Filenews 24 May 2021
By Faye Flam
One knows that there is something wrong with public health messages when a car trailer driver provides clearer information about the transmission of Covid-19 by the World Health Organization (WHO) or the U.S. Centres for Disease Control and Prevention (CDC).
The distillation of wisdom that the driver acquired and shared with me when he came to tow my car to the garage earlier in the spring was that if you are indoors with many people and one of them is a carrier of coronavirus, one can be infected even if everyone wears a mask. If again a group of people is outdoors and one of them is infected, probably no one else will get stuck.
The driver spoke, as I said, based on his direct experience, having worked hard in the worst phase of the pandemic. He even said he'd seen his colleagues get sick and his boss die of the coronavirus.
Transmission regardless of mask or distances
And he was right. The SARS-CoV2 virus can travel in very small particles that dissolve quickly outdoors, but can accumulate in an enclosed environment. Indoors, these particles can affect people who are more than two metres apart. And the masks that the Americans have adopted may provide some protection, but they do not make an object unsafe situation safe.
Although scientists have been discussing "airborne" transmission for months, only last week the WHO and CDC officially accepted it as an event. With the vaccine still available at an early stage if we look at it on a global scale, health officials should accompany this belated assumption with guidance that unvaccinated people can follow in order to minimise the risk to themselves and those around them.
What does "airborne" mean?
Clarifying the word "airborne" would be a good starting point. The scientific meaning of the word is not the same as its common meaning and so people could mistakenly assume that the outer air is dangerous. As reported in a recent article in the New York Times, news about the concept of airborne transmission led people in India to close their windows instead of opening them.
Indeed, references to airborne transmission can cause unnecessary panic, implying that danger is almost inevitable and that there is no safe distance from our fellow human beings.
It is true that the virus can accumulate indoors in a way that can pose a risk even if people wear masks and stay more than two metres away from each other. However, this risk can be mitigated by opening windows, wearing N95 masks and limiting exposure time.
A quick visit to the supermarket is safer than a long meal in a restaurant or a fitness class. And because the virus travels mainly in microparticles, the risk is tiny outdoors, even if a carrier is less than two metres away from you.
The key: interiors and time
Restaurant interiors are therefore not made safe by rules that dictate that people wear a mask while they are not eating or place plexiglass dividers between tables. Opening windows helps, as well as a warning that unvaccinated people are at risk of going to eat indoors.
This has long been known - although officials were slow to admit it. Last May, I interviewed Muge Cevik, an infectious diseases expert at the University of St. Andrews in the United Kingdom. The latter collects all the data it can find from tracking contacts around the world in order to determine how the disease is transmitted.
There were reports that so-called "superspreading events" had taken place primarily in offices, business conferences, retail outlets where people remained for a long time, and in restaurant interiors. In addition to these incidents of over-transmission, there was a large transmission of the virus inside homes.
The professor also found that the amount of time people spend in a closed environment is of great importance. And the higher the number of people in an enclosed space, the higher the chances that one of them is a carrier of the virus to others.
That is why in Japan, people have long been warned to avoid three things: large crowds, enclosed spaces and close contact with third parties. Useful public health messages need not be complicated at all.
Time for clear messages
It is not too late to do a better job on public health messages and formulate priorities. In countries where people return to offices and other workplaces, ventilation should be a higher priority than surface disinfection.
In India, where the pandemic is raging, officials should stop wasting resources on drones that spray parks with disinfectant.
In America, we are very concerned about 15-minute visits to the grocery store and are falsely reassured by the two-metre distance. We have spent too much mental energy to rage with each other about whether we go with or without a mask on the beach or whether we take off the masks in an open parking lot - attributing to the behaviour of others an outrageously large role in terms of our own, individual risk.
A better understanding of what "airborne transmission" really means can help us better manage our own personal risks and maintain our ability to feel good about our fellow human beings. And, of course, it should motivate more of us to make the vaccine against Covid-19 as soon as possible
Source: Bloomberg
