On Jan 14, 2021, at 10:54 AM, McLaren III, Jim A. <james.mclaren**At_Symbol_Here**TRINCOLL.EDU> wrote:

 

I love you Monona.

They also state the idea that 13 ply cotton is as good as the N-95's------------------where in the market are there 13 ply masks?  I see three plys at best.

 

Jim McLaren

Jim McLaren

Lab Technician/Chemical Hygeine Officer/Nuclear Safety Officer

300 Summit Street, Trinity College Chemistry Department,

Hartford, CT  06106-3100

Telephone:  860-297-2512

 

From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU> On Behalf Of Monona Rossol
Sent: Thursday, January 14, 2021 10:41 AM
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Subject: Re: [DCHAS-L] 3' Social Distancing "Rule"

 

Here's the first paragraph of the Discussion:

 

Discussion The findings of this systematic review of 172 studies (44 comparative studies; n=25697 patients) on COVID-19, SARS, and MERS provide the best available evidence that current policies of at least 1 m physical distancing are associated with a large reduction in infection, and distances of 2 m might be more effective. These data also suggest that wearing face masks protects people (both health-care workers and the general public) against infection by these coronaviruses, and that eye protection could confer additional benefit. However, none of these interventions afforded complete protection from infection, and their optimum role might need risk assessment and several contextual considerations. No randomised trials were identified for these interventions in COVID-19, SARS, or MERS

From my perspective, and having read a great number of those 176 studies, it seems like a lot of trouble to conclude what we have known for many months.  I suppose it might be helpful for those last holdouts who are still against wearing masks and distancing, but they should all drop dead by Thursday anyway.

 

And the major flaw in the studies is there rarely is any measurement of the ventilation parameters or directional air flow that would transport the aerosol.  So it's pretty much a math exercise in my view.  Then there is the following in the conclusions:

 

Our findings accord with those of a cluster randomised trial showing a potential benefit of continuous N95 respirator use over medical masks against seasonal viral infections.79 Further high-quality research, including randomised trials of the optimum physical distance and the effectiveness of different types of masks in the general population and for health-care workers' protection, is urgently needed

 

I'm really annoyed by all of the efforts to figure out how to make better cloth masks when we well-know how to manufacture N95s.  The damn things are a polyfiber fabric and a couple of straps. How hard is that to manufacture?  By now, we should be knee-deep in N95s and we'd have been busy training lay people to use them safely.  I can only conclude that the leaders of this country truly don't gave a damn.

 

There's a reason from my low pH attitude that I'll discuss later.

 

Monona

 

 

-----Original Message-----
From: John Callen <jbcallen**At_Symbol_Here**GMAIL.COM>
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Sent: Thu, Jan 14, 2021 9:48 am
Subject: [DCHAS-L] 3' Social Distancing "Rule"

Good Morning Ladies and Gentlemen,

 

As you may know, just as ACS/DCHAS operate this important dialogue on various topics of timely interest, so does the American Industrial Hygiene Association (AIHA) operate "catalyst/AIHA" as open discussion for its community.

 

For those of you who are not members of the AIHA, Jeremy DeWitt, CIH (DuPont Protection Technologies, Midlothian, VA) just posted the following question with an attached reference.

 

"I am wanting the objective feedback from the (AIHA) community about the Harvard study citing that 3ft is adequate space for social distance in school."

 

He states, "This study (see attached below) is currently being used as justification for returning children to school in the central Virginia region"

 

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31142-9/fulltext

 

And further states, "The effectiveness seems to be contingent upon effective mask usage.  This does not seem to be a realistic layer of protection when dealing with elementary age children."

 

Any comments you have would be welcome here for DCHAS members to review.  

 

Those of you who are AIHA members might want to comment on "catalyst/AIHA" as well.  David M. Lipton, CIH from the NC Division of Public Health (Raleigh, NC) just posted the first reply 30 minutes ago.

 

Also, in keeping with our current dialogue on  "Eyewear," do scroll down to the section of the study which discusses use of protective eyewear to help reduce exposure which is based upon mostly SARs and MERs data.  Will non-vented/gas-tight Z877.1+ D3/D4/D5 be the best solution for not only frontline heathcare workers but also the general public?

 

Be Safe and Stay Well!

 

All My Best,

 

John B. Callen, Ph.D

3M Personal Safety Division - Retired

ACS/DCHAS Founding Member 

(312) 632-0195

 

 

--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.org Follow us on Twitter **At_Symbol_Here**acsdchas

--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.org Follow us on Twitter **At_Symbol_Here**acsdchas

--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.org Follow us on Twitter **At_Symbol_Here**acsdchas