Distancing and masks cut COVID-19 risk, says largest review of evidence
LONDON (Reuters) – Keeping at least one metre apart and wearing face masks and eye protection are the best ways to cut the risk of COVID-19 infection, according to the largest review to date of studies on coronavirus disease transmission.
In a review that pooled evidence from 172 studies in 16 countries, researchers found frequent handwashing and good hygiene are also critical – though even all those measures combined can not give full protection.
The findings, published in The Lancet journal on Monday, will help guide governments and health agencies, some of whom have given conflicting advice on measures, largely because of limited information about COVID-19.
“Our findings are the first to synthesise all direct information on COVID-19, SARS, and MERS, and provide the currently best available evidence on the optimum use of these common and simple interventions to help ‘flatten the curve’”, said Holger Schünemann from McMaster University in Canada, who co-led the research.
Current evidence suggests COVID-19 is most commonly spread by droplets, especially when people cough, and infects by entering through the eyes, nose and mouth, either directly or via contaminated surfaces.
For this analysis, an international research team conducted a systematic review of 172 studies assessing distance measures, face masks and eye protection to prevent transmission of three diseases caused by coronaviruses – COVID-19, SARS and MERS.
The researchers noted that the findings, while comprehensive, have some limitations for the current pandemic since most of the evidence came from studies of SARS and MERS.
Ooo … I’m askeerd, hold me Uncle Bob!
Since I’ve gone on record saying that I don’t believe them without certain studies being performed in a certain manner with certain credentialed professionals, am I now so beaten down by the academic bureaucrats that I retract my position?
Then there’s this.
They found, however, that physical distancing of at least 1 metre lowers risk of COVID-19 transmission, and that a distance of 2 metres could be more effective. Masks and protective eye coverings may also add protective benefits, though the evidence for that was less clear cut, they added.
Yea, it’s less clear cut because not a damn thing has been done to prove it.
I repeat myself.
I won’t believe any of your models or data until [at least] the following has been done. Assemble an interdisciplinary team of experts, in fields such as industrial hygiene, air filtration engineering, physics, chemistry, and medicine. Formulate hypotheses on the distribution of particle sizes (there isn’t one particle size, there is a distribution, and it may be a normal distribution, or it may not, it may be a right skewed distribution, or it may be a left skewed distribution); back up your hypothesis with experimental data; assemble a panel of experts to test filters of various types, from cotton, to N95, to HEPA filters, on those particle sizes; report the results; next, do the same with the [possibly] polar composition of viruses and their travelling companion water molecules or other particles, and report results; results shall at least include and consider (a) trajectory, (b) evaporation, (c) re-evolution of particles and viruses into the air stream, (d) and where the collection of particles occurs.
Determine, based on this team’s judgment, whether there is an unhealthy buildup of viruses on the masks you have tested, both for the patient and the worker (or any passerby). Include in this analysis not only SARS-CoV-2 viruses, but other pathogens as well. Specifically include in your analysis the buildup and concentration of Legionella bacteria, what we found to be so problematic at the Bellevue-Stratford Hotel when the HVAC engineers directed intake air flow over the top of the condensate discharge from the evaporator units. Masks collect moisture.
Considering the whole of the findings of this investigation, perform a probabilistic risk analysis for various populations wearing masks under various conditions (including people who have a low oxygen saturation level anyway). After coming to agreement between the entirety of the committee of experts, prepare a formal report under the authority of a professional engineer’s seal and signature. Publish all mathematical models, data and test results for peer review. I want this seal because the researchers have nothing to lose if the contents are wrong. A professional engineer has his reputation and livelihood to lose.
Only then are you doing science. Only then will I believe anything you have to say.
Nothing has changed, and no one to date has done anything even remotely approaching real science on this matter. Everything thus far has been fake. I do science. I know fake science when I see it.



