The effect of clinical face shields on aerosolized particle exposure

Background: Face shields protect healthcare workers (HCWs) from fluid and large droplet contamination. Their effect on smaller aerosolized particles is unknown. Materials & methods: An ultrasonic atomizer was used to simulate particle sizes equivalent to human breathing and forceful cough. Particles were measured at positions correlating to anesthetic personnel in relation to a patient inside an operating theatre environment. The effect of the application of face shields on HCW exposure was measured. Results & Conclusion: Significant reductions in particle concentrations were measured after the application of vented and enclosed face shields. Face shields appear to reduce the concentration of aerosolized particles that HCWs are exposed to, thereby potentially conferring further protection against exposure to aerosolized particles in an operating theatre environment. Plain language summary Face shields protect health workers from splash contamination. We do not know if they protect against smaller invisible aerosol drops that can carry diseases like coronavirus 2019/COVID-19. The authors tested whether face shields can stop floating droplets using different types of face shields. This included one that was designed and made by a 3D printer, and traditional face shields. The shields were tested in a hospital operating room. A machine was designed that made invisible saltwater droplets. A monitor was used to measure the droplets present at a doctor's or nurse's mouth and then if this changed when a face shield was used. The face shield might be helpful in stopping health workers from catching diseases by stopping the flow of aerosol drops.