The Effect of Noise on Blood Pressure and Heart Rate in an Automotive Industry

Abstract

Introduction: One of the possible effects of occupational exposure to high levels of noise is high blood pressure and cardiovascular disease. The aim of this study was to investigate the association between the sound pressure level with blood pressure and heart rate in an automotive industry. Methods: This cross-sectional study was conducted on 78 male workers of an automobile factory in Tehran, Iran. Blood pressure and heart rate were measured in the morning and in the middle of the day. All measurements were performed at three noise levels: 85-95, 75-85 and 60-70 dB (A). All data were analyzed using SPSS and MATLAB. Results: The results of the post-hoc test showed that noise has the same effect on the average systolic and diastolic blood pressure levels (P = 0.733), but the results of the box-whisker plot showed that after exposure, the variation ranges of blood pressure and heart rate are much more than the other groups (85-95 dB (A) ) . Although no specific correlation was observed between the increase in the noise level and heart rate, the variance analysis showed that the increased noise level could lead to changes in heart rate (P = 0.049). After exposure to noise, systolic and diastolic blood pressure levels increased at 75-85and 85-95 dB (A) compared to before exposure. Conclusions: This study shows that noise exposure can cause both heart rate and blood pressure to increase. So, it seems that noise can be considered as a synergism factor of cardiovascular diseases and implementing workers' training programs, reducing the noise level and periodic monitoring of blood pressure of the workers, especially those with a history of hypertension, can be recommended.