Exceedance of air quality standards in Europe
European Union legislation has led to significant improvements in air quality. The percentage of urban citizens exposed to pollutant levels above legal standards set in 2004 and 2008 to protect human health fell steadily between 2000 and 2024. Still, in 2024, 16%, 8% and 6% of EU citizens were exposed, respectively, to ozone, benzo(a)pyrene and particulate matter PM 10 levels above EU standards. The World Health Organization defines more stringent guideline levels, with around 95% of urban citizens exposed to levels of fine particulate matter (PM 2.5 ) and ozone above these levels.