Correlation between atmospheric pollution and contagion intensity in Italy and Lombardy

Analysis of air pollution levels aims to verify potential correlations between the territorial
spread of major atmospheric pollutants, fine dust and nitrogen dioxide and the severity of
territorial Covid-19 contagion. A diachronic reading of pollution levels also makes it possible
to correlate the impact of restriction measures for combating the SARS-CoV-2 epidemic with
data on atmospheric pollution. It needs to be stressed from the start that any estimate of potential correlations should
never be taken as final or absolute: atmospheric pollutants do present variations in dispersion
and intensity that depend on atmospheric conditions. These considerably affect pollutant
accumulation or dispersion, and consequently also monitoring-station measurements. In
fact, data reliability increases whenever the reference timeframe is extended, as in the case
of monthly or annual averages.
Nonetheless, in atmospheric pollution analysis, space is as important as time, for at least
two reasons: (i) analyses conducted in the Lombardy region rely on an IT model that returns
approximate information from the data acquired via the network of survey-monitoring
stations; (ii) data are mapped with reference to municipal administrative units. In mountain
areas, data record a sharp difference in air condition between the urbanized valley bottoms
and the sparsely settled area of the medium-high sections on mountain slopes.
It follows that the maps are more reliable in detecting the atmospheric conditions of fields
and extended territorial areas, rather than individual areas on a municipal basis.