Assessment of the effectiveness of policy interventions for Air Quality Control Regions in Delhi city.

Government has implemented various scattered and un-quantified control actions in Delhi city to reduce the air pollution levels; however, it still exceeds the National Ambient Air Quality Standards (NAAQS). The present study has been designed to assess the air quality status, identify Air Quality Control Region (AQCR), and evaluate control strategies in the city. Out of eight selected locations, ambient PM10, PM2.5, and NO2 concentrations were found exceeding the daily as well as annual standards at selected AQCR with peak levels during post-monsoon than winter and summer. Anand Vihar was found to be most polluted and thus, selected as an AQCR. AERMOD performed satisfactorily in predicting pollutant concentration during winter and summer having an index of agreement in the range 0.54-0.80. PM10 and PM2.5 can be reduced substantially by increasing frequency of efficient mechanized cleaning of roads and sprinkling of water on the roads. Progressive decrease in NO2 concentrations can be achieved by restricting entry of truck in the study area through alternate path. The cumulative impact of all selected control strategies indicates a substantial decrease in air pollution within AQCR. The study also suggests a policy framework to manage the urban air quality through local scale air quality guidelines.