| Popis: |
One of the trends for ensuring the safe operation of sealed inhabited objects is the creation of hypoxic gas environments, suitable for breathing and reducing the risk of fires. The aim was to test the effect of normobaric hypoxic environments of various compositions on a person, to select envitonments that are potentially applicable to improve fire safety of inhabited sealed objects. Methods. The randomized controlled study involved 60 men aged 20-55 years, divided into 3 groups (20 people each) depending on the composition of the gas environment in which they were kept for 4 hours. The composition of the tested gas environments: No. 1 - oxygen = 1617 %, nitrogen - the rest; No. 2 - oxygen = 14-15 %, nitrogen - the rest; No. 3 - oxygen = 14 %, argon = 35 %, nitrogen - the rest. The functional state of the subjects was assessed using complaint forms, physiological criteria and functional tests. Results. The most pronounced negative changes in subject's functionality were found when the subjects were in the gas environment No. 2, and the most of the indicators showed significant (p < 0.05-0.001) differences compared to other groups. The revealed facts indicate the inadmissibility of using such environments. The stay in gas environments No. 1 and No. 3 was accompanied by comparable and acceptable changes in the functional state of the subjects, despite the significantly lower oxygen content in the argon-containing medium (No. 3). Conclusions. 1. To increase the fire safety of inhabited pressurized objects, it is permissible to use gas environments No. 1 and No. 3. 2. Addition of argon to hypoxic environments reduces the negative effects of oxygen deficiency, which makes it possible to use gas environments with a higher degree of hypoxia and, therefore, more effective for ensuring fire protection of inhabited sealed objects. |
