Monona is right (as usual). The virus can live longer than one day on a hard surface. But probably not 17. That number is based on a study of surfaces in staterooms
on the Diamond Princess that had been inhabited by confirmed positive cases. They were sampled 17 days later, but before any disinfection. What the researchers found was viral RNA, not live virus. That was no surprise. You'd expect viral fragments to
persist long after the virus is broken up. CDC did a poor job of reporting this, so journalists got the impression that a fomite could be infectious for several weeks. The consensus seems to be that the maximum is 3 days on a hard surface, less on a porous,
absorbent one. But those numbers don't matter all that much. Surfaces where positive cases have been or in high-traffic areas ought to be disinfected a lot more often than every couple of days, and at the moment people ought to be washing up after touching
anything outside their own house.
I have one other small quibble. The video talks about droplet and fomite transmission, but not aerosol. Even the CDC now admits that possibility (although WHO
isn't there yet). Droplets fall out fast. Aerosols are not as infectious, but they linger.
Nevertheless, it's a terrific teaching tool. The best I've seen.
Mike Wright
Michael J. Wright
Director of Health, Safety and Environment
United Steelworkers
412-562-2580 office
412-370-0105 cell
"My friends, love is better than anger. Hope is better than fear. Optimism is better than despair. So let us be loving, hopeful and optimistic. And we'll change
the world."
Jack
Layton
From: ACS Division of Chemical Health and Safety [mailto:DCHAS-L**At_Symbol_Here**PRINCETON.EDU]
On Behalf Of Monona Rossol
Sent: Saturday, April 04, 2020 9:02 AM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: Re: [DCHAS-L] Recommend: Video explaining COVID-19
Peter, Brilliant, beautiful and perfect for explaining to people. But I have to tell you there is one error in it.
Peter, The statement that the bug lives for 24 hours on surfaces, is incorrect. There are now 4 studies of COVID-19 on surfaces, and the people who did the studies,
except for one, erred in not recording the humidity and temperature over the time of the tests. So lengths of time that live virus was found on surfaces appear to be inconsistent ranging from hours to 17 days. But these results are not inconsistent when you
factor in what is known about viruses. For example, the 17 day and other long survival times were found on hard surfaces on a cruise ship study where the humidity is very high. This is easy to explain when you look at the three major factors that influence
survival time:
a) humidity (higher humidities --> longer survival)
b) temperature (too low inactivates but may not kill; mid-range with an optimum temp some where; too hot kills)
c) the nature of the surface. (porous = shorter life; hard surface = longer life; toxic surface , e.g., copper, = shorter)
So the NIOSH study for reusing N95s by putting them in paper bags for 5 days showed the virus dead in 2-3 days. Paper bags are necessary to dry out the mask and
keep humidity from being trapped in the bag.
The 24 hour number in the video unfortunately made it more difficult to convince our people who are subletting to HCWs that it would be best to disinfect hard contact
surfaces after occupancy by virus positive/exposed tenants.
Any chance this one wee boo could be repaired and a perfect video release?
Monona
-----Original Message-----
From: Reinhardt, Peter <peter.reinhardt**At_Symbol_Here**YALE.EDU>
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Sent: Sat, Apr 4, 2020 6:55 am
Subject: Re: [DCHAS-L] Recommend: Video explaining COVID-19
Thank so much. So proud to work with amazing people like her.
Yes. Please link to
https://medicine.yale.edu/media-player/4989/, which is a site made available to the public by the Yale School of Medicine. Its proper title is, "Covid-19: An Illustrated Scientific Summary"
posted April 1, 2020.
Pete
From:
ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU> on behalf of "Wright, Mike" <mwright**At_Symbol_Here**USW.ORG>
Reply-To: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Date: Saturday, April 4, 2020 at 6:47 AM
To: "DCHAS-L**At_Symbol_Here**PRINCETON.EDU" <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Subject: Re: [DCHAS-L] Recommend: Video explaining COVID-19
Pete, this is by far the best thing I've seen on COVID-19 science for a general audience.
A lot of my union's members and families could benefit from this - those staying home, those at work in because they are essential (or their employers think they
are), including about 50,000 health care workers on the front lines.
Our website includes a page COVID-19 resources. Could we have permission to post a link to the video? We would, of course, credit Yale and Ms. Liao.
Mike Wright
Michael J. Wright
Director of Health, Safety and Environment
United Steelworkers
412-562-2580 office
412-370-0105 cell
"My friends, love is better than anger. Hope is better than fear. Optimism is better than despair. So let us be loving, hopeful and optimistic. And we'll change
the world."
Jack
Layton
From: ACS Division of Chemical Health and Safety [mailto:DCHAS-L**At_Symbol_Here**PRINCETON.EDU]
On Behalf Of Reinhardt, Peter
Sent: Friday, April 03, 2020 6:43 AM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: [DCHAS-L] Recommend: Video explaining COVID-19
This 8 minute video is worth every second of your time. It brilliantly explains the molecular and cellular biology, medicine, and epidemiology of COVID-19.
Created by Clara Liao, a first year Neuroscience Ph.D. Student at Yale.
Pete Reinhardt
Yale EHS
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