Everyone knows how difficult it is to stay in an unventilated area for a long time: headache starts to ache from stuffiness, lethargy, weakness, drowsiness appear … Many people explain this by the lack of oxygen. And they are mistaken.
In the air of a poorly ventilated room, the oxygen content decreases so slightly that it can not have any negative effect on the body. Glory, for example, about the beautiful air of Kislovodsk spread throughout the world. And in this city. located at an altitude of about 1000 meters above sea level, the oxygen content, or rather its partial pressure (the pressure that only this gas molecules produce), is 20 millimeters lower than the mercury column. than in Moscow.
At the foot of Elbrus, where the height is already 2,000 meters, the partial pressure of oxygen is lower than in Moscow by 34 millimeters of mercury. However, everyone who comes to relax, go in for skiing or on a trip to the Elbrus region, rightly admire the healing air of these mountain places. Consequently, the cause of the unpleasant feeling in a stuffy room is not the lack of oxygen.
The culprit is a whole complex of factors, and, in the opinion of many scientists, primarily carbon dioxide.
Experiments show that in an unventilated room where people are. the content of carbon dioxide (CO2) from 0.03% (which can be considered the norm) can increase to 0.3–0.5%, and sometimes even to 0.8%, that is, more than 20 times! This is not surprising – because carbon dioxide is released from exhaled air, and the concentration of carbon dioxide in it reaches 3–4%!
Carbon dioxide is a powerful regulator of the function of respiration and blood circulation. In insignificant quantities, it constantly circulates in the blood, has a stimulating effect on the respiratory and vasomotor centers located in the brain. Reflexively stimulating vasomotor centers, carbon dioxide raises blood pressure. Directly affecting the vessels of the brain, it expands them, and the more active, the greater the concentration of carbon dioxide in the blood. And this, in turn, can cause a feeling of heaviness in the head and a headache, a state of discomfort, and rapid fatigue.
In addition to carbon dioxide, we breathe in so-called harmful impurities, such as carbon monoxide, or carbon monoxide (CO). During the day, a person can release up to 10-15 milliliters of CO into the surrounding atmosphere. And if there are a lot of people in the room and it is not ventilated for a long time, the content of carbon monoxide in the air increases, and it can begin to have a toxic effect on the body. Getting through the lungs into the blood, carbon monoxide molecules are introduced into the red blood cells, displacing oxygen from its compounds with hemoglobin, forming carboxy hemoglobin. This disrupts the transport of oxygen to the tissues, which leads to the development of oxygen deficiency – hypoxia.
In addition, carbon monoxide and violates the process of biological oxidation in the tissues, causing oxygen starvation in the body, why suffer all its systems and disrupt many functions.
Other harmful impurities are also contained in the air of the unvented premises: methane, ammonia, aldehydes, ketones. They enter the air around us from the lungs when breathing (just 149 substances are released with exhaled air), as well as from the surface of the skin, with evaporation of sweat (271 substances).
Aldehydes, for example, by systematically interacting with tissue proteins, can cause pathological changes in the internal organs, primarily respiratory organs. They negatively affect the activity of the central nervous system, and because of this there is increased fatigue, headache.
The inhalation of ammonia, a chemical combination of nitrogen with hydrogen, also leads to adverse effects. In the air of a poorly ventilated room, the content of this substance is, of course, not so significant as to cause a typical picture of poisoning. But the trouble is. that the effects of ammonia on the body increase other harmful impurities in the air. And such a double or triple blow is already quite pronounced: its consequences can be increased respiration, increased blood pressure, irritation of the mucous membranes of the upper respiratory tract, lethargy, drowsiness, decreased performance, headache.
A significant role in the development of adverse changes in the body is also played by the lack of negatively charged ions in the air of unventilated rooms and, conversely, an excess of positive ions. It is already well known that it is negative ions. which are abundant in fresh air, tone up the autonomic nervous system through peripheral receptors embedded in the skin, in the mucous membranes of the upper respiratory tract. As a result, increases vitality, vivacity, good mood.