ACUTE AND CHRONIC EFFECTS OF NOISE EXPOSURE ON BLOOD-PRESSURE AND HEART-RATE AMONG INDUSTRIAL EMPLOYEES - THE CORDIS STUDY

The effects of industrial noise on resting heart rate and blood pressu re were studied in 3 105 blue-collar workers. Heart rate and blood pre ssure were measured in different workers at various times during the w orkday. After controlling for several possible confounders, we found t hat resting heart rate in females was associated positively with noise intensity (p = .036) and with time of day (p = .054). In males, resti ng heart rate was associated with noise intensity; however, such assoc iation was related to time of day (p = .046). No such associations wer e found for blood pressure in either sex. We plotted the mean resting heart rate by time of day for workers exposed to high [greater than or equal to 80 db(A)] and low noise, and no difference was evident with respect to morning heart rate in either sex. After 4 h of noise exposu re for males (and less time for females), individuals who were exposed to high noise had higher heart rates; however, in females this was no t observed at the end of the workday. Thus, recurrent daily exposure t o high noise at work has an acute, though not residual, effect on rest ing heart rate.