The blog covers issues broadly related to sustainability in Minnesota and the world both from an environmental perspective and from an interpersonal perspective. It also covers issues related to mycology (the study of fungi) with a specific emphasis on the interaction with fungal organisms and buildings.
The above chart helps individuals differentiate between the cold, flu, and COVID-19. The CDC has recently published and updated list of COVID-19 symptoms. The list previously included the top three symptoms. The symptoms in Bold are new additions to the list.
Fever
Cough
Shortness of breath or difficulty breathing
Chills
Repeated shaking with chills
Muscle pain
Headache
Sore throat
New loss of taste or smell
The CDC has a Coronavirus Self-Checker to help people get a better idea if they have symptoms of COVID-19
Please see below about gastrointestinal symptoms and a recent NEJM publication noting a higher than normal incidents of stroke in younger coronavirus patients in New York City.
A doctor at the Mayo Clinic notes that patients can have gastrointestinal symptoms that are associated with COVID-19 with or without respiratory symptoms. 1 min.
Washington Post summary of symptoms - 1 min.
Dr. Justin Springer on the association between COVID-19 and increase incidence of stroke - 3 min.
UV-C light in the range of 280 to 200 nm (254 nm the most effective) is a disinfectant used in laboratories and ventilation systems. Direct exposure to the light at this wavelength can severely damage skin and damage vision. UV light can also produce ozone, Ozone health effects are noted by the CDC.
The following links describe the use of UV-C lights for room disinfection. One of the concerns is making sure that the light exposes all surfaces. There are also concerns about the length of time needed. The light does generate heat so no flammable objects can be close to the light. The UV-C light will decay in effectiveness over time. Specific meters are used in the UV-C light range to determine the level of exposure needed to kill the virus. Refer to the Wikipedia article on Ultraviolet Germicidal irradiation
Paper bag with handles 8.5" x 6.5" x 3.5" Name and date are clearly marked on the bag
Respirator straps are hung from paper bag handles
The respirator is suspended above the bottom of the bag
A 2 gram desiccant pack is placed at the bottom of the bag to absorb moisture from the mask to slow down bacterial and fungal growth. The amount of desiccant needed may vary dependent on storage conditions.
Please see the disposable respirator post for links to the Minnesota Department of Health and the CDC for the number of times these respirators can be used. Guidance on the number of uses will vary by health care provider. The length of storage time will vary from 5 to 7 days. This is based on the anticipated COVID-19 survival time on surfaces.
Experience from nurses indicate that moisture in the masks is an issue. The straps also tend to wear out after repeated use.
To reduce particle loading on the mask, staff are asked to refrain from wearing make-up in areas that will contact the surface of the mask.
Surgical Masks: Surgical masks provide some protection from droplets but they are primarily designed to protect the patient from the provider because the mask does not provide a tight face seal. Never reuse, wash or disinfect surgical masks. Please see Delaware Health and Social Services Division of Public Health - Proper use of surgical masks
According to an April 2, 2020 Medscape article on coronaviruses on fabrics researcher still need to study how the virus survives on clothing. The CDC recommends washing clothes on the warmest possible setting and drying the clothes thoroughly. Please review CDC's home cleaning recommendations for a suspected or known COV-19 person in the house.
There are worse jobs than cleaning up a space for COVID-19. The video below from National Geography shows extreme cleaners in action. Not recommended for viewing by those that are easily nauseated.
In an effort to prolong the life of N-95 face masks, many institutions have been using UV-C light disinfection. It is being looked at by 3M and they list testing results on their masks. FDA recommends following the guidelines of the manufacturer for UVC decontamination procedures. CDC references a article from the Infectious Disease Journal providing guidance on UVC decontamination. The CDC lists UVC as a method of N-95 respirator decontamination.
Here are some safety notes to note up front. UV-C light is hazardous. Do not expose skin or look at the light as it will cause damage. The light must be turned on remotely without individuals present in the room. The lamps can get hot, and ozone may be produced.
There are concerns with making sure all parts of the mask are disinfected. There are also concerns that the UV-C light will cause the material to photo degrade and loose its effectiveness.
Not all UV lights are equivalent (notes from Nancy Rolstad and Wikipedia UV)
UV-A lights (the ones used in a tanning bed) do not have sufficient germicidal properties (long-wave UV) It is associated with skin aging
UV-B light is a shorter wavelength of light associated with skin burning.
UV-C lights are necessary for disinfection. (aka UVGI germicidal irradiation or shortwave UV)
UV-C light bulbs efficiency is reduced over time. A UV meter is necessary to measure the quality of the light source.
UV-C light is absorbed by the ozone layer and the atmosphere. That is why the sunlight that reaches the earth does not have good disinfecting properties for COVID-19.
In Science Daily: Researchers report a 99.9% reduction in surface COVID-19 levels with a 30 second dose of UV-C light. The dose was not specified.
U of M's CIDRAP has weighed in on N-95 reuse. Current methods are for an emergency use only to extend the amount of stock available. The UV-C light does begin degrading the material. Under the emergency circumstances they recommend 5 cycles at 1 J/cm2 per cycle.
Applied Environmental Microbiology - This was a study on the use of biological indicator strips to verify sterilization with plasma, UV-C, and blue light.
