especially relevant in the cold season, because... In summer, almost everyone has their windows open all the time. And with the onset of cold weather, the windows are opened less and less often, ultimately reducing to occasional ventilation. And, what a coincidence, it is during the cold season that depression, drowsiness and loss of strength appear.

3. Previously, there was even such a tradition - to seal the cracks in the windows before the cold weather. Often, together with vents, they completely excluded the flow of fresh air into the house. I once again emphasize that fresh air is needed not because it contains the oxygen necessary for breathing, but in order to reduce the excess carbon dioxide content by replacing the air in the room.

4. Many people think that they have a hood (in apartments, at least in the kitchen and bathroom), and the room will be ventilated through it. Yeah, in addition, installing plastic windows that are completely sealed. But how will the air go into the exhaust if you don’t have an inflow in the form of either cracks in the frames or an open window? And with good draft, it usually pulls air from the entrance.

5. The only thing worse is to install an air conditioner in the form of a split system and use it with the windows closed. Remember, when the air conditioner is running, DO NOT close the windows! Here is a modern airtight country house that has no gaps in the building envelope. And you don’t need to be fooled by stories that wood or aerated concrete “breathe” and therefore you can not give a damn about ventilation. Remember, this term refers to the high vapor permeability of the material, and not the ability to supply fresh street air into the house.

6. Most are limited to an exhaust fan from the bathroom and kitchen. Okay, the fan is turned on, all the windows and doors in the house are closed. What will be the result? That's right, there will be a vacuum in the house, because there is nowhere for new air to come from. For natural ventilation to work, fresh air must enter the house.

7. To measure the level of carbon dioxide in the air, relatively affordable sensors with an NDIR sensor have now appeared. Non-dispersive infrared (NDIR) is based on the change in infrared intensity before and after absorption in an infrared detector with selective sensitivity. Initially, I was going to buy such a sensor on Aliexpress last year (then it cost about $100), but the increased price due to the rise in the dollar exchange rate made me think and look for alternative options. Unexpectedly, this sensor was found in Russia under a Russian brand for the same $100 at last year’s exchange rate. In total, I found the best deal on Yandex.Market and purchased the sensor at a price of 3,500 rubles. The model is called MT8057. Of course, the sensor has an error, but it is not important when it comes to the fact that we need measurements with carbon dioxide concentrations several times higher than normal.

8. Closed plastic windows, air conditioners - all this is nonsense compared to the gas stove in the apartment (for the photo I lit a gas burner, because to photograph the stove it had to be washed).

9. So, all attention to the schedule. Kitchen 9 square meters, ceilings 3 meters high, open door to the kitchen (!), closed window, there is a natural draft hood (in summer the draft is weak), one person. The sensor stands at a height of 1 meter from the floor, on the dining table. The “normal” CO₂ level in a room without people is about 600 PPM. One person comes and the CO₂ level immediately rises. Leaves - falls. It comes again - it rises again. And after that he turns on one (!) gas burner. CO₂ levels rise above 2000 PPM almost instantly. Anxiety! We open the window. We observe how the concentration of carbon dioxide in the air slowly decreases. And add 1-2 more people here. Even if you don’t turn on the gas stove, 3 adults without doing heavy physical work raise the CO₂ level in the room to a critical level in 30 minutes.

Do you cook on a gas stove? Be sure to open the window and turn on the hood (do both at the same time).

Have you turned on the air conditioner? Be sure to open the window.

Are you just in the room? Be sure to open the window. And if there are many people in the room, open the window.

And at night, while sleeping, the window must be kept open.

In short, you either have to have a supply vent or a window that is always open.

10. Regarding trees and how they can be useful. Their most important function during the growth process is the absorption of carbon dioxide. Few people think about why wood burns and where so much energy comes from. So this energy in the form of carbon accumulates in the tree trunk as a result of the absorption of carbon dioxide. Trees produce oxygen as a by-product of the photosynthesis reaction.

11. Opening a window in the warm season is not difficult and, in general, in summer the problem is not so pressing (except for cases of using air conditioners with closed windows). Problems begin in winter, because no one keeps the window open all the time, this means huge uncontrollable heat losses and it will be simply cold. It is precisely at this moment that the alarm should be raised. Health is priceless.

