‘Lenient air quality norms make polluted cities seem clean’

India needs to update its national ambient air quality standards (NAAQS) to meet WHO guidelines and pave way for better monitoring of the pollution levels, an analysis by the Centre for Research on Energy and Clean Air (CREA) said, pointing to lax guidelines showing cities in positive light despite high levels of pollution.

The World Health Organisation (WHO) Guidelines of 2021 set 5 microgram/cubic metre as the annual average of PM 2.5, the particles smaller than aerodynamic diametre of less than 2.5 micrometre which have been classified as harmful to health.

However, the NAAQS allows up to 40 microgram/cubic metre, which is not considered even in the interim targets suggested by the WHO for areas with very high levels of pollution.

Pollution trends from January to April showed that 90% of the 273 Indian cities overshot WHO limits in the first four months, the Centre for Research on Energy and Clean Air said. Researchers noted that even if these cities maintain near zero pollution for the rest of the year, they will still fail to meet the WHO standards.

The analysis looked at data from the Central Pollution Control Board (CPCB) for April.

“As of April 2025, 248 of the 273 cities have overshot the WHO’s annual PM 2.5 standards, indicating widespread non-compliance with global air quality guidelines. In January and February, 109 cities each overshot WHO PM 2.5 standards, followed by 24 cities in March and six in April,” the analysis said.

The problem, however, is masked by the NAAQS. “When evaluated against NAAQS, only one city (Byrnihat) overshot during the January to April 2025 period. This significant disparity reveals that the current NAAQS are inadequate for ensuring public health protection. Given that NAAQS were set in 2009 and have not been updated since,” it noted.

Manoj Kumar, analyst at CREA, said the the current standards, established more than a decade ago, are lenient and continue to contribute to significant health impacts and economic losses,” he added.