SARS-CoV-2, the virus that causes the disease, Covid-19 is spread by sharing breaths.When we breathe, water particles are released. The virus “attaches” to the water. The air-water particles are much larger and are easier to filter out than covid. A good visual example of what happens is exhaling when it is cold outside. Water droplets form in the air. Face Masks and Covid Risks in Homes is important to know about.
How tight the mask fits your face is very important. N95 masks are tight. Surgical masks are loose. They protect the healthcare worker from giving bacteria or viruses to the patient during surgery.
The amount of virus exposure is a critical factor. The riskiest people are those who have symptoms such as coughing and sneezing. If infected, they expel large amounts of particles containing more virus.
What if you want more protection?
No face mask discussed in this post can keep outside air from coming in. You have to breathe the air to live.
To be safest, don’t let any person’s breath come inside your lungs. Wear a full body and head covering with oxygen supplied through a hose. The ultimate is a special containment room with no outside air coming in and air going out completely cleaned, used by pathogen researchers. Hoses run overhead from the air system to the researchers.
You may have seen recently on TV news that nurses and doctors caring for Covid patients sometimes use a portable device on their backs with long air hoses coming to their head and face coverings. They have complete body and head protection. I assume they use portable heavy-duty battery-operated air cleaners for the room air.
Which type of face masks to use inside homes
Click “continue reading” link for info about FDA approved n95 and surgical masks plus some info on cloth masks.
This analysis has some of the best illustrations I have seen, using a living room, a bar, and a classroom.
One time examples, such as the church choir in Seattle or infections in bars, are useful. But we are a visual species. Illustrations and animations can help understand what is happening.
Spanish paper El Pais ran various simulations using the Covid Airborne Transmission Estimator developed by scientists from the University of Colorado. Excellent Illustrations of Covid spreading indoors.
A few excerpts: Irrespective of whether safe distances are maintained, if the six people spend four hours together talking loudly, without wearing a face mask in a room with no ventilation, five will become infected, according to the scientific model explained in the methodology.
The infection risk drops to below one when the group uses face masks, shortens the length of the gathering by half, and ventilates the space used.
If two hours are spent in the classroom with an infected teacher and 20 students, without taking any measures to counter the number of aerosols, there is the risk that up to 12 students could become infected.
To watch the Excellent Illustrations of Covid spreading indoors, translated into English, click here.
From the first stay at home recommendations in March, we assumed that we were safe at home. We knew that Covid-19 transmission occurs within households. However, transmission estimates varied widely, and the data on transmission from children was limited. This CDC study shows that A home is not always safe from Covid-19.
The research, part of an ongoing CDC-supported study, followed 101 people initially infected with Covid-19. Locations were Nashville, Tennessee, and Marshfield, Wisconsin, between April and September 2020.
What is useful from this report?
A 53% household infection rate, the study said, is higher than what has been documented so far. To date, related research has reported only a 20% to 40% infection rate.
Findings from a prospective household study with intensive daily observation for equal or greater than 7 consecutive days indicate that transmission of Covid-19 among household members was frequent from either children or adults.
Podcast. 9-28-20. 16 minutes. Research has shown that COVID-19 transmission is largely through airborne droplets and particles expelled during sneezing, coughing, talking, and singing. There’s little evidence that surfaces are making us sick. Deep Cleaning For Covid Is Not Very Effective
Microbiologist Dr. Emanuel Goldman talks with Stephanie Desmon about the science behind COVID transmission research, the strong evidence that infection comes from aerosols and not surfaces, and how excess sanitation in public spaces may be giving us a false sense of security.
Hygiene Theater: The Deep Cleaning Performances That Offer Little Protection from COVID-19To listen click here Note: play button is below the orange image on the right side.
Link to Dr. Goldman’s Lancet article, “Exaggerated risk of transmission of COVID-19 by fomites“ referenced in the podcast. Lots of references. A bit technical, but no too bad. Dr. Goldman did literature research and has many references and links to other articles. Many thanks to him. To read the article click here
My comments:The best explanation I have heard about Covid and surfaces (fomites!!)!
Note from all the experts: We don’t know much yet about how the virus is transmitted.
Podcast (16 minutes) “Open the Window: Talking about Airborne Transmission”
“Can the novel coronavirus be spread through the air? And if so, what can we do to make sure the air inside our homes and buildings is as clean as possible? Dr. Sanjay Gupta talks with Joseph Allen, Director of the Healthy Buildings program at the Harvard T.H. Chan School of Public Health, about the science behind airborne transmission.”
A very good, understandable and interesting, discussion by an expert from many angles, focusing on homes. But also discusses schools. Starts with tenement housing many years ago, which often lacked windows, and what was done to provide windows. I see many older apartment buildings, pre-1940, built with small “air vents” in the middle of the building providing ventilation.
On CNN Fact vs. Fiction with Dr. Sanjay Gupta. One of my favorite Covid podcasts. To listen to the Podcast Click here