Which of the following is an incorrect way to reduce air pollution at the individual level?

At an individual level, one can reduce air pollution in the following ways:

1. By not using vehicles for short distances.
2. By using clean fuels such as LPG and CNG instead of diesel and petrol.
3. By using public transport instead of using personal vehicles. 
4. Using fuels such as LPG that emit fewer toxins and disposing of garbage in bins properly.