Authors

Biostatistics and Epidemiology, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran

Abstract

INTRODUCTION: Exposure to noise and heat causes individuals to experience some changes in
the function of cardiovascular system in workplaces. This study aimed to find the combined effect
of heat and noise on systolic and diastolic types of blood pressure in experimentally controlled
conditions.
METHODS: This quasi‑experimental study was performed with 12 male students in a climatic chamber
in 2014. Blood pressure including systolic and diastolic was measured in the following conditions:
15 min after rest in exposure to heat (40°C, relative humidity [RH]: 30%), exposure to noise with
75, 85, and 95 dB rates in thermal comfort condition (22.1 ± 0.9 wet‑bulb globe temperature), and
combined exposure to heat (40°C, RH: 30%) and noise with 75, 85, and 95 dB. Friedman test was
used to analyze the data.
RESULTS: The mean change of systolic blood pressure was different significantly before and after
exposure to heat and noise levels including 75, 85, and 95 dB (P = 0.015, P = 0.001, P > 0.001,
P = 0.027, respectively). Although systolic and diastolic blood pressures changed drastically, it was
not significantly different in simultaneous exposure to heat and noise.
CONCLUSION: Both systolic and diastolic blood pressures decreased in exposure to heat,
while exposure to different levels of noise elevates systolic and diastolic blood pressures.
However, when exposed to a combination of heat and noise, subtle changes of blood pressure
were traced, which can be characterized as average, considering heat‑only and noise‑only
tension situations.

Keywords

1. Konings A, Van Laer L, Van Camp G. Genetic studies on
noise‑induced hearing loss: A review. Ear Hear 2009;30:151‑9.
2. Lusk SL, Hagerty BM, Gillespie B, Caruso CC. Chronic effects of
workplace noise on blood pressure and heart rate. Arch Environ
Health 2002;57:273‑81.
3. Kopke RD, Weisskopf PA, Boone JL, Jackson RL, Wester DC,
Hoffer ME, et al. Reduction of noise‑induced hearing loss using
L‑NAC and salicylate in the Chinchilla. Hear Res 2000;149:138‑46.
4. Givoni B, Goldman RF. Predicting effects of heat acclimatization
on heart rate and rectal temperature. J Appl Physiol 1973;35:875‑9.
5. Dehghan H, Parvari R, Habibi E, Maracy M. Effect of fabric stuff of
work clothing on the physiological strain index at hot conditions
in the climatic chamber. Int J Environ Health Eng 2014;3:14.
6. International Labor Organization (ILO). Encyclopedia of
Occupational Health and Safety. 3rd ed., Vol. 2. Geneva:
International Labor Organization; 1983.
7. Chen ML, Chen CJ, Yeh WY, Huang JW, Mao IF. Heat stress
evaluation and worker fatigue in a steel plant. AIHA J (Fairfax,
VA) 2003;64:352‑9.
8. Logan PW, Bernard TE. Heat stress and strain in an aluminum
smelter. Am Ind Hyg Assoc J 1999;60:659‑65.
9. Neghab M, Maddahi M, Rajaeefard A. Hearing impairment and
hyperexposure associated with long term occupational exposure
to noise. Iran Red Crescent Med J 2009;11:160‑5.
10. Smith A. A review of the non‑auditory effects of noise on health.
Work Stress 1991;5:49‑62.
11. Ising H, Michalak R. Stress effects of noise in a field experiment
in comparison to reactions to short term noise exposure in the
laboratory. Noise Health 2004;6:1‑7.
12. Stotz A, Rapp K, Oksa J, Skelton DA, Beyer N, Klenk J, et al.
Effect of a brief heat exposure on blood pressure and physical
performance of older women living in the community‑a
pilot‑study. Int J Environ Res Public Health 2014;11:12623‑31.
13. Barnett AG, Sans S, Salomaa V, Kuulasmaa K, Dobson AJ; WHO
MONICA Project. The effect of temperature on systolic blood
pressure. Blood Press Monit 2007;12:195‑203.
14. Horvath SM, Bedi JF. Heat, cold, noise, and vibration. Med Clin
North Am 1990;74:515‑25.
15. Bovenzi M, Franzinelli A, Strambi F. Prevalence of
vibration‑induced white finger and assessment of vibration
exposure among travertine workers in Italy. Int Arch Occup
Environ Health 1988;61:25‑34.
16. Niimi Y, Matsukawa T, Sugiyama Y, Shamsuzzaman AS, Ito H,
Sobue G, et al. Effect of heat stress on muscle sympathetic nerve
activity in humans. J Auton Nerv Syst 1997;63:61‑7.
17. Belojevic G, Saric‑Tanaskovic M. Prevalence of arterial
hypertension and myocardial infarction in relation to subjective
ratings of traffic noise exposure. Noise Health 2002;4:33‑37.
18. Melamed S, Froom P. The joint effect of industrial noise exposure
and job complexity on all‑cause mortality – The CORDIS study.
Noise Health 2002;4:23‑31.
19. Jacks DE, Sowash J, Anning J, McGloughlin T, Andres F. Effect of
exercise at three exercise intensities on salivary cortisol. J Strength
Cond Res 2002;16:286‑9.
20. Bigert C, Bluhm G, Theorell T. Saliva cortisol – A new approach
in noise research to study stress effects. Int J Hyg Environ Health
2005;208:227‑30.
21. Schulz P, Kirschbaum C, Prüßner J, Hellhammer D. Increased
free cortisol secretion after awakening in chronically stressed
individuals due to work overload. Stress Health 1998;14:91‑7.
22. Kohut ML, Davis JM, Jackson DA, Colbert LH, Strasner A,
Essig DA, et al. The role of stress hormones in exercise‑induced
suppression of alveolar macrophage antiviral function.
J Neuroimmunol 1998;81:193‑200.
23. van Kempen EE, Kruize H, Boshuizen HC, Ameling CB,
Staatsen BA, de Hollander AE. The association between noise
exposure and blood pressure and ischemic heart disease: A
meta‑analysis. Environ Health Perspect 2002;110:307‑17.
24. Chang TY, Jain RM, Wang CS, Chan CC. Effects of occupational
noise exposure on blood pressure. J Occup Environ Med
2003;45:1289‑96.
25. Tomei F, Fantini S, Tomao E, Baccolo TP, Rosati MV. Hypertension
and chronic exposure to noise. Arch Environ Health 2000;55:319‑25.
26. Yousefi Rizi HA, Dehghan H. Effects of occupational noise
exposure on changes in blood pressure of workers. ARYA
Atheroscler 2013;8:S183‑6.