A family member from the US sent me this. I'm not registered to the Washington Post so can't validate the content.
https://www.washingtonpost.com/healt...ebsite-states/
So based on the guidance below, it would appear that "short term" mass gatherings outdoors, such as protests that we've seen in Australia, is not as risky as being stuck indoors with a few hundred people screaming and carrying on...which is what is going to happen at those election campaigns.
. Not sure how something like the MCG would be classified, where it is a bit of mix. We do know the Italy outbreak was kicked off from a football match in Bergamo where 40,000 attended.
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The US Government’s Centre for Disease Control (GCDC) has made official the emerging scientific evidence on Coronavirus Transmission
Very low risk of transmission from surfaces.
Very low risk from outdoor activities.
Very high risk from gatherings in enclosed spaces like offices, religious places, cinema halls or theatres.
These findings that have been emerging for a while need to be applied by people to manage the situation in the best manner possible.
Time to reduce panic about surface transmission, and time to not be too eager to go back to office.
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WHAT IT TAKES TO INFECT
To successfully infect you, the virus needs a dose of ....
~1000 viral particles (vp)
The typical environmental spread of activities: -
Breath: ~20 vp minute
Speaking: ~200 vp minute
Cough: ~200 million vp (enough of these may remain in air for hours in a poorly ventilated environment)
Sneeze: ~200 million vp
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FORMULA
Successful infection = Exposure to Virus Time SCENARIOS
* Being in vicinity of someone (with 6 ft distancing) Low risk, if limit to less than 45 minutes
* Talking to someone face to face (with mask): Low risk if limit to less than 4 minutes.
* Someone passing you walking/jogging/cycling: Low risk
* Well-ventilated spaces, with distancing: Low risk (limit duration)
* Grocery shopping: Medium risk (can reduce to low by limiting time and following hygiene)
* Indoor spaces: High risk
* Public Bathrooms/Common areas: High fomite/surface transfer risk.
* Restaurants: High risk (can reduce to Medium risk by sitting outdoors with distancing and surface touch awareness)
* Workplaces/Schools (even with social distancing): Very high risk, including high fomite transfer risk.
* Parties/Weddings: Very high risk.
* Business networking/conferences: Very high risk.
* Arenas/Concerts/Cinemas: Very high risk.
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RISK FACTORS
The bottom line factors you can use to calculate your risk are...
- indoors vs outdoors
- narrow spaces vs large, ventilated spaces.
- high people density vs low density
- longer exposure vs brief exposure.
The risks will be higher for former scenarios.
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