Comparison of Correlation between Wet Bulb Globe Temperature, Physiological Strain Index and Physiological Strain Index Based on Heart Rate with Heart Rate and Tympanic Temperature on Workers in a Glass Factory

Abstract

Backgrounds and Objective: Heat stress is one of the main and the most common problems in the work environments. Extreme heat exposure can cause different clinical symptoms, including headache, nausea, vomiting. The aim of this study is to compare the correlation of Wet Bulb Globe Temperature, Physiological Strain Index and Physiological Strain Index based on heart rateheat stress indices with tympanic temperature and heart rate among the workers of a glass factory. Materials and Methods: This cross- sectional study was conducted in a glass factory located in Tehran. 72 male subjects were participated in the study. Atmospheric parameters including dry temperature, natural wet bulb temperature and globe temperature were measured to determine the heat stress indices. Tympanic temperature and heart beat rates were also measured. The data were statistically analyzed using the Pearson and Spearman correlation as well as the linear regression tests. Results: The correlation between tympanic temperature and heart rate with heat stress indices was significant (p-value<0.05). The poly-nominal correlation (R2) between Wet Bulb Globe Temperature Index with heart rate and tympanic temperature was 0.208 and 0.214 respectively. This correlation between Physiological Strain Index with heart rate and tympanic temperature was 0.423 and 0.701 respectively. The correlation between Physiological strain index based on heart rate with heart rate and tympanic temperature was 0.579 and 0.068 respectively. Conclusion: The Physiological Strain Index heat stress index had higher correlation with measured physiological parameters in this study. REFERENCES 1. Sung T-I, Wu P-C, Lung S-C, Lin C-Y, Chen M-J, Su H-J. Relationship between heat index and mortality of 6 major cities in Taiwan. Science of the total environment. 2013;442:275-81.2. Brahmapurkar P, Ashok G, Sanjay PZ, Vaishali KB, Gautam MK, Subhash B, et al. Heat Stress and its Effect in Glass Factory Workers of Central India. International Journal of Engineering Research & Technology. 2012;1(8):9-12.3. Dehghan H, Habibi E, Khodarahmi B, Yousefi HA, Hasanzadeh A. The relationship between observational–perceptual heat strain evaluation method and environmental/physiological indices in warm workplace. Pakistan Journal of Medical Sciences. 2013;29(1).4. knottnerus JA. presentation of advisory letter heat stress in the workplace :Health Council of Netherlands; November 24, 2008.5. Dehghan H, Mortazavi S, Jafari M, Maracy M, Jahangiri M. The evaluation of heat stress through monitoring environmental factors and physiological responses in melting and casting industries workers. International Journal of Environmental Health Engineering. 2012;1(1):21.6. Falahati M, Alimohammadi I, Farshad A, Zokaei M, Sardar A. Evaluating the reliability of WBGT and P4SR by comparison to core body temperature. Iran Occupational Health. 2012;9(3).7. Pourmahabadian M, Adelkhah M, Azam K. Heat exposure assessment in the working environment of a glass manufacturing unit. Iranian Journal of Environmental Health Science & Engineering. 2008;5(2).8. Golbabaie F, Monazam Esmaieli MR, Hemmatjou R, Gholam Reza Pour Y, Hosseini M. Comparing the Heat Stress (DI, WBGT, SW) Indices and the Men Physiological Parameters in Hot and Humid Environment. Iranian Journal of Health and Environment. 2012;5(3):245-52.9. Dehghan Shahreza H, Mortazavi SB, Jafari MJ MM, Khavanin A, Jahangiri M, . Combined application of Wet Bulb Globe Temperature (WBGT) and Physiological strain index based on heart rate (PSIHR) in hot wet and hot dry conditions: A guide to better estimation of the heat strain. Seven Congress of Occupational Safety and Health; Iran2011. p. 1-11.10. Golbabaei F, Omidvar M, . man thermal environment. second, editor: university of tehran; 2008.11. Lee J-Y, Nakao K, Takahashi N, Son S-Y, Bakri I, Tochihara Y. Validity of Infrared Tympanic Temperature for the Evaluation of Heat Strain While Wearing Impermeable Protective Clothing in Hot Environments. Industrial health. 2011;49(6):714-25.