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Evaluation of Noise Environment and Noise Mapping with ArcGIS in Chittagong City, Bangladesh
Md. Abdul Aziz,Ahasanul Karim,Md. Mehedi Hassan Masum,Kazi Kader Newaz 대한환경공학회 2021 대한환경공학회지 Vol.43 No.4
Objectives : Noise pollution in Chittagong City of Bangladesh is a big concern because of huge population growth and urbanization. The objective of the study was to evaluate and mapping the noise levels in twelve locations of this city at different periods. Methods : Noise level data were collected at various locations by a precision grade sound level meter and the noise pollution parameters (Lmin, LAeq,2h and Lmax) were calculated. Furthermore, the noise pollution maps of Chittagong City were developed using geographical information system to address the locations which are prone to the environmental hazards. Results and discussion : The study revealed that the average noise levels were 64.6, 76.9, and 75.5 ㏈(A) for residential, commercial and silence zones, respectively. The interpolated noise maps showed that noise environment of this city was unsatisfactory, especially, in the areas of New Market, Nasirabad, and Bawa School & College were exposed to high noise pollutions. The afternoon and evening periods were experiencing higher noise pollution in the commercial and silence zones than the morning period of the day. Conclusions : The study suggests that the noise levels are above the acceptable limit and hence urgent measures should be taken into consideration to control the level of noise pollution in the city.
Evaluation of heavy metal pollution risk associated with road sediment
Kazi Kader Newaz,Sudip Kumar Pal,Shahadat Hossain,Ahasanul Karim 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.3
A detailed investigation has been conducted to assess the heavy metal pollution risk associated with the road deposited sediment collected from the 32 major road sites in Chittagong city. The acid digestion of road sediments for metals extraction was carried out prior to determine total concentrations of Zn, Pb, Cr, Cu, Ni, Cd by using Polarized Zeeman Atomic Absorption Spectrophotometer (Z-2000) following standard analytical protocol. The contamination and pollution risk level were assessed using degree of contamination, potential ecological risk index and integrated pollution index. The study revealed that the mean heavy metal concentrations of Zn, Pb, Cr, Cu, Ni, Cd were found as 975, 84, 77, 74, 32, 1.6 ㎎/㎏, respectively, across the road sites in Chittagong city. The mean concentrations are found 1.1 to 44 times higher in comparison to soil background, signifying relatively greater enrichment for Zn, Cd and Pb across the sites, suggesting vehicular emission on roads with site-specific characteristics. Based on pollution indices, Ruby Cement, City Gate and Enayeth Bazar road sites pose high risk, while eight other sites are found with moderate to considerable risk potential, and remaining 21 sites pose low to moderate risk potential.