For the first time, researchers assessed the impact of air pollution on the number of deaths from Covid-19 globally, and determined that long-term exposure was on average responsible for 15 % of them.
Inflammation and severe oxidative stress
As part of this work published in theEuropean Heart Journal, scientists fromMax-Planck Institute (Germany) determined the fraction of deaths that could have been avoided in the absence of harmful fossil fuel emissions. According to them, around 19% of deaths due to Covid-19 in Europe would be attributable to the cumulative effects of air pollution on health, against nearly 27% in East Asia.
However, the document recalls that these estimates “ do not imply a direct cause and effect relationship between air pollution and mortality from Covid-19 But rather refer to the relationship between the virus and air pollution, which worsens pre-existing health conditions and can lead to life-threatening complications.
” When people inhale polluted air, very small pollutant particles, called PM 2.5, migrate from the lungs to the blood and blood vessels, causing inflammation and severe oxidative stress, which results in an imbalance between free radicals. and oxidants which normally repair damage to cells », Explains the professor Thomas Münzel.
” This causes damage to the inner lining of the arteries, the endothelium, and causes the arteries to narrow and stiffen. Also entering the body through the lungs and causing similar damage to blood vessels, the virus is now considered endothelial disease.. “
Air pollution involved in 18% of deaths from Covid-19 in France
The study drew on data from previous studies conducted at United States and in China, examining the effects of air pollution, Covid-19 and the epidemic of SARS in 2003. This information was combined with satellite data on atmospheric concentrations of PM 2.5 to create a model that could predict the number of coronavirus deaths attributable to long-term exposure to fine particles.
In particular, researchers estimated that air pollution contributed to 29% of coronavirus deaths in Czech republic, 27% in China, 26% in Germany, 18% in France and 16% in Sweden, compared to 3% in Australia and 1% in New Zealand.
” When long-term exposure to air pollution and virus infection are combined, we have an additional negative effect on health, especially on the heart and blood vessels, resulting in greater vulnerability and strain. less resistance to Covid-19 “, valued Münzel. ” If you already have heart disease, air pollution and coronavirus infection will cause disorders that can lead to heart attacks, heart failure, and strokes.. “
A double effect highlighting the need to reduce anthropogenic emissions
The German researchers also refer to previous studies that suggested that fine particles in air pollution could prolong the lifespan of infectious viruses in the atmosphere, helping them to spread further.
” The particles appear to increase the activity of a cell surface receptor called ACE-2, which is known to be involved in how Covid-19 infects cells “, highlighted Münzel. ” So we have a double effect, with air pollution damaging the lungs and increasing the activity of ACE-2, which in turn results in better absorption of the virus by the lungs and possibly by the blood vessels and the heart. “
According to the authors of the study, these results highlight the need to quickly reduce anthropogenic emissions, via the transition to a green economy, because if the possibility of finding an effective cure for the coronavirus exists, there is no chance to find a vaccine against climate change and poor air quality.