WHO slashes guidelines on air pollution levels

22 September 2021

The World Health Organization has updated its guidelines for air pollution levels. The recommended limit for small particles (PM2.5) has been cut by half, and the limit for Nitrogen Dioxide by 75%.

The new guidelines for annual average exposure to PM2.5 have been reduced from 10 to 5 micrograms per cubic metre (µg/m3). and for Nitrogen Dioxide, they have cut the annual average limit from 40 to 10 µg/m3.

“Air pollution is a threat to health in all countries,” said Tedros Adhanom Ghebreyesus, the WHO director general. The guidelines are not legally binding but can be used by countries to plan their action. “I urge all countries to put them to use to reduce suffering and save lives,” he said. The WHO said dirty air often affected the most vulnerable people and that clean air should be a “fundamental human right”.

The new guidelines are based on the latest scientific studies – but scientists stress that even these new limits should not be considered safe, as there appears to be no level at which air pollutants stop causing damage.

The environmental group Client Earth say that these tighter air pollution guidelines should trigger immediate action from governments. They state that the new guidelines mean “that across EU and the UK, legal limits for NO₂ are now 4 times higher than WHO recommendations, while legal limits for PM_2.5 are now 4, and in some cases, 5 times higher than the new guidelines.”

Clean Air Cheltenham spokesperson Peter Frings said: “We know that PM2.5 pollution in most areas of Cheltenham is at least double the new WHO limit of 5 ug/m3; and many areas of the town are 3 or 4 times higher than the new Nitrogen Dioxide limit. The Borough Council still hasn’t published it’s much delayed Air Quality Action Plan. These new guidelines, which reflect the best available science, show that levels of air pollution in Cheltenham are seriously endangering people’s health.”