Respirator physiological effects under simulated work conditions.
Bansal-S; Harber-P; Yun-D; Liu-D; Liu-Y; Wu-S; Ng-D; Santiago-S
J Occup Environ Hyg 2009 Apr; 6(4):221-227
This study compared the physiological impacts of two respirator types in simulated work conditions. Fifty-six subjects included normal volunteers and persons with mild respiratory impairments (chronic rhinitis, mild COPD, and mild asthma). Respiratory parameters and electrocardiogram were measured using respiratory inductive plethysmography while performing eight work tasks involving low to moderate exertion using two respirators: (1) a dual cartridge half face mask (HFM) respirator, and (2) the N95. Mixed model regression analyses evaluating the effect of task and respirator type showed that task affected tidal volume, minute ventilation, breathing frequency and heart rate; all were greater in heavier tasks. Although respirator type did not affect respiratory volume parameters and flow rates, the HFM led to increase in the inspiratory time, reduction of the expiratory time, and increase in the duty cycle in comparison with the N95. The magnitude of differences was relatively small. The results suggest that most individuals, including persons with mild respiratory impairments, will physiologically tolerate either type of respirator at low to moderate exertion tasks. However, because effective protection depends on proper use, differences in subjective effect may have greater impact than physiological differences. Using respirators may be feasible on a widespread basis if necessary for maintaining essential services in the face of widespread concern about an infectious or terrorist threat.
Occupational-exposure; Occupational-hazards; Statistical-analysis; Respirators; Respiratory-equipment; Respiratory-protective-equipment; Respiratory-rate; Ventilation; Personal-protective-equipment; Protective-equipment; Workplace-studies; Work-environment; Work-practices; Infection-control; Physiological-factors; Physiological-testing;
Author Keywords: Physiology; Plethysmography; Pulmonary ventilation; Respirator; Terrorism
Occupational and Environmental Medicine, Department of Family Medicine, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, CA 90024
Journal of Occupational and Environmental Hygiene
University of California, Los Angeles