Air quality in Europe has improved considerably over the last two decades. It's quite a paradox. We breathe increasingly cleaner air, but this does not prevent us from being far from the levels that would be desirable taking into account the recommendations established by the WHO in 2021. For this reason, despite everything, 86% of the European population lives in areas that exceed the annual limits recommended by the WHO for nitrogen dioxide (NO2), a pollutant mainly caused by traffic.
The improvement in air quality has been confirmed in a study by the Barcelona Institute for Global Health (ISGlobal), a center promoted by the La Caixa Foundation, and the Barcelona Supercomputing Center. It analyzed pollution levels in 35 European countries (543 million people) between 2003 and 2019.
The results show a decrease in the levels of both nitrogen dioxide (NO2), a pollutant mainly due to exhaust pipes, and suspended particles PM2.5 and PM10 (with maximum diameters of 2.5 and 10 microns), of very diverse origin (and of domestic, agricultural, industrial, transportation or natural origin).
Specifically, the levels of PM10 particles decreased the most during the study period, followed by NO2 and PM2.5, with annual decreases of 2.72%, 2.45% and 1.72%, respectively. In contrast, levels of ozone (O3), a secondary pollutant, increased annually by 0.58% in southern Europe, which almost quadrupled the number of days with poor air quality. These results largely coincide with estimates from the European Environment Agency for the 27 EU countries.
Xavier Querol, a CSIC researcher (but who has not participated in this study), considers that there are four factors that explain this improvement in air quality. The first is the implementation of the Euro5 regulations for vehicles, which includes particle filters. The second is the entry into force of the directive on industrial emissions and large combustion plants, which has led to drastic decreases in coal emissions, for example. The third is better planning of public works, which reduces dust and particles. And the fourth is the extension of low-emission zones in cities, which restricts the most polluting traffic. Carlos Bravo, an expert in public policies, also points out a decrease in pollution from ports in the North Sea and the Baltic. Querol recalls that the European Environment Agency estimated in 2018 that the number of premature deaths caused by pollution was one million in 1990, a figure that a 2023 study reduced to 238,000 in the EU-27 in 2021.
Despite everything, 98.1% of the European population suffers from excessive levels – according to the WHO – of PM2.5 suspended particles, which are very dangerous, as they enter the bloodstream through the lung alveoli. And in the case of the largest particles (PM10), this percentage reaches 80.15%.
The study results therefore highlight significant improvements in air quality in terms of NO2 (due to traffic) and larger particles, while improvements are smaller in the case of ultrafine particles.
The most favorable evolution achieved in traffic emissions occurred above all in the urban areas of Western Europe, while the decrease in particles was seen more in Central Europe.
But above all, it is worrying that no country met the annual guidelines for tropospheric ozone (O3), a pollutant that is not emitted directly into the atmosphere, but is formed from certain precursors, such as volatile organic compounds and oxides. of nitrogen –in certain conditions of solar radiation–. At high concentrations, ozone can harm human health, vegetation and ecosystems. “Specific efforts are needed to address PM2.5 and O3 levels and composite pollution days (with impact of several associated pollutants), especially in the context of rapidly increasing climate change threats in Europe,” explains Zhao-Yue Chen , ISGlobal researcher and lead author of the study.
The highest particle levels were measured in northern Italy and Eastern Europe. Likewise, elevated levels of NO2 were observed in northern Italy and in areas of Western Europe, such as the south of the United Kingdom, Belgium and the Netherlands.
