Dr Michael Osterholm at CIDRAP, Center for Infectious Diseases Research and Policies at Univ. of Minnesota states that there is little to no substantiated data or evidence that cloth and/or surgical masks will offer ex/inhalation protection against micro aerosol droplets containing CV19.
However wearing these mask types can/does mitigate /divert larger droplets from sneezing/coughing individuals from being sprayed into the air.
The issue: asymptomatic/presymptomatic carriers exhale ~50 micron aerosol droplets/sec or 3000 droplets/min based upon normal breathing/exhalation patterns.
If these individuals yell or sing they exhale/expel a larger volume of the air at increased air passage flow rates from the 6-8 liters of air/micro aerosol droplets contained in their lungs.
These micro aerosol droplets have been shown to travel up to 26 ft (MIT studies) from a source in an invisible gaseous cloud which can remain suspended in the air for several hours depending upon air currents/turbulence/movement in a closed facility or room.
Venues like rallies, church choirs, and other mass gatherings, such as sporting events in closed facilities are prime opportunities for super spreader events and mass infections.
Brownian motion and electrostatic charges present in an environment/atmosphere/mask material may prevent some of these micro aerosol droplets from being ex/inhaled by some mask wearers. More qualified studies need to be conducted to verify percentage of protection from various mask material types.
These hypotheses/theories has been studied using N95-N100 masks which prevent 95-98% particles measuring 0.3 microns and larger from being ex/inhaled. Virus particles measure ~0.08-0.17 microns.
There are scientific studies which have been performed and more studies which need to be performed.
No one, CDC, NIH, NIAD, or WHO has all the answers because all studies have not been performed and data have not been generated/determined/evaluated/peer reviewed.
Politics does get involved when the entire economy is shut down.
However, we all need to approach this disease and it’s prevention with open minds and utilize the best available science we have at this time and practice utilizing hygiene and best available PPE for mitigating this virus.
I would also recommend fortifying our immune system by eating proper foods, supplementing vitamins, minerals, enzymes, probiotics, exercising, getting a good night’s sleep, and reducing mental stress/anxiety.
Initial studies ( Nature/Science Articles) using table salt water impregnation into paper and cloth masks we’re shown to desiccate vision particles upon contact with the dried salt mask and prevent viral infection because the virus is stripped of essential fluids.
However, further studies need to be conducted on duration of exhaled breath and effect of total moisture accumulation over time on salt dissolution/solubility/protection. Same with nano silver impregnation and other possible anti viral disinfectants mask applications.
Let’s all try to practice patience, respect, and reserve judgments of others because of being in this extended quarantine and economic recession together.
We can defeat this virus using science and safe logic but it will take time.
Excerpt from CIDRAP MASK studies:
While this is not an exhaustive review of masks and respirators as source control and PPE, we made our best effort to locate and review the most relevant studies of laboratory and real-world performance to inform our recommendations. Results from laboratory studies of filter and fit performance inform and support the findings in real-world settings.
Cloth masks are ineffective as source control and PPE, surgical masks have some role to play in preventing emissions from infected patients, and respirators are the best choice for protecting healthcare and other frontline workers, but not recommended for source control. These recommendations apply to pandemic and non-pandemic situations.
Leaving aside the fact that they are ineffective, telling the public to wear cloth or surgical masks could be interpreted by some to mean that people are safe to stop isolating at home. It’s too late now for anything but stopping as much person-to-person interaction as possible.
Filter efficiency was measured across a wide range of small particle sizes (0.02 to 1 µm) at 33 and 99 L/min. N95 respirators had efficiencies greater than 95% (as expected). For the entire range of particles tested, t-shirts had 10% efficiency, scarves 10% to 20%, cloth masks 10% to 30%, sweatshirts 20% to 40%, and towels 40%. All of the cloth masks and materials had near zero efficiency at 0.3 µm, a particle size that easily penetrates into the lungs.
Another study evaluated 44 masks, respirators, and other materials with similar methods and small aerosols (0.08 and 0.22 µm).5 N95 FFR filter efficiency was greater than 95%. Medical masks exhibited 55% efficiency, general masks 38% and handkerchiefs 2% (one layer) to 13% (four layers).