Validation of a temperature-humidity index (Humidex) in evaluating heat stress at a tile factory in Iran.

BACKGROUND: Several heat indices have been developed in industrial health, but each has its limitations. OBJECTIVE: The objective of this article is to determine the validity and applicability of a temperature-humidity index, named Humidex compared with the Standard Wet-Bulb Globe Temperature (WBGT) index (ISO 7243). METHOD: This cross-sectional study was conducted in the summer of 2019, in a tile factory in the west of Iran. 59 measurements were performed in 8 different workstations. Environmental parameters including natural wet bulb temperature (T_nw), dry bulb temperature (T_a), globe bulb temperature (T_g), and heat stress (WBGT) were measured. Humidex was calculated according to an equation. SPSS software (version 16) was used for data analysis. RESULTS: There was a high correlation between Humidex and WBGT in the estimation of heat stress (R=0.912, P<0.001). The Kappa Coefficient between Humidex and WBGT was 0.298, P=0.001. CONCLUSION: Humidex is highly correlated with WBGT. Humidex can be used instead of the WBGT index, especially in hot and humid environments. [ABSTRACT FROM AUTHOR]