European air quality crisis: Cross-border zone pollution deaths soar

According to researchers from the Barcelona Institute for Global Health, over 60% of all deaths related to ground-level ozone (O3) in 35 European countries are caused by ozone originating from other states. Ground—level ozone forms in the troposphere through the interaction of sunlight with several precursor gases.

Ground-level ozone, which results from the reaction of sunlight with nitrogen oxides and volatile organic compounds, has a harmful impact on the respiratory system, leading to asthma, chronic obstructive pulmonary disease, and infections. Researchers thoroughly examined data from the warm months, from May to October, when O3 concentrations reach their highest levels.

The analyses used the CALIOPE air quality system, which monitors ozone concentrations and their precursors across Europe. Additionally, scientists analyzed models of long-distance air pollution spread, which helped identify the sources of pollution.

The average O3 concentration in the surveyed countries was 101.9 µg/m³, ranging from 76.7 µg/m³ in Finland to 130.1 µg/m³ in Malta. It is estimated that the number of ozone-related deaths reached 114,447, with a mortality rate of 72 deaths per million people annually. The highest death rates were recorded in Germany, Italy, France, the United Kingdom, Spain, and Poland, as well as in southeastern countries like Bulgaria, Serbia, and Romania.

The largest supplier of ozone to neighboring countries turned out to be France, followed closely by Germany. Ozone from France most significantly impacted Luxembourg (32.3% of ground-level ozone-related deaths), Switzerland (29.3%), Belgium (24.4%), and Spain (16.8%). Meanwhile, ozone from Germany significantly impacted Luxembourg (24.2% of deaths), the Czech Republic (23.3%), and the Netherlands (21.5%).

Scientists highlighted the crucial role of westerly winds in the spread of ozone, causing a higher number of deaths in Eastern Europe due to ozone influx from the west. The research results indicate the necessity of systematically monitoring the contribution of individual EU and non-EU countries to air pollution. This monitoring is the first step towards meeting the air quality standards set by the WHO, which can prevent premature deaths and chronic diseases.

In their final conclusions, the researchers noted that climate warming favors the formation of tropospheric ozone. Therefore, actions aimed at preventing climate change are key to improving air quality and should form the basis of long-term global policy, the experts summarized.