The Dhaka Metro Rail Line 1, also known as DMRT Line 1, is the first subterranean metro rail project in Bangladesh, and is currently undergoing depot construction work under contract package-1 (CP 01). The construction of depot work is mainly susceptible to ambient air quality due to the land development and soil improvement activities. The long-term construction period can significantly impact the surrounding air quality of the project area and so it is crucial to identify air pollution concerns and analyze the impact of air quality on the environment. This study evaluated ambient air quality in four distinct zones of the depot area from June 2023 to September 2024. There were several pollutants measured in the ambient air including Particulate Matters (PM10 and PM2.5), Ozone (O3), Lead (Pb), Sulfur Dioxide (SO2), Nitrogen Dioxide (NO2), Carbon Monoxide (CO). The air quality monitoring machine Oceanus AQM-09 and Haz-Scanner (HIM, 6000) were used for 8 hours on the site. The power-law equation of Schroeder and Jugloff, 2012 was applied to provide 24-hour and 8-hour averages for the air quality parameters. It is observed that in pre-monsoon period of 2024, there is quite high intensity of particulate matter (PM2.5) present in the air, whereas other air pollutants values were found in all four zones are moderate in the air samples as prescribed by Air Pollution Control Rules, 2022.