Doctors who have been monitoring air quality data for the last month suggest that the best time to take a stroll for those vulnerable to pollution-related diseases is around 2pm.
This is because PM 10 (coarse) and PM 2.5 (fine, respirable particles) levels stabilize briefly around that time. However, they found that different pollutants dominate at different monitoring stations, for instance benzene levels were much higher than the standard near Mandir Marg while carbon monoxide levels were higher near Anand Vihar.