Aloha is not Breathless or Dangerous

 ​   There has been a lot of discussion about facemask requirements. 
   Are they useful?  We know, objectively, that they are - Studies have revealed that not only are N95 types masks useful, but so are homemade masks (1,2). Subjectively, we understand this: would you undergo surgery if your surgical team was not wearing face masks?
 
   Are laws mandating the use of masks, when out in public, Constitutionally flawed? Or is a shop owner’s requirement of wearing  a mask on private property a violation of a person’s rights? I’m mostly leaving those question to lawyers, but I would guess neither. As a society, we seem to accept the custom to wear "appropriate" clothing. Even here in Hawaii where shoes are much less required than the Mainland, there are standards which reflect a consideration towards others. Private businesses, public buildings, churches, parks, and schools, all have clothing requirements for a reason.
 
   Will the use of face masks injure a person in same way? This point is still widely 'debated' by laymen who are not associated with the medical field. Some claim that they should be excused from wearing a mask due to under lying respiratory conditions. Overall the idea of injury by the mask seems to be the important question as clusters of COVID-19 cases are erupting at gyms and bars in Hawaii. One remarkable interview of a gym owner struck me as troublesome: In describing measures taken to ensure that the disease was not spread, the gentleman mentioned that everyone wears masks except during exercise. That single statement seemed to encapsulated the idea that wearing a mask is potentially harmful.
   In comparison, medical professionals, who may include  doctors, nurses, as well as, therapists, technicians, medical cleaners, secretaries, and assistants don't debate the safety of face masks. These professionals often perform strenuous tasks for long periods while masked. One often-cited study (3) did find that there is more discomfort as the heart rate increased while wearing an N95 mask, the type worn by these professionals. However the conclusions seemed to emphasize that this was a discomfort issue and NOT a safety issue. I have not found a study that identifies home made face masks as problematic in the same way. In fact, there did not appear to be any reputable research which found the use of face masks dangerous for those with diagnosed respiratory problems. Indeed some medical professionals who customarily wear face masks all day, also have respiratory disorders. With this in mind one doctor on Facebook posted a ‘viral’ post about the non-existence of anyone who died from wearing a mask all day in his 40-year career.
 
   Wearing a mask is uncomfortable to be sure; and some with genuine respiratory problems might need to contact their doctor for guidance if they experience problems wearing a mask, but I wanted to explore what happens when a person wears a mask and exercises, speaks, and sings. I thought it would be ideal to use a person who has a diagnosis of a respiratory condition, so I selected myself as the subject.

Assertion
   The claim, as commonly referenced, states that a 'typical' human would have trouble breathing, and subsequently intake a lower level of oxygen, by wearing a cloth face mask. 
 
Hypothesis
   Given the above, it would follow that I, a human with moderate to severe asthma, would also have trouble breathing. As such, this lowered oxygen intake would be matched by a lower blood oxygen saturation level either during, or after, exercise. The subject should also experience clinical signs of distress which might include wheezing (whistling sound made while breathing), shortness of breath, chest tightness or pain, or coughing.

Methods & Results

​Blood Saturation levels while exercising
   Like the mouse in Lara Numeroff’s book, I started with one procedure and it evolved into a series of tasks. The first question was this:  As a person who has moderate to severe asthma would I have significantly more difficulty breathing with a facemask while exercising. So, with an assistant and a handy pulse oximeter, I set out to measure the average blood oxygen level as measured by the ingenious tool.
 
   A pulse oximeter uses light to measure the amount of oxygen saturation within the hemoglobin coursing through the arteries. A normal reading showing typical function are 95% and above. The error rate is plus or minus 2%, which means any reading has a likelihood of being within 2% of the true measure (e.g. 95% might actually be 93% or 97%). This 2% margin of error will be important to remember, because all of my findings fell within the margin error.
 
   I also noted my subjective feelings which are important to observe in those with respiratory disorders. Asthmatics are well known for having great oxygen levels, but clinical signs of breathing trouble such as coughing, wheezing, chest pressure or pain, and of course a feeling of shortness of breath. Here is the intro video which shows the equipment and procedure:

Here is the time lapsed video collecting the data:

   After compiling the data, we realized we could understand the implications better if we compared my masked performance to an unmasked performance. So, the next week with occasional assistance I did the procedure again.
 
