Jun. 21, 2020

masks for viruses ?

The use of 'face masks' to control or halt the spread of a virus has become a hot topic for debate in the past five months. Masks can indeed stop droplets and droplets are where the virus is most likely to be when someone infected coughs or sneezes, but out of curiosity, when is the last time someone purposefully got within 6 ft of someone else to cough or sneeze in that person's face as TV ads love to use as a demonstration? What seems to have been forgotten is that extensive randomized controlled trials (RCT) with meta-analysis of those studies have been done over many years. These studies have repeatedly shown that masks do not work to prevent respiratory influenza type illnesses transmitted by contact, droplets, and/or aerosol particles. The transmission path for a virus involves a particle less than 25 nanometers in size, too small a particle to be effectively filtered by a mask through which one can comfortably or effectively breath. Meanwhile the minimum infective dose (MID) for a virus is smaller than a single aerosol particle. For any of this to make sense, one needs to understand the size relationship of such tiny terms. 

    1 meter (about a yard ) = 1000 millimeters

    1 millimeter                 = 1000 micrometers

    1 micrometer (micron) = 1000 nanometers (nM)

an air molecule (oxygen, nitrogen, inert gases like argon ) = about 1 nM

a viral particle (Flu, Coronavirus) = 20-300 nM

bacteria ( staph., strep. etc )       =200-10,000 nM (.2-100 microns)

As a reference, if a one dollar bill was 1 nM, one could stretch them end to end 1/2 way to the moon (120,000 MILES) . A Nanometer is VERY small.

If over-the-counter masks can filter out particles down to 100 microns 30% of the time, a quality surgical mask can filter down to 100 microns 95% of the time and an N95 mask can filter out 99% down to 300 microns (tighter mask needs bigger pores because of less bypass breathing), then one can hypothesize that some benefit exists to stop droplets and larger bacteria, but viruses? What happens when the filtration rate needed is measured in nanometers rather than micrometers (microns) ? If a single viral particle is 25 nM, (that's .025 microns) it would seem the single viral particles could certainly pass most barriers short of a full hazmat suit with rebreather. However, since the virus is usually (as far as we know) carried in a droplet, often one will see 1000-1,000,000 particles per droplet with the droplet large enough to be halted in most cases. what happens when the droplet evaporates? Can the viral particle then be shed elsewhere from the outside of the mask....or even from the inside if the wearer is a carrier ?  Do repeated coughs concentrate more virus within the mask and just how dangerous does that mask become and how easily is virus shed from insde and outside the mask ? Obviously there are a number of unanswered questions.

With this information, one can assume that masks can be helpful in filtering large particles including some bacteria and viruses that are carried by droplets. This might reduce but not likely prevent all viral particles in a given airspace from reaching a potential host to infect. The sheer numbers and particle size demonstrate that. If a given airspace contains billions of viral particles, many within millions of water droplets, yet only1-2 viral particles can transmit disease, the futility of mask wearing becomes more apparent. Age old physics and physiology tells us that particles will disperse evenly throughout a given space. When a virus is shed by a host, it's not a single viral particle, it's multiples of multiples. The MID (minimal infective dose) becomes the more important number. If it took a high number of viral particles to start the infection, then there would be some validity to mask usage. Unfortunately, the current Covid-19 virus of 2020  seems to have a low MID as a single particle can intiate a response....and there are 1000-1,000,000 particles in a droplet. In a 2009 study J.L.Jacobs reported in the American Journal of Infection Control that the wearing of masks by healthcare workers did not reduce flu symptoms among wearers, but those wearing the masks suffered significantly more headaches." This is another area needing more investigation. The important note in the study is that N95 mask wearers, above all others, should have shown a reduction as HCW (healthcare workers) should be more knowledgeable regarding proper use of any mask compared to the general public

What are the possible ill effects of wearing a mask? Some have suggested that decreased oxygen/carbon dioxide exchange could be a problem; however, as most surgeons can attest, wearing a mask in the operating room for 4-14 hours while saving someone's life never seem to effect any of us. We wore surgical masks to prevent OUR germs form entering an open wound. Granted we were wearing surgical masks and ventilation along the sides was always an added adjunct, but if those masks had been N95s, one can only wonder if we might have experienced other side effects as referenced in the Jacobs study. The general public for the most part are not wearing N95 masks and most of those wearing masks do so improperly. A damp or wet mask can lead to the proliferation of bacteria deposited by the wearer. Although that person may be somewhat protected from their own natural oral microflora, new pathogens can be introduced by eating or drinking and if one were to rapidly replicate and be inhaled deep into the lung, a pneumonia could be the end result. The social aspect of mask wearing may be more of an issue with western cultures as facial recognition is important for social interaction. Humans are social animals and need the interaction from a psychological standpoint. Many feel the overall response to the covid virus is one of the things contributing to the social unrest and turmoil now being experienced in large urban populations locked down " for your safety". Masks also embolden people to act foolishly, recklessly, or even criminally. 

In conclusion, it's important to consider how future situations like a pandemic should be addressed. Responses should be regionalized with input form local doctors rather than nationalized by a government employed doctor using a large metroplex as the model. Living conditions and social interaction varies across this nation as it does across similar sized regions that make up entire countries in Europe. Further studies about the relationship of humidity and viral survival/transmission is needed as the viruses seem to do poorly in tropic environments while proliferating in drier places. Our air conditioned society with the attendant dehumidification may be contributing to the spread and one of the reasons people are better off outdoors than locked down in an apartment complex. UV light is beneficial as are vitamin supplements that boost the immune system or provide needed elements ( like B6, C, E and D3).  D.G. Rancourt from Ottawa University in Canada wrote " By making mask-wearing recommendations and policies for the general public, or by expressly condoning the practice, governments have both ignored the scientific evidence and done the opposite of following precautionary principle. In absence of knowledge, governments should not make policies that have a hypothetical potential to do harm. The government has an onus barrier before it instigates a broad social-engineering intervention, or allows corporations (or individuals) to exploit fear-based sentiments." Personally, I feel a person should be free to decide for themselves whether or not they need to wear a mask unless they are actively showing symptoms, have been exposed in a closed room to a known carrier (of course they should be tested), frequently sneeze or have excess drainage due to allergies or even if they are simply angry by nature and shout a lot. People should be free and encouraged to pursue outdoor activities, especially younger, healthy individuals as the greatest future concern in the absence of a vaccine, will be lack of herd immunity among working class individuals. Freedom of choice to decide whether to use "outside the box" treatments including the use of the chloroquines as recommended by CDC and NIH in a 2005 paper regarding corona viruses, nebulized steroids, plasma infusion and even stem cell usage should be allowed.  We have inadvertly set the stage for a logistical nightmare of administering 1/4 BILLION vaccinations! Are we sacrificing our freedoms including freedom of choice for the false sense of security of a mask mandate, business closures and social lockdowns ?

Studies: 

            Cowling, B. (2010) "Facemasks to prevent transmission of influenza virus, a systematic                                           review". Epidemiology and Infection

             bin-Reza (2012) " Use of masks to prevent transmission of influenza, a systematic                                                review of scientific evidence" ...review of 17 eligible studies

             Smith, J.D. (2016) "effectiveness of N95 vs. Surgical Masks"

             Offendda, V. (2017) Clinical infectious Diseases

             Randonovich, L.V. (2019) Journal of the American Medical Assoc.

To date, no study exists that shows a benefit of a broad policy to wear masks in public. Time will tell what approach is correct. So far, leading health experts have been using the wrong approach using misleading computer models as their guide.

                                                                           Dr. D.R.Spence