Since Oct 9, 1999

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02 May 2021 Geert Vanden Bossche, DMV, PhD website: and open letter:

Critique of the open letter:

20 Nov 2020 Danish study showing that masks are almost useless for preventing infection: It didn't study whether masks stop people from transmitting. Suffice to say, don't expect a mask to protect you.

19 Nov 2020 Now there's a claim that masks don't work because "Even a Military-Enforced Quarantine Can’t Stop the Virus, Study Reveals" Not many people click through to read the science: The control group wore masks too. The main difference was the study group was isolated and supervised.

Here's a study showing that bars and restaurants are a good place to get the virus,-CoV-2%20test%20results My conclusions is there are essentially two ways to get it: at home and close contact outside of home. A bar definitely qualifies as close contact. A restaurant might or might not. I've gone to restaurants but they were mostly empty.

26 July 2020 Basket_of_Deplorables linked this study: From the paper
Additional measures were developed and implemented by the company. Hygiene regulations like hand hygiene and one-way traffic in hallways were reinforced, and an internal multi-lingual information campaign was enrolled to raise awareness for prevention and self-detection of early COVID-19 symptoms. A body temperature thermo scanner was set up to check all employees’ body temperature entering the building. Workers have been made aware of the company’s SARS-CoV-2 test center and were motivated to report any events where they see themselves being at risk. Specific work place assessments were performed to decipher possibilities to extend distances between workers. Simple one-layer face masks were made compulsory. Regulations were in place to prohibit rotation between working places for the workers. Measures in the canteen were imposed to reduce physical contact and to enforce that workers would spend their break times exclusively with workers from their own shift. Since the outbreak of the pandemic, the company managed to prevent intra-company infection chains until the event described in this paper.

Their conclusion: "Our findings indicate that a physical distance of 2 meters does not suffice to prevent transmission in environmental conditions such as those studied here; additional measures such as improved ventilation and airflow, installation of filtering devices or use of high-quality face masks are required to reduce the infection risk in these environments."

In other words, they are proposing using N95 masks, which would obviously need to be properly fitted, and with their valves they do not provide any source control.

22 July 2020 Adding Al Asmary: Unlike the above-mentioned report of ARI among Hajj pilgrims from Riyadh,6 in our study regular use of facemasks offered no significant protection against ARI. ...Furthermore, we found that intermittent use of surgical-type masks was actually associated with more than a 2.5-fold greater risk of infection. It is possible that once a facemask is worn in the presence of an infected patient, the mask could become contaminated with infectious material and touching the outside of the device could result in hand transmission of the infection to the respiratory tract during nose-rubbing.9 The study suggests (to me) that casual mask use similar to the "intermittent" mask use in the study is not useful and can actually be harmful.

A study of college dorms includes source control whidh is important to match the public mask use in the American experiment. The article talks about a study but does not give the specific numbers for effectiveness. They just say it is significant. They are referring to and they show the results in Fig 1 which is worth looking at. The mask and mask/hand washers are not that much better off. I still believe that masks are better than nothing, but obviously based on these two studies people are going to have to decide for themselves.

21 July 2020 Short version: cloth masks don't really work. their effectiveness is not statistically different from zero. Nearly the same for surgical masks, although they are better than cloth. Most importantly the authors address the issue of source control. Many studies are based on ingestion control (someone who is not infected staying that way), not source control (someone who is infected not passing it on).

Their source control conclusion is that there is no or low effectiveness. My conclusion is that there is non-zero effectiveness based on ."There is moderate evidence that surgical masks worn by patients in healthcare settings can lower the emission of large particles generated during coughing and limited evidence that small particle emission may also be reduced." I would include speaking as part of my argument because speaking and coughing both release droplets.

17 July 2020 Just a quick update, the Jacobs study had only 32 people in it, and there was one cold in the maskless group and one cold in the masked group. That's the weakest study I have ever seen.

CDC study of the case of the salon I mentioned previously:

16 July 2020 I still see the NEJM throwaway line cited: "We know that wearing a mask outside health care facilities offers little, if any, protection from infection" from "Universal Masking in Hospitals in the Covid-19 Era" The line is unsupported. The references aren't about masks. The paper actually supports wearing nasks in public by this line "More compelling is the possibility that wearing a mask may reduce the likelihood of transmission from asymptomatic and minimally symptomatic health care workers with Covid-19 to other providers and patients. " That's more true in public than in a hospital.

I also see this study now: "Use of surgical face masks to reduce the incidence of the common cold among health care workers in Japan: a randomized controlled trial" from The study was not blinded and is only 33 people which is way too small. Also the specificity of the infection is debatable (not well defined)

10 July 2020 I think that link was from Li'l Farmer. The paper basically says masks leak, but droplets are fairly large and many are stopped.

