More than 70 % of EU citizens live in urban areas, where high population densities and economic activities cause high levels of air pollution. Such exposure is linked to adverse health effects, such as respiratory and heart problems, and cancer. Particulate matter (PM), O3, NO2 and SO2 are associated with serious health problems. The EU Air Quality Directive aims to protect health, vegetation and natural ecosystems by setting limit and target values for air pollutants (and long-term objectives for O3). The Clean Air Programme, published in 2013, aims to comply with this legislation by the time 2020 data are available.
For most pollutants, there is progress, with the percentage of people exposed to levels above EU standards decreasing since 2000. However, potentially harmful levels are still recorded in many areas. For instance, although substantially lower than the 47 % peak in 2003, in 2019, 10 % of urban citizens were still exposed to PM with a diameter of 10 µm or less (PM10) above the EU daily limit value.
Exposure to harmful levels of fine PM (PM2.5) and NO2 is less common, but 3 % of the urban population lived in zones exceeding the EU limit values for NO2 and only 1% in urban areas exceeding the EU limit values for PM2.5 in 2019. For SO2, the percentage exposed to levels above the limit value decreased between 2000 and 2019, to less than 0.1 % in the last 10 years (with a maximum of 3% in 2006). Therefore, these values are also not exhibited in Figure 1.
O3 is a secondary pollutant formed from other pollutants in the presence of solar light. Its levels are determined by emissions and climatic conditions. The proportion of the population exposed to O3 above EU target levels has fluctuated from a 64 % peak in 2003 to 7 % in 2014. Since this low value, however, Europe has seen the two warmest years on record — 2015 and 2018 — resulting in 30 % or more of the population being exposed to O3 above the target value. However, in 2019, this ratio decreased to 21%.
As there are relatively few reported measurements of BaP and these were not considered to be homogeneous across Europe until 2008, the values are not presented in the Figure 1. Considering data reported after that year, the portion of the urban population exposed to concentrations above the BaP target value has shown little variation within the range of 14-17 % in 2017-2019.
Despite progress driven by EU policies to reduce emissions and protect citizens from pollutants, addressing the causes of poor air quality remains a challenge. Given the widespread exceedance of EU limit and target values in urban areas, the EU is not on track to meet air quality standards by 2020. Substantial efforts in relation to agriculture and energy use for transport and in buildings are needed to improve air quality and advance EU progress towards meeting climate change policy objectives.