Self-FFP-masks do not help: The big Corona Unknown, researchers riddles
The big drop of Snot falls quickly to the ground, that much is clear. However, the Coronavirus is tiny and can stay in Mini-droplets longer in the air. These aerosols are increasingly becoming the focus of the research.
In the study of Corona Infection, scientists are increasingly called aerosols under the magnifying glass. Thus, a mixture of solid or liquid suspended particles is referred to – like particles of Sars-CoV-2 – in the air. "We are pretty sure that aerosols are one of the ways that Covid-19 verbreitet", the former President of the International society for aerosols in medicine, Gerhard Scheuch said, in Gemünden (Wohra), the German press Agency. Lubrication infections about played less of a role.
There are many questions that are still open, so Scheuch – for example, how the Virus is ride while you Speak, or what role temperature plays. "There’s a lot of research work done werden", he said. "But it is being researched more and more in the direction of." Long is not clear, therefore, how infectious the dried aerosols.
Studies lead to different results
According to the Robert Koch Institute (RKI), the Transmission of the novel Virus, mainly through droplets produced during coughing and Sneezing, and when Compared with the mucous membranes are included. Aerosols are defined as droplet nuclei smaller than five microns – but could also contribute "even if a final evaluation at the present time, ist" difficult;.
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There are already studies that deal with the dissemination of droplets and aerosols in the air. However, the to part different results come. So a Team of Christian Kähler by the Institute of fluid mechanics and aerodynamics at the Universität der Bundeswehr in Munich with a singer, has made experiments, and comes to the conclusion that the air while Singing only added to 0.5 meters in front of the mouth in the movement – regardless how loud the sound was. As a tip-it-yourself test, the researchers advise, to stand in front of a burning candle, and to look to flicker when the flame starts, if you approach it when you Speak.
Height of the room and the ventilation have an impact
The scientists Talib Dbouk and Dimitris Drikakis, in turn, have calculated how far the saliva drops spread with a slight cough: without Wind is not more than two meters, but in winds of 4 and 15 kilometres per hour, also six meters. Although the concentration and size of drops to take, but perhaps a distance of two meters is not enough. Researchers from the Washington analyzed the infection within a Choir, and suspected that the Transfer was due to a distance of two meters. However, Kähler makes it clear that, in addition to the distance, whether each of the hygiene rules were complied with, or, for example, shaken hands, and chairs were crazy.
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Other aspects that can have an influence on the routes of infection are about the height of the room and the ventilation. So Kähler advises, for example, it " should;on the one hand, the air exchange rate in times of the pandemic is to be significantly increased, on the other hand, should be in an ideal room ventilation, the air from below through the floor and flat across the ceiling sucked werden".
Life with laser light measured
In the Chinese city of Wuhan researcher for a study looking for in hospitals after the Sars-CoV-2-the genetic material in aerosols. The amount was about rooms in ventilated patients is very low, in toilet areas, however, higher. The fresh air was not detectable, except in two areas, which are prone to Overcrowding. Also, Kähler says in Free, there was a risk hardly. You breathe out about a pint of air, which is quickly diluted. Dangerous it will be if it comes about because of a brass band in the Background, closer and louder speaks. But then that is again a question of distance.
More on Coronavirus
As long as there is a potential threat, researchers have examined already: another Team from the USA has been measured with laser light, the life time of small droplets in the air produced when Speaking. Thus, they disappear in a closed environment with a stationary air only after 8 to 14 minutes. In conclusion, it is, "that there is a significant likelihood of regular Talk verursacht" in limited environments, Transmission of viruses in the air;. According to Scheuch, the leading company for Bio-Inhalation, could keep aerosols in closed spaces, even over hours, and can be infectious. A push of breath containing 1000 particles. "Outside, the dilution is strong, inside it accumulates."
Self-FFP-masks are not enough
Remedy of the mouth-nose is to create protection. However, you have to know that the so-called Community-masks, particles may not be able to stop with a diameter of up to two micro-meters almost at all, what has shown Kählers Team is impressive, with video recordings. Nevertheless, the simple masks had a significant effect, says the Professor: "They offer resistance to flow. Rather than particles the far outside of the blow, keep you close to the head."
Tickler goes even one step further: Because the Coronavirus is only around 0.1 to 0.14 microns in size, not enough time, the so-called FFP-masks. "Are for larger bacteria. Such small particles are difficult to filter." Particulate filters were a better fit. But this is yet to be explored.
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