Experimental Investigation of Industrial Noise Intrusion in the Residential Areas as an Effect of Settlement Pattern and Land Use Planning
This study investigated the intrusion level of industrial noise from five factories in 40 surrounding residences in Anambra state, Nigeria as an effect of settlement pattern and land use planning. Three categories of measurements were considered: engagement of electric power generators, job operation dependency on the national on-grid connection – Power Holding Company of Nigeria (PHCN), and off-work hours. All measurements were conducted in compliance with the Nigerian Environmental Standards and Regulation Enforcement Agency using a digital sound level meter. A-weighted equivalent sound pressure level (LAeq) for the measured noise levels at each assessed residence was evaluated. The result showed the following LAeq value ranges: 63.2 - 78.7 dBA for factory operations during generator use; 44.5 - 62.9 dBA for PHCN use; and 41.1 - 59.7 dBA for off-work hours. Based on the recommendations from the World Health Organization and the US Department of Housing and Urban Development for acceptable noise levels in residential areas, the analysis of the data showed that significant unacceptable noise levels were present only during generator use, leading to issues of temporal hearing impairment and moderate to serious levels of annoyance. The multiple independent t-tests analyses of the LAeq categories disclosed p < 0.05 – significant in all cases. This study concluded that clustered and intermixed development of the residences and industries in the same area can create significant noise hazards for the residential areas.