STUDY OF NOISE, HEARING IMPAIRMENT AND HYPERTENSION IN EGYPT

This study included 295 workers of Assiut Generation Station (Upper Eg ypt). Two hundred and twenty-one of the workers were exposed to differ ent levels of noise (80 to 107 dBA) and the remaining 74 were used as a control group. There were no significant differences in risk factors viz age, duration of work, body mass index, weight, height, smoking, and previous work as determined by a questionnaire. The relationship b etween occupational exposure to noise, the degree of hearing loss and hypertension was determined. The results showed that there were statis tically significant differences between the average hearing threshold levels of the two groups (P<0.01) which were more in those workers exp osed to noise than in the control group. The mean systolic and diastol ic blood pressures were also statistically Significantly different in the two groups (P<0.001) and they were positively correlated (P<0.001) to the percentage of impairment of the whole body at 4 and 6 kHz, and hearing disability at 0.5, 1, 2, and 3 kHz. Stepwise multiple regress ion analysis revealed that age, noise level and body weight could each be used as a predictor of hypertension. A predictive formula was deri ved between the amount of hearing loss and blood pressure in the subje cts exposed to occupational noise.