Pollution increases COVID-19 deaths worldwide by 15%
Researchers warn that air pollution is a very important cofactor of COVID-19 deaths globally, but it is still underestimated.
COVID-19 and air pollution do not mix well, such is the conclusion of a study published in the specialized journal Cardiovascular Research and broadcast by the European Society of Cardiology. It states that prolonged exposure to air pollution is not only related to an increased risk of dying from COVID-19, but the proportion of deaths from coronavirus could be attributed to the exacerbating effects of air pollution for all countries in the world. without exception.
Specifically, the authors note that around 15% of deaths worldwide from COVID-19 could be attributed to prolonged exposure to air pollution.
In Europe, this proportion would be around 19%, in North America around 17% and in East Asia around 27%. "The figures are an estimate of the proportion of deaths from COVID-19 that could have been avoided if the population had been exposed to lower levels of air pollution, with no emissions from the use of fossil fuels and other anthropogenic sources (caused by humans ) ". Explains the Max Planck Institute for Chemistry (Germany) that conducted the study. The danger would not be direct but indirect due to its aggravating effect on comorbidities (other health problems), which can have fatal consequences in the case of viral infection.
The dangerousness of fine particles was proved once again
Estimates of deaths from COVID-19 associated with air pollution differ widely from country to country: they are highest for the Czech Republic with 29%, China with 27% and Germany. with 26%. On the contrary, they are lower for Italy (15%), Brazil (12%), Israel (6%), Australia (3%) and New Zealand (1%). For France, the rate would increase to 18%, behind Belgium (21%) and the Netherlands (19%). In the UK, for example, around 44,000 people have died from COVID-19 from the start of the pandemic to mid-June, and researchers estimate that the proportion due to air pollution was 14%, or 6,000. deaths.
"Although our results are uncertain, the contribution of air pollution to mortality from COVID-19 is clear. However, actual mortality is influenced by many factors, such as the countrys health system," says Dr. Andrea. Pozzer, lead author of the study. The hazard is linked in particular to the general exposure of the population to fine polluting particles with a diameter of 2.5 micrometers or less (called PM2.5). As the World Health Organization (WHO) already explains on the subject, "chronic exposure to fine particles contributes to the risk of developing cardiovascular and respiratory diseases and lung cancer".
"There are no vaccines against poor air quality"
"When people breathe in polluted air, very small and harmful fine dust particles migrate from the lungs to the blood and blood vessels," the researchers explain. "They cause inflammation and strong oxidative stress, which disrupts the balance between free radicals and oxidizing agents that normally repair cellular damage. This in turn damages the inner lining of the arteries, the endothelium, and leads to narrowing and stiffness of However, the SARS-CoV-2 virus that causes COVID-19 also enters the body through the lungs and causes similar damage to blood vessels, "they note.
The scientific team was able to more precisely identify the mechanism involved in this dangerous association. The fine particles appear to increase the activity of the ACE-2 receptor located on the surface of cells. In fact, to infect its host, SARS-CoV-2 attaches itself to a protein present on the surface of cells, especially in the lungs: the ACE2 receptor. The latter is the center of attention because it is a key protein in Covid-19 physiology, necessary for the virus to enter host cells. According to the authors, this is a double whammy: "Pollution damages the lungs and increases ACE-2 activity, leading to increased uptake of the virus by the lungs."
In their conclusions, they make a clear call to politicians: "Our results suggest that reducing pollution can bring significant benefits. The environmental aspect of the pandemic shown here is that we need to implement effective measures to reduce anthropogenic emissions, which cause so much air pollution such as climate change. The pandemic will end with the vaccination of the population or with herd immunity, however there is no vaccine against poor air quality and climate change. "
According to the WHO statistics as of 2018, 9 out of 10 people in the world breathe air that contains high levels of pollutants.