Work load and physiological responses during asbestos removal with protective clothing

Summary The removal of asbestos-containing building materials requires the use of dust-repelling protective clothing and a respirator. The present study was aimed at measuring physiological responses to asbestos removal in actual work situations. The subjects were eight asbestos workers. During the work, the men wore permeable or impermeable clothing along with a powered or non-powered filtering device including a full-face or half-face mask. Environmental parameters, work postures, heart rate (HR), the skin temperature at two sites and the rectal temperature were recorded every minute during work. Perceived exertion, thermal sensation, thermal comfort, and skin wetness were rated by the subjects. The ambient temperature at work sites ranged from 19° to 37.5°C and relative humidity, from 21% to 50%. The mean HR ranged from 101 to 141 beats min^–1. The calculated (from HR measurements) average oxygen consumption (VO₂) varied from 0.9 to 1.9 1 min^–1 , which corresponded to 27%–60% of the maximal value. The peak rectal temperature and the highest mean of two measurements of skin temperature were 37.7° ± 0.3° C and 34.4° ± 0.9°C, respectively. The sweat rate varied from 162 to 583 g h^–1. Poor work posture was common during asbestos removal. The arms were elevated over shoulder level for 35% of the work time. During the work the mean physiological strain was considered to be moderate, with some heavy peak loads being registered. The increases in HR and the thermal responses seemed to be due primarily to the use of simple, nonpowered hand tools, which often required the performance of heavy manual work with the arms held above shoulder level, and less to the protective clothing used. The heat strain during asbestos removal was not excessive because most of the work was done under thermoneutral conditions, and a rest pause of 10–15 min every hour also decreased the thermal strain during work. Improvements in work methods and tools are needed to reduce the peak loads and postural strain experienced during asbestos removal.This study was financially supported by the Finnish Work Environmental Fund