Delhi’s PM2.5 level in November reached its highest monthly average in eight years despite the implementation of GRAP measures, a recent report has revealed.

A report by the Centre for Research on Energy and Clean Air (CREA) highlighted that Delhi’s PM2.5 concentration soared to an average of 249 micrograms per cubic metre in November — the highest since 2017 — despite enforcement of the Graded Response Action Plan (GRAP) and a decrease in stubble burning incidents.

In November 2016, the average PM2.5 level was recorded at 254 micrograms per cubic metre, the highest November reading, followed by 249 micrograms per cubic metre this year.

PM2.5 are fine particles with a diameter of 2.5 micrometres or less, about the width of a human hair. These are so small that these can penetrate deep into the lungs and even enter the bloodstream, posing significant health risks.

A report by the Centre for Research on Energy and Clean Air (CREA) highlighted that Delhi’s PM2.5 concentration soared to an average of 249 micrograms per cubic metre this November, the highest since 2017, despite the enforcement of the GRAP and a decrease in stubble burning incidents.

The Commission for Air Quality Management in the National Capital Region and Adjoining Areas (CAQM) — a statutory body responsible for formulating strategies to combat pollution in the region — implements anti-pollution measures under the Graded Response Action Plan (GRAP).

In November 2016, the average PM2.5 level was recorded at 254 micrograms per cubic metre, the highest for the month, followed by 249 micrograms per cubic metre in 2024.

In comparison, the average was 241 micrograms per cubic metre in 2023, 181 micrograms per cubic metre in 2022, 238 micrograms per cubic metre in 2021, 214 micrograms per cubic metre in 2020, 204 micrograms per cubic metre in 2019, 200 micrograms per cubic metre in 2018, and 248 micrograms per cubic metre in 2017, the data said.

These fine particles pose significant health risks as they can penetrate deep into the lungs and enter the bloodstream.

The report highlights a concerning trend, with 159 out of 268 cities across India exceeding the National Ambient Air Quality Standards (NAAQS) for PM2.5 levels in November.

The NAAQS limit for PM2.5 is set at 60 µg/m³.

Speaking to PTI, Manoj Kumar, an analyst at CREA, said, “After 2017, this November saw a continuous eight-day stretch in the Severe category (PM2.5 >250 µg/m³) from November 13 to November 20. This was due to the delayed implementation of stricter GRAP stages (3 and 4), despite IITM predicting a Severe AQI category on November 13.” Stubble burning contributed an average of 19 per cent to Delhi’s PM2.5 levels in November, with the remaining pollution originating from year-round sources.

This underscores the need for a long-term, airshed-based strategy to address emissions from perennial sources, rather than relying solely on short-term GRAP measures.

The report, published by CREA, an independent research organisation, further revealed that Delhi experienced 20 days in the “Very Poor” category (121-250 µg/m³) and 10 days in the “Severe” category (>250 µg/m³) in November.

It added, “GRAP’s on-ground impact remained questionable, as transportation contributed over 20 per cent to the city’s PM2.5 levels, mirroring pre-GRAP periods.” Meanwhile, Ghaziabad, Gurgaon, Noida, and other cities in the Delhi NCR region also struggled with severe pollution, with 28 NCR cities surpassing the NAAQS threshold.

According to CPCB data, Delhi’s air quality dipped into the “Very Poor” category on October 30 and has remained between the “Very Poor” and “Severe” categories since then, as of December 1.