• Thursday, June 4, 2020

Cover Up: To use a face-mask or not?

Discussion in 'COVID-19 Coronavirus' started by RescueRanger, Apr 3, 2020.

  1. RescueRanger

    RescueRanger PDF THINK TANK: CONSULTANT

    Messages:
    8,006
    Joined:
    Sep 20, 2008
    Ratings:
    +113 / 13,670 / -0
    Country:
    Pakistan
    Location:
    Pakistan
    There are many posts on social media and misinformation / confusing and contradictory advice by both people in official and unofficial capacities regarding face masks during the coronavirus outbreak.

    And as I write this I am well aware that the World Health Organisation is reviewing data from China, South Korea and Hong Kong that suggests the general public should wear face-masks and that by doing so could help contain the pandemic. [1]

    This practice of spreading misinformation or misleading claims that certain masks help protect against coronavirus has created a vacuum in the supply available in the market for those who need it most and the rising demand for these items has resulted in sky rocketing prices by unscrupulous vendors looking to make a quick penny in a time of crisis.

    In this write up I hope to explain how the virus is transmitted and summarise scientific evidence in support of or against each of the available masks in the Pakistani Market. Before I begin with the meat of the article, let me lay down it's bones and discuss the difference between what constitutes a face mask and what constitutes a respirator:

    Paper Mask / Surgical Mask:

    [​IMG]
    • Paper dust masks: Also called surgical masks, these loose-fitting masks have only one strap and don’t form a tight seal to the wearer’s face. They are designed to stop liquid droplets and aerosols coming out of the wearer’s mouth, not filter the air coming in. With no filter and no facial seal, they are not designed to prevent the inhalation of respirable particles found in smoke. Although they may look the same, dust masks are not respirators and should not be used for that purpose.
    N95 and P100 respirator:
    [​IMG]
    • N95s and P100s: These respirators have two sets of straps and form a tight seal to the face. The entire respirator is made of filtering material. N95s are the most common, with P100s being more protective (similar to a HEPA filter). Both types can often be found in hardware stores and other retail outlets. These respirators are certified by the National Institute for Occupational Safety and Health (NIOSH), so look for “NIOSH” and the designation “N95” or “P100” on the respirator.

    [​IMG]
    Within the N95 range of masks, 3M makes a very specific mask called the 3M N95 1860S (S = Surgical) this mask is solely designed for the health care sector and is the mask that is needed in hospitals at the moment but due to hoarding and increased demand is not available.

    When worn correctly, these respirators are effective at filtering out the small respirable particles found in wildfire smoke. However, they do not filter out fumes and gases; for that, see the next type of respirator listed.

    Half-face or full-face respirator:
    [​IMG]
    • Half-face or full-face respirator: Unlike N95s and P100s, which are disposable, half-face and full-face respirators offer a tight-fitting, flexible facepiece with replaceable filter cartridges. N95 particulate filters or purple (P100 or HEPA) filter cartridges will protect against particulates in wildfire smoke. When used with a combination filter that has an organic vapor cartridge, these respirators would also protect against harmful fumes and gases. However, neither these respirators nor N95s supply oxygen.
    So at a time when you are already practising physical distancing/social distancing, staying at home, washing your hands, why are we talking about masks? As presented in my opening paragraph, the issue circulates data that supports the view that SARS-CoV-2 that virus that causes COVID is transmitted by aerosols both large and small at or near to source. The available data also suggests that people who may not show any symptoms (asymptomatic) or yet to develop symptoms (pre-symptomatic) are spreading the virus this way. [2, 3, 4]

    [​IMG]
    Figure 1: Droplet larger than aerosols, when exhaled (at velocity of <1m/s), evaporate or fall to the ground less than 1.5 m away. When expelled at high velocity through coughing or sneezing, especially larger droplets (> 0.1 mm), can be carried by the jet more than 2m or 6m, respectively, away.[5]

    What the above graph shows is that when someone coughs or sneezes they disperse a gas spray / aerosol that initially cluster near the person, being next to someone when they sneeze or cough will mean you will be exposed to the aerosol spray and larger particles given your proximity (distance) from the person coughing or sneezing.

