Noise induced hearing loss of Kathmandu Valley Traffic Police : a self reported occupational health study

Introduction
Noise level is increasing rapidly in Kathmandu Valley with the increasing number of vehicles in the last few years. But, noise pollution is still not looked at as a major environmental pollution, as people are not aware of the adverse health effects. The aim of this study was to assess the perception, knowledge, attitude and practices of traffic policemen towards the physiological and psychological health effects caused by traffic noise.

Methods
This is a questionnaire based study carried out among 110 randomly selected traffic policemen from Kathmandu Valley. The questionnaire was designed to evaluate their perception about noise pollution, duration of exposure, hearing ability, use of personal protective equipments etc. Data analysis was carried out using SPSS 15.0 version.

Results
The mean age of the respondents was 26 years, and the mean year of exposure was 2.8 years. Around 12% of the traffic policemen complained of below average hearing ability. Eight percent of the respondents complained of regular tinnitus, while 57.3% had tinnitus during working hours. Only 7.3% of respondents used earplugs during working hours. Reasons for not using earplugs included non availability (49.1%), uncomfortable (13.9%), poor fitting (6.5%), personal dislike (22.2%) and headache caused by its use (8.3%). Seventy seven percent of respondents did not use any method to reduce exposure to noise. The remaining of traffic policemen used their fingers, hands or cotton balls to avoid exposure to noise.

Discussion
The study respondents were in the economically productive age group. The self assessment of hearing by traffic policemen suggests that most of them have normal hearing, which could be due to their ignorance about the health hazards caused by exposure to noise and non usage of protective devices. Further study with audiometric tests of these respondents is recommended.