Richard Davis, Director of the Clinical Microbiology Laboratory at the Providence Sacred Heart Medical Center in Spokane, Washington convinced those who were not yet sure about the effectiveness of protection in the prevention of the pandemic.
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To protect ourselves from the coronavirus mask, yes or no? World experts practically all agree that nose and mouth protection can really make a difference if you come in contact with a positive. However, to convince those who were not yet sure of its effectiveness in the prevention of the pandemic – and there are many just see the photos on the beaches or the nightlife in many Italian cities – here is the experiment by Richard Davis, Director of the clinical microbiology laboratory at the Providence Sacred Heart Medical Center in Spokane, Washington. The professor demonstrated what it means to wear a mask.
The experiment
On Twitter first Davis demonstrates how the mask blocks respiratory droplets from the mouth and throat with two simple experiments. “First of all – explains the professor – I sneezed, sang, spoke and coughed towards an agar culture plate with or without a mask. The colonies of bacteria show where the droplets have landed. A mask blocks practically all of them ”. Obviously in this case it is bacteria that are normally present in people’s respiratory droplets (large and heavy ones) and it is not Sars-CoV-2 virus, but you can see how a surgical mask blocks most of the droplets.
Social distance
In the second demonstration, the expert explains the importance of spacing together with the effectiveness of the masks. “I put the open bacterial culture plates 2, 4 and 6 feet apart and coughed for about 15 seconds. I repeated the experiment without a mask, “writes the doctor. The distances are 60 cm, 120 and 180. As can be seen from the number of colonies of bacteria, the droplets have mostly landed at distances below 180 cm, but the mask has blocked almost all of them. Davis recalls that there is nothing “scientific” in his demonstration but “the colonies of normal bacteria that come from my mouth / throat – he writes – show the dynamics of the spread of large respiratory droplets, like the ones we think mainly spread the # covid19 and how a mask can block them! “.
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