Did green crackers fail to check air pollution? Delhi records worst post-Diwali AQI in three years

Delhi is choking a day after Diwali as pollution levels spiked sharply through the night, reaching the highest concentrations recorded in the last three years. Delhiites woke up to a thick layer of smog blanketing the National Capital on Tuesday, October 21.

The air quality deteriorated, despite the Supreme Court only allowing ‘green’ crackers. Real-time data from the Delhi Pollution Control Committee (DPCC) showed Particulate Matter (PM) 2.5 and PM10 concentrations surging by 15 to 20 times above safe limits across several stations, the Indian Express reported.

Air Quality Index in ‘very poor’ zone

Several locations, such as Anand Vihar, Dwarka Sector 8, Patparganj, and Jahangirpuri, recorded peaks above 1,400 to 1,800 µg/m³, which is 15-20 times higher than the permissible standards.

The capital city’s air quality index (AQI) at 11 PM stood at 347, in the ‘very poor’ category, as per Central Pollution Control Board (CPCB) data. It remained nearly unchanged, at 346 at 6 AM on Tuesday, and climbed further to 359 by 11 AM.

Data indicates that this year’s Diwali pollution levels were the highest in recent years, despite the promotion of ‘green’ crackers.

Delhi's air quality on Diwali this year was worse than last year, which stood at 328 in 2024, and higher than the previous two years — 218 in 2023 and 312 in 2022.

Worst-affected areas

According to DPCC data, Anand Vihar recorded the highest PM10 concentration around 2 AM, followed closely by Dwarka Sector 8, Patparganj and Jahangirpuri.

Stations such as Mundka, Ashok Vihar, and Okhla Phase 2 also reported values exceeding the safe limits during late-night hours.

At several locations, including Patparganj, Nehru Nagar, JLN Stadium, and Okhla Phase 2, data were missing for multiple hours between 11 pm and 5 am, which suggests a possible instrument saturation due to extremely high particulate concentrations. The reading, which was resumed early in the morning, remained beyond the safe limits.

Dr Mohan George, former Additional Director at DPCC, questioned the data gaps during the peak pollution window. “Why was CPCB’s continuous air quality tracking unavailable for several hours, and why did most monitoring stations show missing data during the peak pollution window?" he asked.

“Many stations have data missing from 11 pm to 6 am… If this was a ‘Green Deepawali’, then the public deserves to know what exactly they breathed during the night,” George told the Indian Express.