The problem is very serious and global in nature. For example, until last fall I didn’t think at all about the importance of ventilation for health: whether in an apartment or in a country house. If you look into the past, it was the regular autumn depression, drowsiness and bad mood during the cold season in a city apartment that prompted us to think in the direction of leaving the city, so to speak, and building, because... In the fall and winter, I had a headache and general weakness of the body when I was in the city. But as soon as I went out into nature, the problem disappeared. I chalked it all up to a lack of sunlight, but that wasn’t the issue. In winter, I stopped keeping the window open (it was cold) and the CO₂ in the apartment was many times higher.

The simplest and most affordable solution to the problem is to constantly keep the window open, or ventilate based on the readings from the CO₂ sensor. A normal level of CO₂ in a room can be considered a concentration of up to 1000 PPM; if higher, it is necessary to urgently ventilate. Humidity can be considered an indirect indicator of high concentrations of carbon dioxide in the air. If, without objective reasons and a decrease in temperature in the room, the humidity begins to rise, this means that the CO₂ level is increasing.

The danger of increased concentrations of carbon dioxide in the air is that the human body reacts with a very long delay. By the time you felt that the room was stuffy and needed to be ventilated, you had already been in a room with a high CO₂ content in the air for at least half an hour.

In the next post I will talk about what problems there are with ventilation in public transport (buses, trains, planes). I’ll also show you how to properly organize ventilation in a country house, which everyone somehow forgets about.

To be continued.

Articles on the topic for self-study.

The normal functioning of all vital systems depends on the amount of carbon dioxide in the human bloodstream. Carbon dioxide increases the body's resistance to bacterial and viral infections and participates in the metabolism of biologically active substances. During physical and intellectual stress, carbon dioxide helps maintain the body's balance. But a significant increase in this chemical compound in the surrounding atmosphere worsens human well-being. The harm and benefits of carbon dioxide for the existence of life on Earth have not yet been fully studied.

Characteristics of carbon dioxide

Carbon dioxide, carbonic anhydride, carbon dioxide is a gaseous chemical compound that is colorless and odorless. The substance is 1.5 times heavier than air, and its concentration in the Earth's atmosphere is approximately 0.04%. A distinctive feature of carbon dioxide is that it does not form a liquid when pressure is increased - the compound immediately turns into a solid state known as “dry ice”. But when certain artificial conditions are created, carbon dioxide takes the form of a liquid, which is widely used for its transportation and long-term storage.

Interesting fact

Carbon dioxide does not become a barrier to ultraviolet rays that enter the atmosphere from the Sun. But the infrared radiation of the Earth is absorbed by carbon anhydride. This is what causes global warming since the formation of a huge number of industrial productions.

During the day, the human body absorbs and metabolizes about 1 kg of carbon dioxide. It takes an active part in the metabolism that occurs in soft, bone, and joint tissues, and then enters the venous bed. With the blood flow, carbon dioxide enters the lungs and leaves the body with each exhalation.

The chemical is found in the human body primarily in the venous system. The capillary network of pulmonary structures and arterial blood contain a small concentration of carbon dioxide. In medicine, the term “partial pressure” is used, which characterizes the concentration ratio of a compound in relation to the entire volume of blood.

Therapeutic properties of carbon dioxide

The penetration of carbon dioxide into the body causes a respiratory reflex in a person. An increase in the pressure of a chemical compound provokes thin nerve endings to send impulses to the receptors of the brain and/or spinal cord. This is how the processes of inhalation and exhalation occur. If the level of carbon dioxide in the blood begins to rise, the lungs accelerate its release from the body.

Interesting fact

Scientists have proven that the significant life expectancy of people living in high mountains is directly related to the high content of carbon dioxide in the air. It improves immunity, normalizes metabolic processes, and strengthens the cardiovascular system.

In the human body, carbon dioxide is one of the most important regulators, acting as a main product along with molecular oxygen. The role of carbon dioxide in human life is difficult to overestimate. The main functional features of the substance include the following:

• has the ability to cause persistent dilation of large vessels and capillaries;
• can have a sedative effect on the central nervous system, provoking an anesthetic effect;
• takes part in the production of essential amino acids;
• stimulates the respiratory center with increasing concentration in the bloodstream.

