Environmental noise induced hearing loss in Nepal.

INTRODUCTION Noise pollution in urban cities is a serious problem and steadily increasing over the years. This has direct and indirect affect to the people that can lead to the health hazard. OBJECTIVES To find out environmental noise induced health effect on people residing in an urban community and to predict the risk of the environmental noise induced hearing loss. MATERIAL AND METHODS One hundred fifty questionnaires were filled up for the environmental noise pollution survey. For the case control study, 36 exposed and 25 non-exposed residents of Kupondole were included. Based on the place of residence (main road and 20 min. walking distance from the main road), subjects were divided into exposed and non-exposed group concerning environmental noise. Demographic data and information about health problems was obtained by a structured interview. Audiometric test was performed using manual audiometer. Odds ratios (OR) and their 95% confidence intervals (95% CI) for noise induced hearing loss were estimated using logistic regression. Adjustment for occupational noise was done. RESULTS The major health effect induced by the environmental noise was observed as lack of concentration followed by irritation, fatigue and headache. The crude OR and 95% CI for the exposed subjects was 4.2 (1.4, 12). After adjustment for occupational noise, the OR (95% CI) was 4.0 (1.2, 13). CONCLUSION This study shows that exposure to noise causes wide range of health effects. For the exposed subjects there was an increased risk of noise induced hearing loss. The risk was significantly increased also after adjusting for occupational noise.