114,447 over the period 2015-2017. This is the number of deaths for which tropospheric ozone (O3) is responsible in Europe according to a study carried out by Inserm, the Barcelona Institute for Global Health (ISGlobal), and the Barcelona Supercomputing Center – Centro Nacional de Supercomputación (BSC). -CNS), the results of which are published this Monday, June 3 in Nature Medicine.
This is Europe in the continental sense, which includes 35 countries with a total population of around 530 million people.
Asthma, COPD, impaired lung function…
Tropospheric ozone forms in the troposphere, the first and lowest layer of Earth’s atmosphere. It is a harmful air pollutant formed by the interaction of sunlight with two other pollutants, volatile organic compounds (gasoline combustion, evaporation of liquid fuels, gas and oil production, etc.) and nitrogen oxides (industries, coal combustion, gasoline, etc.) emitted largely by human activities.
Responsible for migraines, eye and throat irritations, coughs, exposure to O3 causes respiratory problems, including worsening asthma and chronic obstructive pulmonary disease (COPD). , decreased lung function and infections.
These disorders can lead, in the most serious cases, to hospitalizations and deaths.
Ozone from countries outside Europe
The scientific team relied on the Caliope air quality measurement device, which covers Europe, but also on a modelling technique which allowed them to assess the dispersion and transport of atmospheric pollutants, from land and sea, over long distances.
The researchers were thus able to assess the number of deaths due to O3 emitted in Europe but also imported.
According to the results, among the 114,447 deaths attributable to O3 – making it one of the leading causes of premature mortality from air pollution:
- 88.3% of deaths are linked to exposure from other countries;
- 11.7% to exposure of national origin.
In detail, according to the Inserm press release, “20.9% of all observed deaths are linked to ozone originating in the other European countries analyzed, 60.2% to ozone originating outside Europe and the remaining 7.2% to ozone from maritime transport.
In addition, the majority of O3 attributable to mortality is emitted by the most industrialized countries, including France. “O3 from France had a significant impact on its border countries such as Luxembourg (32.3% of deaths attributable to O3), Switzerland (29.3%), Belgium (24.4%) and Spain (16.8%).”
A phenomenon accentuated by global warming
“Our study highlights the need for systematic quantification of national, EU and extra-EU contributions to air pollution levels and their associated health impacts. The aim is to put in place regulatory and mitigation measures to combat the effect of air pollutants such as O3 that are easily transported across borders. », explains Hicham Achebak, researcher at Inserm (France) and ISGlobal (Spain).
Especially since “ “Global warming will enhance the conditions for tropospheric O3 formation in the future, as photochemical mechanisms for O3 formation are favored during heat waves and periods of high solar radiation. Combating global warming is necessary to sustainably improve air quality.”
To know : According to a study published in The Lancet Planetary Health, air, water and soil pollutants are responsible for 9 million deaths each year worldwide. According to the WHO in 2019, 4.2 million deaths were attributable to air pollution.
