Spatial Distribution of Air Quality in Rangpur Metropolitan, Bangladesh

This study investigates the spatial distribution of air quality in Rangpur metropolitan city, Bangladesh, by analyzing particulate matter (PM) concentrations across various land use categories. Using a portable Air Quality Monitor, Indoor Outdoor Formaldehyde (HCHO) Detector (Model: DM106), and Garmin ETrex 10, data was collected from 40 locations categorized into sensitive, residential, mixed, commercial, road intersection, industrial, and village areas. Furthermore, ArcGIS software (version 10.4.1) was applied for spatial analysis, and a dendrogram plot was developed to classify and interpret pollutant clusters. Descriptive statistics and whisker box plots were employed to analyze and visualize variations in pollutant concentrations across different locations. The average concentrations of PM<sub>1</sub>, PM<sub>2</sub>.<sub>5</sub>, and PM<sub>10</sub> were found to be 42.22 µg/m³, 70.13 µg/m³, and 89.66 µg/m³, respectively. The Department of Environment (DoE) established the Bangladesh National Ambient Air Quality Standards (NAAQS) for PM<sub>2</sub>.<sub>5</sub> and PM<sub>10</sub>, which were 65 µg/m³ and 150 µg/m³, respectively. Notably, the PM<sub>2</sub>.<sub>5</sub> concentration (70.13 µg/m³) across different land uses exceeded the NAAQS by 1.07 times. Furthermore, the average PM<sub>2</sub>.<sub>5</sub> and PM<sub>10</sub> concentrations were 2.80 and 1.79 times higher than the World Health Organization's (WHO) 24-hour standard levels of 25 µg/m³ and 50 µg/m³, respectively. Commercial areas exhibited the highest pollution levels, attributed to high traffic volumes, ongoing construction, and limited green spaces. In contrast, the industrial area recorded the lowest PM levels, likely due to stringent regulatory measures and lower population density. The study also highlighted that fine particulate matter constitutes a significant proportion of total particulate pollution. Statistical analysis revealed no significant variation in PM concentrations across different locations, while cluster analysis indicated interconnected pollution sources. These findings emphasize the need for targeted pollution control measures and increased awareness to address air quality concerns in Rangpur metropolitan and similar urban settings.