Less than one-fifth of the cities worldwide met the international criteria for clean air in 2024, a global study has found.
The IQAir World Air Quality Report, which analysed data from over 40,000 air quality monitoring stations across 8,954 locations in 138 countries, found that only 17 per cent of cities met the World Health Organisation’s (WHO) annual PM2.5 guideline of 5 micrograms per cubic metre (µg/m³).
