It may not be a coincidence that the virus that is scourged Italy (first country in the world for deaths, yesterday the record of 627 in 24 hours) is mainly affecting the North and Lombardy (where 10% of the sick die). The conditional is a must, but according to a study carried out by two professors of industrial chemistry from the University of Bologna, Leonardo Setti and Fabrizio Passarini, together with colleagues from the Universities of Bari, Trieste and Milan, and researchers from the Italian Society of Medicine Environmental (Sima), it seems that air pollution contributes to the spread: and in fact the most affected areas are those of the Po Valley, where smog notoriously reaches very high levels especially in winter.
Furthermore, last winter, precisely in the weeks in which the coronavirus began to spread, between January and February, was particularly dry and this favored the accumulation of polluting particles in the atmosphere: the Pm10 peaks reached in a city like Milan, together with Bergamo and Brescia the most affected by the contagion, confirm this. Basically, according to the researchers, the virus it would "stick" to the smog to travel faster and go further. Here's how it works: “We all produce micro drops when we sneeze or cough that can reach a meter or a meter and a half away – explains Professor Setti -. It's the famous droplet distance we're all talking about. In reality, however, we also emit micro-droplets, nuclei of much smaller dimensions, which can aggregate with the particulate matter in the air".
Smog therefore behaves like an airplane: it carries the virus, stabilizes it and keeps it in suspension for a distance that can be much greater than one metre, thus multiplying the possibilities of contagion on the street, by bus, in stations. Most likely what happened in many Lombard cities in the fateful weeks of the contagion boom. On the other hand, a correlation with pollution has already been seen in the past with other viruses, from Ebola to bird flu, and also in China itself for the coronavirus: "Many elements that tell us that this correlation is probable", confirm the scientists, recalling however that at the moment "there is still no scientific proof".
The correlation would also explain why the coronavirus, for now, has not spread much in the Center-South, or at least not to the levels it was in the North. “In Rome between January and February we recorded an average of 0,4 Pm10 limit violations at the control unit, while Milan also had 8. This could explain why in Rome, where the first infections were already present in those same days, the virus has not grown so fast,” adds Setti. So the hope is that in these weeks when the smog has dropped, thanks also to the restrictions that effectively limit the use of the car, the virus may have some more difficulty circulating in the atmosphere.
“I would say – closes Setti – that certainly staying away is perfectly fine, but perhaps we should also wash the streets and further reduce the number of vehicles on the road. But I certainly don't decide." Meanwhile, the debate has widened and in addition to the question of smog, the question of ventilation systems has also arisen: “Sars 1 – said the virologist Ilaria Capua – had begun to circulate in the air conditioning system of a hotel in Hong Kong. In Lombardy we must immediately understand if the Covid-19 has entered ventilation systems, perhaps old ones, which have accelerated and multiplied its circulation precisely among those with more fragile defenses ".
