Applicability of Universal Thermal Climate Index (UTCI) in occupational heat stress assessment: a case study in brick industries

The present study aimed to investigate the applicability of Universal ThermalClimate Index (UTCI) as an innovative and science-based index in public health researches,in occupational heat stress assessment. All indoor and outdoor workers (200 people) ofBrick industries of Shahroud, Iran participated in the research. First, the environmentalvariables such as air temperature, wet-bulb temperature, globe temperature, air velocityand relative humidity were measured; then UTCI and WBGT (wet-bulb globe temperature)indices were calculated. Simultaneously, physiological parameters including systolic anddiastolic blood pressure, oral temperature, skin temperature, tympanic temperature andheart rate of workers were measured. UTCI and WBGT indices were 34.2 ± 2°C, 21.8 ± 1.8°Cin the outdoor environments and 38.1 ± 4.4°C, 24.7 ± 3.3°C at the indoor environments,respectively. There were the weak inverse relationships between UTCI and WBGT indices atthe outdoor environments and physiological responses such as systolic blood pressure, anddiastolic blood pressure. However, there were no similar results for indoor environments.The significant relationships were found between UTCI and WBGT at both indoor and outdoorenvironments. Both UTCI and WBGT indices are suitable for assessing the occupational heatstress. Although, UTCI index seems more appropriate for heat stress assessment in theenvironments with low humidity and air velocity.