Long-term exposure to ambient air pollution could lead to an increased risk of dying from Covid-19, by around 15% on average worldwide, according to an international study published on Tuesday.
The study published in the specialized journal Cardiovascular Research sets out to assess the extent to which this pollution, already the cause of premature death, could also influence Covid mortality.
This proportion would be around 19% in Europe, 17% in North America, around 27% in East Asia, according to estimates by Professor Jos Lelievel of the Max Planck Institute for Chemistry in Mainz (Germany).) and his colleagues.
Long-term exposure to air pollution would have contributed to 29% of deaths due to Covid in the Czech Republic, 27% in China, 26% in Germany, 22% in Switzerland, 21% in Belgium, 19% in the Netherlands, 18% in France, 15% in Italy, 14% in the United Kingdom, 12% in Brazil, 11% in Portugal, 9% in Spain, 3% in Australia and only 1% in New Zealand.
The researchers used previous epidemiological data from the United States and China on air pollution and Covid-19 and on SARS of 2003, a disease similar to Covid.
They combined them with satellite data on global exposure to fine particulate matter (PM2.5) and data from ground pollution monitoring networks to make their calculations. The authors do not establish a direct cause and effect relationship between this pollution and Covid mortality.
The polluting particles appear to increase the activity of a receptor, called ACE-2, located on the surface of cells, involved in how Covid-19 infects patients, according to the researchers.
“We therefore have a + double blow +: air pollution damages the lungs and increases the activity of ACE-2, which leads to better absorption of the virus”, according to Prof. Thomas Munzel (Johannes Gutenberg University, Mainz), co-signatory of the study.
“The transition to a green economy with clean and renewable energy sources will promote both the environment and public health, at the local level by improving air quality and at the global level by limiting climate change”, they plead.
Deeming “extremely probable” the existence of a link between air pollution and mortality due to Covid-19, Anna Hansell, professor of environmental epidemiology (University of Leicester) considers for her part “premature to try to quantify it precisely “.
She mentions “many other good reasons to act now to reduce air pollution, which the WHO already associates with 7 million deaths per year worldwide (4.2 million of these deaths linked to air pollution). outdoor air and the rest to indoor air pollution). “