The World Health Organization has made its air pollution standards stricter, lowering the recommended concentration for several pollutants.

The global health agency on Wednesday issued its first update on the guidelines since 2005. It said that since 2005 there had been a noticeable increase in evidence showing the impact of air pollution on health.

“Air pollution is one of the biggest environmental threats to human health, alongside climate change,” it said.

WHO estimated that exposure to air pollution causes 7 million, or 70 lakh, premature deaths every year.

“In adults, ischaemic heart disease and stroke are the most common causes of premature death attributable to outdoor air pollution, and evidence is also emerging of other effects such as diabetes and neurodegenerative conditions,” the statement said.

The WHO said that the risk of diseases due to air pollution was at par with smoking tobacco and keeping unhealthy diets.

In its new guidelines, the WHO has reduced the recommended limit for the average annual level of PM2.5 from 5 micrograms per cubic meter as against the earlier level of 10, Reuters reported. The recommended limit for PM10 was brought down from 20 micrograms to 15.

PM2.5 is fine particulate matter of a diameter of 2.5 micrometres in the air, while PM10 is of 10 micrometres. These pollutants can fester deep in the lungs and bloodstream of humans.

“Almost 80% of deaths related to PM 2.5 could be avoided in the world if the current air pollution levels were reduced to those proposed in the updated guideline, according to a rapid scenario analysis performed by WHO.”

The global health agency’s chief Tedros Adhanom Ghebreyesus said citizens in low and middle-income countries are the most affected by air pollution.

“WHO’s new Air Quality Guidelines are an evidence-based and practical tool for improving the quality of the air on which all life depends,” he added. “I urge all countries and all those fighting to protect our environment to put them to use to reduce suffering and save lives.”

Delhi’s pollution levels exceed WHO standards

After the WHO’s new guidelines were released, non-governmental organisation Greenpeace flagged the high pollution levels in Delhi. It noted that 57,000 premature deaths in the city in 2020 could be attributed to exposure.

“In Delhi, city-wide annual average air pollution levels exceeded the 2005 WHO guidelines by nearly eightfold in 2020, the highest margin of all cities in the dataset,” the Greenpeace said.

Greenpeace India’s senior climate campaigner Avinash Chanchal pointed out that WHO’s new guidelines show there is no safe level of pollution.

He added that the Central’s Pollution Control Board’s National Ambient Air Quality Standards needed to be revised.

“All the Non-attainment cities [that fall short of standards] should express the ambition to move to NAAQS in a time bound manner first and then should have a timeline to move towards the WHO guidelines,” Chanchal said.