Travelling by car in Delhi exposes people to black carbon levels five times higher than Europe and America, say scientists who found that Asian residents are exposed to nine times more air pollution than their Western counterparts.

According to the World Health Organisation (WHO), about 88 percent of premature deaths in low- and middle-income countries in Asia can be attributed to air pollution.
The number of road vehicles in Beijing increased from 1.5 million in 2000 to more than 5 million in 2014 and the number in Delhi is expected to increase from 4.7 million in 2010 to 25.6 million by 2030.