Thursday, March 26, 2020

Pandemic ponderings: Indications that High levels of Air Pollution exacerbate Covid19 spread (virus may be airborne)

First published as a Linked-in Blog post on March 26,2020.

While we all hunker down in physical distancing with Covid19. I have been chasing up reports on preliminary research by Italian scientists between high levels of Pm10 and Pm2.5 air pollution particulates increasing intensity and spread of Covid19 based on their research in northern Italy. 

I intially followed a link from a CMCC climate observatory (strong science reputation) post What Science Has to Say About the Coronavirus – Climate Crisis Connection. A Press Review (An excellent article by the way)

I came across a linked Italian news report dated 18 March reporting on a preliminary study by several Italian scientists regarding Pm10 and Pm2.5 particulates exacerbating Covid19 intensity and spread in northern regions of Italy. I documented this in my facebook timeline post with an english translation.

Sentinel-5P satelite NO2 (atmospheric conc.) data for February and March in below graphics:

Sentinel-5P  NO2 (atmospheric conc.) data air pollution February 2020 data
Sentinel-5P  NO2 (atmospheric conc.) data air pollution March 2020 data
The research in Italy could have ramifications for communities in Australia, especially in the La Trobe Valley and the Hunter Valley, where air pollution sometimes exceeds safe levels, and during large scale hazard reduction burns which could exacerbating the corona virus virulence for regional communities.

It could also have implications globally for areas of high particulate pollution in this global pandemic.Read the Position Paper from Italian Society of Environmental Medicine (Società Italiana di Medicina Ambientale (SIMA)) linked from the Position Paper Page - The Paper is available in Italian, English, Portuguese.

Evaluation of the potential relationship between Particulate Matter (PM) pollution and COVID-19 infection spread in Italy
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"Moreover, taking into account that COVID-19 incubation period (time elapsed between the human exposure and the manifestation of symptoms until the diagnosis) was estimated to be on average 14 days and considering the monitored period (starting from 24 th February to 15 th March), it can be assumed that the virulent stage occurred between 6 th February and 25 th February. Infection spread trends for Southern regions are in agreement with epidemic models based on the typical transmission mode ‘person-to-person contact’ whilst anomalies in COVID-19 infection spread across Northen regions in Pianura Padana are observedsuggesting that the diffusion was promoted by a carrier agent (Figure 3)."

As far as I am aware this paper has not yet been peer reviewed, but given the short timeframes it should be treated with high relevance and importance. It is authored by 12 Italian academics with expertise in environmental medicine and air pollution adding to it's scientific authenticity. 

The 12 Italian medical and environmental researchers conclude in their paper:

In conclusion, the rapid COVID-19 infection spread observed in selected regions of Northen Italy is supposed be related to PM 10 pollution due to airborne particles able to serve as carrier of pathogens. As already highlighted in previous studies, it is recommended to take intoaccount PM 10 contribution and make policymakers aware of the need to take direct actions for pollution control.

I want public health authorities in Australia to seriously look at this issue and include a proper threat assessment given the Corona Virus pandemic is rapidly scaling up at an exponential rate with an increasing rate of daily confirmed cases, hospitalisations and deaths in Australia. See Coronavirus (COVID-19)

Update 6 April: Chris Mooney in the Washington Post highlighted the association issue between Covid19 and air pollution in an article published on March 16: The coronavirus is deadly enough. But some experts suspect bad air makes it worse.

Update 6 April: Smoking poses incresed Covid19 risk.

A yet to be peer reviewed paper in a pre-print repository by Joan C. Smith, Jason M. Sheltzer highlights that cigarette smoking poses increased risk with Covid19. The paper was submitted 312 March 2020: Cigarette smoke triggers the expansion of a subpopulation of respiratory epithelial cells that express the SARS-CoV-2 receptor ACE2.

