Air quality in Europe has improved in the last 20 years

Despite this positive aspect of air quality, according to a study carried out by ISGlobal from Barcelona, ​​98,10%, 80,15% and 86,34% of the European population lives in areas that exceed the levels recommended by WHO PM suspended particulate matter2.5, MP10 and nitrogen dioxide, respectively.

A study carried out by the Barcelona Institute for Global Health (ISGlobal) and the National Supercomputing Center (BSC-CNS) evaluated air quality according to daily PM concentrations2.5, MP10, I have not2 me3 in many regions of Europe between 2003 and 2019 with machine learning methods.

The goal was to estimate the number of days exceeding the 2021 World Health Organization (WHO) guidelines for one or more air quality pollutants.

The research team analyzed pollution levels in more than 1.400 areas in 35 European countries, where 543 million people live.

The results published in the journal Nature Communications. show that global levels of suspended particulate matter (PM2.5, MP10) and nitrogen dioxide (NO2) have declined in most of Europe. Specifically, PM concentrations10 were the ones that 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. On the contrary, the concentrations of O3 increased by 0,58% annually in southern Europe, almost quadrupling the number of days with poor air quality.

The study also looked at the number of days the limit was exceeded for two or more pollutants at the same time.
This fusion is called "compound pollution day". The results highlight significant improvements in air quality in Europe in terms of PM10 and not2, while PM levels2.5 me3 in many regions continue to exceed WHO recommendations, leading to increased exposure to air pollution.

"Specific efforts needed to address PM levels2,5 me3 and associated composite pollution days, especially in the context of rapidly increasing climate change threats in Europe”says Zhao-Yue Chen, researcher at ISGlobal and lead author of the study, especially in the context of the growing threat of climate change in Europe.

"Our estimate of population exposure to composite air pollution events provides a solid basis for future research and policy development to address air quality management and public health concerns across Europe," said Carlos Pérez. García-Pando, ICREA and AXA Research Professor at the BSC-CNS

Geographic distribution of air quality is not uniform

The research team developed machine learning models to estimate high-resolution daily concentrations of major air pollutants, such as PM2.5, MP10, I have not2 me3. This data-driven approach creates a complete daily picture of air quality across the European continent, going beyond scattered monitoring stations.

The models collect data from a variety of sources, such as satellite aerosol estimates, existing atmospheric and climate data, and land use information. Analyzing air pollution estimates, the team calculated the annual average number of days when WHO daily limits for one or more air pollutants were exceeded.

The analysis shows that during the study period, approximately 98,10%, 80,15% and 86,34% of the European population lived in areas that exceeded annual PM levels.2.5, MP10, I have not2 of the WHO, respectively. These results are largely consistent with the European Environment Agency (EEA) estimates for the 27 EU countries that used data from urban stations only.

No country met the annual ozone standard (O3) during the peak season of 2003-2019. Regarding short-term exposure, more than 90,16% and 82,55% of the European population lived in areas that exceeded the WHO daily guidelines for PM2.5 me3 at least 4 days in 2019, when NO concentrations2 and PM10 They are 55,05% and 26,25%.

During the study period, PM levels2.5 and PM10 were highest in northern Italy and Eastern Europe, and PM levels10 They were highest in southern Europe. Elevated concentrations of NO were observed2 mainly in northern Italy and parts of Western Europe, such as the south of the United Kingdom, Belgium and the Netherlands.

Similarly, the O3 it increased by 0,58% in southern Europe, while it decreased or showed little trend in the rest of the continent. However, the largest PM reductions2.5 and PM10 were observed in Central Europe, while those in NO2 They occurred mainly in urban areas of Western Europe.

Integrated ozone management

The average exposure time and number of days people are exposed to PM2.5 me3 They are much longer than those of the other two contaminants. According to the research team, this highlights the need for greater control of these pollutants, as well as the importance of addressing the growing trends and impacts of O exposure.3.

The O3 Tropospheric emissions occur in the lower atmosphere and are considered a secondary pollutant because they are not emitted directly to the atmosphere but are formed from various precursors, such as volatile organic compounds (VOCs), carbon monoxide (CO), and carbon monoxide (CO). nitrogen oxides (NOx), which are produced in combustion processes, mainly in transportation and industry. At high concentrations, ozone affects air quality and can be harmful to human health, vegetation and ecosystems.

"Ozone management presents a complex challenge due to its secondary training path. Conventional air pollution control strategies, which focus on reducing emissions of primary pollutants, may not be sufficient to effectively mitigate high levels of O3 and days with associated compound contamination"says Joan Ballester Claramunt, ISGlobal researcher and senior author of the study.

"However, address climate change, which affects ozone formation through increased sunlight and rising temperatures, is critical to long-term management of the ozone layer and protecting public health"he concluded.


Ballester, J. et al. "Population exposure to multiple air pollutants and their compound episodes in Europe", Nature Communications..

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