The Limitations of WBGT Index for Application in Industries: A Systematic Review
Introduction: The Wet Bulb Globe Temperature (WBGT) is still widely applied as a preliminary tool for evaluating the heat stress. This index faces some limitations not considered yet. This systematic review was conducted aiming at highlighting some limitations for development of the WBGT index.
Method: The present study was organized using more extensive databases: PubMed, Google Scholar, Scientific Information Databases (SID), Elsevier, Web of Science, Scopus, Irandoc, Magiran, and Iran Medex. The used search terms were WBGT index, Heat stress, Thermal Stress, Heat strain, Wet Bulb Globe Temperature, Hot Condition, Occupational Health and Occupational Exposure indices. In this study, 69 articles from 1950 to December 2020 were assessed.
Conclusion: The WBGT index, despite having some advantages, suffers limitations which should be considered for a more accurate estimate of thermal stress. This study pointed to the new limitations; including, the value of WBGT is not clear for persons whose working in a seated posture. In addition, this index is used for adapted people who have used enough water and salt while water and salt are not always available to workers in all hot working environments, hence using this index will come with an error. Also, in heterogeneous environments, if the heat source is at the height of the face and legs, no coefficient would be taken into account for these areas.
2. Moran DS, Epstein Y. Evaluation of the environmental stress index (ESI) for hot/dry and hot/wet climates. Ind Health. 2006;44(3): 399-403.
3. Moran DS, Epstein Y. Evaluation of the environmental stress index (ESI) for hot/dry and hot/wet climates. Ind Health. 2006;44(3): 399-403.
4. Heidari H, Golbabaei F, Shamsipour A, Forushani AR, Gaeini A. Outdoor occupational environments and heat stress in IRAN. J Environ Health Sci Eng. 2015;13(1): 48.
5. Lundgren K, Kuklane K, Gao C, Holmer I. Effects of heat stress on working populations when facing climate change. Ind Health. 2013;51(1): 3-15.
6. Chen ML, Chen CJ, Yeh WY, Huang JW, Mao IF. Heat stress evaluation and worker fatigue in a steel plant. Aiha J. 2003;64(3): 353-359.
7. Wang Y, Meng X, Yang X, Liu J. Influence of convection and radiation on the thermal environment in an industrial building with buoyancy-driven natural ventilation. Energ Build. 014;75: 394-401.
8. Ciriello VM, SH. S. The prediction of WBGT from the Botsball. Am Ind Hyg Assoc J. 1977;38:264-271.
9. Ansari M, Mazloumi A, Abbassinia M, Farhang DS, Hosseini S, Golbabaei F. Heat stress and its impact on the workers'cortisol concentration: A case study in a metal melding industry. Health Saf Work. 2014;4(2): 59-68. [In Persian].
10. Nassiri P, Monazzam MR, Golbabaei F, Abbasinia M, Chavoshi M, Taheri F, Asghari M.. Exposure to heat stress in the workplace: A systematic review. Iran Occup Health. 2018;15(2): 111-128. [In Persian].
11. Hajizadeh R, Golbabaei F, Dehghan SF, Beheshti MH, Jafari SM, Taheri F. Validating the heat stress indices for using in heavy work activities in hot and dry climates. J Res Health Sci. 2016;16(2):90.
12. Nassiri P, Monazzam MR, Golbabaei F, Dehghan SF, Rafieepour A, Mortezapour AR, Asghari M. Application of Universal Thermal Climate Index (UTCI) for assessment of occupational heat stress in open-pit mines. Ind Health. 2017; 55(5): 437-443.
13. Hajizadeh R, Farhang DS, Mehri A, Golbabaei F, Beheshti MH, Haghighatjou H. Heat stress assessment in outdoor workplaces of a hot arid climate based on meteorological data: a case study in Qom, Iran. J Mil Med. 2015.
14. Vatani J, Golbabaei F, Dehghan SF, Yousefi A. Applicability of Universal Thermal Climate Index (UTCI) in occupational heat stress assessment: a case study in brick industries. Ind Health. 2015; 17: 89-95.
