The stricter air quality standards issued by the World Health Organization (WHO) on Wednesday are a welcome move but it will be challenging for Delhi to achieve the new limits, experts and officials said.
“The new norms will put more pressure on the government to form policies to achieve stricter standards of air pollution. But achieving the new standards is going to be challenging,” said an official of the Delhi Pollution Control Committee.
The WHO, in the first update of its air quality guidelines in 15 years, has tightened global air pollution standards in recognition of emerging science that the impact of air pollution on health is much more serious than earlier envisaged.
For instance, the upper limit of annual PM2.5 (particulate matter) as per the 2005 standards, which is what countries now follow, is 10 microgram per cubic metre. That has now been revised to five microgram per cubic metre.
Anumita Roychowdhury, head of Clean Air Programme at the Centre for Science and Environment, said the WHO’s air quality norms are not legally binding on countries, but rather a general guide for what nations should set as goals.
“The Central Pollution Control Board is expected to revise the national ambient air quality standards soon and the new WHO guidelines need to be the reference point for developing appropriate intermediate targets for India,” she said.
For Delhi and large parts of north India, it will be difficult to achieve these new guidelines, but the WHO has proposed a step-by-step approach through progressive tightening of intermediate standards, she added.
“During the lockdown, air pollution halved in Delhi when local pollution and regional influence could be minimised. Even then we were not near the WHO guidelines. In 2020, the annual average level of PM2.5 in Delhi was 98 micrograms per cubic metre, against the national standard of 40. The WHO is asking for annual average of 5 micrograms per cubic metre. This bears out the scale and speed with which we need to push action in Delhi and across the regions to meet our own standards first,” the expert said.
She said that it is not clear why the WHO has increased the bar for SO2 levels from 20 to 40 ug/m3.
