Prevalence and correlates of noise induced hearing loss among traffic policemen in the City of Colombo

Abstract

BACKGROUND AND OBJECTIVE: Noise induced hearing loss (NIHL) is a high frequency sensory-neural hearing loss in subjects who are exposed to environmental noise, but this diagnosis is made only after excluding other reasons for the hearing. Traffic policemen are exposed-to environmental noise due to the nature of their doty and are susceptible to develop NIHL The objective of this study was to determine the prevalence and correlates of NIHL among traffic policemen in the city of Colombo. METHODS: A cross sectional study was carried out among traffic po icemen in the city of Colombo, 350 participants were selected by cluster sampling. Pure-tone ; udionietry test was performed to assess the level of NIHL. Hearing levels of participants were classified using a classification obtained by modifying the Clark's classification. Correlates of NIHL were assessed using an Interviewer Administered Questionnair (IAQ). RESULTS: High frequency hearing of, 169 (total 287} participants (5->.9%) was normal. Seventy nine participants (27.5%) had minor NIHL and 39 participants (13.6%) lad major NIHL. In bivariate analysis 23 variables showed statistically significant association with mild and major NIHL while multi-variate analysis showed only age had statistically significant association with major NIHL with odds-ratio(OR) of 1.088 and only 'duration of work as a policeman" had statistically significant association with any NIHL (major or minor) with OR of 1.007. Conclusions: Prevalence of NIHL among traffic policcrien working in the city of Colombo was 41.1 %(95% CI=35.5%-46.9%). A third of those having r IHL had major NIHL. Traffic policemen should undergo periodic hearing assessment. The police department should explore the feasibility of reducing the number of HOLTS per day spent on the road by traffic policemen. Traffic policemen with NIHL must be transfe'-red to a different division immediately.