Evaluation of Heat Stress in Dry Cleaner Units: A Case Study in Qom, Iran

Background & Aims of the Study: Nowadays, heat stress is one of the most harmfulphysical agents in workplaces. According to the consequences of heat stress and have noinformation about it in Qom dry cleaner units, Iran, this study have been designed toevaluate the heat stress among workers of dry cleaner units in Qom province of Iran, in Jul-Aug 2011.Materials & Methods: This cross-sectional study was conducted in 113 units of active drycleaner units. WBGT (Wet Bulb Globe Temperature) index was selected for heat stressevaluation. In order to measure the requisite parameters, WBGT meter made of CasellaCompany had been used according to ISO 7243. Data had been analyzed according toOccupational Exposure Limits (OELs) with SPSS V.16, using analysis of variance,independent T and LSD tests.Results: The average of WBGT index in Qom dry cleaner units of Iran were 28.98±1.64°C. The average of WBGT index in 66.4% of units was up to 28°C. The average of relativehumidity was 42.86%, the average of wet bulb temperature and globe temperature were25.56°C and 36.72°C, respectively. The findings showed a significant correlation betweenthe average of WBGT index and the standard recommendation level (p<0.0001). In drycleaner units with less than 10 m2 area, heat stress was higher than other units significantly(p<0.05).Conclusions: Heat stress in many dry cleaner units in Qom, Iran, was more thanrecommended OELs. Because of wet bulb and globe temperature in units were high value,the most important measures to heat controls, are technical engineering controls such asradiation shield, insulation on boilers and modify the cooling systems.

کلیدواژه ها:

Heat stress ، WBGT ، Workers ، Occupationalexposure ، Iran