Analyzing Air Quality Index (AQI) and PM₂.₅ Concentration for Dhaka City from 2016 to 2022, Bangladesh

The air quality in Dhaka is progressively declining over time. This study employed a comprehensive research methodology to analyze the air quality in Dhaka city over seven years, from 2016 to 2022. AQI and PM₂.₅ data has been collected from the U.S. Embassy Dhaka and meteorological data from the Bangladesh Meteorological Department (BMD). Data processing and analysis have been conducted using SPSS and Microsoft Excel. Annual variations indicated that 2021 and 2022 experienced the highest pollution levels. In 2021 annual PM₂.₅ concentration was found an average of 94.6 µg/m³ which is 2.7 times higher than the national Standard level. Furthermore, shifting variation analysis demonstrated that air quality deteriorated in the morning, reaching an unhealthy level, largely attributed to heavy traffic. Along with that seasonal variations indicated that winter had the highest PM₂.₅ levels, linked to factors like biomass burning and reduced rainfall. This variance is due to the interaction of a number of different meteorological phenomena. It has been observed that there exists a robust and statistically significant negative relationship between rainfall and the concentration of PM₂.₅. Moreover, Weekly variations showed Thursdays to have the highest air pollution, likely due to ongoing industrial activities. Monthly analysis highlighted January as the worst month, with extremely high PM₂.₅ levels, while July and August exhibited relatively good air quality. The frequency of days with "Unhealthy" and "Very Unhealthy" AQI categories significantly increased, posing a serious threat to public health. To address this, a range of short, mid, and long-term strategies are recommended, including improved public awareness, sustainable transportation options, and stricter environmental regulations.