Thus, one of the factors affecting the feeling of a lack of indoor air can be increased carbon dioxide concentration. So, is because of what occurs in human feeling of lack of air in the room: Because of low oxygen or high concentrations of carbon dioxide? If we analyze the the above example, if a person critical to the decrease of oxygen level even up to 18%, and increased carbon dioxide levels up to 2%? As we know the concentration of oxygen in the highlands of the planet is less than 20.9%, the difference in the level of oxygen at sea level. may amount to several percent, depending on altitude. Nevertheless, people live and work in such conditions, as well as we who live in the plains of the planet. Leaving go skiing in the alpine area, people can sometimes experience some discomfort due to the lower concentration of oxygen in the air of high mountains, but know that these feelings pass quickly and are connected As a rule, the lower the atmospheric pressure.

So in the article "FEATURES OF PULMONARY FUNCTIONAL STATUS KROVOOBRASCHENIYAI MIOKARDAPRI SHORT-TERM ADAPTATION TO HIGH ALTITUDE" published in the Journal of KRSU / 1, 2002 ( authors IS Sabirov – candidate. med. Science, AS AS Sadykov – R. et al., INC. Sarybaev-candidate. med. Sciences) concluded that "pulmonary hypertension that develops in a short stay in the highlands, mainly due to pulmonary vasoconstriction and is reversible. "Journal of Ecology Russian Journal 9, 2008 provides the following data:" The graphs measuring the level of CO2 and O2 in the classroom, clearly show that even in a time when CO2 levels increased to 1650 ppm or 0.165% (this peak is in the end the lesson), the oxygen level was kept within the 20.15% that is quite normal for a human level, where his condition is not change.