Urban population exposed to air pollutant concentrations above 2021 WHO air quality guidelines and reference levels, EU-27

PM_2.5: particulate matter with a diameter of less than 2.5μm; PM₁₀: particulate matter with a diameter of less than 10μm; O₃: tropospheric ozone; NO₂: nitrogen dioxide; BaP: benzo(a)pyrene.

Criteria for each pollutant: PM_2.5 - population exposed to annual concentrations above 5µg/m3; PM₁₀ - population exposed to annual concentrations above 15µg/m³; O₃ - population exposed to maximum daily 8-hour mean concentrations exceeding 100µg/m³ for more than 3-4 days per year; NO₂ - population exposed to annual concentrations above 10µg/m³; BaP: population exposed to annual concentrations above 0,12ng/m³.

Different numbers of countries and stations are included over time in the illustrated data sets.