RISK FACTORS INDUCED BY INSULATED MINE SELF-RESCUERS ON CHEMICALLY RELATED OXYGEN AFFECTING ON RESPIRATORY COMFORT
The high methane hazard of coal mines, despite safety measures, has led to a change in the structure of fatal injuries. More than 54% of miners die from carbon monoxide poisoning, which predetermines the need to study risk factors when activating a mine selfrescuer with chemically bound oxygen. These factors include normobaric hyperoxia, "nitrogen hazard", hyperoxic hypoxia, high temperature and dryness of the inhaled gas mixture, increasing hypercapnia, increased resistance to ventilation. The current situation predetermined the need to study the tolerability of physical loads when activating the mine self-rescuer. 18 healthy volunteers were examined. The obtained results demonstrated that already from 15 minutes the volume fraction of carbon dioxide begins to increase, indicating the formation of a "break point" of the mechanisms of voluntary control of breathing. The volume fraction of oxygen in the respiratory bag reaches its maximum values by the 25-35 minute and ranges from 96.0 to 97.3% v/v at a barometric pressure of 770.5 ± 1.70 mm Hg. Resistance to breathing during inspiration and expiration during physical exertion reached 77.5 ± 9.95 mm WG and 85.0 ± 9.06 mm WG, respectively, on the 30th minute. At the 40th minute, the aerodynamic resistance to ventilation reaches its maximum value and this zone can be considered as a kind of "reference point", with which deactivating of the self-rescuer due to severe dyspnea begins. Threat also consists in a decrease in the percentage of nitrogen in the gas mixture. Already from the level of 1.7 volume percent of the nitrogen content in the respiratory bag, the mine self-rescuer is deactivated under physical exertion. The main reason for stopping work is the lack of GDS for inhalation, which is probably due to micro-teleclactisation of the lungs and compensatory hyperventilation. Thus, the traditional system of training miners for the use of self-rescuers in emergency conditions does not allow miners to adequately compensate for the effects of negative factors associated with activation of the self-rescuer.