«Nitrogen dioxide levels also correlated with case trends during the summer, confirming the well-known deleterious effects on human health and susceptibility to Covid-19″. As far as dust is concerned, the thinner ones (Pm2.5) have led «a worsening of the spread of the disease in Northern Italysuggesting that environmental pollution has played a non-negligible role in promoting the infection process throughout the Po valley.
If other research had already reached these conclusions, the article just published in the scientific journal Heliyon da a group of researchers from the University of Milan and the University of Insubria it allows for the advancement of knowledge: because it is elaborated on a statistical model which has been correlated demographic factors (from the population density, to the composition of families), environmental (the main pollutants) e climatic variables: in particular the level of solar radiation, which had never been used for this kind of study in Italy.
The research therefore does not dwell on the direct relationships between a single environmental factor and the trend of the pandemic, because it is concentrated on the overall correlation of all the elements. This is why the conclusions, beyond the reconstruction of the history of Covid in Lombardy, are projected into the future: “Special attention should be paid to highly populated areas, especially if heavily polluted and poorly exposed to the sun”.
Health effects
The analysis of the overall correlation is able to reveal new aspects. For example, the one relating toozonewhich remains a pollutant with «detrimental action on health for both irritant effects, both for oxidative stress on the respiratory system». However, the analysis revealed that ozone may have had a “protective” role against Covid in interrelationships. The explanation concerns a specific chemical reaction: “The concentrations of ozone are inversely proportional to those of Nox, given that it is the product of a photochemical reaction of nitrogen dioxide” (it is a secondary pollutant). Translated: the pollutant that played a more harmful role in the pandemic, nitrogen dioxide (No2), tends to transform into ozone under the sun’s rays. Presence of ozone is therefore equivalent to a lower concentration of the more harmful gas. It’s just about the conditions of the contagion. Furthermore, ozone has a damaging action on viruses.
A virus from the heat
The role of temperature in the spread of Covid is controversial, particularly since the contagion in some areas of the United States it has “galloped” even with temperatures close to 40 degrees. The conclusion is that temperature alone, contrary to what was hypothesized at the beginning of the pandemic, does not have a decisive correlation (therefore a role) in containing the contagion, except below twenty degrees. The most innovative aspect of the study, however, is that of having included data on solar radiation in the analysis models, to investigate the connections between the various climatic and environmental factors in relation to the spread of the pandemic. This is complex data that was provided by the Air Force meteorological center.
Radial protection
Among the meteorological variables, exactly the sun’s rays seem to have played a significant role in containing the contagion, “both for direct effects and for the correlation with other factors”. For example, in colder periods, a slightly higher temperature played a protective role when combined with greater solar radiation: an aspect that may have safeguarded the central and southern regions in the first Covid wave of 2020. Furthermore, the sun’s rays tend to trigger the transformation of nitrogen dioxide, a polluting gas which, as we have seen, has the most negative effects on health and is most closely related to the spread of viruses. Then there are biological processes: the sun’s rays, on the one hand, deactivate the power of viruses; on the other, they stimulate the production of vitamin D, which strengthens the immune system against viruses and bacteria.