A decade back, the enormous vehicular traffic in Delhi had made Delhi rank 4th among polluted cities of the world. Two measures taken by the Delhi Government brought marked improvement in air quality by 2005.
1.What were these two measures and how did they reduce air pollution ?

2. What is the norm set by Euro II for petrol and diesel vehicles ?

1. The two measures taken to reduce the vehicular traffic in Delhi were:
(i) All the buses of Delhi were converted to run on CNG by the end of 2002. CNG being a better fuel than diesel burns more efficiently and has very little left behind.

2. Phasing out of old vehicles and use of unleaded petrol.

(ii) Euro II norms imposed that Sulphur should be controlled at 350 ppm in diesel and 150 ppm in petrol. Aromatic hydrocarbons need to be at 42 per cent in the concerned fuel. The goal was to reduce sulphur to 50 ppm in petrol and diesel and bring down the level to 35 per cent. The vehicles had to be upgraded too.