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

ObjectivesTo examine the impact of concentrations of ambient fine particulate matter (PM2.5) air pollution on the incidence of COVID-19. MethodsPublicly 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. ResultsOn 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). ConclusionsA 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. Key messagesO_ST_ABSWhat is already known about this subject?C_ST_ABS{blacktriangleright}{blacktriangleright} Due to their small dimensions, airborne particles are able to penetrate through inhalation into many human organs, from the lungs to the cardiovascular system and the brain, which can threaten our health. Research has shown that air pollution is an important cofactor increasing the risk of mortality from coronaviruses. What are the new findings?{blacktriangleright}{blacktriangleright} Evidence exists that the magnetic fraction of PM has modulated the transmission of SARS-CoV-2 in Thessaloniki, and potentially in any other region in the world. How might this impact on policy or clinical practice in the foreseeable future?{blacktriangleright}{blacktriangleright} Policymakers should take care not to overestimate the effect of social distancing interventions and should consider the impact of air pollution in current or future epidemic waves.