Another paper discussed in a thread: Respiratory virus shedding in exhaled breath and efficacy of face masks

02 July 2020 Aguments for and against using masks to slow the spread of the coronavrius below. I wear one for work and wear it into stores even though a lot of people don't in rural Virginia.

  1. N95 masks do not filter odors: The argument is made that if they don't filter odors then they don't filter the virus. That's obviously not correct since odors can come from single molecules as small as 0.0004 microns Virus particles are as small as 0.125 microns.
  2. Cloth or surgical masks have gaps. I believe a lot of cotton masks are useless because of the gaps. I tried some and my breath just went around it. OTOH I wear disposable surgical masks and most of my breath goes through the mask.
  3. Like a mosquito going through chain link fence. The masks are supposed to filter droplets not virus particles. Paper says: Acquired data indicates that 97% of droplets, expelled in one second during coughing, are smaller than 1 μm. The virus particles are smaller and are more numerous in smaller droplets:

    We collected samples of exhaled particles (one with and one without a facemask) in two size fractions ("coarse">5 µm, "fine"≤5 µm) from 37 volunteers within 5 days of seasonal influenza onset, measured viral copy number using quantitative RT-PCR, and tested the fine-particle fraction for culturable virus. Fine particles contained 8.8 (95% CI 4.1 to 19) fold more viral copies than did coarse particles. Surgical masks reduced viral copy numbers in the fine fraction by 2.8 fold (95% CI 1.5 to 5.2) and in the coarse fraction by 25 fold (95% CI 3.5 to 180). Overall, masks produced a 3.4 fold (95% CI 1.8 to 6.3) reduction in viral aerosol shedding.

    With speaking, the vast majority of droplets were above 0.5 microns It's not clear what the particle size distribution is and how that relates to the mesh. But cloth is probably inadequate:

  4. Evidence from events. No masks: the church choir practice. See The community choir in Washington State. Even though people were aware of the virus and took steps to minimize transfer; e.g. they avoided the usual handshakes and hugs hello, people also brought their own music to avoid sharing, and socially distanced themselves during practice. They even went to the lengths to tell choir members prior to practice that anyone experiencing symptoms should stay home. A single asymptomatic carrier infected most of the people in attendance. (I would note that it is not clear that it was just a single carrier).

    With masks: the salon where two stylists tested positive: After about 14 days, there were no positive tests: 46 tested out of 140, all negative, so a very low likelyhood (< 0.1% if the 46 are random) that any of the untested are positive.

  5. NEJM article: "We know that wearing a mask outside health care facilities offers little, if any, protection from infection. " But the study has five references, none of which are about masking. The study does not consider masking patients. Generally it's a bad idea to mask a patient who is already suffering from low oxygen. So the study has no applicability and the line is a throwaway line.
  6. Undboutedly there's less oxygen inside the mask, and I have to compensate by consciously breathing deeper. For the first half second I breathe stale warm air, then fresher air through the mask. It's noticeable because the fresher air is cooler, I only wear masks indoors with AC.

Feb 13, 2016: "A system of government that makes the People subordinate to a committee of nine unelected lawyers does not deserve to be called a democracy."

Sep 21, 2008. I'm putting this link: on my home page, not because I want to, and not because it is well written. But it pretty well explains the degree of risk that the financial community has created by credit default insurance. Unlike MBS, there are no assets, no income stream, no regulated reserves, just a promise that money will magically appear right when the economy runs out of money.

But before we tar and feather those insurers, let's properly assign blame where it belongs: the Fed and its creators, FDR (created moral hazards in Fannie and Freddie), Burns, Greenspan, Bernanke and all the apologists for the credit-based economy who can see no wrong with creating multiple dollars of debt for every dollar of GDP. Here's another link with the numbers for the hole we've dug (50 trillion in debt - see table L.1 against a 14 trillion GDP): This level of debt cannot be paid off (think about the proportion of GDP that would be needed, it would eat up the money needed for startups, R&D, etc). The only choices are default (what is looming today) or inflation.

Mar 24, 2007: Here's my web page with what I see as perpetuated myths of global warming: When you find errors, please ping or email. I have already been taken to the woodshed for some and I appreciate the patience of the readers who corrected what I had muddled.

Dec 14, 2003. We've captured Saddam! A big congratulations to our military. Many have sacrificed a lot including their lives to achieve this and I will always remember them.

This is a perfect opportunity to switch to the Afghanistan strategy: a few well protected bases and special forces missions to eliminate specific threats. If the the vast majority of Iraqis want freedom and democracy then they can earn it by keeping the peace, turning in the remaining radicals and building their own government.

Nation-building is mostly liberalism: handouts, price controls, political correctness, and a religious belief in changing people from the top down. We have given the Iraqis the foundation to build a nation, but we can't give them a functioning country, they have to do that themselves