Delhi breached WHO set annual air quality limit in Jan

Delhi exceeded the World Health Organization annual pollution limits within the first month of this year, reported TOI. The city surpassed national air quality standards for PM2.5 and PM10 by May and April, respectively, according a study on the national capital's population.

Sunil Dahiya, a South Asia analyst at CREA, said, “This ongoing issue highlights the need for stronger regulations and a focus on reducing emissions. Using better technology and data can help control pollution.”

He added, “India’s standards are more lenient than WHO’s, which can lead to long-term exposure to harmful particles. Research shows that even short-term exposure to PM2.5 in India poses significant health risks, suggesting that air quality standards need to be updated to better align with international guidelines to prevent diseases.”


On January 11 and 17, PM2.5 and PM10 levels in Delhi exceeded WHO guidelines. Therefore, even if pollution levels were reduced to 0.1 micrograms per cubic meter from those dates onward, Delhi would still fail to meet the annual WHO guidelines, said a study by the Centre for Research on Energy and Clean Air (CREA). Similarly, Delhi surpassed national standards for PM2.5 and PM10 on May 7 and April 2, respectively. The WHO annual limits for PM2.5 and PM10 are 5 and 15 micrograms per cubic meter, while the national standards are 40 and 60 micrograms per cubic meter, respectively, noted the TOI report.

An "overshoot day" is defined as a day when pollution levels are so high that even a minimal amount of pollution for the rest of the year would still result in non-compliance with annual standards.

The CREA analysis, covering the past five years, shows that pollution levels exceeded limits before the winter season, when Delhi typically faces even worse air quality. During winter, the air quality index often falls into the ‘poor,’ ‘very poor,’ or ‘severe’ categories. "Delhi’s ongoing air pollution problem is worrying, with the city consistently exceeding air quality standards. Our data from 2019 to 2024 shows that the year often begins with Delhi already breaching critical guidelines, which is a troubling trend," said Manoj Kumar from CREA.

According to the National Ambient Air Quality Standards (NAAQS), which are set by the Central Pollution Control Board, PM2.5 and PM10 levels should meet the daily limits 98% of the time. They can exceed limits only 2% of the time, and not on two consecutive days.

From January to June, Delhi met daily pollution standards only on three days. The city met the daily PM10 standard on two consecutive days in late June, thanks to rainfall. For PM2.5, only 15% of the days met the standards, with the first compliance occurring on March 2.