Delhi-NCR AQI Hits Crisis Point: Key Details On GRAP Stage-4 Restrictions

As Delhi faces its worst air quality crisis, with the Air Quality Index (AQI) soaring to 481-classified as "severe plus"-authorities have enforced Stage 4 of the Graded Response Action Plan (GRAP). These stringent measures are aimed at reducing pollution levels and safeguarding public health amid worsening air conditions in the region.

What is GRAP Stage 4?

The Graded Response Action Plan (GRAP) is a set of emergency measures implemented in stages, based on air quality levels. Stage 4, the highest level of emergency measures, comes into play when the AQI crosses the "severe" threshold (above 400), which can have severe health implications for all individuals, not just those with pre-existing respiratory conditions.

With Delhi's AQI reaching a hazardous level of 481 by 6 am on November 18, 2024, authorities had no choice but to implement GRAP Stage 4. The air quality in Delhi-NCR has remained in the "severe plus" category, posing major risks to the health of the city's population.

Key Measures Under GRAP Stage 4:

Ban on Diesel Vehicles:

• Medium and Heavy Goods Vehicles: Diesel-run vehicles with BS-IV or lower emissions standards are banned in Delhi unless they are carrying essential goods. This is a significant step, given that diesel vehicles are major contributors to particulate matter in the air.
• Non-Essential Trucks: All trucks carrying non-essential goods are prohibited from entering Delhi. The exception is for trucks that run on alternative, cleaner fuels like LNG, CNG, or BS-VI diesel engines.

Restrictions on Light Commercial Vehicles (LCVs):

• Non-essential light commercial vehicles (LCVs) registered outside Delhi are also restricted from entering the capital unless they are powered by cleaner fuels such as CNG, BS-VI diesel, or are fully electric vehicles. This targets the large number of trucks and light commercial vehicles that contribute heavily to pollution levels.

School and Workplace Adjustments:

• School Closures and Online Classes: In response to the severe air quality, the Centre for Air Quality Management (CAQM) has recommended shifting students in classes 6-9 and class 11 to online classes. This is to reduce the exposure of children to hazardous levels of air pollution.
• Workplace Restrictions: Public and private offices in Delhi-NCR have been advised to operate at 50% capacity. The remaining workforce is instructed to work from home, reducing the number of commuters and limiting vehicular emissions.

Suspension of Construction and Demolition Activities:

• All construction and demolition activities are suspended under the GRAP Stage 4 measures, including public infrastructure projects like roads, flyovers, and power transmission lines. This aims to curb dust pollution and other harmful emissions generated by construction activities.

Health Risks and Pollution Data:

The health implications of such high levels of pollution cannot be overstated. The AQI readings across Delhi show "severe" levels of pollution, with many stations reporting AQI levels exceeding 400. This kind of pollution is categorized as "severe plus," meaning it poses serious health risks even to healthy individuals, including respiratory issues, eye irritation, and aggravated heart conditions.

PM2.5-fine particulate matter-remains the primary pollutant. These tiny particles, smaller than 2.5 micrometers, are capable of penetrating deep into the lungs and even entering the bloodstream, leading to serious health complications over prolonged exposure.

Contributions to Pollution:

1. Vehicle Emissions: According to the Centre's Decision Support System for Air Quality Management, vehicles contributed 15.8% of Delhi's pollution on Sunday, November 17. The restrictions on diesel vehicles and non-essential trucks are designed to cut down on this source of pollution.
2. Stubble Burning: Stubble burning remains a significant contributor to Delhi's pollution. On Saturday, it accounted for 25% of the total pollution. The practice of burning crop residue in neighboring states of Punjab and Haryana sends large amounts of smoke and particulate matter into Delhi's air, exacerbating the already dire situation.
3. Weather Conditions: Unfavorable weather conditions, such as low wind speeds and high humidity, trap pollutants close to the ground, further intensifying the smog in Delhi. The Indian Meteorological Department forecasts smog conditions with low wind speeds to persist until at least the end of the week, prolonging the crisis.

Challenges and Future Steps:

The implementation of GRAP Stage 4 comes as a necessary response to the deteriorating air quality in Delhi. However, experts warn that these measures, while important, are not enough to address the root causes of pollution. Long-term solutions, such as stricter vehicle emission norms, better management of stubble burning, and improved waste management practices, are needed to reduce Delhi's air pollution sustainably.

The Centre and Delhi state government are under increasing pressure from environmentalists and the public to take stronger actions, including stricter enforcement of pollution control measures and incentives for cleaner technologies. As Delhi continues to struggle with severe pollution, the effectiveness of GRAP Stage 4 will depend on the cooperation of the public and the implementation of long-term solutions that target pollution sources beyond vehicular emissions and stubble burning.