Investigation of the Effect of Occupational Noise Exposure on Blood Pressure and Heart Rate of Steel Industry Workers

Background and Objectives. This study aimed to investigate the effect of noise exposure on blood pressure and heart rate of steel industry workers. Materials and Methods. In the present cross-sectional study, 50 workers were selected from a steel company in Fars province, Iran, and exposed to 85, 95, and 105？dB noise levels for 5 minutes. The participants' blood pressure and heart rate were measured using Beurer BC16 pulse meter both before and after the exposure. Results. The study results showed no significant difference in blood pressure and heart rate before and after the exposure. However, the workers' systolic blood pressure had increased compared to before the exposure; of course, the difference was not statistically significant ( ). Besides, although the subjects' heart rate had reduced in comparison to before the exposure, the difference was not statistically significant ( ). Conclusion. No significant change was observed in blood pressure and heart rate after acute exposure to 85, 95, and 105？dB noise levels. 1. Introduction Noise is one of the physical factors in industries, and, today, more attention is being paid to its harmful effects. After smoking and air pollution, noise pollution is considered as the third cause of heart attack among the residents of Berlin [1]. World Health Organization (WHO) also considers noise as the third dangerous pollutant of megacities [2]. Moreover, damage to the hearing system, interference in conversation, effects on the organs of vision, effects on balance system, social disorders, psychological as well as nervous effects, impacts on electrolytes, physiological effects, and mental effects are among the noise health effects on human body [2]. Almost two thousand years ago, Pliney stated that the individuals living near noisy waterfalls tend to suffer from hearing loss sooner than other people. Also, Ramazzini reported several cases of occupational deafness in 1700 [3]. The results of a study which was conducted in 2000 showed hearing loss as the main harmful effect of long exposure to occupational noise [4]. Furthermore, Neghab et al. performed a study on the workers of petrochemical complex and revealed that noise had led to an increase in blood pressure and hearing loss in the exposed workers [5]. In the same line, Smith et al. investigated the body’s physiological responses when being exposed to high-noise levels and showed that exposure to repeated, continuous noise caused the incidence of physiological as well as psychological responses and resulted in changes in heart rate as well as blood pressure [6,