15. Monazzam M, Golbabaei F, Hematjo R, Hosseini M, Nassiri P, Farharng-Dehghan S. Evaluation of DI, WBGT, and SWreq/PHS heat stress indices for estimating the heat load on the employees of a petrochemical industry. Int J Occup Hyg. 2014;6(1): 6-10.
16. Heydari H, Golbabaei F, Shamsipour A, Rahimi-Forushani A, Gaeini A. Evaluation of heat stress among farmers using Environmenta l and biological monitoring: a study in north of Iran. Int J Occup Hyg. 2015;7(1): 1-9.
17. Heidari H, Rahimifard H, Mohammadbeigi A, Golbabaei F, Sahranavard R, Shokri Z. Validation of air enthalpy in evaluation of heat stress using wet bulb globe temperature (WBGT) and body core temperature: A case study in a hot and dry climate. Health Saf Work. 2018;8(1): 81-92. [In Persian].
18. Kakaei H, Omidi F, Ghasemi R, Sabet MR, Golbabaei F. Changes of WBGT as a heat stress index over the time: A systematic review and meta-analysis. Urban Clim. 2019;27: 284-292.
19. Hamerezaee M, Dehghan SF, Golbabaei F, Fathi A, Barzegar L, Heidarnejad N. Assessment of semen quality among workers exposed to heat stress: a cross-sectional study in a Steel Industry. Saf Health Work. 2018;9(2): 232-235.
20. Heidari HR, Golbabaei F, Arsang Jang S, Shamsipour AA. Validation of humidex in evaluating heat stress in the outdoor jobs in arid and semi-arid climates of Iran. Health Saf Work. 2016;6(3): 29-42. [In Persian].
21. Mazloumi A, Golbabaei F, Khani SM, Kazemi Z, Hosseini M, Abbasinia M, Dehghan SF. Evaluating effects of heat stress on cognitive function among workers in a hot industry. Health Promot Perspect. 2014;4(2): 240-246.
22. Teimori G, Monazzam MR, Nassiri P, Golbabaei F, Dehghan SF, Ghannadzadeh MJ, Asghari M. Applicability of the model presented by Australian Bureau of Meteorology to determine WBGT in outdoor workplaces: A case study. Urban Clim. 2020;32:100609.
23. Heidari H, Golbabaei F, Shamsipour A, Forushani AR, Gaeini A. Consistency between sweat rate and wet bulb globe temperature for the assessment of heat stress of people working outdoor in arid and semi-arid regions. Int J Occup Environ Med. 2018;9(1): 1-9.
24. Hajizadeh R, Farhang Dehghan S, Golbabaei F, Jafari SM, Karajizadeh M. Offering a model for estimating black globe temperature according to meteorological measurements. Meteorol Appl. 2017;24(2): 303-307.
25. Golbabaei F, Rostami Aghdam Shendi M, Monazzam M, Hosseini M. Investigation of heat stressbased on WBGT index and its relationship with physiological parameters among outdoor workers of Shabestar city. J Health Saf Work. 2015;5(2): 85-94. [In Persian].
26. Epstein Y, Moran DS. Thermal comfort and the heat stress indices. Ind Health. 2006;44(3): 388-398.
27. Yaglou C, Minaed D. Control of heat casualties at military training centers. Arch Ind Health. 1957;16(4): 302-316.
28. Golbabaei F, Monazzam MM, Hematjo R, M. H, Farhang-Dehghan S. The assessment of heat stress and heat strain in pardis petrochemical complex, Tehran, Iran. Int J Occup Hyg. 2013;5(1): 6-11.
29. Golbabaei F, Panjali Z, Borhani M, Rahmani A, Afzali M, Asghari M. The effect of environmental factors on job Performance using manual and mental tests. J Health Saf Work. 2014;4(2): 79-92.
