Wednesday, March 24, 2021

Researchers search for the perfect face mask fit

A team of researchers at the U of Minnesota has been working on designing masks hoping to achieve fit factors approaching an N-95 respirator. They are also working on 3D modeling of faces to aid in customizing the fit of respirators/masks. Below is a report by WCCO TVs Jennifer Mayerle. (3/22/2021)


Jennifer Mayerle WCCO TV - Finding the perfect face mask fit - 3:04

Monday, December 14, 2020

Minnesota Covid Aware app


One method of slowing the transmission of COVID 19 is to download the Minnesota COVID Aware App.  This app will notify you anonymously if someone that you have interacted with for more than 15 minutes has tested positive for COVID -19. It was fairly easy to download and is available for both Apple and Android phones. 

Why you should download the Covid aware app. - 4 min. 

Monday, September 14, 2020

Thursday, June 18, 2020

Origins of COVID and other Zoonotic diseases

U of Minnesota Origins of COVID and other Zoonotic Diseases

This webinar covers the origin of HIV via the SIV in primates in Africa. Other wildlife based or zoonotic diseases are also covered.

Saturday, June 6, 2020

Use of Face Shields to Protect Against Transmission of COVID-19

Medical Xpress - Could Face Shields replace masks in preventing COVID-19. 

CDC - Efficacy of Face Shields - CDC report that face shields are protective for health care workers from initial large droplets but provide very little protection over longer periods. 

MDH - Best practices for masks and face shields for persons with disabilities. - Information on masks with clear openings for lip reading and when face shields are appropriate as sole protection. 

JAMA ...Face Shields and the Containment of COVID-19. The authors suggest that using face shields to prevent COVID-19 transmission would be easy to implement. Data suggest that they may protect the person wearing it from large aerosol transmission. They will not protect against small aerosol transmission. 

Contagion Live - Interview with an author of the JAMA paper. Encouraging the universal use of face shields could reduce the r naught to below one. The use is based on similar diseases but not specifically on COVID-19. 

PMC - Safety Guidelines for Sterility of Face Shields for the COVID-19 outbreak - They list specifications for the design and cleaning of face shields. The chemical list is rather limited. 

Lancet - Physical Distancing, Face Masks, and Eye Protection ... Distances of 2 meters or greater are recommended to reduce transmission. All three of these measures can combine to potentially reduce exposure but not eliminate it. There is a need form more specific COVID - 19 data. 

FDA - Emergency Use Authorization for the production of face shields - The authorization lists the specific approved methods for the production of face shields. 

Interview with Michael B. Edmund on the use of face sheilds - 11:30 min. 

Wednesday, May 6, 2020

The use of Heat for SARS-CoV-2 disinfection

There are four main methods to disinfect SARS-CoV-2 the virus that causes COVID-19.

  1. Time: The virus eventually no longer will be viable after a period of time. This depends on several things including the surface type, the temperature, and relative humidity. 
  2. Ultraviolet light (UV-C) also known as UVGI (Ultraviolet Germicidal Irradiation) at 254 nm works to alter the RNA of the SARS-CoV-2.
  3. Vaporized Hydrogen Peroxide 
  4. Temperature. Elevated temperatures reduce the viability of the virus.  


Decontamination of respirators was effective at 70 degrees Celsius for 60 minutes. These elevated temperatures may cause damage to respirator components.  

Stanford Medicine has done multiple studies decontaminating respirators with UV-C and heat. In there study they found repeated heating of masks with hot air at 75C for 20 cycles did not damage a respirator. An 8 W UVGI (254 nm) for 30 minutes for 10 cycles did not damage the respirator.

As I reviewed the 3M website masks appeared to have different temperature tolerances. 

Friday, May 1, 2020

Guidelines for Reopening Businesses and schools during COVID-19

The deeper you look the more you find - photo N. Carlson

Many places of employment are working through plans to reopen while minimizing transmission of SARS cov 2 the virus that causes COVID-19. The following is a list of guidances primarily from the CDC about opening businesses, schools and Universities. In the near future more specific information will become available, and this information will be added to the post. 

General guidance:

Back to Work Safely - AIHA offers industry specific guidance for getting back to work safely.

Business guide for responding to COVID-19 - CDC

Reopening Guidance for Schools and Businesses - CDC

How to clean and conduct risk management for COVID-19:

Cleaning and Disinfecting Tool - CDC

Disinfect Non-Emergency Vehicle with COVID-19 positive occupant - CDC

Reopening guidance for cleaning and disinfecting areas - CDC

Cleaning and Disinfecting Your Facility - CDC

Guidance for Schools for COVID-19  - CDC

Guidance for Higher Education Administration - CDC

Cleaning for CoVID -19 - Sustainable Mycology summary

LBC - General information on Deep Cleaning for Coronavirus - 3 min. 

Private Sector call on COVID-19 response from CDC 4/29/2020 -46 Min.

COVID-19 School response - March 26, 2020 - CDC - 61 min.