Delhi’s Toxic Air Mostly Due to Local Pollution, Not Stubble Burning, Says Study

A new study by Japanese researchers challenges the long-held belief that crop burning in Punjab and Haryana is the main culprit behind Delhi-NCR’s hazardous air pollution. According to findings from the Aakash Project, led by the Research Institute for Humanity and Nature (RIHN) in Kyoto, local pollution sources play a much bigger role in Delhi’s poor air quality than previously thought.

The study, published in npj Climate and Atmospheric Science, analyzed data from a network of 30 monitoring sites across Delhi-NCR, Haryana, and Punjab. It found that even during the peak stubble-burning months of October and November, crop fires were not the primary factor driving high PM2.5 levels in the capital. Instead, local emissions and meteorological conditions were the key contributors.

Lead author Dr. Poonam Mangaraj emphasized the importance of continuous monitoring across different regions—Punjab (source), Haryana (intermediate), and Delhi-NCR (receptor)—to develop effective pollution control strategies.

The research team used a combination of real-time air pollution data from 2022 and 2023, satellite fire detection counts, wind pattern analysis, and atmospheric chemistry simulations. While Punjab and Haryana saw a drop in stubble-burning incidents between 2015 and 2023, PM2.5 levels in Delhi remained consistently high.

Interestingly, the study found that while northwesterly winds transported pollution from Punjab to Delhi in November 2022, the situation was different in 2023. That year, weak southwesterly winds led to the accumulation of locally generated pollutants, making the air quality even worse.

The study also highlighted a direct link between PM2.5 levels and the implementation of the Graded Response Action Plan (GRAP) by the Commission for Air Quality Management (CAQM). When pollution-control measures were enforced, PM2.5 levels dropped; when restrictions were lifted, pollution surged again—further reinforcing the idea that local factors play a dominant role.

Professor Prabir Patra, the project leader from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), explained that their extensive network of sensors allowed them to clearly separate the effects of stubble burning from Delhi’s overall pollution levels.

These findings suggest that tackling Delhi’s air pollution crisis requires a stronger focus on local emissions, such as vehicular pollution, industrial activities, and construction dust, rather than blaming stubble burning alone.

News Source : “Information for this article was gathered from a variety of reliable news outlets.”