If there is an acute deficiency of carbon dioxide in the body, then all systems are mobilized and increase their functional activity. All processes in the body are aimed at replenishing carbon dioxide reserves in tissues and the bloodstream:

• the vessels narrow, bronchospasm of the smooth muscles of the upper and lower respiratory tract, as well as blood vessels, develops;
• bronchi, bronchioles, structural parts of the lungs secrete an increased amount of mucus;
• the permeability of large and small blood vessels and capillaries decreases;
• Cholesterol begins to deposit on cell membranes, which causes their compaction and tissue sclerosis.

The combination of all these pathological factors, combined with a low supply of molecular oxygen, leads to tissue hypoxia and a decrease in the speed of blood flow in the veins. Oxygen starvation is especially acute in brain cells, they begin to collapse. The regulation of all vital systems is disrupted: the brain and lungs swell, the heart rate decreases. Without medical intervention, a person may die.

Where is carbon dioxide used?

Carbon dioxide is found not only in the human body and in the surrounding atmosphere. Many industrial production actively use chemicals at various stages of technological processes. It is used as:

• stabilizer;
• catalyst;
• primary or secondary raw materials.

Interesting fact

Oxygen dioxide helps convert into delicious, tart homemade wine. When the sugar contained in the berries ferments, carbon dioxide is released. It gives the drink a sparkling feel and allows you to feel the bubbles bursting in your mouth.
On food packaging, carbon dioxide is hidden under the code E290. Typically, it is used as a preservative for long-term storage. When baking delicious muffins or pies, many housewives add baking powder to the dough. During the cooking process, air bubbles are formed, making the baked goods fluffy and soft. This is carbon dioxide - the result of a chemical reaction between sodium bicarbonate and food acid. Aquarium fish hobbyists use the colorless gas as a growth activator for aquatic plants, and manufacturers of automatic carbon dioxide systems put it in fire extinguishers.

Harm of carbonic anhydride

Children and adults love a variety of fizzy drinks because of the air bubbles they contain. These accumulations of air are pure carbon dioxide, released when the bottle cap is unscrewed. Used in this capacity, it does not bring any benefit to the human body. Once in the gastrointestinal tract, carbonic anhydride irritates the mucous membranes and provokes damage to epithelial cells.

For a person with stomach diseases, it is extremely undesirable to use them, since under their influence the inflammatory process and ulceration of the inner wall of the organs of the digestive system intensify.

Gastroenterologists prohibit patients with the following pathologies from drinking lemonade and mineral water:

• acute, chronic, catarrhal gastritis;
• stomach and duodenal ulcers;
• duodenitis;
• decreased intestinal motility;
• benign and malignant neoplasms of the gastrointestinal tract.

It should be noted that according to WHO statistics, more than half of the inhabitants of planet Earth suffer from one form or another of gastritis. The main symptoms of stomach disease: sour belching, heartburn, bloating and pain in the epigastric region.

If a person is unable to refuse to drink drinks with carbon dioxide, then he should opt for slightly carbonated mineral water.

Experts advise eliminating lemonades from your daily diet. After statistical studies, the following diseases were identified in people who drank sweet water with carbon dioxide for a long time:

• caries;
• endocrine disorders;
• increased fragility of bone tissue;
• fatty liver;
• formation of stones in the bladder and kidneys;
• disorders of carbohydrate metabolism.

Employees of office premises that are not equipped with air conditioning often experience excruciating headaches, nausea, and weakness. This condition occurs in humans when there is an excessive accumulation of carbon dioxide in the room. Constantly being in such an environment leads to acidosis (increased blood acidity) and provokes a decrease in the functional activity of all vital systems.

Benefits of carbon dioxide

The healing effect of carbon dioxide on the human body is widely used in medicine in the treatment of various diseases. So, recently dry carbon dioxide baths have become very popular. The procedure involves the effect of carbon dioxide on the human body in the absence of extraneous factors: water pressure and ambient temperature.

Beauty salons and medical institutions offer clients unusual medical procedures:

• pneumopuncture;
• carboxytherapy.

