Noise Pollution Assessment in Sylhet City Corporation Using Geographic Information System (GIS)

Background: Noise pollution is a risk factor for human health which is continuously increasing in Sylhet City corporation, located in the Sylhet division in Bangladesh. Methods: In this study, we assessed the noise pollution level in Sylhet City by comparing it with the standard noise level. Also, the outcomes of this study were compared to other studies from different countries. In order to measure the noise level in decibel, BSWA 308 device was used in this study. A total of 38 samples were taken from different geographical locations in Sylhet City Corporation. The 38 samples provided 96 to 99% accuracy with a 95% confidence level of >36. Results: The decibel values ranged from 72 to 86 dB. From the observed data we calculated the values as follows: L10, L50 and L90 and Noise Climate (NC)=12.7 dB, equivalent continuous noise level Leq=77.18 dB and noise pollution level Lnp=89.88 dB. A contour map of the area was made using Arc GIS software version 10.5. Every line in the contour map defined a specific decibel value. The map was made by 2 dB intervals between the corresponding contour lines. More than 30% of the study area was vulnerable to a high level of noise (>82 dBA), and about 30% had the lower level of noise (<77 dBA). Only 40% of the area had moderate noise levels (i.e., between 77 to 82 dBA). Conclusion: After comparing the outcomes of noise level in this study with previous studies, we observed that the noise level of this area was more than acceptable limit for all parameters.