‘Green’ crackers fail, Delhi chokes’: Post-Diwali smog hits four-year high, PM2.5 peaks at 675

New Delhi: Delhi woke up on Tuesday under a blanket of grey haze and acrid air, recording its worst post-Diwali air quality in four years with PM2.5 levels peaking at 675 micrograms per cubic metre — the highest since 2021. This came despite the Supreme Court allowing the bursting of ‘green’ firecrackers within specified hours, as celebrations reportedly continued well past the 10 pm deadline, leaving the Capital engulfed in smog and a swirl of political recriminations.

According to the Central Pollution Control Board (CPCB), Delhi’s 24-hour average Air Quality Index (AQI) at 4 pm on Diwali stood at 345, classified as “very poor”, compared to 330 in 2024, 218 in 2023, 312 in 2022, and 382 in 2021. By Tuesday afternoon, the AQI remained almost unchanged at 351. Hourly readings showed sustained high pollution through the night — 344 at 10 pm, 349 at midnight, and above 350 through the next morning.

The PM2.5 concentration, representing fine particles that can deeply penetrate the respiratory system, climbed steadily through the evening—from 91 micrograms per cubic metre at 5 pm to 371 at 9 pm, 537 at 10 pm, and eventually 675 by midnight. For comparison, PM2.5 levels were 609 in 2024, 570 in 2023, 534 in 2022, and 728 in 2021. Experts noted that the readings far exceeded the safe limit of 60 micrograms per cubic metre.

The Decision Support System (DSS), Delhi’s pollution source tracker, reported that transport emissions contributed 14.6 per cent to the city’s air pollution on Tuesday. Neighbouring regions also added to the problem — Ghaziabad (6 per cent), Noida (8.3 per cent), and Gurugram (3.6 per cent). Stubble burning, though officially estimated at only 1 per cent contribution on the day, continued to dominate the political narrative.

“This is the thickest smog I’ve seen since 2021. My children are coughing constantly despite keeping all windows shut,” said Meenakshi Sharma, a Dwarka resident. “We followed all the rules — no firecrackers, air purifiers in every room — and yet the air feels like poison.”

Doctors across the city reported a sharp rise in respiratory cases. “Outpatient visits doubled this morning,” said Dr. Rachita Mehra, a local physician. “People with asthma, bronchitis, and even cardiac distress are reporting symptoms aggravated by poor air quality.”

Dr Mehra called PM2.5 a “silent killer”, warning that the particles “enter the bloodstream and affect every organ, from lungs to heart to brain. Each Diwali, we lose years of collective health.”

Residents in multiple neighbourhoods echoed similar distress. Shahid Ansari of Lajpat Nagar said his elderly mother required a nebuliser twice since Diwali night. “Even stepping out for a walk feels dangerous now,” he said.

The political fallout was swift. Delhi Environment Minister Manjinder Singh Sirsa said the city’s AQI had risen “only marginally” from 345 to 356 post-Diwali despite the use of green firecrackers. He accused the Aam Aadmi Party (AAP) government in Punjab of worsening Delhi’s air through unchecked stubble burning. “The AAP government in Punjab forced farmers to burn a record amount of paddy stubble on Diwali night,” Sirsa alleged.

Delhi Home Minister Ashish Sood said those bursting firecrackers after 10 pm “behaved irresponsibly” but added that firecrackers were “not the sole reason behind the pollution spike.”

AAP leaders hit back, accusing the BJP-led Delhi administration of “failing to implement artificial rain” and not enforcing the Supreme Court’s restrictions on cracker use. AAP’s Delhi unit chief Saurabh Bharadwaj said, “Banned firecrackers were freely available. Why did the government allow this? Was it hand in glove with the firecracker lobby?”

Congress leaders, meanwhile, blamed “years of administrative neglect” and demanded sustained anti-pollution measures.

Adding to the tensions, BJP leader Amit Malviya posted on social media, “Unless AAP-ruled Punjab stops stubble burning, Delhi will keep choking. It’s not Diwali lamps, but AAP’s misgovernance that darkens the skies.”

AAP ministers countered that the Centre had “failed to enforce cracker bans or provide clean energy alternatives.”

Dipankar Saha, former head of air laboratories at CPCB, said a depression in the Bay of Bengal created low wind speeds that trapped pollutants. “With stagnant winds, there’s no dispersion. Pollutants simply accumulate,” he said.

Environmental activist Ritika said the same cycle repeats annually. “Bans are announced, crackers burst anyway, and then everyone blames stubble burning. Delhi needs year-round preventive measures, not post-Diwali firefighting.”

The Commission for Air Quality Management (CAQM) had already invoked Stage II of the Graded Response Action Plan (GRAP) before Diwali, anticipating deterioration. Despite that, satellite data detected 45 stubble-burning incidents in Punjab, 13 in Haryana, and 77 in Uttar Pradesh on Diwali. Punjab Pollution Control Board data also showed over 3,500 farm fires in the past ten days — a threefold increase since early October.

Even as air quality deteriorated, Delhi endured one of its noisiest Diwalis in recent years. Real-time data from the Delhi Pollution Control Committee (DPCC) revealed that 23 of the city’s 26 noise monitoring stations recorded levels above permissible limits, up from 22 last year and 13 in 2023.

Karol Bagh was the loudest, with noise levels peaking at 93.5 dB(A) at 11 pm — far above the 55 dB(A) night limit for residential areas. Silence zones such as Sri Aurobindo Marg and Maharshi Valmiki Hospital also recorded peaks of 75.7 dB(A) and 77.9 dB(A) respectively, nearly double the permissible limits.

Even residential areas like Vivek Vihar (85 dB) and Dwarka (80 dB) saw heavy violations, while commercial hubs like Lajpat Nagar stayed noisy past midnight.

A 2022 order by the National Green Tribunal had directed authorities to treat noise pollution at par with air pollution, but implementation remains poor.

Hospitals reported a surge in burn and respiratory cases. More than 250 people sustained burn injuries across the city, with Safdarjung Hospital alone treating 129 cases — the highest among government hospitals.

The Delhi Fire Services (DFS) received 269 emergency calls on Diwali night, a nearly 15 per cent drop from last year’s 318, though still among the highest in recent years.

The New Delhi Municipal Council (NDMC) deployed 30 anti-smog guns, mechanical sweepers, and water sprinklers along arterial roads, including Connaught Place and Lodhi Road. “We’re spraying water twice a day to suppress dust, but these are short-term measures,” said NDMC Vice-Chairman Kuljeet Singh Chahal.

Meanwhile, firecracker sales soared this year. Traders estimated total sales at Rs 500 crore, with the Sadar Bazar Association reporting nearly 40 per cent higher business than in 2024.

Despite the pollution, Chief Minister Rekha Gupta described this year’s Diwali as “unique in radiance and brilliance” and thanked the Supreme Court for “balancing tradition with environmental concerns” through the limited allowance of green firecrackers.

Environmental experts have urged coordinated, long-term measures. “Delhi’s air quality lies in shambles. Thirty-six out of thirty-eight monitoring stations are in the red zone. Only ruthless and sustained execution can save this city,” said Amitabh Kant, India’s G20 Sherpa and former NITI Aayog CEO.

He called for a unified national action plan targeting crop residue burning, electric vehicle adoption by 2030, and strict control on construction dust.

The Ministry of Earth Sciences has warned that pollution levels could remain high until at least October 24 due to continued stubble burning and unfavourable weather.