There is an upgraded DIY mask from Allina Health with a built in pipe cleaner to improve the fit of the mask around the nose. I will give it a try. I could not locate 1/4 inch elastic bands because all stores were sold out. I will try with larger elastic bands and see how it goes.
If available, the proper use of a HEPA filtered powered air purifying respirator (PAPR) can be used to reduce the use of N-95s by health care workers as the HEPA filter on the device may be used for an extended period of time without changing. The face shield and covers can also be disinfected. These series of videos show proper assembly, donning and doffing of one style of 3M PAPR.
These supplemental notes to the videos on PAPR use and decontamination were developed by Nancy Rolstad from the BioSafety group at University Health and Safety.
Before Starting:
Eyeglass users:
Consider a strap retainer to hold the eyeglasses in place. This may take a little adjusting as the hood is donned and more care when doffing to not be tempted to reach for glasses before hand hygiene is performed. People may also use medical tape over the frame to their temples too but not without some discomfort.
Test airflow with the ball tube (set out of the way so it doesn't become contaminated during doffing)
Hand over the output to test alarm (shown in the video posted below)
Verify that there is enough battery power
The battery may need a good thump to get it locked in on the respirator, try pulling it off to verify it's tight.
To facilitate decontamination, install a plastic sleeve over the tube and secure with twist ties, tucking ends of twist ties in a way to prevent snagging. (Consider taping, with a tab for easy removal as another option)
Check the hood for leaks before donning by gathering up the shoulder shroud (as if choking it) to verify it fills with air and you don't hear or feel any air pushing out any little holes.
Donning:
Shroud Layering- Leave the longer shroud inside the disposable gown to help protect in from contamination
Use the gown to cover the unit to help protect it from contamination as shown in the video.
Doffing:
Follow the demonstration in the video with respect to doffing the disposable gown and gloves to prep for decontamination between patients or end of the shift.
Assure that there is a large enough space for two people.
Decontamination post doffing:
All items to be disinfected must remain visibly wet for the contact time listed on the (EPA approved) disinfectant's container and left to air dry. Do not attempt to wipe it dry.
Wipe down the plastic sleeve being careful not to poke gloves with the twist tie ends which may be pointy. Wipe down and carefully remove and properly dispose of the plastic sleeve at the end of the shift or if it becomes damaged.
Gently hang shroud to dry for next use.
Wipe down table.
Battery:
Battery connection points can become corroded if they get wet during decontamination. Avoid contact with disinfectant and battery connection points, if they do get wet be sure the battery contact points are dry before starting to charge.
Verify the battery is charging.
If there seems to be a connectivity issue a soft pencil eraser on the copper contact points can help to gently remove residue.
Locate the battery charger in a place where it will not come into contact with items being doffed/ decontaminated.
Versaflow TR300 Mask 3 min. 27 seconds.
S- series head cover information. View the first 2 minutes and 15 seconds
Donning, Doffing and disinfecting 3M PAPR breathing apparatus - 10 min. Please note this head cover is different from the s-series head cover in the previous video.
This is an early prototype of a two layer cloth mask made by my sister. The final mask will reposition the straps and have a twist tie sewn in above the nose bridge to get a better fit. I will be offering support for her to make masks to prolong the life of N-95 respirators, and to help protect others from people who do not know they have symptoms. The newer mask is an updated version of the Olson Mask
The fabrics used in a mask as well as the mask air leakage affect the ability of the cloth mask to filter out large and small particles. Combining multiple layers of different fabrics improves the mask filter efficiency. ACS Nano April, 2020.
The University of Minnesota has a MN COVID Mask Sewist Group. You participate by making masks or requesting a cloth mask. It also has a Face covering FAQ on the requirement that all people on campus are required to wear face coverings. Please also see the UHS guide for fabric face coverings.
Research paper (NIH) that does a comparison of cloth mask materials - Testing the efficacy of home made masks. It is interesting that the results of this study is slightly different from my current limited tests of recent home made mask designs.
Lisa Brosseau offers a commentary that masks for all is not based on sound science. Filter efficiency and fit are key to the effectiveness of respirators. The filtering efficiency and face fit of the cloth mask is variable and deficient when compared to a properly fitted N-95 respirator.
A recent summary at Fast.ai suggests that combining social distancing with cloth mask usage appears to be helpful in flattening the curve in some countries notably the Czech Republic. The video below explains how the Czech republic successfully established their Masks4All program using the phrase, "I protect you. You protect me."
Amy L. Baxter, MD in a Medscape article asks Is it Time that We All Start Wearing Face Masks?
She offers strong arguments that it will reduce the efficiency of transmission from an infected individual to another person.
My comments:
The cotton masks do not work as well as a properly fitted and worn N-95 respirator. However a multi-ply cloth respirator covering the mouth and nose will limit the amount of droplet aerosols produced during coughing, speaking, sneezing, or singing. Wearing a cloth mask will reduce a person's ability to infect another person. It will also make it more difficult for a person to directly touch their nose or mouth.
Breathing through a mask can cause more resistance from breathing. If you have questions about the use of one of these masks consult with your super busy health care provider.
Hand hygiene after mask removal is important. These masks will need to be washed and dried daily in a dryer on high temperature setting. Others have recommended washing, drying, and steam ironing for additional disinfection.
Maybe this will be another way we can all do our part to flatten the curve.