30. Haji-Azimi E, Khavanin A, Aghajani M, Soleymanian A. Thermal stress measurement according to WBGT index in smelting industry. Iran J Mil Med Summer. 2011;13(2): 59-64.
31. ACGIH. Threshold Limit Values and Biological Exposure Indices for Chemical Substances and Physical Agents-Heat Stress and Heat Strain. American Conference of Governmental Industrial Hygienists, 2016; Cincinnati, USA.
32. Parsons K. Heat Stress Standard ISO 7243 andits global application. Ind Health. 2006;44(3): 368-379.
33. Yaglou CP, Minard D. Control of heat casualties at military training centers. Arch Ind Health. 1957;16(4): 302-316.
34. Leithead CS, Lind AR. Heat stress and heat disorders. Open J Prev Med. 1964; 6(1).
35. ACGIH. Heat Stress and Strain TLV®. In Threshold Limit Values and Biological Exposure Indices for Chemical Substances and Physical Agents. Cincinnati, OH, USA, 2013.
36. Budd GM. Wet-bulb globe temperature (WBGT)—its history and its limitations. J Sci Med Sport. 2008;11(1): 20-32.
37. d'Ambrosio F, Palella B, Riccio G, Alfano G. Criteria for assessing severely hot environments: from the WBGT index to the PHS (predicted heat strain) model. Med Lav. 2004;95(4):255-274.
38. ISO 8996. Ergonomics of the thermal environment – determination of metabolism heat production. 2001.
39. Mahdavi S, Esmaelzadeh A, Ebrahemzadeh F, Rashidi R, Naeimi N. Comparing the Core Body Temperature and the Heat Stress indices of HSI and WBGT in lorestan Steels Industry Workers. Arch Hyg Sci. 2014;3(4):160-6.[In Persian].
40. ISO 7243. Ergonomics of the thermal environment—assessment of heat stress using the WBGT (wet bulb globe temperature) index. International Organization for Standardization (ISO). 3rd edn. Geneva.. 2017.
41. ACGIH. TLVs and BELs, Threshold Limit Values For Chemical Substances and Physical Agents and Biological Exposure Indices, , ACGIH Signature Pub- lications, Cincinnati. 2004; pp168-176.
42. NIOSH. Criteria for a recommended standard. Occupational exposure to hot environments. Revised criteria 1986. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control. National Institute for Occupational Safety and Health. DHHS (NIOSH) Publication, 1986; pp 86-113.
43. Golbabaie F, Monazam Esmaielpour MR , Hemmatjou R, Nasiri P, Pouryaaghoub GR, M H. 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): 245-252. [In Persian].
44. Brake R, Bates G. A valid method for comparing rational and empirical heat stress indices. Ann Occup Hyg. 2002;46(2): 165-174.
45. Peters H. Evaluating the heat stress indices recommended by ISO. Int J Ind Ergon. 1991;7(1): 1-9.
46. Moran D, Pandolf K, Laor A, Heled Y, Matthew W, Gonzalez R. Evaluation and refinement of the environmental stress index for different climatic conditions. J Basic Clin Physiol Pharmacol. 2003;14(1): 1-16.
47. Pulket C, Henschel A, Burg WR, Saltzman BE. A comparison of heat stress indices in a hot-humid environment. Am Ind Hyg Assoc J. 1980;41(6): 442-449.
48. R. Golmohammad, M. Hassani, A. Zamanparvar, M. Oliaei, M. Aliabadi, S. Mahdavi. Comparing the Heat Stress Index of Hsi and Wbgt in Bakeryworkplaces in Hamadan. Iran Occup Health. 2006;3(2): 8-10.
49. Brake DJ, Bates GP. Deep body core temperatures in industrial workers under thermal stress. J Occup Environ Med. 2002;44(2): 125-135.
50. 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. Saf Promot Inj Prev (Tehran). 2014;2(1): 55-64.
