This editorial discusses a new hypothesis that links the dramatic impact of COVID-19 outbreak in Northern Italy with the high concentrations of particulate matter (PM10 and PM2.5) that characterize this area, along with its well-known specific climatic conditions.

The presence of SARS-COV-2 RNA has been found on particulate matter in Bergamo, which is not far from Milan and represents the epicenter of the Italian epidemic. Some believe this confirms (at least in case of atmospheric stability and high PM concentrations, as it usually occurs in Northern Italy) that the virus can create clusters with the particles and be carried and detected on PM10.

Given that these are preliminary findings, it would be premature to regard particulate matter as a “carrier” of COVID-19 or a “boosting factor” in the epidemic. Rather, the authors suggest that the presence of SARS-COV-2 RNA on PM10 of outdoor air samples could represent a potential early indicator of COVID-19 diffusion or severity. At the same time, it is possible that long term exposure to high levels of particulate matter may chronically impair human health and possibly influence the clinical course of infections acquired by already debilitated individuals, especially in most vulnerable age groups.