<p>The present study was intended to emphasize the assessment of ambient air quality of Dhanbad city with respect to PM₁₀, PM_2.5, SO₂ and NO_Xconcentrations, in order to investigate the impact of mining and transportation activities. From the monitoring and analysis at four selected monitoring stations during winter and summer seasons, significant spatial variation in pollutant (PM₁₀, PM_2.5, SO₂ and NO_X) concentrations is quite evident. The concentrations of PM₁₀ were observed highest in mining area (at Dhansar PS; 291 &micro;g/m³), whereas the PM_2.5 the concentrations were observed higher along traffic routes (especially, at Bank More; 218 &micro;g/m³). Higher concentratios of PM₁₀ in mining area indicates the substantial impact of dust emanated from mining and associated activities on air quality. Whereas, the higher PM_2.5 concentration along the transportation routes shows the influence of transportation activities on the airshed of the area. The significant seasonal variation in pollution levels is also apparent, as the concentrations of every pollutant were observed higher during the winter, than the summer season, at all sites. The mean concentration levels of PM₁₀ and PM_2.5were observed 267 &micro;g/m³, 173 &micro;g/m³ and 234 &micro;g/m³, 108 &micro;g/m³during winter and summer seasons, respectively. From the calculated values of air quality index, it is evident that Dhansar PS and Bank More are most polluted sites and PM₁₀ is the most alarming pollutant in the area under investigation.</p>