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 PM₁₀ 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.

Figure 1. Urban population exposed to air pollutant concentrations above selected EU air quality standards, EU-27

More than 70% of EU citizens live in urban areas, where high population densities and economic activities cause high levels [RF1] [AG2] of air pollution. Air pollutants, such as particulate matter (PM), ozone (O₃), nitrogen dioxide (NO₂), sulphur dioxide (SO₂) and benzo(a)pyrene (BaP) are associated with serious health problems, such as respiratory and heart diseases, and cancer.

The revised EU Ambient Air Quality Directive (2024) aims to protect human health, vegetation and natural ecosystems by setting air quality standards[RF3] [AG4] for a range of air pollutants. The World Health Organization (WHO) has also set air quality guideline levels, lower in general than the EU standards, and aim to prevent significant impact on human health.

The European Green Deal’s Zero Pollution Action Plan has a 2050 vision of achieving pollution levels which are no longer harmful to health and natural ecosystems. It also set the 2030 health-related interim goal of reducing the number of premature deaths caused by fine particulate matter (PM_2.5) by at least 55% compared with 2005 levels. The EU is currently on track to achieve this target.

Analysis of Individual Pollutants

Figure 1 shows that percentages of urban population exposed to levels above EU standards has decreased since 2000 for all pollutants except O₃. Almost no urban population was exposed to concentrations above the annual limit values for PM_2.5and NO₂ or above the SO₂ daily limit value in 2024. For PM₁₀ and BaP, respectively, 6.3% and 8.3% of the urban population was exposed to concentrations above the annual standards. The SO₂ values are not included in Figure 1 as they have been consistently below 0.1% since 2010. PM_2.5 and BaP are only presented from 2006 and 2008, respectively, when enough measurements were available to consider them homogeneous and representative across Europe.

O₃ is a secondary pollutant formed from other pollutant reactions, mainly nitrogen oxides and volatile organic compounds, and strongly dependent on meteorology. The proportion of the urban population exposed to O₃ above the EU target value threshold for human protection has fluctuated from a 63.8% peak in 2003 to 8.4% in 2014, with a 2024 value of 16.1%. As shown in Figure 1, there is no clear trend but a high interannual variability.

Figure 2. Urban population exposed to air pollutant concentrations above 2021 WHO air quality guidelines and reference levels, EU-27

The 2021 WHO air quality guideline levels are lower than the EU air quality standards presented in Figure 1, except for SO₂. In contrast to the existing EU standards, there are significant proportions of the European populations living in cities where air pollution is above the WHO guideline values (Figure 2).

For PM_2.5, the share of the urban population exposed to annual averages above 5µg/m³ (WHO annual guideline level) has slightly fluctuated between 100% in the first two years to 95.1% in 2024. For O₃, the proportion of the urban population exposed to concentrations above the WHO short-term guideline level of 100µg/m³ remained around 95% since 2013, with a value of 95.1% in 2024.

The proportion of the EU urban population exposed to concentrations above the WHO annual guideline levels for PM₁₀, NO₂, and SO₂ reached historical minimum values in 2024: 81.0% above the guideline level for NO₂, 59.7% for PM₁₀ and 0.2% for SO₂. Finally, 57.5% of the EU urban population was exposed to concentrations above the BaP ‘reference level’ in 2024.

Supporting information

Definition

The indicator is based on measurements of air pollutants as reported under the Air Quality Directives and the Decision on the exchange of information, and received by 17 March 2026.

This indicator shows the fraction of the EU-27 urban population that is potentially exposed to ambient air concentrations of six key pollutants (PM_2.5, PM₁₀, O₃, NO₂, SO₂ and BaP) that are in excess of some air quality standards for the protection of human health, and to concentrations of these pollutants in excess of the 2021 WHO Air quality Guideline levels. For BaP, the reference level (0.12 ng/m³) was estimated assuming WHO unit risk for lung cancer for polycyclic aromatic hydrocarbon (PAH) mixtures and an acceptable risk of additional lifetime cancer risk of approximately 1 in 100 000 (ETC/ACM, 2011).

The EU standards assessed in this report are the more restrictive ones for each pollutant, i.e. the annual limit value for PM_2.5 (25µg/m³) and NO₂ (40µg/m³), the daily limit value for PM₁₀ (50µg/m³, not to be exceeded on more than 35 days per year), the target value threshold for O₃ for the protection of human health (120µg/m³, not to be exceeded on more than 25 days per year), the annual target value for BaP (1ng/m³) and the daily limit value for SO₂ (125µg/m³, not to be exceeded on more than 3 days per year).

