A cross-sectional study of occupational noise exposure and blood pressure in steelworkers

To determine the association of occupational noise exposure and blood pressure in a group of workers at the metallurgical plant. Noise exposure at the workplace and blood pressure were measured in 178 male workers of steel mill company. Criteria for including in the study group were: age below 35 years, employment-exposure duration longer than 3 years, hearing threshold level in normal range and no cardiovascular history. Program of examination included: individual questionnaire, ORL - examination, tone audiometry, measure of weight, height and blood pressure. Cigarette smoking, diet habits and other risk factors of elevated blood pressure were controlled. Noise exposure was assessed for each work place, by means of direct and indirect measurements. Systolic blood pressure was statistically significantly higher in the group exposed to the higher noise levels and the results of multiple regression analyses revealed a significant relationship between the occupational exposure to noise and systolic blood pressure. No such relationship with diastolic blood pressure was found. The results suggest the positive association between occupational exposure to noise and blood pressure.