Corona Daily 090: A Paradigm Shift

When I worked for a tobacco company, I came across research that said the smoke exhaled by a single cigarette is roughly the size of a golf ball. Now if you were to stand next to the smoker in a park, that golf ball dissipates into the vast open space. The risk of secondhand smoke is almost non-existent. However, if you were sharing with a smoker a table in an office or a restaurant, the passive smoking can be a risk factor. That learning can be applied to the coronavirus.

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Three days ago, on 14 May, 40 scientists from 14 countries presented a policy paper called “a paradigm shift to combat indoor respiratory infection”.

“We expect to have clean water from the taps,” said Lidia Morawska, the group’s leader and an aerosol specialist.  “We expect to have clean, safe food when we buy it in the supermarket. In the same way, we should expect clean air in our buildings and any shared spaces.”

In 1842, a landmark report on sanitation by Edwin Chadwick highlighted the shocking plight of poor urban residents suffering from diseases caused by contaminated water. It led to a major investment programme to supply clean water and to better handle sewage. A similar effort is needed now to clean indoor air, say experts.

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Current WHO guidelines on indoor air quality cover benzene and carbon monoxide, but there are no standards for bacteria or viruses. We know air pollution affects our health. But air quality inside the offices or other closed spaces is invisible, so we ignore it, though it may affect us on a daily basis. Experts are now proposing the public places should have “ventilation certificates” like those for hygiene.

Adding filters to existing ventilation systems, using portable air cleaners, and UV light to kill bacteria are some suggestions. Something simple like opening the windows, where possible, can also help. These are not expensive suggestions. In-room air filters are priced at 50 cents per square foot, UV lights incorporated in the building’s ventilation system cost $1 per sq foot. Those installed in individual rooms would be more expensive, but may be still worth it when compared to the cost of the pandemic.

We live for years with cold and flu and accept them as a way of life. One expert says we don’t really have to.

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This month, for the first time, CDC acknowledged in large, bold letters that airborne virus can be inhaled (indoors) even when one is more than six feet away.

Lancet has published a paper offering enough evidence that the virus can be airborne. (a) Superspreading events, such as choir concerts, cruise ships, care homes. (b) People in adjacent rooms in quarantine hotels got infected without meeting one another. (c) Asymptomatic transmission. (d) The virus was found in the air in lab experiments. (e) Found in air filters and building ducts in hospitals. (f) Caged animals got it from other caged animals.

The WHO had long held that the coronavirus is spread by large respiratory droplets expelled by infected people in coughs and sneezes. The organization was, unfortunately, relying on an outdated concept of airborne transmission. It believed an airborne pathogen, like the measles virus, has to be highly infectious and travel long distances. The droplets can hang in the air, drift down streets, and find their way to people’s homes.

Experts agree coronavirus doesn’t behave that way. Prolonged contact at close range indoors allows aerosol transmission. That is where cleaning indoor air, and building special ventilation systems become critical.

To bring indoor air on the same platform as clean water and safe food is indeed a paradigm shift. Our current life has made us understand the importance of this initiative for the future.

Ravi