WHO updates air quality norms after 15 years

Hyderabad: The World Health Organization (WHO) on Wednesday updated its air quality guidelines for the first time in 15 years.

The new guidelines which have been derived from strong scientific evidence of the damage air pollution inflicts on human health recommends new air quality levels based on reducing concentrations of key air pollutants.

According to the new guidelines, the annual particulate matter 2.5 microns in thickness (PM2.5) has now been updated to 5mg/m3 compared to 10 mg/m3 in 2005. Similarly, annual mean for PM10 is updated to 20 mg/m3 to 15 mg/m3 and NO2 to 10 mg/m3 from 40 mg/m3.

Greenpeace India’s senior climate campaigner Avinash Chanchal said, “We have all the economically viable tools we need to solve the air pollution crisis. In most parts of the world, it is more-cost effective to develop renewable energy sources than to keep burning coal, oil or gas, even before taking the economic burden of air pollution into account. At this point, addressing air pollution is a question of political will, not technology.”

According to Greenpeace India’s report, out of 287 cities, more than 80 percent (231) cities or towns have PM 10 levels exceeding the 60 mg/m 3 limits for PM10 prescribed under National Ambient Air Quality Standards (NAAQS) set by CPCB in 2018.  

“The new WHO air quality guidelines establish the fact that there is no ‘safe’ level of air pollution. They indicate that the current NAAQS is insufficient and needs to be revised. All the non-attainment cities 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,” added Chanchal.

WHO Air Quality Guidelines. Source: WHO

Pollutant	Guideline Concentration (µg/m3) in 2005	Guideline Concentration (µg/m3) in 2021	Averaging Period
PM2.5	25 10	15 5	24-hour mean Annual mean
PM10	50 20	45 15	24-hour mean Annual mean
SO2	20	40	24-hour mean
O3	100	100	8-hour mean
NO2	200 40	25 10	24-hour mean Annual mean