Delhi-NCR Air Turns Very Poor: What GRAP Stages Mean

Delhi-NCR is grappling with dangerous air quality, as several areas record readings that have crossed safe limits. Noida's live Air Quality Index stood at 303 on Saturday, which is categorised as 'very poor'. Meanwhile, PM2.5 levels reached 222 micrograms per cubic metre and PM10 hit 269 micrograms per cubic metre.

Amid this worsening situation, authorities have appealed to people to avoid using vehicles that add to pollution while GRAP-1 is active, and to help the government in its efforts. The Graded Response Action Plan, which surfaces every winter, has once again become a point of discussion. Below is an explanation of what the plan is, who enforces it, and the curbs it places at each stage.

The Graded Response Action Plan, or GRAP, is an emergency action framework for dealing with air pollution in Delhi and the National Capital Region. In simple terms, it consists of a set of stringent rules that depend on pollution levels, with restrictions tightening as the air becomes more hazardous. The Environment, Forest and Climate Change Ministry first notified it in 2017.

Responsibility for implementing GRAP currently lies with the Commission for Air Quality Management (CAQM). The commission monitors predictions from the India Meteorological Department (IMD) and the Indian Institute of Tropical Meteorology (IITM), alongside air quality data. Once the AQI exceeds a set level, or forecasts show that air is likely to become severely polluted within a few days, the CAQM orders the relevant GRAP stage to take effect.

GRAP operates in four stages, graded by the seriousness of pollution. Stage one is linked to 'poor' air, with an AQI between 201 and 300. Dust control rules tighten at construction and demolition sites, open burning of garbage is fully prohibited, roads are sprinkled with water, and older vehicles of 10 to 15 years face stricter enforcement. People are also urged to rely on public transport.

Stage two addresses 'very poor' air, with an AQI between 301 and 400. Diesel generators cannot be used, though essential services receive exemptions. Parking fees go up to encourage people to use their private vehicles less, and CNG and electric buses along with Metro trips are increased. Coal-based tandoors at hotels and dhabas are banned.

Stage three is for 'severe' air, with an AQI between 401 and 450. This is considered extremely dangerous. All construction and demolition work is banned, except for national security and vital projects. Four-wheelers with BS-III petrol and BS-IV diesel engines are not allowed to run in Delhi-NCR, and primary schools may be closed.

Stage four covers 'severe plus' or emergency conditions, when the AQI rises above 450. This is the most extreme phase. All trucks except those carrying essential supplies are barred from entering Delhi. Schools and colleges shut down and classes are conducted online. Government and private offices may be directed to have 50 per cent of employees work from home, and odd-even schemes can also be introduced.

On Friday, Delhi's Environment Minister Manjinder Singh Sirsa had asked residents not to bring pollution-causing vehicles onto roads while GRAP-1 is in place, and to back the government's efforts. Speaking to the news agency, Sirsa said conditions were not good.

When the AQI nears 201 in regions like Delhi-NCR, the air starts becoming a serious concern. The 201 to 300 band is a warning level, where even healthy individuals can face difficulties, and people with heart and lung disease are especially at risk. An AQI above 301 is classed as hazardous and creates a health emergency. In this range, PM2.5, particles smaller than 2.5 micrometres, are the most dangerous because they penetrate deep into the lungs and dissolve into the bloodstream.