Methodology

Methodology for indicator calculation

Information on cities is obtained from the Urban Audit (UA) data. UA data collection, maintained by Eurostat, provides information and comparable measurements on the different aspects of the quality of urban life in selected European cities. The urban population considered is the total number of people represented by any of the urban monitoring stations in the 'core city' and the 'greater city' of the UA cities taking part in the calculations.

Initially, stations in the EEA air-quality database are spatially joined with UA core and, from 2016, greater cities in a geographical information system in order to select those stations that fall within the boundaries of the cities included in the UA collection. The selected stations include station types classified as 'urban traffic', 'suburban traffic', 'urban background' and 'suburban background'. Stations classified as 'industrial' are influenced by other local emissions and such environments are generally not representative for residential areas. The industrial stations are therefore not selected for the indicator calculations.

From 2022 onwards, the 2020 version of the UA is used.

According to a study for the European Commission by Entec UK Limited, in Europe, on average, 5% of the city population lives closer than 100 metres from major roads and is therefore potentially exposed to concentrations measured at traffic stations. The remaining 95% of the city population is assumed to be exposed to urban and suburban background concentrations.

These percentages vary from country to country. To calculate them, national data on the population living closer than 100 metres from major roads have been taken from Appendix D of the above-mentioned study. These data have been divided by the total population figures for 2001 according to the Eurostat census.

For Croatia and Malta there are no data on the 2001 population in that census, so the data in the publication Europe in Figures – Eurostat yearbook 2006-07 have been used. Furthermore, for Cyprus and Malta there are no data for people living close to roads in the study, so for them, and for Türkiye, the average value of 5% was used.

For PM₁₀, PM_2.5, O₃, NO₂ and SO₂, only stations with at least 75% of valid data per calendar year are used. That is, in the case of daily values, those having more than 274 valid daily values per calendar year (or 275 days in a leap year). And in the case of hourly values, having more than 6,570 valid hourly values per calendar year (or 6,588 hours in a leap year). For PM random fixed measurements and for BaP, the minimum data time coverage accepted is 13% (51 days), according to the data quality objectives related to indicative measurements in the Air Quality Directives.

For every year, each city (i) in country (j), and every pollutant, the total number of urban or suburban traffic stations (n_it) and the total number of urban or suburban background stations (n_ib) are obtained. P_tj % of the total population of the city (Pop_i) is proportionally assigned to each of the traffic stations and P_bj % of Pop_i is proportionally assigned to each of the background stations. So, every traffic station has an allocated population equal to ((P_tj / 100) * Pop_i / n_it) and every background station has an allocated population equal to ((P_bj /100) *Pop_i / n_ib).

For city and/or greater city geometries with no information on population in the Urban Audit data collection, population data have been retrieved from http://www.citypopulation.de/.

Methodology for gap filling

No related methodology for gap filling has been specified.

Policy/environmental relevance

Context description

This indicator is relevant for current European air quality legislation related to the protection of human health in the Air Quality Directive (EU) 2024/2881. Besides EU policies on air quality, it is also related to the 2021 WHO Air Quality Guidelines for protecting public health.

The European Green Deal, adopted by the European Commission on 11 December 2019, will improve the well-being and health of citizens and future generations by providing, among others, fresh air, more public transport, cleaner energy or longer lasting products.

As part of the European Green Deal, the Zero Pollution Action Plan has the 2050 vision of reducing air pollution to levels no longer considered harmful to health and natural ecosystems and the 2030 target of reducing premature deaths due to air pollution by more than 55%, in comparison with those in 2005.

The 8th Environment Action Programme (8EAP) entered into force in 2022, as the EU’s legally agreed common agenda for environment policy until 2030. The 8thEAP supports the environment objectives of the European Green Deal and reiterates the commitment to the 2050 vision of living well, within planetary boundaries.

Targets

No related targets have been specified.

Accuracy and uncertaintiesData sources and providers

Metadata

DPSIRTopicsTagsTemporal coverageGeographic coverage

TypologyUN SDGsUnit of measureFrequency of dissemination

Exceedance of air quality standards in Europe

Figure 1. Urban population exposed to air pollutant concentrations above selected EU air quality standards, EU-27

Figure 2. Urban population exposed to air pollutant concentrations above 2021 WHO air quality guidelines and reference levels, EU-27

Supporting information

Methodology for gap filling

Context description

Targets

Data sets uncertainty

Rationale uncertainty

Metadata

References and footnotes