New Delhi: After the end of Delhi's odd-even formula, capital is facing an increase in air pollution again, the Centre for Science and Environment said.

The gains of the 15 days long odd-even scheme have been lost, and pollution levels can worsen further unless the authorities act, it said in a statement.

"New analysis by the CSE shows air pollution is back with a vengeance. The first three working days after the completion of the odd-even scheme have seen the rapid worsening of air quality more than 57 percent jump in PM 2.5 levels on the first working day, and has stayed at severe levels," it said further in the statement.

The Delhi government enforced the odd-even scheme to restrict traffic on the roads, with odd-numbered four wheelers allowed to ply on odd dates and even-numbered vehicles on even dates.

"This validates the importance of emergency action," said Anumita Roy Chowdhury, executive director of CSE.

"The fortnight when the programme was implemented has clearly demonstrated that the peak pollution levels are lower than the normal smog peaks of the season despite adverse weather conditions."

Experts say that during winter, pollutants in the air stay close to the ground and get trapped in the air.

Without an emergency action plan, the delayed winter can lead to rapid building up of pollution levels, CSE said.

"The odd-even scheme has proved that the city needs curbs on high traffic volume to pull down peaking of pollution, reduce congestion that further increase emissions.

"The Delhi government should expedite action for more systemic solutions," it said.

Directives from the Supreme Court to control pollution in the National Capital Region (NCR) like the advancement of Euro VI emission standards, augmentation of public transport, notice on the closure of Badarpur power plant, and action on construction and road dust must be taken, CSE said.(IANS)