Air Quality in Europe Shows Significant Improvement Since 2003 – But Unhealthy Pollution Remains Widespread
Air pollution
Despite significant air quality gains, air pollution remains the 10th leading cause of death in the European Union.

Average concentrations of small and fine particulates (PM2.5 and PM10)  decreased across Europe between 2003-2019 – with the largest reductions in PM10,according to a new study published in Nature on trends over the past two decades. Despite air quality improvements, more than 98 of the European population lives in areas exceeding the WHO recommended annual levels for PM2.5, the pollutant most closely associated with premature mortality, and more than 86.34% for Nitrogen dioxide (NO2), associated with impaired lung development and chronic lung disease.    

The study of trends in 35 European countries was led by the Barcelona Institute for Global Health (ISGlobal).  It estimated daily ambient concentrations of four pollutants, based on machine learning techniques, to assess days exceeding the WHO 2021 guidelines.

In particular, PM10 levels decreased the most over the study period, with annual decreases of 2.72%, followed by NO2 and PM2.5, which declined by 2.45% and 1.72% annually respectively.  Notably, for PM2.5, the pollutant most closely associated with adverse health impacts, the number of ‘unclean air days’ – in excess of WHO guidelines levels of 15 micrograms of pollution per cubic meter (15μg/m3)  declined from nearly 150 days in 2002 to around 90 days in 2019, the study found.

Average daily PM10 concentrations across 35 European showed the biggest declines between 2003-2019.

It is estimated that there were more than 250,000 deaths in the European Union from air pollution-related cardiovascular and respiratory illnesses, as well as cancers, according to the European Environment Agency.

In the wider European region, which includes Scandanavia, Turkey, Russia and independent republics of the former Soviet Union, there were an estimated 569,000 premature deaths in 2019, according to WHO.

While the health impacts of PM2.5 are the most measured, ozone (O3) along with NO2 are responsible for considerable morbidity and mortality related to asthma, and chronic respiratory disease.


Declines in “unclean air” days from PM2.5, as per WHO guidelines, alongside population increases (blue line) in the European countries studied, between 2003-2019.

The most significant reductions in PM2.5 and PM10 were observed in central Europe, while for NO2 they were found in mostly urban areas of western Europe.

Southern and eastern Europe remained pollution hotspots with PM2.5 and PM10 levels highest in northern Italy and eastern Europe, while PM10 levels were highest in southern Europe. Similarly, O3 increased by 0.58% in southern Europe, while it decreased or showed a non-significant trend in the rest of the continent. Warmer temperatures and stronger sunlight in summer boost O3 formation through chemical reactions with NO2 and other pollutants.  

High NO2 levels, associated with vehicle emissions, were mainly observed in northern Italy – although also in some areas of western Europe, such as in the south of the United Kingdom, Belgium and the Netherlands, the study found.  

Trends in NO2 levels across 35 European countries, 2003-2019

Key drivers of the reductions

Dr Zhaoyue Chen, lead author of the study, attributed the trend of tightening European Union regulations for the air quality improvements.

“The European Union has implemented various regulations and directives aimed at curbing emissions. For example, the Ambient Air Quality Directive (2008) setting air quality standards and the National Emission reduction Commitments Directive (2016) targeting specific pollutants. And also those efforts made by each local government,” he told Health Policy Watch.

“However, we are still far away from enjoying clean air in Europe. Most Europeans are still breathing unhealthy air,” he added.

“Our study showed 98.10%, 80.15% and 86.34% of the European population live in areas exceeding the WHO recommended annual levels for PM2.5, PM10 and NO2, respectively, while no country met the ozone (O3) annual standard during the peak season from 2003 to 2019.”

In late February, the European Council, which reprents the EU’s political leadership, agreed witht he European Parliament on the final outlines of a new EU Air Quality Directive which would further tighten EU air quality standards reducing permitted pollution levels from the current annual average of 25 μg/m3  to 10μg/m3  for PM2.5 and from 40 µg/m3 to 20 µg/m3 for NO2. However, those standards are still double the WHO recommended guideline limit for each pollutant.

The new EU directive also calls for member states to meet the new standards by 2030 – pushing back on political pressures to delay implementation to 2035.  States could, however, extend the 2030 deadline for compliance under strict conditions, like climate factors, as stipulated in the final agreement.

Anne Stauffer, deputy director of the Health and Environment Alliance (HEAL), called the EU agreement “a major step forward”, despite its shortcomings.

“While regrettably the compromise falls short on fully updating with the scientific recommendations, the package has a huge potential to lessen people’s suffering, prevent disease and achieve economic savings,” Stauffer said.

Said Chen, current EU air quality standards still “need to align more closely with the new WHO guidelines,” referring to the stricter standards recommended by the global health agency.

“I know the EU is still seeking a way to bring EU air quality standards in line with the World Health Organization (WHO) recommendations,” he added. “If that comes true, I believe it would be good news for public health, as it means people will be exposed to less harmful air.”

Image Credits: Mariordo, Nature, 2024 , Nature , Nature .

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