Jason Sheltzer explains the implications in this twitter thread on 1 April:

"In general, three factors have been linked with COVID-19 susceptibility: being male, being elderly, and smoking. For instance, in one cohort, 12.3% of current smokers required ventilators, were admitted to an ICU, or died, compared to <5% of non-smokers." (link to Clinical Characteristics of Coronavirus Disease 2019 in China, in the New England Journal of Medicine)

"We show that quitting smoking is associated with a decrease in lung ACE2 expression. I’m not an MD, but when faced with an epidemic respiratory virus, giving up cigarettes is probably a good idea - for multiple reasons." says Jason Sheltzer.

Lifespan of Corona Virus as aerosol and on surfaces

Correspondence published this month in the New England Journal of Medicine - Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1 found that the virus may be airborne in aerosols for 2-3 hours. 

It also persists on certain surfaces like plastic and stainless steel for up to 3 days. It remains detectable for up to four hours on copper, and up to 24 hours on cardboard.

"This virus is quite transmissible through relatively casual contact, making this pathogen very hard to contain," said James Lloyd-Smith, a co-author of the study and a UCLA professor of ecology and evolutionary biology. "If you're touching items that someone else has recently handled, be aware they could be contaminated and wash your hands." according to a media release (March 20).

Physical Distancing above 80% needed to Flatten the Curve

We are yet to see signs the Covid19 pandemic curve is starting to flatten to avoid hospitals being overwhelmed in Australia, like in northern Italy. There is modelling done by Sydney University researchers that this point may be reached for New South Wales during April. As Victoria is less advanced along the epidemic curve our hospitals have a little more time to prepare.

Whatever everyone does in physical distancing will help to Flatten the curve of the epidemic. This is paramount.

If too many people don't stay at home, it means all our sacrifice will be for little gain in preventing hospitals being overwhelmed and deaths eascalating. Here is the image by ABC News based on Sydney University research: Modelling transmission and control of the COVID-19 pandemic in Australia. (The study has not yet been peer reviewed)
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Air pollution may prove to be not a big issue for most communities in Australia as the epidemic ramps up, but some communities - Hunter Valley, La Trable Valley in particular - might need much better air pollution and public health monitoring and special health preparedness. It is so important this is included as part of health risk assessments and preparedness.


  • 2019-NCOV EPIDEMY: POSITION PAPER OF THE ITALIAN SOCIETY OF ENVIRONMENTAL MEDICINE AND THE UNESCO "HEALTH EDUCATION AND SUSTAINABLE DEVELOPMENT" - REPORT ON THE EFFECT OF ATMOSPHERIC PARTICULATE POLLUTION AND THE DIFFUSION OF VIRUSES IN THE POPULATION: POSITION PAPER OF THE SPECIAL WORKING GROUP SIMA EMERGENCY COVID19 (Leonardo Setti - University of Bologna; Fabrizio Passarini - University of Bologna; Gianluigi de Gennaro - University of Bari; Alessia Di Gilio - University of Bari; Jolanda Palmisani - University of Bari; Paolo Buono - University of Bari; Gianna Fornari - University of Bari; Maria Grazia Perrone - University of Milan; Andrea Piazzalunga - Expert Milan; Pierluigi Barbieri - University of Trieste; Emanuele Rizzo - Italian Society of Environmental Medicine; Alessandro Miani - Italian Society of Environmental Medicine, University of Milan)

  • Our World in Data (Oxford University) - Coronavirus Disease (COVID-19) – Statistics and Research - detailed mapping and charting of the pandemic - Max Roser, Hannah Ritchie and Esteban Ortiz-Ospina (2020) - "Coronavirus Disease (COVID-19) – Statistics and Research". Published online at Retrieved from: '' [Online Resource]

  • Sheryl L. Chang1 , Nathan Harding1 , Cameron Zachreson1 , Oliver M. Cliff1 , and Mikhail Prokopenko, University of Sydney, Westmead, NSW 2145, Australia "Modelling transmission and control of the COVID-19 pandemic in Australia", [Online Resource]

  • Joan C. Smith, Jason M. Sheltzer, "Cigarette smoke triggers the expansion of a subpopulation of respiratory epithelial cells that express the SARS-CoV-2 receptor ACE2", doi: (This article is a preprint and has not been certified by peer review)

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