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Original Article | Open Access | Am. J. Pure Appl. Sci., 2024; 6(2), 39-51 | doi: 10.34104/ajpab.024.039051

Spatial Distributions of Gaseous Air Pollutants Including Particulate Matter in the Narsingdi City of Dhaka Division

Mir Md. Mozammal Hoque* Mail Img Orcid Img ,
Jakia Begum Mail Img ,
Mahdi Hasan Mail Img ,
Mehedi Hasan Khan Mail Img ,
Sarathy Datta Mail Img

Abstract

This study summarizes the concentration of major gaseous air pollutants in Narsingdi city of Dhaka division. To accomplish this study, we investigate fifteen sampling stations (Velanagar, Railway Station, Boro Bazar, Ghoradia, Brahmondi, Shaheprotap, Launch Terminal, Satirpara, Bus Terminal, Silmandi, Gangpar Bridge, Panchdona, Shekherchar and Anandi) of the study area. In this study, we measured six gaseous air pollutants together with PM2.5 and PM10 during September 2022 using the air quality meter Aeroqual (Series500). The highest concentration of PM2.5 was detected at 58 µg/m3 at Boro Bazar whereas the highest concentration of PM10 was 165 µg/m3 at Anandi of the study area where emissions from vehicles, construction activities and waste burning are predominant. Moreover, in this study, we found a statistically significant correlation with CHand CO2 (r = 0.679, p > 0.01), PM2.5 and PM10 (r = 0.630, p > 0.05) indicating their sources of emission might be similar including fossil fuel burning in vehicles, industrial emissions, and road dust. Furthermore, we calculated the AQI value based on PM2.5 concentration, and the highest AQI (152) value was observed in Boro Bazarof the study area followed by Bus Terminal (129), Gangpar Bridge (117), Anandi (112), Ghoradia (102), Brahmondi (89), Panchdona (84), Satirpara (83), Shaherpotap (82), Silmandi (80), Railway Station (78), Madhabdi (78), Shekherchar (76), Launch Terminal (76), Velanagar (59) and was very much compatible with US consulate, Bangladesh published data.

INTRODUCTION

Air pollution poses worlds most serious environmental health threats towards people and their properties (Hoque et al., 2020; Mukta et al., 2020). Other environmental implications of air pollutants include global warming, acid rain, and effects on wildlife (Gauderman et al., 2004; Jansen et al., 2005; Epton et al., 2008). The principal air pollutants of concern are ozone (O3), nitrogen dioxide (NO2), carbon monoxide (CO), sulfur dioxide (SO2), methane (CH4), chlorine (Cl2), and particulates (PM2.5 and PM10), which are emitting due combustion of fossil fuels as well as biomass burning (Dianat et al., 2016; Khaefi et al., 2017; Hoque at al., 2020). Air pollution is a pressing issue for Bangladesh, which ranks 169th (out of 178 countries) at the Environmental Performance Index for Air Quality (APT, 2016). Here, main sources of air pollution include emission from faulty vehicles, especially diesel run vehicles, brick kilns and dust from roads and construction sites and toxic fumes from industries (Hoque et al., 2020; Mukta et al., 2020). According to the Department of Environment (DoE), the density of airborne particulate matter (PM) reaches 463 micrograms per cubic meter (µg/m3) in Dhaka city during the dry season (Dec-ember-March), which is the highest level in the world (Air Pollution Reduction Strategy for Bangla-desh, Final Report, 2012). Although, World Health Organization (WHO) air quality guidelines (2006) recommend a maximum acceptable PM level of 20 µg/m3, whereas cities with 70 µg/m3 are considered as highly polluted.

Poor ambient air quality is instigating damage to human health, agricultural production and materials (Mukta et al., 2020; Hoque et al., 2022b).  So, it is high time to create awareness and motivation about air pollution management and control all over Bangladesh. However, in different times air pollution issues have been considered, and often guided by the multinational agencies like the World Bank (WB), Asian Development Bank (ADB), United Nations Environment Program (UNEP), which have taken measures or have made schemes to minimize and limit air pollution. However, the Department of Environment (DoE), the Government agency funded with conserving the environment in Bangladesh, sought plans to create a policy which will reduce air pollution in Bangladesh under the framework of the Male declaration to regulate and avoidance of air pollution and its possible trans-boundary consequences for South Asia (Air Pollution Reduction Strategy for Bangladesh, Final Report, 2012). 