    As further time passes the larger particles settle from the air and the chance of exposure is limited. The best way to explain this is to use the diagram below:
    aerosol_transmissionfig3_1.jpg
    Figure 2: In the above figure you can see that Person B will breath in both the larger and smaller particles whereas because person C is further way, whilst s/he will still inhale the particles these will be finer and smaller in concentration and this is why social distancing is so important. Source: Absolute Science Illustration

    Now that we understand the basics of the transmission, we will explore the available PPE options and I will hopefully set my stall argue against mass public use of expensive masks.

    1. Home made cloth masks:
    A randomised trial comparing the effect of medical and cloth masks on healthcare worker illness found that those wearing cloth masks were 13 times more likely to experience influenza-like illness than those wearing medical masks.6

    2. Surgical paper mask:
    Several randomised trials have not found any statistical difference in the efficacy of surgical masks versus N95 FFRs at lowering infectious respiratory disease outcomes for healthcare workers.[7] However it should be noted that both the CDC and the WHO guidelines recommend N95 or FFP3 rated respirators for doctors and health care professionals working in a setting where there are procedures that would involve aerosol generating particles, procedures including swabbing, intubation/extubation, suction and ventilation.

    3. N95 / P100 Masks:
    A study found that health care workers risk of SARS (severe acute respiratory syndrome, also caused by a coronavirus) was lower with consistent use of N95 FFRs than with consistent use of a surgical mask.[8]

    So does this mean that surgical masks are useless? Not quite, surgical masks still provide a barrier and are excellent for use by people who may be showing symptoms and people caring for people who may have symptoms.

    Does this also mean that you should go out and buy N95 or FFP3 respirators to protect yourself? No, I want to make this clear that using a FFP3 respirator is pointless unless it is fit-tested and used by trained personnel, an N95 respirator or any FFP3 rated respirator should not be seen as a silver bullet and unless you are working with patients in a "hot" ward, you should please reserve these items for health care professionals who need it most.

    For N95 and FFP3 masks to offer the correct protection, they have to be put on in the correct fashion and fit-tested by the user and using a "qualitative fit test":
    [​IMG]

    Speaking to a friend who is a leading supplier of PPE, there is a global shortage of respirators and this is where you need to play your part and be sensible in your purchasing, do not bulk buy or hoard masks and ppe, even if it's face masks, leave some for others, if people bulk buy, it will lead to a shortage and with rising demand, business owners will hike up the prices and the poor will suffer.

    It is important to mention that leading experts in their field such as Dr. Brosseau in the U.S. still advocates for the general public "not to wear masks". In comparison, in Germany The Robert Koch Institute has updated its position regarding people wearing protective face masks in public places, saying more widespread use could help slow the coronavirus spread.

    To conclude, this was a non exhaustive desktop study on the transmission of COVID19 and the efficacy of the PPE available, I am in no position to predict if the WHO will change its existing position of everyone wearing masks, the data from China and elsewhere does support the general opinion that wearing masks coupled with physical distancing, staying at home and practising good hygiene can flatten the curve.

    [​IMG]
    Source: Prof. Sui Huang.

    [1] Devlin H, Campbell D. WHO considers changing guidance on wearing face masks. Guardian Newspaper UK 2020 Apr 1. https://www.theguardian.com/world/2...patients-should-wear-masks-says-doctors-group
    [2] Gralton J, Tovey E, McLaws ML, et al. The role of particle size in aerosolised pathogen transmission: a review. J Infect 2011 Jan;62(1):1-13
    [3] Yang S, Lee GWM, Chen CM, et al. The size and concentration of droplets generated by coughing in human subjects. J Aerosol Med 2007 winter;20(4):484-94
    [4] Yan J, Grantham M, Pantelic J, et al. Infectious virus in exhaled breath of symptomatic seasonal influenza cases from a college community. Proc Natl Acad Sci USA 2018 Jan
    [5] Van Doremalen N, Bushmaker T, Morris D, et al. Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV-1. medRxiv 2020 Mar 13
    [6] MacIntyre CR, Seale H, Dung TC, et al. A cluster randomised trial of cloth masks compared with medical masks in healthcare workers.BMJ Open 2015 Apr 22;5(4):e006577
    [7] Loeb M, Dafoe N, Mahony J, et al. Surgical mask vs N95 respirator for preventing influenza among healthcare workers: a randomized trial. JAMA 2009 Nov 4;302(17):1865-71
    [8] Loeb M, McGeer A, Henry B, et al. SARS among critical care nurses, Toronto.Emerg Infect Dis 2004 Feb;10(2):251-5

    @Foxtrot Alpha @WebMaster as requested, thread created.
     
