As
the year moves into the middle of spring in the northern hemisphere the
coughing and sneezing hasn’t abated. We’re not out of the woods with viruses,
whether the common cold or flu, but we are also getting our regular pollen
doses Too early for grass around here, but we do have a lot of pine trees,
which are wind pollinated.
So
coughs and sneezes are exploding round us, but we do have government
recommendations. We should cough into our elbow. That is now our preferred
method. Handkerchiefs are so last century. Shirtsleeves backed by the inside
of an elbow joint is much more efficient, at least that is the knowledge
handed down from wise government officials.
With
eager teams of scientists at large, the cough capture problem is one that has
been begging for quantification. A team, Tang et al from the National U of Singapore, have tackled the airflow
dynamics of the aerosols ejected into the air by coughs from healthy men and
women (1).
They
found that women didn’t put as much effort into coughing as men. The average
for women was a cough velocity between 2.2-5 m/s with a range of less than half
a meter, while men could up the velocity to between 3.2-14 m/s which gave a
range of up to two-thirds of a meter.
With
the shirtsleeve/elbow in place, the airflow was bifurcated and the range
minimized although the velocities were not always changed very much. Short
sleeves can be different from long sleeves, but how much wasn’t clear. Of course
the change of direction would help to capture the larger aerosol droplets, but
the smaller ones could still drift downwind.
It
doesn’t look like we have a sure-fire solution to the problem of elevator
coughs and sneezes. We’ll have to keep relying on our immune system.
