Road Traffic Noise-induced Sleep Disturbances in Some Cities in Eastern Nigeria

Abstract

This study, was conducted between April 2011 and July 2012, to estimate the degree of impact of road traffic noise on the exposed population in terms of sleep disturbances in daytime and nighttime periods in order to suggest ways of minimizing the impact if it appears adverse. Acoustical and social surveys were conducted. From acoustical survey, noise level data were obtained, while in social survey, responses of how road traffic noise affects city dwellers during sleep were obtained as well. This is to correlate acoustical (objective) data with social (subjective response) data to help estimate the degree of impact of the road traffic noise on the people exposed to it. Five (5) cities were randomly chosen after pilot study. These are Calabar, Uyo, Umuahia, Owerri and Port Harcourt cities. The cities were found to be of huge road traffic volume, with enormous environmental noise pollution indicators. A precision sound level meter (SLM), Bruel and Kjaer (B&K), type 732 was used after calibration, to obtain noise level data, while a questionnaire carefully designed by these authors, was used to generate subjective response data from respondents. Five thousand (5000) copies of the questionnaire were distributed carefully to 5000 persons, 2500 each for both high and low road traffic noise pollution zones. Response rates were 93.5% (high noise zone) and 94.8% (low noise zones). One hundred (100) measurement sites were chosen in all (50 sites each for both high and low noise zones). Results obtained show that the degree of sleep disturbance during daytime range between 93.8% to 95.8%, and during nighttime was 98.5 to 98.8%. From these findings, it is very clear that people living along busy roads in the cities under study are really suffering from serious sleep disturbances both at night and day times