A recent study carried out by the World Health Organisation (WHO) confirms that diesel exhaust fumes can, in fact, be carcinogenic. The WHO has consequently deemed diesel exhaust fumes to be as harmful as tobacco and asbestos.

India has seen a substantial spurt in diesel car sales thanks to the heavy subsidisation of diesel carried out in order to ease the burden on farmers who run irrigation pump sets. However, the subsidisation is inadvertently also benefitting a range of owners with diesel vehicles, including those made by high-end car manufacturers like Mercedes Benz, BMW and Audi. The current prices for diesel and petrol are Rs 40.91 and Rs 71.92 respectively in Delhi.

Recently, the International Agency for Research on Cancer (IARC) bumped up diesel exhaust fumes to Grade 1 – the highest level possible – after providing indisputable evidence that it contains carcinogens. The spanner in the works is the price of diesel and the advancements in diesel technology over the years, which has led to a surge in the amount of diesel cars bought. According to the Society of Indian Automobile Manufacturers (SIAM), diesel vehicles made up 60 percent of the 2 million cars sold in the last fiscal itself.

Indian diesel vehicle engines are based on European standards. Of the two currently followed (Bharat Stage III and IV), the former is enforced in 13 major cities. This stipulates that the fuel is permitted to have a sulphur concentration ranging from 350 to 550 parts per million (ppm). Bharat Stage IV norms permit 50ppm, which could further be reduced to 10ppm once the oil ministry agrees to supply Euro V fuel.