Delhi chokes under post-Diwali smog as air quality dips to 'very poor'

Residents of the national capital woke up to a dense blanket of smog on Wednesday morning, as air quality in Delhi plummeted following Diwali celebrations. At 5.30 a.m., the Air Quality Index (AQI) stood at 345, categorised as ‘very poor’, according to data from the Central Pollution Control Board (CPCB).

Despite Supreme Court restrictions on firecracker usage, several areas across Delhi and the National Capital Region (NCR) reported widespread violations on Diwali night. Many monitoring stations recorded AQI levels exceeding 500 on Tuesday, a level considered ‘severe’, while the 24-hour average AQI for Tuesday was 351, up from 345 on Monday.

Experts note that the spike in pollution is not unexpected. Low wind speeds, combined with emissions from firecrackers and stubble burning in neighbouring states such as Punjab and Haryana, typically exacerbate Delhi’s air quality during the post-monsoon and winter months.

Authorities are reportedly considering emergency measures to tackle the worsening situation. The Commission for Air Quality Management (CAQM) has indicated that Stage II of the Graded Response Action Plan (GRAP) could be activated.

GRAP-4 restrictions reintroduced in Delhi-NCR as AQI worsens

Under GRAP-II, stricter measures include banning diesel generators except for essential services, imposing tighter controls on construction and demolition, and intensifying dust suppression efforts.

Special task forces are also expected to be deployed in pollution hotspots to manage vehicular emissions and traffic flow.

CPCB data over the past four years suggests that Diwali 2025 ranks among the most polluting in recent memory, highlighting a recurring deterioration in breathable air quality directly linked to unchecked firecracker use.

The high levels of particulate matter are already affecting public health. Post-Diwali PM2.5 concentrations averaged 488 micrograms per cubic metre (µg/m³) on Tuesday, with doctors reporting an increase in respiratory issues, eye irritation, flu-like symptoms, and joint pain.

Health experts have urged residents, particularly children, the elderly, and those with pre-existing respiratory conditions, to minimise outdoor exposure and wear protective masks when necessary, as the city grapples with the toxic haze.