Scientists are continuously looking for additional information on the behavior of the novel coronavirus. In particular, it is important to understand why in some cases the virus seems to cause more serious consequences and more problematic courses than in others. Attention immediately focused on the possible role of smog and cigarette smoke as aggravating factors. A debate has started between scientists. Indeed, there are scientists that claimed the validity of this hypothesis and those who refuted it. Well, two scientific studies of a few days ago have finally clarified the link between air pollution and cigarette smoke and an increase in lethality and complications of the virus. Both studies were performed by researchers of Harvard University (Vardavas et al, Tob Induc Dis, 2020 - Xiao Wu et al, in preprint).
The researchers noted, in particular, that, in the long term, an increase in exposure to PM 2.5 particulate, a type of microscopic particles emitted by cars, motorcycles, heating system and factories, even by just 1 micro gram per cubic meter is associated to a 15% increase in the mortality rate from COVID-19. According to these data, it appears clear the importance of persevering in the policies of controlling air pollution emissions. If these results are addressed to governments, the second study is aimed at the general population and, more particularly, at those who have not yet abandoned cigarette smoking. The study starts from general considerations, that is that smoking cigarette weakens the immune system and makes it less active against infections. Not only that, smokers are more at risk of contracting the flu and, as observed in the previous MERS epidemic, another type of coronavirus, the risk of mortality was higher among smokers. The researchers then analyzed the particular situation of COVID-19 and what emerged, even though with limitations since the studies are still few, is that cigarette smoke causes a higher probability of severe effects and difficult clinical courses with a 2.4 times higher risk to need ICU. In addition, as indicated by government guidelines, smokers are more likely to put their hands on their faces causing, in the act of smoking, contacts between fingers and cigarettes potentially infected with the lips, thus increasing the risk of contagion. So here's another great reason to stop smoking now!
