Cafes and restaurants fill up, more and more people are walking around the streets with shopping bags, and Instagram posts and stories from the fitness studios are piling up again. On the one hand, almost everyone is happy about the regained freedom after the weeks of restrictions. On the other hand, many are probably wondering: Can I really trust peace again? Can I eat, shop and go to sports without worrying about being infected? Is everything that is allowed safe? We have with the pulmonologist Dr. med. Thomas Voshaar from Bethanien Hospital.
Under what circumstances is the greatest risk of infection?
At the beginning and during the first few weeks of the spread of the coronavirus, we kept hearing the importance of washing our hands and sneezing into the crook of our arms. These measures are primarily used to protect yourself and others from so-called smear or droplet infections. However, it is now known that there is another transmission path that plays a very large – probably the largest – role in the spread of the corona virus: One Infection via aerosols.
"Aerosols are very, very small droplets that are already in normal breathing from our lungs come out and their small size floating in the ambient air for a very long time"explains Dr. Voshaar. The harder we breathe, for example during physical exertion, the more aerosols we emit. The output is also increased when we speak, even more when we sing. If we breathe through the nose, less of it comes Super mini droplets in the air, but even then some go through.
That means: "Outdoor transmission of the virus by aerosols is almost impossible", says Dr. Voshaar," unless you are practically nose to nose or mouth to mouth with an infected person. "The fine droplets outside are immediately blown away by the wind and air circulation and their concentration in the wide open space becomes so diluted and scattered that they can no longer be dangerous to us. Again, let’s imagine the opposite, a small room in which there are several people and which is not ventilated, we also have the other extreme with regard to the risk of infection: The situation with the highest risk of infection. In a closed, poorly ventilated room, a person who is infected without knowing it is enough to infect the others. On the other hand, there is hardly any risk of infection from aerosols outdoors, even with several infected people, unless you breathe in directly.
We can now apply this knowledge to different everyday situations and activities.
In which activities is the greatest risk of infection?
Sports
Even if many gyms have reopened: the risk of infection is comparatively high for indoor sports such as a spinning course and device training. The forceful breathing associated with physical exertion is similar to an aerosol pump that an unwittingly infected person uses to carry their viruses into the air and infect others. In general, the following applies: the smaller the sports rooms and the less ventilation is possible, the higher the risk. So if you want to be on the safe side, stick to homeworkouts and outdoor sports.
Shopping
The same applies to shopping: the smaller the space, the greater the risk. In this respect, on the one hand, huge markets or department stores with high ceilings are less problematic than small boutiques in a mall. On the other hand, the sales rooms with goods are safer than changing rooms, especially if they are closed to the floor. So: In case of doubt, simply inquire about the right of return and try on the jeans at home! ?
Museums and sights
We can visit cultural sites such as museums and sights with relatively little concern, as they are usually very spacious. With crowds and very narrow spaces, caution is of course also necessary here.
Excursions by bus, train, boat and plane
Public transport such as buses, trains and planes are comparatively small and can hardly be ventilated. In this respect, the risk of infection is relatively high there, if someone among the passengers is infected and you spend a long time together. Although masks stop larger droplets, aerosols only partially. A boat tour, where you can stay outside on deck, is relatively harmless.
Outdoor pools, beaches, lakes, parks
Visits to the beach, trips to the outdoor pool or to a swimming lake are just as harmless as picnics or walks in the park, because we are outdoors during all these activities. Only when it is so full that we are close to each other and are crowded together, do we have to take a high risk into account.
Restaurants
If you want to eat or have a coffee, you are well advised to choose an outdoor space. Even when the tables are deliberately left empty and there is a large distance, the aerosols of an infected person can accumulate in the air and be inhaled by others when staying longer in a restaurant or café. Special filters can contain this danger in the near future, according to Voshaar.
Services
Even though numerous people were infected with the corona virus at a church service of a Baptist congregation in Frankfurt in May: church services and the practice of religion are not per se dangerous. The traditional Christian churches with their super high ceilings usually offer a relatively large space in which aerosols can evaporate. Institutions such as that of Jehovah's Witnesses or prayer rooms of other faith communities pose a higher risk. Singing together, as the participants of the prayer in Frankfurt did, increases the risk of infection either way.
Thank you very much, dear Dr. Voshaar, for the interesting and insightful interview!