Reference:
Experimental Design
Researchers set up two mannequins that faced each other. One mannequin wore a face shield and another mannequin was attached to a cough simulator that sprayed droplets containing the influenza virus. After each cough, researchers collected an air sample from behind the receiver mannequin’s face shield and measured how much virus was present.
This procedure was repeated at different distances. In the first set, the mannequins were 46 centimeters apart, which simulated a patient coughing in a doctor’s face. In the second set, they were 183 centimeters (around 6 feet) apart.
This procedure was repeated at different distances. In the first set, the mannequins were 46 centimeters apart, which simulated a patient coughing in a doctor’s face. In the second set, they were 183 centimeters (around 6 feet) apart.
Results
- Face shields work best against large particles, reducing exposure by 96%.
- When the cough simulator sprayed smaller droplets, the face shield only blocked 68% of the cough.
- However, after the cough dispersed across the room, the face shield was far less effective. It only reduced exposure by 23%.
- When the mannequins were set 6 feet apart, exposure was reduced by 92%.
What does this mean?
Face shields are good sneeze guards. They catch the large droplets that you’re exposed to when someone coughs in your face. However, they don’t block smaller aerosols from moving in through the gaps.
As a result, face shields can not replace masks and social distancing.
As a result, face shields can not replace masks and social distancing.
