Noise Induced Hearing Loss at Two Textile Plants in Sudan

Background: Noise is a major health threat in occupations where the level exceeds the permissible limit (85 decibel). Noise causes discomfort or adverse health effect. The degree of negative effects of noise depends on its intensity, spectrum of frequency nature, duration of exposure and individual sensibility. Materials and Methods: This cross-sectional study was performed on Alhodhood and Alsabagoon textile factories employees who were exposed to noise in Khartoum - Sudan. Noise levels (dBA) were measured by sound level meter. Data was collected using questionnaire; and Pure tone air conduction audiometric test was conducted by calibrated Kamplex Diagnostic audiometer (KLD 23 mha, BSEN 60645) to determine the employees’ hearing thresholds. Data was analyzed to determine the overall prevalence of hearing loss. Results: The highest recorded sound pressure level SPL reading at Alhodhood factory was 88.9±2.7 dB and Leq 88.0±6.5 measured at the weaving section. Max p ranged from 83.61±6.5 to 104±2.1. The highest recorded sound pressure level reading at Alsbagoon factory was 93.8±1.7 dB and Leq 93.2±1.1, measured at the preparing section flowed by weaving record 87.0±3.0 which were more than permissible level. Max p ranged from 92.34 to 108.2±1.4. Workers at Alhodhood and Alsbagoon perceived the level of noise at their work environment is high, prevalence of noise-induced hearing loss (right ear), the highest 31.5% was among Alsbagoon workers and 14.3% among Alhodhood and noise-induced hearing loss (left ear) was 24.1% among Alsbagoon workers and 17.1% among Alhodhood. Conclusions: Workers in weaving section of both factories and preparing section in Alsbagoon factory were exposed to average levels of noise above 85 dBA, the major risk factors for NIHL were the duration and the level of noise exposure and hearing loss was significantly associated with working experience of more than 10 years.