For medical professionals in close contact with patients and dealing with airborne-protocol pathogens (which is what a droplet-mediated pathogens like SARS2 becomes classed as once patients are coughing and being intubated) then a bad mask is quite probably worse then no mask (this has precedent: ineffective masks obstruct breathing, which makes you take deeper breaths and draw more particles in deeper in your lungs - it's a big problem when dealing with fine dusts in construction).
You’re saying you think anything less than an N95 has 0 effectiveness. Why do you believe this is likely? Are you aware of the data that says otherwise?
https://news.ycombinator.com/item?id=22655436
https://www.researchgate.net/publication/258525804_Testing_t...
https://jamanetwork.com/journals/jama/fullarticle/2749214
“As worn by health care personnel in this trial, use of N95 respirators, compared with medical masks, in the outpatient setting resulted in no significant difference in the rates of laboratory-confirmed influenza.”
To be clear, this trail was for outpatient care — not necessarily applicable to shoving tubes down throats, but probably applicable to people walking down the street.
> However, these masks would provide the wearers little protection from microorgan- isms from others persons who are infected with respiratory diseases. As a result, we would not recommend the use of homemade face masks as a method of reducing transmission of infection from aerosols.
https://www.cdc.gov/coronavirus/2019-ncov/hcp/ppe-strategy/f...
Unfortuately, the CDC really is giving out conflicting guidance here. For example, higher up in the section for lay-people is this: “You do not need to wear a facemask unless you are caring for someone who is sick (and they are not able to wear a facemask). Facemasks may be in short supply and they should be saved for caregivers.” https://www.cdc.gov/coronavirus/2019-ncov/prepare/prevention... (In “How to Prepare | Protect Yourself”)
If you are not exposed to high levels and are not required to put yourself at risk to care for patients, you are at low risk. You can protect yourself with milder measures like social distancing and face protection that is not as effective but not in such short supply
Current CDC guidance is “facemasks are an acceptable alternative when the supply chain of respirators cannot meet the demand”.¹
¹ https://www.cdc.gov/coronavirus/2019-ncov/infection-control/...
