Hypertension and hearing impairment in workers of iron and steel industry.

The objectives of the present study were to study the (i) prevalence of hypertension and hearing impairment in iron and steel industry workers, (ii) association between hypertension and hearing impairment, (iii) association between hypertension and hearing impairment, with duration of exposure, and (iv) correlation between levels of sound and noise induced health problems viz. hypertension and hearing impairment in a cross sectional study involving Workers working in iron and steel industry at Nagpur. Of a total of 804 workers, 770 workers participated in the study. There were five sections in the factory; Steel melting section (SMS), rolling mill section (RMS), quality control department (QCD), maintenance department (MD) and administration department (AD). Workers working in SMS, RMS, & QCD formed a continuously exposed group (CEG); workers of MD and AD formed intermittently exposed group (IEG). Workers were interviewed, examined and information was collected in a pre-tested pro-forma. Blood pressure was measured, and tuning fork tests were done to assess hearing ability. Prevalence of hypertension among CEG (25.51%) was significantly higher than IEG (14.05%). (X2-14.28, df-1, P<0.001). There was positive association between duration of exposure and prevalence of hypertension. The prevalence of hearing impairment was significantly more in CEG (20.5%) as compared to IEG (8.91%). (X2-11.69, df-1, P<0.001). Occurrence of hearing impairment was also directly proportional to the duration of exposure. The correlation between level of sound exposure and hearing impairment was found to be significant (r=0.98; P<0.05), the correlation between level of sound and hypertension was found to be statistically insignificant (r=0.84; P>0.05). The results of the present study indicate that hypertension and hearing impairment are commoner in workers continuously exposed to high levels of occupational noise.