    Last edited: Apr 3, 2020
    • Thanks Thanks x 7
    • Positive Rating Positive Rating x 2
  2. DESERT FIGHTER

    DESERT FIGHTER ELITE MEMBER

    Messages:
    45,164
    Joined:
    Jan 1, 2010
    Ratings:
    +114 / 85,438 / -22
    Country:
    Pakistan
    Location:
    Pakistan
    Thank you for sharing. I dont go out much except for walk in the afternoon.
    Or once a week to market to buy stuff.

    Im using a cheap cloth made mask as it was the only thing available in local market.

    Question is that does it protect me? I try to maintain social distancing but i do shake hands out of habit. And use sanitizer afterwards.

    Today I met my office staff at the market, shook his hand told him to maintain a distance. And he coughed like a mothalova ! Now im kinda worried.

    I have now ordered N-95 online.:lol:
     
  3. PakGuns

    PakGuns FULL MEMBER

    Messages:
    1,325
    Joined:
    Oct 17, 2014
    Ratings:
    +0 / 1,411 / -1
    Country:
    Pakistan
    Location:
    Pakistan
    there's a point in wearing disposable face masks, the infected person can reduce chances of others to get infected from contaminated air

    I wear double disposable face mask, there's a certain way to air tight it around your nose... strip side and push strip along ur nose....

    people here are stupid. .. i have seen people on stores and banks gathering like there's apocalypse and this is their last day if they didn't complete the task they gathered around for.... and police is not doing much to stop this

    you may not need n95 afterall... you won't be able to breathe properly in those masks in hot weather like Lahore's... you'll feel dizzy after a while
     
    • Thanks Thanks x 1
  4. DESERT FIGHTER

    DESERT FIGHTER ELITE MEMBER

    Messages:
    45,164
    Joined:
    Jan 1, 2010
    Ratings:
    +114 / 85,438 / -22
    Country:
    Pakistan
    Location:
    Pakistan
    True, includes me too. But I try not to got to markets or crowded places like stores or banks.
    I use drive by ATMs and the neighbourhood shops from where I buy smoke cartons , medicine , sanitizers etc.

    But as usual the few big chain stores are open and people are panic buying or just hanging out.
     
  5. RescueRanger

    RescueRanger PDF THINK TANK: CONSULTANT

    Messages:
    8,006
    Joined:
    Sep 20, 2008
    Ratings:
    +113 / 13,670 / -0
    Country:
    Pakistan
    Location:
    Pakistan
    A normal cloth mask is not as effective as a disposable mask, there are many reasons for this if you think about this. You don't dispose of the mask, you touch it with dirty hands, you breath into it and it also gets contaminated with residue, particles and gunk which is not removed.

    I tell my friends against re-using masks, even if they are cloth masks, these are meant to be single use items. You can decon N95's but it's not worth the hassle, may as well use until contaminated and dispose safely. As for the common misconception of face-masks being hot and hard to breath in, I have used respirators of all shapes and sizes in Pakistan and NO they don't make it difficult for you to breath, if you are having trouble breathing, your fit is wrong!
     
    • Thanks Thanks x 1
  6. DESERT FIGHTER

    DESERT FIGHTER ELITE MEMBER

    Messages:
    45,164
    Joined:
    Jan 1, 2010
    Ratings:
    +114 / 85,438 / -22
    Country:
    Pakistan
    Location:
    Pakistan
    I dont go out much hardly after a week or 10 days to the nearest shops in the morning when there aren’t many people. And put sanitizer on it.

    But after todays experience, unexpected to say the least. But the man is in his later 40s and a chronic smoker.

