Delhi’s air pollution remains high despite 71% reduction in farm fires: Report

This is despite a 71.2% drop in stubble fire incidents during October-December 2024, the study noted.

Another key finding of the study is the surge in pollution peak levels in 2024. Even as the PM 2.5 average for October to December months at 178.3 µg/m3 remained largely consistent with the average normally observed, the peak pollution levels soared from 580 µg/m3 to 732  µg/m3 — a 26% jump.

The study, authored by Anumita Roychowdhury, Executive Director, Research and Advocacy, CSE, and Sharanjeet Kaur, was conducted using real-time data from functional air quality monitoring stations in Delhi-NCR.

“The worst station-level peak this season was 9% lower than the highest ever recorded — at 806 µg/m3 during the 2018 winter,” noted the study.

It further stated that two major smog episodes were observed. However, Roychowdhury said as per a statement: “This cannot be seen as an annual aberration due to meteorological factors. The consistent rise indicates the impact of growing pollution in the region. Delhi seems to be losing its air quality gains from past actions. Local and regional sources of pollution including vehicles, industries, open burning of waste, use of solid fuels, construction, and dust sources have offset the gains — undermining the longer term progress over the past decade.”

The assessment mentioned that a stabilisation of annual PM 2.5 levels could have been possible since 2018, and even a declining trend could have been recorded with apt implementation of Supreme Court directives on energy transition in transport and industry sectors.

According to a statement by the CSE, Roychowdhury said the action has to “move much beyond reactive emergency measures during winter. The fact that annual trends have risen for two consecutive years, despite the decline in farm fire incidents during winter, shows much deeper systemic changes are required to cut round-the-year emissions from a variety of sources in Delhi and the surrounding region.”

The study also observed that the average PM 2.5 levels in October-December 2024 were 4.6% higher than the three-year winter average (2021-2023).

‘Good’ and ‘bad’ air days

The study noted that approximately 121 days met the National Ambient Air Quality Standards last year. This was similar to 2019 when the second-worst annual average was recorded at 109.1 µg/m3.

It further said the improvement in the number of ‘good’ air quality days from 25 in 2023 to 29 in 2024 was overshadowed by a marginal rise in the number of ‘very poor’, ‘severe’ and ‘severe plus’ category days which rose from 107 in 2023 to 111 in 2024.
For the winter months, as per the assessment, the number of days categorised as “poor” and “very poor” remained unchanged at 57, reflecting no progress in air quality during this critical period.