A reliable and long-standing international scientific literature demonstrates a strong correlation between the incidence of cases of viral infection, and territorial concentrations of atmospheric particulate matter (e.g. PM10 and PM2.5).

The latest Italian research, just disseminated is a Position Paper drafted by SIMA-Italian Society of Environmental Medicine, the FRAME Interdepartmental Centre of the University of Bologna and the University of Bari, declares that "the rate of increase in cases of infection, which has affected in particular some areas of Northern Italy, could be related to the conditions of air particulate pollution that is known to function as a carrier, i.e. a transport vector, for many chemical and biological contaminants, including viruses". These "attach themselves" to atmospheric particulate matter, consisting of solid and/or liquid particles capable of remaining in the atmosphere for hours, days or weeks, and may also be transported for long periods of time in vital conditions. This is because "the rate of virus inactivation in atmospheric particulate matter depends on environmental conditions: while an increase in temperature and solar radiation has a positive effect on the rate of virus inactivation, high relative humidity may favour a higher rate of virus spread".

This analysis, therefore, seems to indicate a "direct relationship between the number of cases of COVID-19 and the state of pollution of the territories". It seems to demonstrate that, "in relation to the period 10-29 February, high concentrations above the PM10 limit in some provinces in northern Italy (e.g. the province of Brescia) may have exerted a boost action, i.e. an impulse to the virulent spread of the epidemic in the Po Valley. This phenomenon was not observed in other areas of Italy that had cases of infection during the same period. In this regard, the case of Rome is emblematic, where the presence of contagion was already evident in the same days of the Po Valley regions without triggering such a virulent phenomenon".