51. McKinnon SH, Utley RL. Heat Stress. Prof Saf. 2005;50(4):41-47.
52. Hamerezaee M, Golbabaei F, Nasiri P, Azam K, Farhang DS, Fathi A, Darabi F. Determination of optimum index for heat stress assessment on the basis of physiological parameters, in steel industries. J Health Saf Work. 2018;8(2):163-175. [In Persian].
53. Hajizadeh R, Golbabaie F, Esmaielpour MRM, Beheshti MH, Mehri A, Hosseini M, Khodaparast I. Assessing the heat stress of brick-manufacturing units’ workers based on WBGT index in Qom city. J Health Saf Work. 2015;4(4): 9-20. [In Persian].
54. Mirzabeigi S, Nasr BK, Mainini AG, Cadena JDB, Lobaccaro G. Tailored WBGT as a heat stress index to assess the direct solar radiation effect on indoor thermal comfort. Energ Build. 2021;242: 110974.
55. Bates GP, Schneider J. Hydration status and physiological workload of UAE construction workers: A prospective longitudinal observational study. J Occup Med Toxicol. 2008;3(1): 21.
56. Miller V, Bates G, Schneider JD, Thomsen J. Self-pacing as a protective mechanism against the effects of heat stress. Ann Occup Hyg. 2011;55(5): 548-555.
57. Bates G, Miller V. Empirical validation of a new heat stress index. J Occup Health Saf Aust N Z. 2002;18(2): 145-154.
58. Taylor NA. Challenges to temperature regulation when working in hot environments. Ind Health. 2006;44(3): 331-344.
59. d’Ambrosio Alfano FR, Malchaire J, Palella BI, Riccio G. WBGT index revisited after 60 years of use. Ann Occup Hyg. 2014;58(8): 955-970.
60. Wang Y, Meng X, Yang X, Liu J. Influence of convection and radiation on the thermal environment in an industrial building with buoyancy-driven natural ventilation. Energ Build. 2014;75: 394-401.
61. Macpherson RK. Physiological Responses to Hot Environments. An Account of Work done in Singapore, 1948-1953, at the Royal Naval Tropical Research Unit with an Appendix on Preliminary Work done at the National Hospital for Nervous Diseases, London. Med J Australia.1960; 2(1): 19-20.
62. Horvath SM, Jensen RC. Standards for occupational exposures to hot environments. Proceedings of a symposium. HEW Publication Number NIOSH -76-100. National Institute for Occupational Safety and Health.1976.
63. Parsons K. Heat Stress Standard ISO 7243 and its global application. Ind Health. 2006;44(3): 368-379.
64. Bernard TE, Barrow CA. Empirical approach to outdoor WBGT from meteorological data and performance of two different instrument designs. Ind Health. 2013;51: 79-85.
65. Konarska M, Soltyñski K, Mazrszalek A. Problems in evaluation heat stress risk of women workers using the WBGT index. In Proceedings of the Human Factors and Ergonomics Society Annual Meeting, July 2000; 44(35); 6-453.
66. Nassiri P, Reza Monazzam M, Golbabaei F, Abbasinia M, Chavoshi M, Taheri F, Asghari M. Exposure to heat stress in the workplace: A systematic review. Iran Occup Health. 2018;15(2). [In Persian].
67. Malchaire J, Kampmann B, Havenith G, Mehnert P, Gebhardt H. Criteria for estimating acceptable exposure times in hot working environments: a review. Int Arch Occup Environ Health. 2000;73(4): 215-220.
68. Jay O, Kenny GP. Heat exposure in the Canadian workplace. Am J Ind Med. 2010;53(8): 842-853.
69. Dehghan H1, Mortazavi SB, Jafari MJ, Maracy MR. Combined application of wet-bulb globe temperature and heart rate under hot climatic conditions: a guide to better estimation of the heat strain. Feyz, J Kashan Univ Med Sci. 2012;16(2):112-120. [In Persian].
70. Hoveizi F, Ghasemkhani M. Determination and comparison of TWL and WBGT thermal stress indices of an onshore drilling rig workers in Ahvaz. Iran Occup Health. 2015;12(4): 1-10. [In Persian].
