The effects of occupational noise on blood pressure and heart rate of workers in an automotive parts industry

Background: one of the most important impacts of industrial noise is physiological andpsychological effects. the increases in workers’ blood pressure and heart rate were detectedduring and after exposure to high levels of noise. the objectives of this research were todetermine whether the noise exposures have any effects on blood pressure and heart rate ofworkers in the automotive parts industry.methods: this case study was done in 2011 at different units of an automotive partsmanufacturing in tehran. sound pressure level was measured at different units of the factorywith a calibrated instrument. demographic features of workers were gathered with anappropriate questionnaire. heart rate and blood pressure were measured twice in a day in thestart time of work day (before exposure to noise) and middle shift hours (during exposure tonoise) in the occupational physician office. for analyzing data, chi-square, independent samplet-test, paired t-test, and analysis of covariance (ancova) were used. p < 0.050 was consideredstatistically significant.results: the average age of workers in the case and control groups was 35.71 ± 8.10 and33.40 ± 10.41 years, respectively. there was no difference between the average age of case andcontrol groups (p = 0.436). the results of ancova revealed the significant differences betweenthe mean changes of heart rate f (1, 37) = 26.68, p < 0.001, systolic blood pressuref (1, 37) = 21.70, p < 0.001, and diastolic blood pressure f (1, 37) = 26.20, p < 0.001 of workers inthe case and control groups.conclusion: exposure to industrial noise may increase the heart rate of workers. althoughrises in heart rate, systolic, and diastolic blood pressure of workers in the case group wereobserved after exposure to noise, the values of heart rate, systolic, and diastolic blood pressurewere in the normal range. further experimental investigations are needed to determine therelationships between these variables.