Comparing the Association between Wet Bulb Globe Temperature (WBGT) and Heat Stress Score Index (HSSI) Thermal Indices with Physiological Parameters in a Melting Plant
Abstract
Introduction: Exposure to heat is one of the workplace risk factors, which may lead to thermal strain, such as rising heart rate and body temperature. To have the best association between a heat stress indices and physiological parameters have always been a major concern for those studying the subject. This study aims to compare the association of two heat stress indices with physiological parameters.
Method: This cross-sectional study was conducted on 54 acclimatized mail subjects working in a steel complex in May 2014. After enrolling individuals based on inclusion criteria, HSSI and WBGT heat indices and physiological parameters were recorded at three times (10 am, 12 pm and 3pm) during their work shift. Then the relationship between physiological parameters and the calculated indices were determined.
Discussion: The study population had a mean age of 29.3±4.2 years. The average value of the WBGT index was 27.3 ± 2.9°C and HSSI index was 22.7±3.6. The average relative humidity and air velocity was 35.9 ±1.9% and 1.5±0.4 m/s respectively. The correlation between WBGT and tympanic temperature was statistically significant (P≤0.01). However the HSSI was not significantly correlated to tympanic temperature (p=0.37). Correlation coefficient between WBGT and HSSI with heart rate was 0.458 and 0.191 respectively.
Result: WBGT is likely to offer a better assessment of thermal stress in comparison to HSSI in melting industry workers.
Dehghan H, Mortazavi SB, Jafari MJ, Maracy MR. Comparision betwen cardiac strain of normal weight and overweight workers in hot and humid weather of the south of Iran. Health System Research 2012; 8(5): 866-75.
Golbabaei F, Omidvari M. Man and thermal environment. Tehran: Tehran University Press; 2008.
Kjellstrom T, Lemke B, editors. Loss of worker productivity due to projected climate change. IOP Conference Series: Earth and Environmental Science; 2009: IOP Publishing.
Epstein Y, Moran DS. Thermal comfort and the heat stress indices. Industrial Health 2006;44(3): 388-98.
Dehghan H. The design of screening method for primary evaluation of thermal risk based on observation and subjective feeling workers under field conditions in center and south parts of Iran, PhD thesis, Tarbiat Modares University, Tehran, Iran, 2012.
ASHREA. Fundamental hand book physiological principal for comfort and health. ASHREH; 1985.
Brake R, Bates G. A valid method for comparing rational and empirical heat stress indices. Ann Occup Hyg 2002; 46(2):165-74.
Dehghan H, Mortazavi SB, Jafari MJ, Maraci MR, Khavanin A. Construction and validation of a heat strain score index with structural equation modeling. Health Sys Res 2011; 7(2): 1-18.
Parsons K. Heat stress standard ISO 7243 and its global application. Indus Health 2006; 44(3):368-79.
NIOSH. Criteria for a recommended standard: Occupational exposure to hot environments (Revised Criteria 1986). Washington DC, USA, April 1986.
Moran DS, Shitzer A, Pandolf KB. A physiological strain index to evaluate heat stress. Am J Physiol-Regulatory, Integ Compar Physiol 1998;275(1):R129-R34.
Moran D, Shapiro Y, Epstein Y, Matthew W, Pandolf K. A modified discomfort index (MDI) as an alternative to the wet bulb globe temperature (WBGT). Environmental Ergonomics VIII, Hodgdon JA, Heaney JH, Buono MJ (Eds). 1998:77-80.
ISO 10551. Ergonomics of the thermal environment— Assessment of the influence of the thermal environment using subjective judgement scales. International Standards Organisation. Geneva2004.
Malchaire J, Gebhardt HJ, Piette A. Strategy for Evaluation and Prevention of Risk Due to Work in Thermal Environments. Ann occup Hyg 1999; 43(5): 367-376.
Falahati M, Alimohammadi I, Farshad A, Zokaii M, Sardar A. Evaluating the reliability of WBGT and P4SR by comparison to core body temperature. Iran Occup Health 2012;9(3): 22-31.
Hostler D, Gallagher Jr M, Goss FL, Seitz JR, Reis SE, Robertson RJ, et al. The effect of hyperhydration on physiological and perceived strain during treadmill exercise in personal protective equipment. European J Appl Physiol 2009;105(4):607-13.
Morioka I, Miyai N, Miyashita K. Hot environment and health problems of outdoor workers at a construction site. Industrial Health 2006;44(3):474-80.
Naghibi A. Evaluation of thermal stress on lead and zinc mine and the determine model for predicting the amount of workers tolerating. Tehran, IRAN: Tehran University; 1996.
Haji Azimi E, Khavanin A, Aghajani M, Soleymanian A. Heat stress measurement according to WBGT index in smelters. J Mil Med 2011;13(2):59-64.
Iguchi M, Littmann AE, Chang S-H, Wester LA, Knipper JS, Shields RK. Heat stress and cardiovascular, hormonal, and heat shock proteins in humans. J Athletic Training 2012;47(2):184.
Aliabadi M, Jahangiri M, Arrassi M, Jalali M. Evaluation of heat stress based on WBGT index and its relationship with physiological parameter of sublingual temperature in bakeries of Arak city. Occup Med Quarterly J 2014;6(1):48-56.
Jafari MJ, Hoorfarasat G, Salehpour S, Khodakarim S, Haydarnezhad N. 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. J Saf Promot Injury Preven 2014;2(1):55-64.
Golbabaie F, Monazam Esmaieli MR, Hemmatjou R, Yaaghoub P, Reza G, Hosseini M. Comparing the Heat Stress (DI, WBGT, SW) Indices and the Men Physiological Parameters in Hot and Humid Environment. Iran J Health Environ 2012;5(2):245-52.
Motamedzade M, Azari MR. Heat stress evaluation using environmental and biological monitoring. Pak J Biol Sci 2006;9(3):457-9.
Dehghan H, Mortazavi SB, Jafari MJ, Maracy MR. Evaluation of wet bulb globe temperature index for estimation of heat strain in hot/humid conditions in the Persian Gulf. J Res Med Sci 2012;17(12):1108.
Falahati M, Alimohamadi I, Farshad A, Zokaie M, Sardar A. Evaluation and Validation of Heat Stress Indices in Iranian Oil Terminals. Int J Occup Hyg 2012;4(2):73-7.
Hoorfarasat G, Jafari MJ, Omidi L, Salehpour S, Khodakarim S, Haydarnezhad N. Correlation between heat strain score index and WBGT index with physiological parameters in a glass manufacturing plant. Int J Occup Hyg 2015; 7(4): 202-208.
Jafari MJ, Norloei S, Omidi L, Khodakarim S, Bashash D, Abdollahi MB. Effects of heat stress on concentrations of thyroid hormones of workers in a foundry industry. Occup Med Quarter J 2016; 7(3): 69-79.
| Files | ||
| Issue | Vol 8 No 1 (2016) | |
| Section | Original Article(s) | |
| Published | 2016-03-05 | |
| Keywords | ||
| Correlation Heat Stress WBGT HSSI Physiological Parameters | ||
| Rights and permissions | |
|
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
