Idk why but the air quality dropped 3x(300->1200) in the past 2-3 days again in Delhi.
Good thing that the 
has managed to label all anti-pollution protests as “Maoist” so nobody dares to protest anymore since the government can and will throw you in jail for a decade without trial.
Most people don’t care and are out enjoying the weekend in this lethal air.
Delhi is also in a valley in a range of low hills, so the wind cannot clear the pollution away. (E.g. Mumbai has more industry etc, but has cleaner air.)