تحقیقات نظام سلامت (Oct 2021)
Investigating the Relationship between Heat Stress and Strain Indices with Human Productivity in Workers of a Steam Power Plant
Abstract
injuries, losses, and reduced productivity. The aim of this study was to investigate the relationship between heat stress and strain indices with human productivity in workers of a steam power plant. Methods: This descriptive cross-sectional study was performed on 104 workers of a steam power plant in summer season. Two indices of Wet Bulb Globe Temperature (WBGT) and Heat Strain Score Index (HSSI) were used to measure heat stress and strain, respectively. Human productivity was also measured using Hersey and Goldsmit 26-item scale. Data were analyzed using analysis of variance (ANOVA) test and Pearson correlation coefficient. Findings: According to ANOVA results, there was no significant difference in WBGT in three heights of head, waist, and ankle. The highest value of WBGT index was related to the 4th floor boiler unit (27.3 ± 5.6) and the lowest value was related to the administrative unit (16.9 ± 3.5). The maximum and minimum values of HSSI were obtained for the 3th floor boiler unit (27.2 ± 0.4) and workshop facilities (12.0 ± 3.0), respectively. The highest and lowest values of human productivity was related to the welding (97.0 ± 25.9) and boiler (28.5 ± 2.8) units, respectively. The results of ANOVA analysis showed that the values of WBGT, HSSI indices, and productivity subscales in different units were significantly different (P < 0.05). Pearson correlation coefficient analysis showed that there was a significant inverse relationship between productivity and its subscales with the amount of heat stress and strain (P < 0.05). Conclusion: There is a negative relationship between productivity, heat stress, and strain. Therefore, to protect workers' health and productivity, precautionary measures should be taken, including an appropriate rest-work ratio, short working hours, fluid replacement, and engineering controls such as the use of efficient cooling methods such as air conditioning, fan, or cooling clothing.
