Abstract

Aims: The aim of the present research was to assess the occupational heat stress using WBGT and ESI indexes in outdoor workplaces of the Qom province as a hot-arid climate based on meteorological data. Methods: This cross-sectional study was performed based on meteorological data of the Qom meteorological stations in 2013 (from June to September). Environmental parameters including dry temperature, dry soil surface temperature, solar radiation, relative humidity and air velocity were measured every 10 minutes from 7 am to 7 pm. The WBGT index based on the formula provided by the Australian Meteorological Organization was prepared and the ESI index was calculated based on the formula proposed by Moran. Results: The mean WBGT and ESI were 27°C and 25.58°C, respectively. The maximum value of WBGT (28.59 °C) was recorded between 15 pm to 16 pm and the maximum value of ESI (27.49 °C) was measured between 14 and 15 pm. According to the independent sample-T-test, ESI and WBGT was significantly higher in July than its values in the other months (p<0.05). Conclusion: The weather conditions in hot seasons are not suitable for outdoor workplaces with heavy workloads; and the administrative and engineering control measures should be considered seriously.