    I hope im not screwed. :lol:
     
  7. RescueRanger

    RescueRanger PDF THINK TANK: CONSULTANT

    Messages:
    8,006
    Joined:
    Sep 20, 2008
    Ratings:
    +113 / 13,670 / -0
    Country:
    Pakistan
    Location:
    Pakistan
    InshaAllah you will be fine, just monitor your health for 7 days and in future...
    lol.gif
     
    • Thanks Thanks x 1
  8. litman

    litman SENIOR MEMBER

    Messages:
    4,386
    Joined:
    Feb 14, 2016
    Ratings:
    +2 / 5,691 / -4
    Country:
    Pakistan
    Location:
    Pakistan
    it is advisable to use masks only once but if you are facing shortage then the easiest way to disinfect them from corona virus is to keep them under direct sunlight for one hour. the virus is heat sensitive and under sunlight as per some studies its half life is 2-5 mins.
     
    • Thanks Thanks x 1
  9. DESERT FIGHTER

    DESERT FIGHTER ELITE MEMBER

    Messages:
    45,164
    Joined:
    Jan 1, 2010
    Ratings:
    +114 / 85,438 / -22
    Country:
    Pakistan
    Location:
    Pakistan
    Damn bro, He was like 3 feet away and coughed.
     
  10. PakGuns

    PakGuns FULL MEMBER

    Messages:
    1,325
    Joined:
    Oct 17, 2014
    Ratings:
    +0 / 1,411 / -1
    Country:
    Pakistan
    Location:
    Pakistan
    I have tried n 95 your experience might be different but felt dizzy and headache and body heated up when i wore n 95 with 3M filter..... and also we should let these masks be available doctors and staff who still have to appear in pharmacies and hospitals..
     
    • Thanks Thanks x 1
  11. RescueRanger

    RescueRanger PDF THINK TANK: CONSULTANT

    Messages:
    8,006
    Joined:
    Sep 20, 2008
    Ratings:
    +113 / 13,670 / -0
    Country:
    Pakistan
    Location:
    Pakistan
    ^ Did you read my article, because that is exactly what I am arguing about in my article. And if you are feeling dizzy or ill, you need to see a doctor to check your VO2 Max via Spirometry
     
  12. American Pakistani

    American Pakistani ELITE MEMBER

    Messages:
    13,852
    Joined:
    May 30, 2010
    Ratings:
    +10 / 19,685 / -0
    Country:
    Pakistan
    Location:
    United States
    If you use N95 masks you will have a headache and you will have a hard time breathing. I have used N95 for last 2 days...no more...i got headache...i believe it's due to lack of oxygen flowing to the brain.

    Any solution to this?
     
  13. RescueRanger

    RescueRanger PDF THINK TANK: CONSULTANT

    Messages:
    8,006
    Joined:
    Sep 20, 2008
    Ratings:
    +113 / 13,670 / -0
    Country:
    Pakistan
    Location:
    Pakistan
    That is because the mask is sealed and hence more CO2 concentration in your body. These are NOT meant to be worn for long periods of time, they are protective equipment. There is no solution for this apart from only wearing the mask when absolutely necessary, removing the mask in a clean area and keeping hydrated.
     
    • Thanks Thanks x 2
  14. American Pakistani

    American Pakistani ELITE MEMBER

    Messages:
    13,852
    Joined:
    May 30, 2010
    Ratings:
    +10 / 19,685 / -0
    Country:
    Pakistan
    Location:
    United States
    Thanks, that's what I thought. Do you think it's also due to lack of oxygen we inhale?

    What happens if you use this mask for a long periods?

    Just curious, are you a professional?
     
  15. RescueRanger

    RescueRanger PDF THINK TANK: CONSULTANT

    Messages:
    8,006
    Joined:
    Sep 20, 2008
    Ratings:
    +113 / 13,670 / -0
    Country:
    Pakistan
    Location:
    Pakistan
    "A wide range of continuous warm and dry weather is conducive to the survival of 2019-nCoV. The coming of spring, in addition to the original Wuhan-Zhengzhou urban agglomeration in central China, means that the prevention and control measures in big cities located in mid-latitude should be strengthened, especially the monitoring of transportation hubs. The Pearl River Delta urban agglomeration is a concentrated area of population in south China, with a faster temperature rise than those in mid-high latitudes, and thus the prevention in this area should be prioritized. From a global perspective, cities with a mean temperature below 24 degree Celsius are all high-risk cities for 2019-nCoV transmission before June."

    Source: https://www.medrxiv.org/content/10.1101/2020.02.13.20022715v1