As the great face mask debate continues on social media, I thought I would offer my own two cents’ worth on the subject since my position has often been misconstrued on those same channels.

Overall, I think face masks can provide an effective defence against the spread of the virus, especially in crowded areas indoors where the ability to social distance is an issue, such as grocery stores, and particularly in areas where people congregate for an extended period of time, such as a funeral service or in a work environment like a manufacturing or food packing plant.

Can wearing a face mask protect you from contracting the virus? Most reports would indicate that face masks, both medical and non-medical (e.g., fabric) are effective in protecting yourself against contracting the virus through airborne water droplets when someone coughs or sneezes.

They don’t, however, protect you from contracting the virus through surface trans-fer. For example, if someone is coughing near you and the water droplets land on your clothing or your hair, you could contract the virus by touching the contaminated clothing or running your hand though you hair and then touching your face or rubbing your eyes. That is why it’s important to continue to wash your hands on a regular basis, or use hand sanitizer.

I rarely find myself in close proximity to someone who is coughing or sneezing. Which brings me to the efficacy of face masks in protecting you from asymptomatic carriers?

There are several studies which have confirmed that you can spread the virus by talking loudly, or to a much less degree, heavy breathing. Both practices can expel microscopic particles called bioaerosols, which can be found in your breath or produced as the water droplets evaporate in mid-air and leave a dried version of the virus which can linger for an extended period of time.

What the virus hasn’t been able to pin down is the potency of these bioaerosols and the length of time it takes for the them to dissipate.

What they have surmised is that you are much more likely to contract the virus through bioaerosols if you are in a closed-in space with an asymptomatic carrier for an extended period of time, such as during a birthday party or in a bar, than you are in a retail or grocery store where you are constantly moving. It’s exponentially less likely to contract the virus through micro-organisms outdoors where airflow can cause them to dissipate fairly rapidly.

And while social distancing is the most effective way to avoid contracting the virus through airborne water droplets, it’s even more effective in avoiding those microscopic bioaerosols produced by asymptomatic carriers.

So how can face masks help? Not in the way you might think. Because of their size, bioaerosols can easily penetrate through most face coverings. In a study conducted by the Southern Research Institute in Birmingham, Alabama researchers found that fabric masks were 11.3 per cent efficient in blocking bioaerosols while surgical masks like the ones that are blue on the outside and white on the inside were still only 33.6 per cent effective. Both results can be compared to N95 masks which were found to be nearly 90 per cent effective. But here’s the catch – the tests were conducted using mannequin heads.

A second study conducted in 2013 using 21 human volunteers found that a single layer cotton mask was 14 per cent effective. The study concluded: "An improvised face mask should be viewed as the last possible alternative if a supply of commercial face masks is not available, irrespective of the disease against which it may be required for protection. Improvised homemade face masks may be used to help protect those who could potentially, for example, be at occupational risk from close or frequent contact with symptomatic patients. However, these masks would provide the wearers little protection from microorganisms from others persons who are infected with respiratory diseases. As a result, we would not recommend the use of homemade face masks as a method of reducing transmission of infection from aerosols."

So yes, masks can be effective in protecting yourself from either contracting or spreading the COVID-19 virus, but that effectiveness is greatly reduced depending on the material and how it is worn. If a cotton face mask is only nine per cent effective that means that 91 per cent of the bioaerosols in the air are still getting through and can still potentially infect you with the virus.

Besides the type of the material, the likelihood of you contracting the virus also depends on the degree and length of exposure. For instance, if you are only going into s grocery store, which is a large space, for a short period of time, the likelihood of you ingesting enough bioaerosols from an asymptomatic carrier are incredibly slim whether you wear a face mask or not. However, if you are in a confined area such as a bus, a train, or a bar, the potential for transmission is much higher, but if you wear a single-layer cotton mask you only nine per cent less likely to contract the virus than someone who isn't wearing a mask.

Whether or not masks are necessary when going outdoors is still up for debate. I personally don’t believe they are necessary when going outdoors unless you find yourself in a mass protest, or rally and are in close proximity to others for an extended period of time.

I also don’t think they are necessary for otherwise healthy individuals indoors in situations where you are moving about like a grocery store or a shopping mall. But hey, that’s just my opinion based on the studies I’ve read. You can form your own opinion.

(If you wish to comment on this or any other View Point column please write to Fred Sherwin at fsherwin@magma.ca)