The deterioration in Delhi’s air quality, which was skirting the ‘very poor’ category on Sunday, was caused more by external factors than by sources within the capital, according to the Centre’s Decision Support System (DSS).
Data on Sunday showed that at least 67.89% of Delhi’s total PM2.5 contribution was from external sources.
For the sources within Delhi, the transport sector in Delhi accounted for 16.43% of the pollution in the city, followed by Delhi’s residential sector (4.27%) and then the industries sector (3.63%).

Studies have previously shown that the city’s particulate matter levels spike sharply in the days leading up to and during Diwali

City’s pollution worsens even before the festival, with Anand Vihar’s AQI hitting 384 (“very poor”) and several areas crossing 200

Ground-level ozone has been the lead pollutant on 10 of the 17 days this October, according to the Central Pollution Control Board (CPCB). While October normally sees the highest ozone levels, this year’s concentration exceeded 90 micrograms per cubic metre on several days, making it the highest for October since 2020.

The pollution build-up in Noida has been peaking between 7 pm and midnight — a pattern distinct from Delhi where spikes tend to occur later at night.

The top eight most polluted cities in India were all in NCR, painting a grim picture of what lies ahead in coming weeks as temperature drops in the region.

In 2024, the Supreme Court had said, “If firecrackers are burst in this fashion, it affects the fundamental right to health of citizens.” 

Experts say many of Delhi’s air quality monitoring stations may give inaccurate readings, because they are not placed properly — for example, too close to trees or buildings, or near roads.

These faults make it hard to trust whether the reported pollution levels reflect real “clean air” conditions.

The Supreme Court’s order to allow green crackers on a “test basis” just days before Diwali has reopened debate over balancing tradition and health.

Experts say there is no clear way to check whether a cracker is truly green, and past attempts at enforcement have been weak.

The Commission for Air Quality Management (CAQM) is currently operating with a 35 per cent staff shortage, while state bodies like the Delhi Pollution Control Committee (DPCC) and the Uttar Pradesh Pollution Control Board (UPPCB) also suffer from similar constraints.

Experts warn that giving short notice for new guidelines will make it very hard to enforce them properly in Delhi. The lack of time, resources, and coordination could mean many people ignore the rules.

After more than a decade of Aam Aadmi Party rule in Delhi that also coincided with the worsening of air quality, 2025 is the first Diwali-air pollution test for the BJP. … For too long, the BJP has been saying that Diwali was being unfairly singled out as the main polluter by environmentalists. Now, Delhi Chief Minister Rekha Gupta faces her first trial-by-firecracker.

The Delhi government, in collaboration with IIT Kanpur, is ready to launch its ₹3.21-crore cloud seeding project soon after Diwali to curb severe air pollution. The initiative awaits IMD’s final approval and favourable cloud conditions for the first artificial rain trial.

Scientists warn that even if green crackers reduce pollution by 30 %, the very large number of fireworks burst during Diwali in Delhi-NCR could cancel out that gain.

They argue the scale of use, weak enforcement, and mixing with conventional crackers limit any real benefit to air quality.

The Supreme Court has allowed the use of green firecrackers in Delhi-NCR from October 18 to 20. The court said they may be used only between 6 am–7 am and 8 pm–10 pm.
The court stressed this is a trial measure, and strict checks will be done to make sure rules are followed.

In 2024, the Supreme Court had said, “If firecrackers are burst in this fashion, it affects the fundamental right to health of citizens.” 

As Diwali nears, the Supreme Court has allowed sale and bursting of green crackers in Delhi-NCR for a limited period. These are fireworks made to emit less pollution and toxic gases. But experts caution that even with reduced emissions, the sheer number of crackers may still harm air quality.

Limited use of ‘green’ crackers allowed, balancing celebration with pollution control

The Supreme Court has allowed the limited use of green crackers during Diwali in Delhi-NCR, under strict monitoring to control pollution levels. The court reiterated that only crackers meeting environmental safety standards can be sold and used, and banned any non-compliant firecrackers.

Can green crackers truly make Delhi’s air cleaner this Diwali? Or does the festive celebration still risk choking the city’s already fragile atmosphere? News9’s Kartikeya Sharma unpacks the science, policy, and politics behind green crackers in conversation with Dr. Sanjeev Agrawal, former Addl. Dir., CPCB; CSE’s Sharanjeet Kaur; Environmental Activist Bhavreen Kandhari; and EnviroCatalysts’ Sunil Dahiya.