Global air quality declined in 2025, with more cities reporting standards below international health guidelines on the impact of severe wildfires and pollution from sectors including fossil fuels and agriculture.
Data from almost 9,500 cities showed 14% met World Health Organization standards for annual average concentrations of harmful fine-particle matter, or PM2.5, according to a report released Tuesday by IQAir Group. That compared to a total of 17% a year earlier when nearly 9,000 cities were surveyed.
Dense smog in Howrah, West Bengal, in Jan. 2026.
Photographer: Debajyoti Chakraborty/NurPhoto/Getty Images
The “productivity of a whole future generation will be linked” to air quality, said Frank Hammes, IQAir’s global chief executive ...