A survey of 2,000 people in the UK and the US has indicated that people over 6 feet tall (1.83 meters) are more than twice as likely to be diagnosed with coronavirus. This, in turn, adds further weight to the argument that the virus can be transmitted through the air as well as via droplets.
Though the study is yet to be peer reviewed, the researchers behind the survey have already released a statement in which they suggest that air purification should be considered as a measure to prevent the spread of the illness.
According to the study authors, taller people would not face an increased risk of being infected if the virus was transmitted exclusively through saliva droplets, as these don’t linger in the air but fall to the floor fairly soon after being expelled from a person’s mouth or nose. Aerosolized particles, meanwhile, can be carried by air currents and tend to accumulate in poorly ventilated spaces.
Commenting on the as yet unpublished data, Professor Evan Kontopantelis from the University of Manchester said: "The results of this survey in terms of associations between height and diagnosis suggest downward droplet transmission is not the only transmission mechanism and aerosol transmission is possible.”
The notion of airborne transmissions has been a major bone of contention since the early days of the pandemic, with many researchers criticizing the World Health Organization (WHO) for insisting that COVID-19 can only be passed on through saliva droplets. In the face of increasing pressure from the scientific community, the WHO finally updated its official scientific brief on coronavirus last month to acknowledge that “short-range aerosol transmission… cannot be ruled out.”
This came after a group of 239 health experts from around the world signed a statement calling on the WHO to end its insistence that the virus is exclusively transmitted via droplets that are discharged when an infected person coughs or sneezes.
Evidence from numerous studies indicates that this may not be the case, and that the virus can also hang in the air in the form of aerosolized particles, which are droplets smaller than five microns. It has even been suggested that the act of flushing a toilet can cause enough air turbulence to whip up clouds of aerosols and facilitate the spread of the virus.
The latest survey was not designed to examine the possibility of airborne transmission but instead aimed to investigate how personal attributes and living conditions affect a person’s chances of catching the virus. Aside from the striking revelation about height, results also revealed that people living in shared accommodation or using a communal kitchen are significantly more likely to become infected.
Given that these types of living arrangements are most common among lower income families and individuals, the researchers say that their findings provide further evidence for the link between COVID-19 and socio-economic status.