Many people are currently working in the home office to prevent the spread of the novel corona virus. With the gradual lifting of the lockdown, however, many had to return to the office.
The most important question when returning to the office is: How can you keep the risk of getting Covid-19 as low as possible in closed rooms? A team of researchers from the Technical University of Central Hesse investigated this question.
According to the Robert Koch Institute, the main route of transmission for SARS-CoV-2 is the respiratory uptake of virus-containing liquid particles that occur when breathing, coughing, speaking and sneezing. Depending on the particle size, a distinction is made between droplets and aerosols.
In order to investigate the distribution of aerosols in the office, scientists created under the direction of the professors Dr. Henning Schneider and Dr. Keywan Sohrabi from Gießen’s Health Department did a simulation.
The worst case scenario: no mask, but a table fan
The simulation showed how an employee sneezes while sitting in a standard office workplace. On his table is a monitor that influences the flow behavior. The scenario in which the sneezing employee did not wear a mask showed that an aerosol cloud spreads more than two and a half meters in a sneezing direction within one second. The aerosol cloud can even reach a maximum of eight meters.
The worst case scenario involved an object that many should have on their table in the current summer heat: a table fan. If you don’t wear a mask and the windows are closed, the aerosol cloud spreads across the room in a few seconds when using a table fan, according to the research team.
What best protects against the spread of the corona virus in the office
The big winner in the investigation is the combination of a face visor and cotton mask. However, as the project managers admit, this is the most exhausting option for the operator – you can’t expect anyone to do it over a longer period of time.
If you only wear a cotton mask, the spread is limited to one and a half meters according to the simulation. The speed of propagation is reduced and the particles sink faster. “It is effective protection if you follow the usual distance rules,” the university stated in a press release. FFP masks that have a higher density and protect the wearer would also have a good effect.
Face shields to protect against corona infection are still controversial. According to the Robert Koch Institute, they can usually only catch the droplets that land directly on the disc. The simulation also showed that the visors mainly deflect aerosols downwards and sideways backwards. But: “At a distance of more than one and a half meters, they offer good protection.”
The scientists’ conclusion: the wearing of masks in “closed rooms” is “highly recommended”. “Even the simplest mouth-nose covers and face shields offer good basic protection when there are several people in one room.”
In this video you can watch the simulation: