Light Dark
  • News

  • Sports

  • Health

  • Uncategorized


  • In English

  • Opinions

  • Conseil présidentiel


  • Load More

Posts in


1 / 1
*to close megamenu form press ESC or close toggle

What is tropospheric ozone (O3), which is responsible for nearly 115,000 deaths in Europe?

  • June 3, 2024
  • 7 Min
  • 15

La pollution is a real public health issue in France, but also around the world. Each year in France, the number of premature deaths over a year due to air pollution is estimated at 48,000, according to Public Health France. This represents 9% of the country’s mortality. Research to understand how air pollution impacts health is increasing.

A Franco-Spanish study from the National Institute of Health and Medical Research (Inserm) looked at a component of atmospheric pollution called tropospheric ozone (O3). According to the results of this research, this air pollutant is responsible for 114,447 deaths, 88.3% of which are linked to exposure to ozone emitted by other countries. Their results are published in the journal Nature Medicine.

Air pollution: what is tropospheric ozone (O3)?

Tropospheric ozone (O3) is a colorless and very irritating gas. The latter is formed in “the troposphere (the part of the atmosphere between the ground and the stratosphere, editor’s note) by the interaction of solar radiation with several precursor gases, mainly nitrogen oxides (NOx) and volatile organic compounds (VOCs) coming from natural and anthropogenic sources (due to human activity editor’s note)”.

Also called a “secondary” pollutant, tropospheric ozone (O3) is a greenhouse gas and a component found in smog, a mixture of gases and particles that form a dry, thick haze. As Inserm researchers point out, high levels of this pollutant “are associated with a range of adverse effects on respiratory health, including worsening of asthmathe chronic obstructive pulmonary diseasedecreased lung function and infections, leading in the most serious cases to hospitalization and death”.

— Inserm (@Inserm) June 3, 2024

Tropospheric ozone (O3) “imported” from other countries would be responsible for 88% of deaths linked to this pollutant

But the researchers wanted to know the effects of “imported” tropospheric ozone (O3), from different countries, on the health of Europeans. To do this, the researchers used data from Caliope, a measurement system air quality on European countries. It measured both the propagation of tropospheric ozone (O3) and the formation of nitrogen oxides (NOx) and the volatile organic compounds (VOCs) that compose it. Data was collected every year from May to September, between 2015 and 2017. The mortality level was calculated using Eurostat data.

Between 2015 and 2017, researchers noted 114,447 deaths attributable to O3 between 2015 and 2017 in the 35 European countries. According to the authors, “88.3% of these deaths would be linked to exposure to O3 from other countries, 11.7% of deaths would be linked to exposure of national origin”. At this level, the most industrialized countries have their share of responsibility. Thus, France’s emissions would be responsible for 32.3% of deaths attributable to O3 in Luxembourg. For Switzerland, this level would rise to 29.3% and 24.4% for Belgium.

Tropospheric ozone (O3): what can be done to combat this pollutant?

In a press release, Hicham Achebak, researcher at Inserm (France) and ISGlobal (Spain), calls for “put in place regulatory and mitigation measures to combat the effect of air pollutants such as O3 which are easily transported across borders”. According to him, these results underline “the need for systematic quantification of national, European and extra-community contributions to air pollution levels and their associated health effects”.

Also, to reduce the presence of tropospheric ozone (O3), the appearance of which is favored by global warming, Hicham Achebak recalls the importance of the fight against climate change in order to improve air quality.

Sources :

  • The majority of tropospheric ozone contributing to premature mortality in European countries is imported – National Institute of Health and Medical Research (Inserm) (press release).
  • Geographic sources of ozone air pollution and mortality burden in Europe – Nature Medicine
  • Public Health France – Air pollution
author avatar
Louis Tardy