Top reasons of pollution in Delhi are :
1. Farmers burn rice stubbles in Punjab, Haryana and Uttar Pradesh.
2. Pollution caused by the traffic
3.Due to stagnant winds, pollutants get locked in the air and affect weather conditions, resulting in smog.
4. Over-population in Delhi ncr
5. Investment in public transport and infrastructure is low, which leads to heavy private vehicular traffic and congested roads
6. Large scale construction in Delhi-NCR
7. Industrial pollution, bhattis in dhabas and burning garbage in dumps
Burning firecrackers is only one day affair