71. Jacklitsch B, Williams WJ, Musolin K, Coca A, Kim JH, Turner N. Criteria for a recommended standards: occupational exposure to heat and hot environments. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication, Cincinnati, OH, USA, 2016.
72. Islam MZ. Influence of gender on heart rate and core temperature at critical wbgt for five clothing ensembles at three levels of metabolic rate. MSc thesis, University of South Florida, Florida, USA, 2005.
73. Ramsey JD. Heat and clothing effects on stay times. Int J Ind Ergon. 1994;13(2): 157-163.
74. Ramanathan N, Belding H. Physiological evaluation of the WBGT index for occupational heat stress. Am Ind Hyg Assoc J. 1974;34(9): 375-383.
75. Mairiaux P, Malchaire J. Workers self-pacing in hot conditions: a case study. Appl Ergon. 1985;16(2): 85-90.
76. Hanson M. Development of a draft British standard: the assessment of heat strain for workers wearing personal protective equipment. Ann Occup Hyg. 1999;43(5):309-319.
77. Hoorfarasat G, Jaafari M, 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.
78. Gharibi V, Mohammadbeigi A, Asadi-Ghalhari M, Heidari H. Investigation of the compatibility of wet bulb globe temperature (WBGT) and predicted heat strain (PHS) in assessing the environmental conditions and heat load imposed on individuals: a case study in bakery workers. Health Saf Work. 2020;10(1): 58-71. [In Persian].
79. Moran DS, Pandolf KB, Shapiro Y, Heled Y, Shani Y, Mathew W, Gonzalez RR. An environmental stress index (ESI) as a substitute for the wet bulb globe temperature (WBGT). J Therm Biol. 2001;26(4-5): 427-431.
80. Heidari H, Rahimifard H, Arsang-Jang S, Sahranavard R, Soltanzadeh A. Correlation between Wet Bulb Globe Temperature and Thermal Work Limit Compared to the Modified Threshold Limit of Tympanic Temperature. J Occup Hyg Eng. 2018;4(4): 31-38. [In Persian].
81. Henschel A, Dukes-Dobos FN. Proceedings of a NIOSH workshop on recommended heat stress standards. US Department of Health and Human Services, Public Health Service, September 1979, Cincinnati, Ohio, USA.
82. Keatisuwan W, Ohnaka T, Tochihara Y. Physiological responses of men and women during exercise in hot environments with equivalent WBGT. Appl Hum Sci J Physiol Anthropol . 1996;15(6): 249-258.
83. Haymes EM. Physiological responses of female athletes to heat stress: a review. Physician Sportsmed. 1984;12(3): 45-59.
84. Konarska M, Soltyñski K, Marszalek A. Problems in evaluation heat stress risk of women workers using the WBGT index. Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 2000; SAGE Publications Sage CA: Los Angeles, CA, USA.
85. Dehghan H, Mortazavi SB, Jafari MJ, Maracy MR, Jahangiri M. The evaluation of heat stress through monitoring environmental factors and physiological responses in melting and casting industries workers. Int J Environ Health Eng. 2012;1(1):21.
86. Brief RS, Confer RG. Comparison of heat stress indices. Am Ind Hyg Asso J. 1971;32(1): 11-16.
87. Beshir M. A comprehensive comparison between WBGT and Botsball. Am Ind Hyg Assoc J. 1981;42(2): 81-87.
88. Sherwood SC. How important is humidity in heat stress? J Geophys Res: Atmos. 2018;123(21): 11808-11810.
89. d’Ambrosio Alfano FR, Malchaire J, Palella BI, Riccio G. WBGT index revisited after 60 years of use. Ann Occup Hyg. 2014;58(8): 955-970.
90. Malchaire J, Gebhardt H, Piette A. Strategy for evaluation and prevention of risk due to work in thermal environments. Ann Occup Hyg. 1999;43(5): 367-376.
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|Exposure to Heat Heat Stress Thermal stress WBGT index|
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