Complex terms hide gas injections or carbon dioxide injections. Such procedures can be classified as both types of mesotherapy and methods of rehabilitation after serious illnesses.

Before carrying out these procedures, you should visit your doctor for consultation and a thorough diagnosis. Like all methods of therapy, injections with carbon dioxide have contraindications for use.

The beneficial properties of carbon dioxide are used in the treatment of cardiovascular diseases and arterial hypertension. And dry baths reduce the content of free radicals in the body and have a rejuvenating effect. Carbon dioxide increases a person's resistance to viral and bacterial infections, strengthens the immune system, and increases vitality.

Most people believe that carbon dioxide is harmful. This is not surprising, because we were told about the negative properties of CO 2 back in school during biology and chemistry lessons. Presenting carbon dioxide exclusively as a harmful substance, teachers usually kept silent about its positive role inside our body.

Meanwhile, it is large, because carbon dioxide, or carbon dioxide, is an important participant in the respiration process. How does carbon dioxide affect our body and how is it useful?

Carbon dioxide in the human body

When we inhale, our lungs fill with oxygen, while carbon dioxide is formed in the lower part of the organ - the alveoli. At this moment, an exchange occurs: oxygen enters the blood, and carbon dioxide is released from it. And we exhale.

Breathing repeated about 15-20 times per minute triggers all vital functions of the body,
and the carbon dioxide generated in this process immediately affects many vital functions. How is carbon dioxide useful for humans?

CO 2 regulates the excitability of nerve cells, affects the permeability of cell membranes and enzyme activity, stabilizes the intensity of hormone production and the degree of their effectiveness, participates in
in the process of protein binding of calcium and iron ions.

In addition, carbon dioxide is the end product of metabolism. By exhaling, we remove unnecessary components that arise during metabolism and cleanse our body. The metabolic process is continuous, so we need to constantly remove end products.

It is important not only the presence, but also the amount of CO 2 in the body. The normal content level is 6-6.5%. This is enough for all the “mechanisms” in the body to work correctly and for you to feel good.

A lack or excess of carbon dioxide in the body leads to two conditions: hypocapnia
And hypercapnia.

Hypocapnia- this is a lack of carbon dioxide in the blood. Occurs when deep, rapid breathing occurs when the body releases too much carbon dioxide. For example, after intense sports. Hypocapnia may lead to mild dizziness or loss of consciousness.

Hypercapnia- This is an excess of carbon dioxide in the blood. Occurs in rooms with poor ventilation. If the concentration of CO 2 in the room exceeds the norm, then its level in the body will also become higher.

This may cause headaches, nausea and drowsiness. Hypercapnia occurs especially often in winter among office workers, as well as in long queues. For example, at the post office or at the clinic.

An excess of carbon dioxide can also occur in extreme situations, for example when holding your breath under water.

We will tell you more about the consequences of hypercapnia and ways to combat it in one of the following articles. Today we will focus on hypocapnia and its treatment.

As mentioned above, carbon dioxide affects many processes in our body, which is why it is so important that its level is kept within normal limits. And one type of breathing exercises will help bring the CO 2 content back to normal.

But such phrases do not look very convincing, especially when we want to solve a specific problem or get rid of a certain disease. Let's figure out how carbon dioxide helps
and breathing exercises in specific cases.

Let's start with the fact that during training on a simulator or standard breathing practices, a person's blood is saturated with carbon dioxide, the blood supply to all organs improves, as a result of which a positive effect appears.

The body begins to heal itself from the inside, having different effects on different groups of organs. For example, improving blood supply and increasing CO 2 levels leads to normalization of the tone of the smooth muscles of the stomach and intestines. This has a positive effect on the functioning of the intestines, restores its basic functions and helps in the fight against various diseases of the gastrointestinal tract.

Carbon dioxide also has a positive effect on membrane permeability, which normalizes the excitability of nerve cells. This helps to cope with stress more easily, avoid nervous overexcitation and, as a result, relieves insomnia and migraines.

CO 2 also helps with allergies: carbon dioxide reduces the viscosity of the cytoplasm that fills the cells. This has a positive effect on metabolism and increases the activity of the body's defense systems.

Defense systems are also activated in the fight against viral diseases. Regular breathing exercises help to avoid acute respiratory viral infections and acute respiratory infections by increasing local immunity.

