Ground-level Ozone
EU annual/period limit for Ground-level Ozone is 120 µg/m³ - upper limit-value tercile among pollutants with station rows here.
EU limit value
120 µg/m³
8-hour max. Directive 2008/50/EC.
WHO 2021 guideline
100 µg/m³
8-hour max
High numeric EU ceiling for Ground-level Ozone
The Directive posts a comparatively high numeric ceiling for Ground-level Ozone (120 µg/m³, 8-hour max). Compare that figure to the WHO line and to peer pollutants before reading the station table as “safe”.
Primary sources: Secondary pollutant formed by sunlight reacting with NOx and VOCs from traffic, industry, solvents.
Health impact: Reduces lung function, triggers asthma, increases respiratory hospitalizations. Highest in summer.
Measurement method: Reference: UV photometry, EN 14625
Directive ceiling 120 µg/m³ versus WHO 2021 guideline 100 µg/m³ (1.2×). The October 2024 Directive revision schedules further tightening toward 2030.
Top stations measuring Ground-level Ozone
| Station | City | Country | Type | Annual mean |
|---|---|---|---|---|
| Rome-Arenula | Rome | IT | background | 73.4 µg/m³ |
| Nicosia-Centre | Nicosia | CY | traffic | 72 µg/m³ |
| Madrid-Retiro | Madrid | ES | background | 70.8 µg/m³ |
| Athens-Piraeus | Athens | GR | traffic | 70.4 µg/m³ |
| Milan-Pascal | Milan | IT | traffic | 67.5 µg/m³ |
| Naples-Centro | Naples | IT | traffic | 67.5 µg/m³ |
| Zagreb-Centar | Zagreb | HR | background | 65.7 µg/m³ |
| Valletta-Msida | Msida | MT | traffic | 65.5 µg/m³ |
| Barcelona-Eixample | Barcelona | ES | traffic | 65.1 µg/m³ |
| Budapest-Erzsebet ter | Budapest | HU | background | 64.7 µg/m³ |
| Paris-Les Halles | Paris | FR | background | 64.3 µg/m³ |
| Marseille-Cinq Avenues | Marseille | FR | background | 64.3 µg/m³ |
| Ljubljana-Center | Ljubljana | SI | traffic | 62 µg/m³ |
| Munich-Altperlach | Munich | DE | background | 61.8 µg/m³ |
| Hamburg-Sternschanze | Hamburg | DE | background | 61.8 µg/m³ |
| Luxembourg-Centre | Luxembourg City | LU | background | 60.7 µg/m³ |
| Lyon-Centre | Lyon | FR | traffic | 59.2 µg/m³ |
| Vienna-Taborstrasse | Vienna | AT | traffic | 59.1 µg/m³ |
| Bucharest-Cercul Militar | Bucharest | RO | traffic | 58.5 µg/m³ |
| Lisbon-Avenida da Liberdade | Lisbon | PT | traffic | 57.7 µg/m³ |
Common European air pollutants · All pollutants with station rows
Source: European Environment Agency, Average Exposure Indicator / Burden of Disease (wired extract, August 2026).
Source: World Health Organization Global Air Quality Guidelines, 2021 update.