Delhi is once again grappling with hazardous air pollution as winter's chill sets in, pushing the city's air quality index (AQI) into the 'very poor' category. The AQI, which measures PM2.5 (fine particulate matter that can penetrate deep into the lungs), has surged past 300, raising serious health concerns for millions of residents.
Health Risks Escalate
Prolonged exposure to such polluted air can lead to respiratory issues and exacerbate existing conditions, with children and the elderly being particularly vulnerable. The city's iconic skyline is often shrouded in a thick haze, forcing residents to wear masks and install air purifiers at home.
Emergency Measures Activated
In response, authorities have implemented Stage II of the Graded Response Action Plan (GRAP), a set of emergency measures that tighten as pollution levels rise. The current restrictions include intensified road cleaning, higher parking fees to discourage private vehicle use, and expanded public transport services. The Delhi Metro has added 20 extra weekday trips, and government office hours have been staggered to reduce traffic congestion.
Officials said the measures were triggered after forecasts indicated that air quality would remain very poor for the coming days.
Annual Crisis Worsens Around Diwali
Delhi and neighboring regions in northern India face hazardous air every winter, especially around Diwali, one of the country's biggest festivals, which falls just days away. The festival is celebrated with lights, lamps, and fireworks, which often worsen the already poor air quality by releasing fine particles and harmful gases.
The annual pollution crisis is driven by a combination of factors: vehicle exhaust, industrial emissions, falling temperatures, low wind speeds, and the burning of crop stubble in neighboring states.
From Clean October to Sudden Spike
The sharp rise in pollution follows an unusually clean October, when Delhi recorded its lowest average AQI for the month in eight years. Experts attribute the sudden deterioration to dropping temperatures, slow winds, and increased crop-residue burning in Punjab and Haryana.
A recent storm had brought rain and stronger winds, helping clear the air. But as the weather settled, northwesterly winds returned, carrying smoke from burning fields toward the capital.
India's pollution watchdog classifies AQI readings between 301 and 400 as 'very poor', while anything above 400 is considered 'severe'. On Wednesday morning, Delhi's AQI stood at 377.
Supreme Court Allows Green Firecrackers
With Diwali just days away, concerns are mounting that fireworks could push pollution levels even higher. Last year, Delhi woke up to a toxic haze the morning after the festival, despite a court directive to use less-polluting firecrackers.
Authorities have imposed restrictions on firecrackers over the years, including outright bans on their manufacture, sale, and use, but enforcement has proved difficult.
On Monday, India's Supreme Court allowed the manufacture, sale, and use of certified green firecrackers in Delhi and neighboring areas for a limited period. The court said the crackers could be set off only between 06:00 and 07:00 local time (00:30-01:30 GMT) and between 20:00 and 22:00 (14:30-16:30 GMT) on 7 and 8 November, during the Diwali weekend. It also banned fireworks within 300m of hospitals, care homes, schools, and other designated silence zones.
Green firecrackers use modified chemical formulations designed to produce fewer emissions than conventional fireworks. They must carry QR codes that allow buyers and authorities to verify details of their manufacturer and certification. But ensuring that only approved firecrackers are sold remains a major challenge.
In its latest order, the Supreme Court acknowledged that conventional firecrackers had continued to be sold as green alternatives, even when a complete ban was in place. It has directed police to patrol designated sales areas, carry out random QR-code checks, and seize illegal firecrackers.
Mumbai Also Affected
The problem is not confined to the capital. Mumbai, India's financial hub, has also recorded elevated pollution levels over the past month, despite benefiting from coastal winds that typically help disperse pollutants. On 24 October, Mumbai's AQI reached 322, placing it in the 'very poor' category. The spike was attributed to low wind speeds, construction dust, garbage burning, firecracker emissions, and pollutants carried from neighboring regions.
The city's air quality has improved in recent days, recording an AQI of 89, classified as 'satisfactory', on Wednesday. Neighboring Navi Mumbai recorded a 'moderate' AQI of 118. The improvement follows nearly two weeks of smoggy conditions, with residents sharing photos and videos of the haze on social media.
