Few of the reasons which lead to increased pollution in Delhi are-
- Ever growing population of Delhi
- Construction of houses at the cost of Green Patches.
- Unstoppable construction activities in the city both by Public Works Department as well as individuals
- Industries operating in the city
- Burning of garbage
- Large number of vehicles on the roads of Delhi
- Climate of Delhi is another factor as on a normal day the air flow in Delhi is 1 metre per second. But in order to end air pollution the speed of air should be 6-10 metre per second
- Garbage is dumped haphazardly and burnt indiscriminately.
- Public roads are used for parking causing congestion.
- Burning of stubble is also an important factor.
All this combined together has led to increase in pollution nodes around Delhi and neighbouring areas.