Carbon dioxide helps with bronchitis and asthma: it reduces vascular spasm, which allows you to get rid of phlegm and mucus in the bronchi, and, accordingly, the disease itself.

Due to the normalization of the lumen of blood vessels, patients with hypotension also improve. Breathing exercises help them gradually cope with low blood pressure.

Despite all the positive changes that occur in our body when carbon dioxide levels are normalized, it is not a panacea for all diseases. It is rather the help that you provide to your body by doing breathing exercises.

Believe me, after several months of exercise, your body will definitely thank you with good health. Before you start exercising, be sure to check the level of CO 2 in your body and make sure that breathing exercises or the Samozdrav simulator will help with your illness.

And in order not to miss material about hypercapnia and receive our new articles by email, on our blog. We will send materials once a week.

Soda, volcano, Venus, refrigerator - what do they have in common? Carbon dioxide. We have collected for you the most interesting information about one of the most important chemical compounds on Earth.

What is carbon dioxide

Carbon dioxide is known mainly in its gaseous state, i.e. as carbon dioxide with the simple chemical formula CO2. In this form, it exists under normal conditions - at atmospheric pressure and “ordinary” temperatures. But at increased pressure, above 5,850 kPa (such as, for example, the pressure at a sea depth of about 600 m), this gas turns into liquid. And when strongly cooled (minus 78.5°C), it crystallizes and becomes so-called dry ice, which is widely used in trade for storing frozen foods in refrigerators.

Liquid carbon dioxide and dry ice are produced and used in human activities, but these forms are unstable and easily disintegrate.

But carbon dioxide gas is ubiquitous: it is released during the respiration of animals and plants and is an important part of the chemical composition of the atmosphere and ocean.

Properties of carbon dioxide

Carbon dioxide CO2 is colorless and odorless. Under normal conditions it has no taste. However, if you inhale high concentrations of carbon dioxide, you may experience a sour taste in your mouth, caused by the carbon dioxide dissolving on mucous membranes and in saliva, forming a weak solution of carbonic acid.

By the way, it is the ability of carbon dioxide to dissolve in water that is used to make carbonated water. Lemonade bubbles are the same carbon dioxide. The first apparatus for saturating water with CO2 was invented back in 1770, and already in 1783 the enterprising Swiss Jacob Schweppes began industrial production of soda (the Schweppes brand still exists).

Carbon dioxide is 1.5 times heavier than air, so it tends to “settle” in its lower layers if the room is poorly ventilated. The “dog cave” effect is known, where CO2 is released directly from the ground and accumulates at a height of about half a meter. An adult, entering such a cave, at the height of his growth does not feel the excess of carbon dioxide, but dogs find themselves directly in a thick layer of carbon dioxide and are poisoned.

CO2 does not support combustion, which is why it is used in fire extinguishers and fire suppression systems. The trick of extinguishing a burning candle with the contents of a supposedly empty glass (but in fact carbon dioxide) is based precisely on this property of carbon dioxide.

Carbon dioxide in nature: natural sources

Carbon dioxide is formed in nature from various sources:

• Respiration of animals and plants.
  Every schoolchild knows that plants absorb carbon dioxide CO2 from the air and use it in the processes of photosynthesis. Some housewives try to make up for shortcomings with an abundance of indoor plants. However, plants not only absorb, but also release carbon dioxide in the absence of light - this is part of the respiration process. Therefore, a jungle in a poorly ventilated bedroom is not a good idea: CO2 levels will rise even more at night.
• Volcanic activity.
  Carbon dioxide is part of volcanic gases. In areas with high volcanic activity, CO2 can be released directly from the ground - from cracks and fissures called mofets. The concentration of carbon dioxide in the mofet valleys is so high that many small animals die when they get there.
• Decomposition of organic matter.
  Carbon dioxide is formed during the combustion and decay of organic matter. Large natural emissions of carbon dioxide accompany forest fires.

Carbon dioxide is “stored” in nature in the form of carbon compounds in minerals: coal, oil, peat, limestone. Huge reserves of CO2 are found in dissolved form in the world's oceans.

