1. Delhi has colder weather during winters.
2. There are stagnant winds which trap smoke from various sources like automobile exhausts and firecrackers.
3. Many farms surrounding Delhi resort to burning crop stubbles.
4. Even in the city garbage is lit.
5. There is more dust on the roads.
6. Automobile traffic is heavy and public transport systems were not efficient, till the metro was started.
Effects caused by this air pollution are as follows:
1. Citizens suffered breathlessness and chest muscle contraction.
2. The irritation in eyes, asthma and allergy were frequently reported.