Airborne Particulate Pollution Measured in Bangladesh from 2014 to 2017

Abstract

Recently, the World Health Organization ranked Narayanganj, Chittagong, and Dhaka among the top 25, 40, and 45 cities, respectively, for high ambient PM 2.5 concentrations. Bangladesh has instituted an air quality monitoring system operated by the Department of Environment. PM 2.5 and PM 10 were measured hourly from January 2014 through December 2017 in Dhaka, Gazipur, Narayanganj, Chittagong, Sylhet, and Barisal. All sites registered concentrations for both pollutants that exceeded the 24-h Bangladesh National Ambient Air Quality Standards. The particulate matter (PM) concentrations varied significantly seasonally and with different diel patterns from city to city. The highest concentrations were observed during the winter, typically when wind speeds and mixed layer heights are low and pollutant concentrations are increased by transport from the northwest. The PM 2.5 concentrations from the 1 st quarters of 2014 and 2015 were compared to assess whether political unrest that appeared to reduce vehicular moment to very low levels affected the observed values. However, the PM 2.5 concentrations were statistically similar at the Dhaka, Narayanganj, and Sylhet sites and different for the Gazipur, Chittagong, and Barisal locations. Thus, the PM 2.5 concentrations during the political unrest in the 1 st quarter of 2015 were not consistently lower across the measurement sites. These results indicate that vehicular emission contributions to PM 2.5 concentrations are smaller than in the past, which agrees with recent source apportionment studies showing that brick kilns have become the dominant source of PM.

A Meteorology Based Particulate Matter Prediction Model for Megacity Dhaka

“…The positive association of PM with the North-South component of wind speed (CosWD) suggests that PM2.5 concentrations increase when winds come from north directions. This finding is in the line with earlier literature (M. M Mahmood et al, 2019). where winds coming from north-west direction…”

“…Although studies have shown that wind coming from the northwest direction of Dhaka during the winter months increases PM concentration Mahmood et al, 2019), wind direction was not included as a predictor in the multilinear regression or correlation analysis in the above-mentioned studies.…”

“…We also assess the performance of the model in explaining spatial variability by employing it in two other monitoring stations of Dhaka. (Mahmood et al, 2019). CAMS also measures meteorological parameters including rainfall, temperature, relative humidity, solar radiation, wind speed, and direction.…”

Vehicular PM Emissions and Urban Public Health Sustainability: A Probabilistic Analysis for Dhaka City

“…Generally, the conventional brick kilns adjacent to the city, vehicles, uncontrolled development activities, stockpiling of uncovered construction materials along with roadside, and the biomass burning in industries in and around the city are considered as the catalysts behind such unhealthy air [25][26][27][28]. However, the pollution level varies depending on the climatic condition.…”

“…However, the pollution level varies depending on the climatic condition. The brick kilns operating during the dry seasons [29,30] contribute about % of the total PM pollution of the city [26,28,31], resulting in higher particulate pollution concentration during this time. Moreover, the low particle deposition rate at dry season facilitates higher pollution levels during this period than the wet season [28,32].…”