The Evaluation of Heat Stress Levels among the Workers of Industrial and Traditional Bakeries in Khorramabad, Iran, Using the WBGT Index in Summer 2016

Heat stress is a physiological reaction against environmental high temperatures. This study aimed to investigate the levels of heat stress in industrial and traditional bakeries of Khorramabad, Iran, using the WBGT index. This was a descriptive/analytical/cross-sectional study. Khorramabad has 267 bakeries, 202 of which are industrial bakeries and 65 are traditional bakeries. 88 bakeries were selected using the simple random sampling method. Using the WBGT device, dry, wet, and globe temperatures and humidity were measured. Next, heat stress was measured using the WBGT index from July 22 to August 21 and in the hours (11:30-13) in the workplace of the workers. The results showed that traditional bakeries showed higher levels of heat stress than industrial bakeries. The mean WBGT index was 6.69 ± 44.49 ˚C in traditional bakeries and 1.52 ± 43.38 ˚C in industrial bakeries. The mean WBGT index value shows greater deviation from the permitted levels in traditional bakeries than in industrial bakeries. The analysis of the results using independent t-tests indicated that there were significant differences in terms of environmental wet temperatures, globe temperatures, humidity, and WBGT between industrial and traditional bakeries (p < 0.05). In this study, heat stress levels were higher than standard which is indicative of the worrying condition of heat stress in the bakeries of Khorramabad. Therefore, it is essential to make plans to control heat stress in the bakeries of Khorramabad.