Effectiveness of facemasks for pediatric populations against submicron-sized aerosols

Background: In the event of a public-health threat involving bioaerosols, such as a terrorist attack or pandemic, options for devices to protect the pediatric population are limited. One strategy involves deployment of facemasks meant for the pediatric population, although protection against bioaerosols was not an intended use of such masks and little is known about their effectiveness.

Methods: We chose 3 brands of facemasks for pediatric use for characterizing penetration. To validate our experimental technique, 2 N95 respirator brands were also tested. All barriers were subjected to neutralized polydispersed sodium chloride aerosols, and their intrinsic penetration was evaluated in the submicron size range at different flow rates.

Results: As expected, the N95 brands had low penetration (5% or less) at the highest flow rates. However, for the facemasks for pediatric use, penetration varied significantly amongst brands at the highest flow rates (~15%->50%). Studies with isopropanol-dipped respirators and facemasks demonstrated that not all brands of facemasks for pediatric use have electret layers.

Conclusions: Our bench tests suggest that the intrinsic penetration through facemasks for pediatric use can be high in the submicron size range. These data can be used in risk-assessment models to determine the extent to which facemasks for pediatric use reduce the likelihood of infection in emergency situations.