    I did feel more discomfort while wearing a mask, but not by much. In neither exercise sessions, did I feel any clinical signs of an asthma attack. The pulse oximeter measurements found that my blood saturation levels, while masked, averaged 98.6% at rest, and 96.6%, during exercise. During the highest level of exertion (around 20 minutes) the masked reading  dipped below the “normal” range of 95%-100% once (93%). During the unmasked exercise session, my blood saturation levels were one percentage higher 97.6%, during exercise and the lowest reading was 96% during the same intense section of exercise. At rest my blood saturation rate was again 98.6%. Similarly to the masked portion of the experiement, I did not experience any symptoms of respiratory distress. With a margin of error of 2%, a 1% difference is probably not reliable and potentially shows no real difference between wearing mask, and not wearing a mask. The low point of blood saturation might be significant as the difference was 3% or outside of the margin of error. However, the limitations of a single case study, means we can't really make a broader generalization, With that in mind, I hope others, will follow the same procedure, or even better designed experiment, in order to be confident of the findings. 
 
Blood saturation levels while singing and speaking
    In order to standardize the measurement points, I divided the eponymous Rainbow Passage (4) into relatively even sections (40-50 syllables each). Taking a baseline first, I then recorded myself reciting the Rainbow Passage with the meter on my finger and recorded the number after reading the section. I read the whole passage first without a mask and then with a mask. After averaging I can report that the percentage of oxygen saturation for unmasked was 98.36% and masked was 97.90%. A difference of .46% is again, probably not a meaningful difference.
 
    Interestingly, as if to emphasize the relatively stable oxygen levels in masked and non-masked vocal tasks, my blood saturation levels were higher for masked singing (97.38) when compared to unmasked singing (97.22). Singing with a mask did present a problem in the types of exercises I could perform for my singing task. Rather than using a song, an exercise was used in an attempt to keep the conditions as close to the same as possible. The first choice was a lip trill or lip buzz, which uses a stream of air to blow the lips apart in a light flopping motion forwards. The mask impeded the movement of the lips. An alternate exercise was the use of the of an octave jump followed by a quick run of a descending scale back to the starting note on the syllables ki-u-ki-u.

Conclusions

In a word? No. Masks do not cause oxygen deprivation. 
    For this singer and vocologist, there was no significant difference in my oxygen levels as measured objectively using the pulse oximeter, either in my performance of exercise or vocal tasks, while wearing a mask compared to not wearing a mask. If you are very uncomfortable wearing a mask while performing exercise or vocal tasks, you might want to consider performing these tasks in a non-public place.

​Here in Hawaii, showing aloha to each other is essential no matter the conditions. Of course, if you are short of breath or experiencing any respiratory difficulties you should follow up with a doctor right away. I will be writing a more detailed account. If you are interested send me a line. Thanks for reading this post and I hope it adds to the conversation. Stay safe, and Hawaii Voice and Speech Studio is ready to help you with on-line, or in person to help you with all your voice and speech needs.

[1] Davies A, Thompson KA, Giri K, Kafatos G, Walker J, Bennett A. Testing the efficacy of homemade masks: would they protect in an influenza pandemic?. Disaster Med Public Health Prep. 2013;7(4):413-418. doi:10.1017/dmp.2013.43

[2] MacIntyre, C. R., & Chughtai, A. A. (2020). A rapid systematic review of the efficacy of face masks and respirators against coronaviruses and other respiratory transmissible viruses for the community, healthcare workers and sick patients. International journal of nursing studies, 108, 103629. https://doi.org/10.1016/j.ijnurstu.2020.103629

[3] Li, Y., Tokura, H., Guo, Y. P., Wong, A. S., Wong, T., Chung, J., & Newton, E. (2005). Effects of wearing N95 and surgical facemasks on heart rate, thermal stress and subjective sensations. International archives of occupational and environmental health, 78(6), 501–509. https://doi.org/10.1007/s00420-004-0584-4
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​[4] https://www.dialectsarchive.com/the-rainbow-passage