Dutch public health officials recently explained why they’re not recommending masks.
"From a medical point of view, there is no evidence of a medical effect of wearing face masks, so we decided not to impose a national obligation,"
said Medical Care Minister Tamara van Ark.
“All these countries recommending face masks haven’t made their decisions based on new studies,”
said Henning Bundgaard, chief physician at Denmark’s Rigshospitale, according to Bloomberg News.
...
they've always known mask don't work
For the Record: Some Other info I ran Across
OSHA document OSHA DOC 1910.134 Appendix D to Sec. 1910.134, part 3, "
"Do not wear your respirator into atmospheres containing contaminants for which your respirator is not designed to protect against.
For example, a respirator designed to filter dust particles will not protect you against gases, vapors, or very small solid particles of fumes or smoke."
2015 web archive OSHA page
https://web.archive.org/web/20150905...ic_health.html
OSHA page that says this in part:
"Frequently Asked Questions on Pandemic Influenza Preparedness and Response Guidance for Healthcare Workers and Healthcare Employers
Respirators:
A respirator is a personal protective device that is worn on the face, covers at least the nose and mouth, and is used to reduce the wearer's risk of inhaling hazardous gases, vapors, or airborne particles (e.g., dust or droplet nuclei containing infectious agents)....
...
•Although some disposable respirators look similar to surgical masks, it is important that healthcare workers understand the significant functional difference between disposable respirators and surgical masks.
•Surgical masks are not designed to prevent inhalation of airborne contaminants.
•Surgical masks are not considered adequate respiratory protection for airborne transmission of pandemic influenza.
•Surgical masks are also used as a physical barrier to protect the healthcare worker from hazards such as splashes of blood or bodily fluids.
•When both fluid protection (e.g., blood splashes) and respiratory protection are needed, a "surgical N95" respirator can be used. This respirator is approved by FDA and certified by NIOSH."
During the Spanish Flu in 1920 they knew it as well
1920 mask study from the
US National Library of Medicine - National Institutes of Health
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1362677/
AN EXPERIMENTAL STUDY OF THE EFFICACY OF GAUZE FACE MASKS
W. H. Kellogg and Grace MacMillan
Am J Public Health (N Y). 1920 Jan; 10(1): 34–42.
doi: 10.2105/ajph.10.1.34
"Abstract
Masks have not been proved efficient enough to warrant compulsory application for the checking of epidemics, according to Dr. Kellogg, who has conducted a painstaking investigation with gauzes. This investigation is scientific in character, omitting no one of the necessary factors. It ought to settle the much argued question of masks for the public."
Among other quotes in the study
"The masks, contrary to expectation, were worn cheerfully and universally, and also, contrary to expectation of what should follow under such circumstances, no effect on the epidemic curve was to be seen. Something was plainly wrong with our hypotheses."
"... Masks have not been demonstrated to have a degree of efficiency that would warrant their compulsory application for the checking of epidemics."
—W Kellogg.