The air of Europe: where are we going?

Air pollution constitutes one of the main threats to public health in Europe. Significant impacts on the health of Europeans in terms of morbidity and mortality have been observed, even in cases of low exposure and where pollutant levels are within limits set by the European Union (EU). The respiratory system is a primary target of the harmful effects of key air pollutants. Emissions of many air pollutants have decreased substantially over the past decades in Europe, resulting in diminished concentrations and improved air quality. However, in several European cities concentrations still exceed EU reference values and, more often, the stricter World Health Organization air quality guidelines for all regulated air pollutants (particles with 50% cut-off aerodynamic diameters of 10 and 2.5 µm, nitrogen dioxide (NO2 ), benzo[a]pyrene and ozone (O3 )) except sulfur dioxide. In addition, current trends indicate that in the absence of substantial changes, particulate matter, NO2 and O3 will still exceed limits in 2020. Additional efforts must be made to comply with current standards and guidelines. These should include a more accurate and detailed monitoring of air pollutants, reduction of emissions and individual behaviour changes.