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OPINION www.ddh1.com.au

Coronavirus and its current

impact on the mining industry

n July 2020, 239 scientists signed an open letter “appealing to the medical community
I and relevant national and international bodies to recognise the potential for airborne
spread of COVID-19”. Indeed, as Wilson N. et al, also point out, “studies in both
humans and airflow models show that particles as large as 50 microns can remain
suspended and travel considerable distances”.

As pointed out by Fernstrom A and Goldblatt M (2013), the The ventilating air stream in underground mines is normally
heterogeneous (diverse) nature of the droplets and airborne fully turbulent, with random eddies continuously being
particles is a complicating factor since they generally formed. Such chaotic airflows are ideal for maintaining
consist of a mixture of single and multiple cells, spores and infected aerosols airborne.
viruses carried by respiratory secretions and fine/ultrafine These exhaled aerosols can, apparently, coalesce with
dust particles. Infectious particles, on the other hand, may water droplets or solid or liquid pollution particulates (e.g.,
come directly from infected persons or by air conditioning smoke, smog or diesel fumes). Indeed, the SARS-CoV-2
systems, and/or cooling towers. aerosols have been observed on airborne particulates
Transmission of infectious diseases by airborne routes is and there is mounting evidence for associating COVID-19
also dependent on several other factors such as particle outbreaks with high levels of particulate pollution in the size
size, the extent of desiccation and the nature of the air range 0.2-10 microns.
movement in the atmosphere at the location of interest. Consequently, COVID-19 aerosol particles could move
Labour-intensive industries are particularly vulnerable with the underground ventilation airflow whilst remaining
to COVID-19, and every effort must be made to avoid infective for an hour or more, which means they could
the rampant spread of the virus in the close confines of potentially travel great distances. Little research has been
underground mines. Indeed, if the virus is released by an directed at this phenomenon and there is a gap in our
infected miner the infected aerosols will be transported to knowledge on how the effectiveness of dispersal depends
other miners at downstream locations due to the nature of on environmental conditions, particularly turbulence,
mine ventilation. because an infected cloud of infected aerosols could in
In a recent article published in The Lancet (April 2021) the more gentle airflows remain reasonably compact (e.g., in
authors concluded that “there is consistent, strong evidence laminar airflows or in the gentler regions in turbulent tunnel
that SARS-CoV-2 spreads by airborne transmission. flows near the roof or sides of mine airways). Even if such a
Although other routes can contribute, we believe that the cloud becomes quite dispersed within the turbulent airflow,
airborne route is likely to be dominant. The public health the aerosols will still remain infective for quite some time.
community should act accordingly and without further Unfortunately, most worksites in hard rock underground
delay”. mines are located at the face of development headings or

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