Here is a video of a presentation by one of the authors along with some demonstrations and explanations.
TLDR: Here is the Abstract:
There is ample evidence that masking and social distancing are effective in reducing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. However, due to the complexity of airborne disease transmission, it is difficult to quantify their effectiveness, especially in the case of one-to-one exposure. Here, we introduce the concept of an upper bound for one-to-one exposure to infectious human respiratory particles and apply it to SARS-CoV-2. To calculate exposure and infection risk, we use a comprehensive database on respiratory particle size distribution; exhalation flow physics; leakage from face masks of various types and fits measured on human subjects; consideration of ambient particle shrinkage due to evaporation; and rehydration, inhalability, and deposition in the susceptible airways. We find, for a typical SARS-CoV-2 viral load and infectious dose, that social distancing alone, even at 3.0 m between two speaking individuals, leads to an upper bound of 90% for risk of infection after a few minutes. If only the susceptible wears a face mask with infectious speaking at a distance of 1.5 m, the upper bound drops very significantly; that is, with a surgical mask, the upper bound reaches 90% after 30 min, and, with an FFP2 mask, it remains at about 20% even after 1 h. When both wear a surgical mask, while the infectious is speaking, the very conservative upper bound remains below 30% after 1 h, but, when both wear a well-fitting FFP2 mask, it is 0.4%. We conclude that wearing appropriate masks in the community provides excellent protection for others and oneself, and makes social distancing less important.
Sadly, a huge portion of the American public don’t have this word in their vocabulary. Masks and vaccines either eliminate all risk, and “work” or don’t completely eliminate all risk and therefore “don’t work.”
This lower ape thinking inflicted so much unnecessary death and suffering here.
It’s an intentional thing, pushed by propagandists. Thinking in absolutes reduces the need for critical thinking skills as whole. When you can make people boil everything in the world down to a binary, its very easy to tell them how to think, and equally easy to define the “out” group you all hate.
To wit, when masks “work or don’t work”, you can look at the people telling you to wear masks, and because masks “don’t work” they’re wrong, and if they’re wrong, then the people we aren’t telling you to wear a mask are right. You should always follow people who are right… right?
TY! Also a physician. So tired of this discussion. Everyone is masked in my clinic. Anecdotal, and my partner and I are still covid free, and hope to continue. Masking, distancing, hand washing, and isolation when sick, these simple, time tested, behavioral changes can significantly reduce risk of infection.
Physician here. Masks absolutely reduce transmission and the chance of contracting COVID.
Here is the definitive study on the subject.
Here is a video of a presentation by one of the authors along with some demonstrations and explanations.
TLDR: Here is the Abstract:
There is ample evidence that masking and social distancing are effective in reducing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. However, due to the complexity of airborne disease transmission, it is difficult to quantify their effectiveness, especially in the case of one-to-one exposure. Here, we introduce the concept of an upper bound for one-to-one exposure to infectious human respiratory particles and apply it to SARS-CoV-2. To calculate exposure and infection risk, we use a comprehensive database on respiratory particle size distribution; exhalation flow physics; leakage from face masks of various types and fits measured on human subjects; consideration of ambient particle shrinkage due to evaporation; and rehydration, inhalability, and deposition in the susceptible airways. We find, for a typical SARS-CoV-2 viral load and infectious dose, that social distancing alone, even at 3.0 m between two speaking individuals, leads to an upper bound of 90% for risk of infection after a few minutes. If only the susceptible wears a face mask with infectious speaking at a distance of 1.5 m, the upper bound drops very significantly; that is, with a surgical mask, the upper bound reaches 90% after 30 min, and, with an FFP2 mask, it remains at about 20% even after 1 h. When both wear a surgical mask, while the infectious is speaking, the very conservative upper bound remains below 30% after 1 h, but, when both wear a well-fitting FFP2 mask, it is 0.4%. We conclude that wearing appropriate masks in the community provides excellent protection for others and oneself, and makes social distancing less important.
Sadly, a huge portion of the American public don’t have this word in their vocabulary. Masks and vaccines either eliminate all risk, and “work” or don’t completely eliminate all risk and therefore “don’t work.”
This lower ape thinking inflicted so much unnecessary death and suffering here.
It’s an intentional thing, pushed by propagandists. Thinking in absolutes reduces the need for critical thinking skills as whole. When you can make people boil everything in the world down to a binary, its very easy to tell them how to think, and equally easy to define the “out” group you all hate.
To wit, when masks “work or don’t work”, you can look at the people telling you to wear masks, and because masks “don’t work” they’re wrong, and if they’re wrong, then the people we aren’t telling you to wear a mask are right. You should always follow people who are right… right?
Lol nice conspiracy theory, but it’s not the truth
TY! Also a physician. So tired of this discussion. Everyone is masked in my clinic. Anecdotal, and my partner and I are still covid free, and hope to continue. Masking, distancing, hand washing, and isolation when sick, these simple, time tested, behavioral changes can significantly reduce risk of infection.
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