Rationale: Inhalation of ambient SARS-CoV-2-containing bioaerosols leads to infection and pandemic airborne transmission in susceptible populations. Filter-based respirators effectively reduce exposure but complicate normal respiration through breathing zone pressure differential and are therefore impractical for long-term use. Objectives: We tested the comparative effectiveness of a prototyped micronized electrostatic precipitator (mEP) to a filter-based respirator (N95) in the removal of viral bioaerosols from a simulated inspired air stream. Methods: Each respirator was tested within a 16-liter environmental chamber housed within a Class III biological safety cabinet within biosafety level 3 containment. SARS-CoV-2 containing bioaerosols were generated into the chamber, drawn by vacuum through each respirator, and physical particle removal and viral genomic RNA were measured distal to the breathing zone of each device. Measurement and Main Results: The mEP respirator removed particles (96.5+/-0.4%) approximating efficiencies of the N95 (96.9+/-0.6%). The mEP respirator similarly decreased SARS-CoV-2 viral RNA (99.792%) when compared to N95 removal (99.942%) as a function of particle removal from the airstream distal to the breathing zone of each respirator. Conclusions: The mEP respirator approximated performance of a filter-based N95 respirator for particle removal and viral RNA as a constituent of the SARS-CoV-2 bioaerosols generated for this evaluation. In practice, the mEP respirator would provide equivalent protection from ambient infectious bioaerosols as the N95 respirator without undue pressure drop to the wearer, thereby facilitating long-term use in an unobstructed breathing configuration.
A Micronized Electrostatic Precipitator Respirator Effectively Removes Ambient SARS-CoV-2 Bioaerosols