The release of carbon dioxide from an open reservoir can lead to a limnological catastrophe, as happened, for example, in 1984 and 1986. in lakes Manoun and Nyos in Cameroon. Both lakes were formed on the site of volcanic craters - now they are extinct, but in the depths the volcanic magma still releases carbon dioxide, which rises to the waters of the lakes and dissolves in them. As a result of a number of climatic and geological processes, the concentration of carbon dioxide in waters exceeded a critical value. A huge amount of carbon dioxide was released into the atmosphere, which went down the mountain slopes like an avalanche. About 1,800 people became victims of limnological disasters on Cameroonian lakes.

Artificial sources of carbon dioxide

The main anthropogenic sources of carbon dioxide are:

• industrial emissions associated with combustion processes;
• automobile transport.

Despite the fact that the share of environmentally friendly transport in the world is growing, the vast majority of the world's population will not soon have the opportunity (or desire) to switch to new cars.

Active deforestation for industrial purposes also leads to an increase in the concentration of carbon dioxide CO2 in the air.

CO2 is one of the end products of metabolism (the breakdown of glucose and fats). It is secreted in the tissues and transported by hemoglobin to the lungs, through which it is exhaled. The air exhaled by a person contains about 4.5% carbon dioxide (45,000 ppm) - 60-110 times more than in the air inhaled.

Carbon dioxide plays a large role in regulating blood flow and respiration. An increase in CO2 levels in the blood causes the capillaries to dilate, allowing more blood to pass through, which delivers oxygen to the tissues and removes carbon dioxide.

The respiratory system is also stimulated by an increase in carbon dioxide, and not by a lack of oxygen, as it might seem. In reality, the lack of oxygen is not felt by the body for a long time and it is quite possible that in rarefied air a person will lose consciousness before he feels the lack of air. The stimulating property of CO2 is used in artificial respiration devices: where carbon dioxide is mixed with oxygen to “start” the respiratory system.

Carbon dioxide and us: why CO2 is dangerous

Carbon dioxide is necessary for the human body just like oxygen. But just like with oxygen, an excess of carbon dioxide harms our well-being.

A high concentration of CO2 in the air leads to intoxication of the body and causes a state of hypercapnia. With hypercapnia, a person experiences difficulty breathing, nausea, headache, and may even lose consciousness. If the carbon dioxide content does not decrease, then oxygen starvation occurs. The fact is that both carbon dioxide and oxygen move throughout the body on the same “transport” - hemoglobin. Normally, they “travel” together, attaching to different places on the hemoglobin molecule. However, increased concentrations of carbon dioxide in the blood reduce the ability of oxygen to bind to hemoglobin. The amount of oxygen in the blood decreases and hypoxia occurs.

Such unhealthy consequences for the body occur when inhaling air with a CO2 content of more than 5,000 ppm (this can be the air in mines, for example). To be fair, in ordinary life we ​​practically never encounter such air. However, a much lower concentration of carbon dioxide does not have the best effect on health.

According to some findings, even 1,000 ppm CO2 causes fatigue and headaches in half of the subjects. Many people begin to feel stuffiness and discomfort even earlier. With a further increase in carbon dioxide concentration to 1,500 – 2,500 ppm critically, the brain is “lazy” to take the initiative, process information and make decisions.

And if a level of 5,000 ppm is almost impossible in everyday life, then 1,000 and even 2,500 ppm can easily be part of the reality of modern man. Ours showed that in rarely ventilated school classrooms, CO2 levels remain above 1,500 ppm much of the time, and sometimes jump above 2,000 ppm. There is every reason to believe that the situation is similar in many offices and even apartments.

Physiologists consider 800 ppm to be a safe level of carbon dioxide for human well-being.

Another study found a link between CO2 levels and oxidative stress: the higher the carbon dioxide level, the more we suffer from oxidative stress, which damages our body's cells.

Carbon dioxide in the Earth's atmosphere

There is only about 0.04% CO2 in the atmosphere of our planet (this is approximately 400 ppm), and more recently it was even less: carbon dioxide crossed the 400 ppm mark only in the fall of 2016. Scientists attribute the rise in CO2 levels in the atmosphere to industrialization: in the mid-18th century, on the eve of the Industrial Revolution, it was only about 270 ppm.