Study on Ambient Air Quality of Megacity Delhi, India During Odd-Even Strategy

Abstract

State Government of Delhi had adopted odd-even scheme on vehicles plying in megacity Delhi to understand and improve the air quality of Delhi. To understand the effect of odd-even scheme on the concentration of pollutants, we have analysed the concentrations of chemical constituents [organic carbon, elemental carbon, water soluble inorganic components, trace elements and stable carbon and nitrogen isotopic composition (13CTC) and N (15NTN)] of PM2.5 and PM10 along with mixing ratios of trace gases (NO x , CO, SO2 and NH3) data collected at an urban site of megacity Delhi during first phase (Phase-I: winter 2016) and second phase (Phase-II: summer 2016). During the Phase-I of the scheme, mass concentrations of PM2.5 and PM10 were changed by 13 and 5%, respectively, whereas, concentrations of PM2.5 and PM10 were changed by +18 and +16%, respectively during the Phase-II as compared to before the implementation of the scheme. The analysis of chemical constituents of PM2.5 and PM10 reveals that the odd-even strategy marginally changed the concentrations (markers) of vehicular emission. During both the phases, mixing ratios of trace gases (NO x , CO, SO2 and NH3) were reduced non-significantly during the odd-even scheme as compared to before the implementation of the scheme.