Effect of Long-Term Noise Exposure on the Blood Pressure in Factory Workers

Kim, Bok Youn; Kim, Cheon Tae; Lee, Jung Jeung; Park, Hong Chin; Kim, Chang Yoon; Kang, Pock Soo

Abstract

The question of an association between occupational noise exposure and blood pressure has important public health implications. The harmful effects of hypertension are well known and noise is considered the mosts pervasive problem of all occupational exposures in Taegu City, Korea. A cross-sectional study on the effect of long-term noise exposure on blood pressure was done for 276 noise exposed workers (203 male workers, 73 female workers). Long-term noise exposure was measured by cumulative noise exposure level and noise-induced hearing loss. Hearing loss=(500Hz+2x1,000Hz+2x2,000Hz+4,000Hz)/6 Questionaire was administered to the workers, which includes age, sex, occupational history on the noise exposure, habits on alcohol drinking and smoking, practice of regular exercise, family history of hypertension. Type A behavior, question on stress, height, weight and blood pressure were measured. Serum triglyceride and low density lipoprotein (LDL) were also measured. Audiometry was done in the closed booth at 1,000, 2,000, 3,000, 4,000, 6,000, 8,000, 1,000 and 500Hz in order. Mutiple logistic regression analysis revealed that cumulative noise exposure level(p<0.05), serum triglyceride(p<0.01), age(p<0.01) and family history of hypertension (p<0.05) predict hypertension (systolic blood pressure: 160mmHg or above, or diastolic blood pressure: 95mmHg or above) in male workers. In female workers, serum triglyceride (p<0.01), LDL (p<0.01) and family history of hypertension(p<0.05) were predictors of hypertension (systolic blood pressure: 160mmHg or above, or diastolic blood pressure: 95mmHg or above). As the number of female workers with hypertension was too small, the multiple logistic regression was done according to hypertension criteria of systolic blood pressure greater than or equal to 140mmHg, or diastolic blood pressure greater than or equal to 90mmHg. Based on this criteria, cumulative noise exposure level (p=0.055) and age (p=0.057) predict hypertension. It is suggested that long-term noise exposure which was calculated by cumulative noise exposure level was a significant predictor of hypertension in noise exposed workers.