Environmental Noise Pollution in Ilorin Metropolis, Nigeria

This paper presents the results obtained from environmental noise measurements at selected locations in Ilorin metropolis. Forty two different locations throughout Ilorin were selected to establish background noise level, peak noise level and dominant noise sources at these locations. It was observed that, the A-weighted sound levels (L_Aeq), background noise level (L₉₀) and peak noise level (L₁₀) measured vary with the location and period of the day. Due to traffic characteristics, especially traffic volume, vehicle horns, vehicle-mounted loudspeakers, unmuffled vehicles, record players and hawking, there is high L_Aeq, L₉₀ and L₁₀ at road junctions (77 dBA, 66 dBA, 77 dBA), passengers loading parks (76 dBA, 66 dBA, 77 dBA ) and commercial centres (73 dBA, 64 dBA, 74 dBA). Average daily noise exposure level (L_Aeq) in Ilorin metropolis varies from 46 dBA to 86 dBA. The result of this study shows that the major source of noise in Ilorin metropolis can be attributed to traffic noise. Other intrusive noise sources include noise from record players and hawking with loud speakers. Based on the recommendations of Committee on Environmental and Occupational Health (CEOH), World Health Organization (WHO) and Housing and Urban Development (HUD), only 6 locations out of 42 are under normally acceptable situation while the noise levels of other areas are not acceptable. Based on the noise descriptors (L_Aeq, L_D, L_N, L_DN, T_NI and L_NP), noise map is developed to identify locations with high noise exposure. The noise map developed reveals high noise exposure at the nucleus of the metropolis where commercial activities, high traffic volume and clustered buildings with high population exist. The result of this study is useful as reference and guideline for future regulations on noise limit to be implemented for urban areas in Nigeria.