Delhi PM2.5 Pollution: Local Dust and Waste Burning Near One-Third Before November Shift

The news

Local sources such as road dust and open waste burning accounted for nearly one-third of Delhi’s PM2.5 pollution in the final week of October 2026, before crop-residue burning and Diwali firecracker emissions became the dominant contributors, according to an analysis of Indian Institute of Tropical Meteorology (IITM) data by The Indian Express. The Commission for Air Quality Management (CAQM) had invoked Stage I of the Graded Response Action Plan (GRAP) on October 21, mandating stricter action against open waste burning and mechanised road sweeping, yet the contribution of open waste burning increased after the order took effect.

Between October 26 and October 29, open waste burning accounted for as much as 15% of Delhi’s daily PM2.5 load, while road dust, soil and mineral matter contributed roughly 18%, IITM data showed. Construction-related emissions also rose after the October 21 restrictions, peaking at around 8% of the total PM2.5 burden during the final week of October, before the Delhi government’s ban on construction activities came into force on November 1. The state government’s restrictions under the Winter Action Plan took effect on November 1, followed by the NCR-wide construction ban imposed by CAQM on November 5 and the invocation of GRAP Stage III on November 6. The relative share of construction dust declined to between 1% and 3% from November 1 onwards.

The pollution profile shifted from predominantly local sources towards regional and episodic contributors in early November. Crop-residue burning increased steadily, peaking at 30% of Delhi’s PM2.5 load on November 4, four days before Diwali. Firecracker emissions accounted for an estimated 71% of Delhi’s PM2.5 load on November 9. On November 14, biomass burning contributed 25.5%, secondary organic aerosols 23.6%, vehicular emissions 17.4%, waste burning 6.8%, and mineral dust and ash 1.5%. Delhi’s daily-average Air Quality Index (AQI) on November 14 was recorded at 367, in the ‘Very Poor’ category, while Noida and Gurugram reported AQIs of 318 and 340, respectively, according to Central Pollution Control Board data.

What is the Graded Response Action Plan?

GRAP was first notified by the Ministry of Environment, Forest and Climate Change in January 2017. GRAP was notified on the directions of the Supreme Court in the M.C. Mehta v. Union of India case. GRAP classifies actions into four stages based on AQI thresholds. Stage I applies when AQI is in the 'Poor' category (201-300). Stage II applies when AQI is in the 'Very Poor' category (301-400). Stage III applies when AQI is in the 'Severe' category (401-450). Stage IV applies when AQI is in the 'Severe Plus' category (above 450). The Commission for Air Quality Management in NCR and Adjoining Areas was established through an ordinance in October 2020. CAQM replaced the Environment Pollution (Prevention and Control) Authority.

How does source apportionment work?

IITM expresses each source as a percentage of Delhi’s real-time PM2.5 load, not as its absolute concentration. Consequently, a decline in the percentage share of local sources does not necessarily indicate an equivalent drop in their emissions. During major pollution episodes, high-intensity sources can substantially increase the total PM2.5 load and thereby reduce the relative share of other sources. For instance, firecracker emissions accounted for an estimated 71% of Delhi’s PM2.5 load on November 9, while secondary organic aerosols contributed 29% on November 11, reducing the proportional contribution of baseline local sources.

What did the restrictions achieve and miss?

The CAQM invoked GRAP Stage I on October 21, Stage II on November 2 and Stage III on November 6. Despite the Stage I mandate for stricter action against open waste burning and mechanised road sweeping, open waste burning’s contribution increased to as much as 15% of daily PM2.5 load between October 26 and October 29. Construction emissions also rose after the October 21 restrictions, peaking at around 8% before the November 1 ban. After the November 1 Winter Action Plan restrictions and the November 5 NCR-wide construction ban, the construction-dust share declined to 1–3%. Crop-residue burning reached 30% on November 4, and firecrackers 71% on November 9, indicating that episodic sources overwhelmed local controls.

What is the farm-fire trend this season?

Data from the Indian Agricultural Research Institute showed that 11,342 paddy-residue burning incidents were detected between September 15 and November 13, around 27% lower than the 15,492 incidents recorded during the same period last year. Punjab accounted for 5,785 incidents, the highest among all states, though still its second-lowest seasonal tally since 2020. Haryana, Uttar Pradesh, Uttarakhand, and Madhya Pradesh recorded their lowest cumulative counts for the period since 2020, while Rajasthan’s tally remained above levels seen during 2020–23.