With nearly 10 million vehicles on Delhi's roads, campaigners say much more needs to be done. (AFP Photo)
With winter approaching, Delhi's pollution woes are about to return, environmentalists have warned, calling for reinstating traffic restrictions, curbs on coal-fuelled power plants and construction projects.
"We are approaching the big winter problem and pollution is going to pick up rapidly now," Anumita Roy Chawdhary, Executive Editor of the Centre for Science and Environment or CSE told NDTV. "There should be emergency restriction measures for vehicles, immediate closure of Badarpur power plant and crackdown on construction projects that violate norms."
The CSE, one of the country's most prominent environmental think tanks, said the slight reduction in pollution last year could be because of the Supreme Court's intervention against heavy commercial vehicles but the figures remained worryingly high.
The clamour comes amid an increasing push by courts, demanding that the authorities take action on the filthy air in Delhi, which has been rated as one of the world's most polluted cities in surveys.
In August, the Supreme Court lifted a ban on the registration of new high-end diesel vehicles in the capital but enforced an additional tax on such cars.
The top court has also ordered a "pollution toll" on thousands of diesel-guzzling trucks that enter the capital every night, as well as a ban on large, new diesel cars.
On its part, the Delhi government announced a string of measures including the odd-even road rationing scheme in January and in April that took around a million cars off the roads for two weeks.
But with nearly 10 million vehicles on Delhi's roads, campaigners say much more needs to be done.
A study of 3,000 cities by the World Health Organisation released in May placed Delhi in 11th position on basis of the annual average concentration of PM2.5 particles.
These particles, less than 2.5 micrometres in diameter, are linked to higher rates of chronic bronchitis, lung cancer and heart disease as they settle deep in the lungs and can pass into the bloodstream.