Maintain a Safe Distance

Maintain a Safe Distance

The health and safety protocols we must follow to help protect our loved ones, those around us and ourselves from the coronavirus are, as we all know, wear a mask, wash hands frequently and maintain a distance of 6 feet from other people.  The 6-foot separation figure was the recommendation of the CDC from the very start of the pandemic.  This figure is not calculated on any specific study, but instead extrapolated from other studies. Those studies measured the distance droplets and aerosols traveled when expired from our respiratory track.

The WHO (World Health Organization), on the other hand, has promoted instead of 6 feet a distance of 1 meter (approximately 39 inches).  Which of the two, the CDC or the WHO,  is right?  The answer is somewhat complicated. The distance the expired particles travel varies by size.  Larger particles may fall  to the ground very quickly, while smaller ones tend to stay airborne and travel further.  Environment factors play a big role as well.  For example, filtration and improved ventilation (open a window, use a window fan, etc.), significantly decrease viral transmission.

Recent studies of transmission of coronavirus in school children determined that a distance of 3 feet was adequate separation for children in a classroom. This classroom situation becomes a little confusing as this 3 foot figure does not apply to teachers who must still adhere to a 6 foot separation.

How does this apply to adults in group situations?  The most obvious analogies might be gyms.  State governments are issuing mandates for gyms which often includes the recommendation that the gyms reduce the size of classes to maintain separation, increase ventilation, and mandate mask wearing. These may not be enough. As people work out and start to sweat and breathe faster, their masks get damper and damper. Not only are they potentially expiring more viruses and pushing the droplets out with more force, but a damp mask is not as efficient in filtering viruses as a dry one.

One recent report described a potentially interesting way to monitor the situation in a gym.  When we breath we are exchanging oxygen (O2) for carbon dioxide (CO2).  During a workout, the increase in the respiratory rate naturally also leads to an increase in the amount of CO2 we are expiring. Measuring the amount of CO2 in the air might be one indirect way to determine the adequacy of the ventilation in a room.  If the CO2 is going up, then ventilation might be inadequate and the occupants of the room at a higher risk of exposure to an airborne agent. We use CO2 monitors every day in the OR. This technology is available now and the devices are relatively inexpensive.

It likely that one of the indirect health hazards of the pandemic is the weight people have gained after gyms closed and home quarantine was begun. We have heard quips about the “pandemic 15” (or even 20!). A recent study published in the JAMA open network by Dr. Gregory Marcus and his colleagues gives credence to this weight gain. They reported that in a group of 269 adults closely monitored during the last year, the average weight gain was 0.6 pounds every 10 days or about 2 pounds a month.  Until your gym opens or, perhaps, if you do not feel comfortable going there yet, please get outside, exercise and, of course, remember to wear your mask!!