Chronic effects of workplace noise on blood pressure and heart rate.

Environmental noise levels in the United States are increasing, yet there are few studies in which the nonauditory effects of workplace noise are assessed. In the current study, the authors examined chronic effects of noise on blood pressure and heart rate in 374 workers at an automobile plant. Data were collected from subjects prior to the start of their workshift. Participants completed questionnaires about diet, alcohol use, lifestyle, noise annoyance, use of hearing protection, noise exposure outside of the work environment, personal and family health histories, and demographic information. Resting blood pressure, heart rate, and body mass index were obtained. Noise exposure levels were extracted retrospectively from company records for each participant for the past 5 yr. Summary statistics were generated for each variable, and the authors performed bivariate correlations to identify any unadjusted associations. The authors then completed statistical modeling to investigate the effects of noise on blood pressure and heart rate, after they controlled for other variables (e.g., gender, race, age). The authors controlled for confounding variables, after which use of hearing protection in high-noise areas was a significant predictor of a decrease in both systolic and diastolic blood pressures. The results suggested that the reduction of noise exposure by means of engineering controls or by consistent use of hearing protection by workers may positively affect health outcomes.