1977 年 31 巻 6 号 p. 657-661
The effect of mouth breathing was studied for the protective method against noxious gas exposure, especially at the sudden accidents with no protective tools.
Ventilatory functions of 22 healthy male volunteers, aged 18 to 36, were examined. The studies were made in normal, nasal and mouth breathing with the bicycle ergometer method.
Oxygen uptake and heart rate per minutes was not significantly different among three different breathings. But respiratory frequency and ventilation volume in mouth breathing showed higher values than those in nasal breathing. This resulted the ventilatory equivalent higher in mouth breathing compared to that in nasal breathing (p<0.05).
The result indicated that the respiratory function in normal or nasal breathing was more efficient among the volunteers than that in mouth breathing alone. This shared the same results with those of mice and rats studied under noxius gas exposure. Possible mechanisms and the application for men were discussed.