Alterations in physiological and perceptual variables during exhaustive endurance work while wearing a pressure-demand respirator.
Wilson-JR; Raven-PB; Zinkgraf-SA; Morgan-WP; Jackson-AW
Am Ind Hyg Assoc J 1989 Mar; 50(3):139-146
The physiological and perceptual effects of respirator wear during exercise were investigated in order to more clearly define the problems associated with long term work and respirator wear. Subjects included 19 fire fighters experienced in the use of respirators and 19 inexperienced individuals. Both physiological and perceptual responses were evaluated during endurance walks to exhaustion both with and without the respirator. Subjects were asked to inform testers when they felt they could continue for only 5 more minutes. Breath by breath metabolic and respiratory data were collected on each subject during these final 5 minutes prior to exhaustion. Use of the respirator resulted in a significant increase in the physiological effort of breathing to overcome the added resistances. The increased effort of breathing increased the perception of exercise intensity and resulted in an earlier termination of exercise, by an average of 13.5 minutes. The continued increase in the maximum pressure measured within the facepiece of the respirator during expiration over the first 30 minutes appeared indicative of an excessive ventilation response, which was confirmed by the significantly greater ventilation volume to aerobic capacity ratio. Individuals who continued for a significantly shorter period of time with the respirator were experiencing respiratory and psychological distress as evidenced by sharp increases in ratings of perceived exhaustion and breathing. The authors conclude that, given current respirator designs, the continuous use of these devices should be limited to a maximum of 30 minutes.
NIOSH-Publication; NIOSH-Grant; Respirators; Respiratory-protective-equipment; Respiratory-protection; Personal-protective-equipment; Endurance-tests; Physiological-response; Firemen; Pulmonary-function; Physical-exercise; Psychological-factors
Physiology Texas College of Osteop'c Med Dept of Physiology Fort Worth, Tex 76107
American Industrial Hygiene Association Journal
Texas College of Osteopathic Medicine, Fort Worth, Texas