For 20 years now we have been breathing cleaner air in Europe, but despite this the majority of the population lives in areas where fine particles (PM2.5 and PM10) and nitrogen dioxide (NO2) still exceed the warning levels indicated by the World Health Organization: Northern Italy, in particular, is among the regions with the highest concentrations.
This is indicated by the study published in the journal Nature Communications by the Barcelona Institute for Global Health (ISGlobal) and the National Supercomputing Center of Barcelona (Bsc-Cns).
Researchers developed machine learning models to estimate daily concentrations of major air pollutants between 2003 and 2019 in over 1,400 regions in 35 European countries, inhabited by a total of 543 million people.
For the study, satellite data, atmospheric and climate data and information regarding land use were collected, to obtain a more defined picture than that offered by monitoring stations alone.
The results reveal that in 20 years, pollutant levels have fallen in much of Europe, especially PM10 (with an annual decline of 2.72%), followed by NO2 (-2.45%) and PM2.5 (-1.72%).
The largest reductions for PM2.5 and PM10 were observed in Central Europe, while for NO2 they were found in predominantly urban areas of Western Europe.
Over the study period, PM2.5 and PM10 were highest in Northern Italy and Eastern Europe.
Elevated levels of NO2 have been observed in Northern Italy and some areas of Western Europe, such as the south of the UK, Belgium and the Netherlands.
Ozone increased annually by 0.58% in southern Europe, while it decreased or had no significant trend in the rest of the continent.
However, the overall improvement in air quality has not solved the problems of citizens, who continue to live mostly in areas where the limits indicated by the WHO are exceeded for PM2.5 (98%), PM10 (80%) and nitrogen dioxide (86%).
These results are in line with European Environment Agency estimates for 27 EU countries, based on data from urban stations.
Furthermore, no country met the annual ozone limit during the peak season between 2003 and 2019.
The study finally looked at the number of days the limits for two or more pollutants were exceeded simultaneously.
It thus emerged that despite the overall improvements, 86% of the European population has experienced at least one day a year with exceedances for two or more pollutants: the most frequent combinations are PM2.5 with nitrogen dioxide and PM2.5 with ozone.
According to the study's first author, Zhao-Yue Chen, "Targeted efforts are needed to address PM2.5 and ozone levels and associated pollution days, especially in light of growing threats from climate change in Europe."
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