Physiological effects associated with the use of respiratory protective devices. A review.

Abstract

LOUHEVAARA VA. Physiological effects associated with the use of respiratory protective devices: A review. Scand J Work Environ Health 10 (1984) 275-281. Several types of filtering (air-purifying) devices, air-line (supplied-air) apparatus, and self-contained breathing apparatus are used at work. The most important parameters of the respiratory protective devices that affect physical work capacity are additional inspiratory and expiratory breathing resistance, dead space, and weight. The main physiological effects of the respirators are alterations in breathing pattern, hypoventilation, retention of carbon dioxide, and increase in the work of breathing. The undesirable effects are accentuated during heavy physical work, maximal physical work capacity thereby being reduced.Key terms: breathing pattern, gas exchange, heart rate.Attempts to prevent health hazards caused by exposure to contaminated atmospheres usually focus on the technical and organizational arrangements of the work involved. The use of respiratory protective devices, or respirators, is required when other preventive controls prove insufficient. Respirators are usually classified into the following three major categories according to their technical factors and efficiency: (i) filtering (air-purifying) devices, (ii) airline (supplied-air) apparatus, and (iii) self-contained breathing apparatus (50). The first type may be mounted with different dust and/or gas filters. The latter two are atmoshpere-supplying respirators. They can be either demand or pressure-demand (continuous safety pressure inside the face mask) in type. Respirators are generally used with a full-face or a half-face mask.Above all else respirators must be efficient. And their efficiency is highly dependent on the amount and manner of use.Research results have indicated that respirators are available and in use in only 20-30 % of the work phases evaluated as needing them (3, 63). Failure to use a respirator is influenced by psychological factors (44,45,46), by the additional burden on the respiratory organs, and by thermal stress (51).The most important parameters affecting physical work performance with a respirator include the additional inspiratory and/or expiratory breathing resistance involved, the external dead space of the equipment, and the weight of the apparatus. These parameters are presented for different types of respirators in table 1. The values are based on recent measurements with new equipment.In industry filtering devices and air-line apparatus are usually worn in light or moderately heavy tasks of a long duration (41). The use of a self-contained breathing apparatus is limited to short durations in rescue and repair tasks which often require maximal or near maximal physical effort (32,35,43, 65).More scientific information about respirators is needed for both their proper use and technical design. The aim of the present review is to highlight the effects of different factors associated with the use of respirators on breathing pattern, respiratory gas exchange, an...

The Impact of Firefighter Personal Protective Equipment and Treadmill Protocol on Maximal Oxygen Uptake

“…The energy cost of walking and/or running increased by 13-18% with 9.3 kg military PPE (23) and 11-21% with firefighter PPE (7) compared with the energy cost of wearing light clothing. On the other hand, studies have found significant decreases in VO 2max by 10-17% wearing SCBA alone, (24,25) 17-20% with wearing PPE and SCBA. (10,20,26) It seems that increased sub-maximal VO 2 and decreased VO 2max due to the use of PPE are attributable to a number of factors, including heat stress inside the semiimpermeable firefighter PPE, (6,8) a hobbling/binding effect caused by bulkiness and stiffness that can interfere with joint movements and/or the frictional resistance that results from clothing layers sliding over one another, (23) tight SCBA harness impeding ventilation and tidal volume, (24,27) and the direct effect of PPE weight.…”

Medical clearance for respirator use: Sensitivity and specificity of a questionnaire

“…However, wearing these devices can impose physiologic and psychologic stress (Dahlback and Balldin, 1984;Dubois et al, 1990;Harber, 1984;Harber et al, 1996Harber et al, , 1982Hodous, 1986;Louhevaara et al, 1985;Louhevaara, 1984;Morgan, 1983). Although wearing a respirator is well tolerated by most individuals, persons with underlying medical conditions or limited cardiopulmonary reserve may be at risk for adverse health events as a result of use of these devices.…”

Effectiveness of Engineering Controls for Airborne Lead Exposure during Renovation/Demolition of a Commercial Building

“…Previous studies [21,29,33] involving asbestos abatement support these findings of the importance of controls in reducing exposure and requirements of respirators. It has been suggested that respirator use at low occupational exposure concentrations may have a more detrimental effect on the worker than benefit [21,29,[49][50][51]. This study along with others [4,12,14,21,29,52] in abatement of hazardous building materials demonstrates the importance of engineering and work practice controls.…”