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

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.

Noise-Induced Hearing Disturbance Textile Weavers by Individual Pure Tone Threshold Determination Test in Taegu City / 예방의학회지

It is generally recognized that the environmental noise of the various working places thought to be the cause of hearing disturbance. This survey was carried out to evaluate the prevalence of noise-induced occupational hearing loss among the weavers of 39 textile industries in Taegu, Korea. For this survey, 432 male workers and 2,023 female workers were examined their hearing acuity by individual pure tone threshold determination test(air conduction), from November, 1972, to January, 1973. Main findings were as follows: 1. The mean of noise intensity of the 54 weaving rooms was, in over all, 95.6+/-4.2dB (A), 95.9+/-4.0dB (B) and 96.2+/-3.9dB (C). 2. The mean hearing threshold levels by service years in the 4,000 Hz were intensively increased from 1st to 3rd year and slightly decreased, than that of 3rd year, from after 3rd to 5th year, after 5th year that increased slightly. 3.The mean hearing threshold levels by frequencies were highest in the 4,000Hz(male:25.0+/-11.3dB, female:22.0+/-10.2dB) and followed by 6,000, 8,000 and 3,000Hz. 4. The mean hearing threshold level of the 6,000Hz(male:17.0dB, female:17.9dB)was higher than that of 4,000Hz(male:16.4dB, female:17.1dB) in the 1st service year. 5. The mean hearing loss of examinees was 16.2+/-8.0dB in male and 15.4+/-7.8dB in female.