The Union environment ministry has tasked a panel to implement the Graded Response Action Plan that specifies multiple actions agencies across the National Capital Region (NCR) will need to implement under a drill when the air quality deteriorates beyond certain levels.

The actions, linked to levels of air pollution measured through tiny particles 2.5 microns (PM 2.5) or 10 microns (PM 10), aim to improve air quality over the NCR but could serve as a template for other cities and regions grappling with air pollution, environmental analysts said.

The ministry's notification assigning the implementation of the decision to the panel called the Environmental Pollution (Prevention and Control) Authority follows a Supreme Court directive last month to the central government to implement an action plan submitted by the Central Pollution Control Board.

"This plan demands multiple agencies in Delhi, Haryana, Punjab and Rajasthan to automatically initiate action each time the air pollution levels exceed certain values," said Anumita Roy Chowdhury, executive director for research and advocacy at the NGO Centre for Science and Environment, New Delhi.

State authorities will, among other actions, need to implement the odd-even plan that uses licence plate numbers to restrict private cars on roads when PM 2.5 persists above 300 micrograms per cubic metre, or five times the safe level, for 48 hours.

The authorities will also need to close brick kiln and stone-crushing operations, shut down a city thermal power plant, increase public transport to encourage off-peak travel, stop use of diesel-generators, raise parking fees up to four-fold when PM 2.5 levels are severe or very poor.

The action plan urges people with asthma, other respiratory disorders or heart disease to avoid exposing themselves when pollution levels are at very poor, severe, or emergency levels. It also asks schools to suspend outdoor activities and sports events during severe and very poor air quality levels.

Resident welfare associations and house-owners have been asked to provide electric heaters during winters to their security staff to discourage them from burning paper or firewood for warmth.

The plan comes amid concerns that air pollution - driven by industrial growth, expanded urbanisation and growth in traffic density - is contributing to an estimated 1.6 million premature deaths across the country each year.

Environmental groups campaigning for cleaner air have welcomed the plan but have questioned the policy of tying actions exclusively to transient air pollution levels.

"More investments in public transport, banning garbage burning and the enforcement of emission standards for power plants and industries are steps that need to be in force throughout the year - not only when air pollution levels become severe," said Sunil Dahiya, a campaigner with Greenpeace India.

Greenpeace has said the plan's focus on curbs on a single thermal power plant on the outskirts of Delhi is insufficient. It said a report from IIT Kanpur had identified 13 thermal power plants within a radius of about 300km from Delhi that also need to be regulated for improvements in the NCR's air quality.

The air quality over NCR is influenced by multiple factors, including vehicle emissions, thermal power plants, construction activities, brick kilns and crop residue burning in Punjab and Haryana just ahead of the winter months.

In November last year, the PM2.5 levels over the capital had persisted above 400 micrograms per cubic metre for several days.