Air pollution is a major anthropogenic environmental concern that has recently gained prominence among all environmental issues in Bangladesh. According to a World Bank report, the economic cost of pollution of air in healthcare sector of Bangladesh alone is estimated annually as U.S. $132-583 for Dhaka city and U.S. $200-800 for the four biggest cities in Bangladesh, which contributes 0.7-3.0% of the countrys per year GDP (C. Brandon, Economic valuation of pollution of water and air in Bangla-desh: World Bank Workshop negotiations draft, 1997). Moreover, a 20 percent cutback from the current level of PM10 in Dhaka would save health costs of around 169-492 million annually (World Bank, 2006). In addition, among the megacities of the world, Dhaka leads the rankings, having 7000/yr cardiovascular mortality and 2100/yr excess cases of hospital admissions for COPD (Chronic Obstructive Pulmonary Disease) attributable to air pollution (Azkar et al., 2012; Gurjar et al., 2010).

Objectives of the study 

This study was conducted to satisfy the following objectives:

1)To find out the concentration level of CO, CO2, NO2, SO2, Cl2, CH4, PM2.5 and PM10 at the ambient air of Narsingdi Sadar. 

2)To show the spatial distribution of these pollutants by using Geographical Information System (GIS). 

3)To calculate AQI (Air Quality Index) for the study area.

MATERIALS AND METHODS

Study area

Narsingdi is a district in central Bangladesh. It is situated north-east of Dhaka, capital  of Bangladesh. It belongs to the division of Dhaka. The district is renowned for its synthetic textile industry. The study was conducted in fifteen areas of Narsingdi Sadar (23°558.79"N and 90°433.80"E) of Dhaka division including Velanagar, Railway Station, Boro Bazar, Ghoradia, Brahmondi, Shaheprotap, Launch Ter-minal, Satirpara, Bus Terminal, Silmandi, Gangpar Bridge, Panchdona, Shekherchar, Madhabdi and Anondi.

Figure 1. Map of study area with sampling locations

Data collection 

The study was conducted from fifteen different locations of Narsingdi Sadar. The research was based on primary air quality data under the direct supervision of a supervisor. Primary data were collected by Aeroqual S500 (New Zealand), a portable air quality monitor during September 2022.

AQI calculation

In our study AQI is calculated by using following formula:

 

Here,

I: AQI (Air Quality Index)

C: the pollutant concentration

C low: the concentration breakpoint that is ≤ C

 C high: the concentration breakpoint that is ≥ C

 I low: the breakpoint Index narrating to C low 

I high: the breakpoint Index narrating to C high 

C low, C high, I low, I high are from the US EPA Pollutant Breakpoint.

Table 1: The US EPA pollutant breakpoint for calculating AQI.



RESULTS AND DISCUSSION

Spatial distribution of PM2.5 in the study area

As shown in Table 2, the concentration of PM2.5 ranged from 16-58 µg/m3, average is 31.55µg/m3. However, this value is lower than the Nanjing, China 65.36 µg/m3 (Hasnain et al., 2021), Dhaka 77 µg/m3 (Khuda K.E., 2020) and Delhi 182.49 µg/m3 (Sethi et al., 2020) and higher than the previous study of Chittagong 21.2 µg/m3 (Hoque et al., 2022a). However, the spatial expansion of PM2.5 showed that the highest value of PM2.5 was observed 58 µg/m3 in Boro Bazar (Fig. 3). The sources of PM2.5 of this area may be associated with fossil fuel burning vehicles, road side construction and public gathering.

Table 2: Concentration of air pollutants in the study area.

Fig. 3: Spatial distribution of PM2.5 in the study area.

Spatial distribution of PM10 in the study area

As displayed in Table 2, concentration of PM10 ranged from 19-165 µg/m3, average 61 µg/m3. Interestingly, this value is lower than the Nanjing, China 102.75 µg/m3 (Hasnain et al., 2021), Dhaka 65.5 µg/m3 (Khuda K.E., 2020), Delhi 299.78 µg/m3 (Sethi et al., 2020) and higher than the previous study of Chittagong 57.3 µg/m3 (Hoque et al., 2022a). However, the spatial expansion of PM10 showed that the highest value of PM10 observed 165 µg/m3 in Anandi (Fig. 4). The sources of PM10 of this area may be associated with roadside construction, waste burning, dust from open land and grinding operation.distribution of CO in the study area

As demonstrated in Table 2, concentration of CO ranged from 0.0-1.7 ppm (avg. 0.22 ppm). In comparison, this value is lower than Nanjing, China 0.89 ppm (Hasnain et al., 2021), Dhaka 1.8 ppm (Khuda K.E., 2020), Delhi 2.51 ppm (Sethi et al., 2020) and Chittagong 1.2 ppm (Hoque et al., 2022a) of the previous study. However, the spatial expansion of CO showed that the highest value of CO observed in Shaheprotap of the study area (Fig. 5). The sources of CO of that area may be associated with incomeplate combustion of vehicular emission.