Spatiotemporal monitoring and assessment of noise pollution in an urban setting

Abstract

The impact of noise pollution in urban healthy livings are not well documented and is seen often get less attention than it should. The increasing noise in urban settings must be studied further due to its site-specific nature for adoption of appropriate control measures or for better zoning of city's land uses. The present study assessed and evaluated the spatiotemporal variability of noise level and noise pollution indices for Chattogram City Corporation (CCC) in Bangladesh as study area. A total of 123 selected points were uniformly distributed to 41 wards under CCC has been taken as measuring sites. An ArcGIS 10.4 software is used to develop and evaluate the variations in noise descriptor and pollution indices in a graphical format. The study found that irrespective of sources, in general, city dwellers experienced moderately high noise with an average noise level of 75 dBA exceeding the limit values set by the Department of Environment (DoE), Bangladesh, World Health Organization (WHO), American Association of State Highway and Transportation Official (AASHTO) for different land uses individually or in combination. With an exception of few wards located far from major roads and with less population and industries, the city dwellers at 14 wards located in the north west, central and few parts of south belt experienced as high as 80 to 90 dBA based on noise equivalent (Leq), noise climate (NC) and noise pollution level (NPL) indices. The higher NPL of its standard value of 88 dBA is found at 14 wards align with the higher Leq and NC located close to major and urban road networks in CCC, while other 12 wards located in the central belt of the city are also with upper bound of limit values. Based on the results and reviewing the recommendations and standards, only three (3) out of the 41 wards or areas considered are under normally acceptable situation, while 12 wards are under normally unacceptable and the noise levels of the rest locations are clearly unacceptable. An immediate zoning of city's land uses and urban settings are to be taken in the identified wards. The outcomes of this study may assist policy makers, regulatory bodies and local council to adopt appropriate measures to ensure healthy living environment for city dwellers.