BACKGROUND: In most industries, workers are exposed to loud noise. Noise is considered as a nonspecific biological stressor that have adverse effects on human physiology. It is associated with hypertension which is in turn one of the most important preventable risk factors of cardiovascular disorders. This study aimed to evaluate the effects of noise on changes of workers' blood pressure.
   METHODS: This cross-sectional study was performed on 90 individuals who were exposed to noise at one of the industries in Isfahan, Iran. Noise levels (in dBA) were measured by means of a sound level meter. Data was collected using a demographic questionnaire and physical examination. Blood pressure was measured by a sphygmomanometer at workplace. The collected data was analyzed by t-tests.
   RESULTS: The workers aged 31.5 ± 5.2 years and were exposed to mean noise level of
97.5 ± 10.1 dBA which was significantly above the standard level (85 dBA).The relationships between blood pressure, heart rate, and noise level were not significant. However, Pearson’s correlation indicated systolic blood pressure to have significant correlations with age (correlation coefficient = 0.302) and work experience (correlation coefficient = 0.299).
   CONCLUSION: Workers exposed to noise levels above the standard, especially in the metal industry but their blood pressures haven’t any associated with noise. it mention that any changes in blood pressure resulting from occupational noise are likely to be small, careful controls, large sample sizes, and long time exposure to noise would be take to identify significant effects.