Airborne magnetic nanoparticles: environmental risk factors for the transmission of SARS-CoV-2

Martinez-Boubeta, C.; Simeonidis, K.

Objectives To examine the impact of concentrations of ambient fine particulate matter (PM2.5) air pollution on the incidence of COVID-19. Methods Publicly available data of COVID-19 deaths in March/October 2020 were compared with concentrations of PM2.5 measured in previous years at urban and suburban areas in Thessaloniki. Similar publicly available data of PM2.5 concentrations from Tehran were gathered for comparison. Cross-correlation and Granger causality analysis were performed in order to assess linkage. Results On the one hand, the mean PM2.5 concentrations in Thessaloniki were significantly higher in the winter, however the magnetic fraction of particulate matter in the autumn is twice its annual average, suggesting that traffic-related emissions alone may not explain the entire variability of PM2.5. On the other hand, it is implied that changes in coronavirus-related deaths follow changes in airborne magnetite, with the correlation between the two data sets being maximized at the lag time of one-month. Further insight is provided by the monthly pattern of PM2.5 mass concentrations in Tehran. We find that air pollution Granger causes COVID-19 deaths (p<0.05). Conclusions A significant association has been found between PM2.5 values and the impact of the COVID-19 pandemic on a bunch of regions. Reported links between pollution levels, climate conditions and other factors affecting vulnerability to COVID-19 may instead reflect inhalation exposure to magnetic nanoparticles. A hypothesis has been set that ubiquitous airborne magnetite pollution, together with certain climatic conditions, may promote a longer permanence of the viral particles in the air, thus favoring transmission.