Assessing the relationship between ground levels of ozone (O3) and nitrogen dioxide (NO2) with coronavirus (COVID-19) in Milan, Italy

• Published in: The Science of the total environment Vol. 740; p. 140005
• Main Authors: Zoran, Maria A., Savastru, Roxana S., Savastru, Dan M., Tautan, Marina N.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 20.10.2020; The Authors. Published by Elsevier B.V
• Subjects: Air Pollutants - analysis; Air Pollution - analysis; Air surface nitrogen dioxide (NO2); Air surface ozone (O3); Betacoronavirus; Climate variables; Coronavirus; Coronavirus COVID-19; Coronavirus Infections; COVID-19; Humans; Italy; Nitrogen Dioxide - analysis; NOAA satellite data; Ozone - analysis; Pandemics; Planetary Boundary Layer (PBL); Pneumonia, Viral; SARS-CoV-2; Italy; Coronavirus COVID-19; Air surface nitrogen dioxide (NO2); Climate variables; Air surface ozone (O3); NOAA satellite data; Planetary Boundary Layer (PBL); Air surface nitrogen dioxide (NO); Air surface ozone (O)
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2020.140005

This paper investigates the correlation between the high level of coronavirus SARS-CoV-2 infection accelerated transmission and lethality, and surface air pollution in Milan metropolitan area, Lombardy region in Italy. For January–April 2020 period, time series of daily average inhalable gaseous pollutants ozone (O3) and nitrogen dioxide (NO2), together climate variables (air temperature, relative humidity, wind speed, precipitation rate, atmospheric pressure field and Planetary Boundary Layer) were analyzed. In spite of being considered primarily transmitted by indoor bioaerosols droplets and infected surfaces or direct human-to-human personal contacts, it seems that high levels of urban air pollution, and climate conditions have a significant impact on SARS-CoV-2 diffusion. Exhibited positive correlations of ambient ozone levels and negative correlations of NO2 with the increased rates of COVID-19 infections (Total number, Daily New positive and Total Deaths cases), can be attributed to airborne bioaerosols distribution. The results show positive correlation of daily averaged O3 with air temperature and inversely correlations with relative humidity and precipitation rates. Viral genome contains distinctive features, including a unique N-terminal fragment within the spike protein, which allows coronavirus attachment on ambient air pollutants. At this moment it is not clear if through airborne diffusion, in the presence of outdoor and indoor aerosols, this protein “spike” of the new COVID-19 is involved in the infectious agent transmission from a reservoir to a susceptible host during the highest nosocomial outbreak in some agglomerated industrialized urban areas like Milan is. Also, in spite of collected data for cold season (winter-early spring) period, when usually ozone levels have lower values than in summer, the findings of this study support possibility as O3 can acts as a COVID-19 virus incubator. Being a novel pandemic coronavirus version, it might be ongoing during summer conditions associated with higher air temperatures, low relative humidity and precipitation levels. [Display omitted] •COVID-19 viral infections are positively correlated with ground level ozone.•Ground level nitrogen dioxide is inversely correlated with COVID-19 infections.•Dry air, low winds and precipitation rates supports COVID-19 virus diffusion.•Warm season will not stop COVID-19 spreading.•Outdoor airborne aerosols might be possible carriers of COVID-19.