Aerosol penetration and leakage characteristics of masks used in the health care industry.
BACKGROUND
Historically, surgical masks have been worn to protect patients from being infected by large, pathogen-containing aerosol droplets emitted by health care personnel. Today, emphasis has shifted from solely protecting the patient to protecting the health care worker as well. As a result of new procedures used in operating rooms and clinical areas, aerosolized hazardous agents in the submicrometer size range are being produced, posing a potential threat to health care workers.


METHODS
Eight surgical masks were tested for aerosol particle penetration through their filter media and through induced face-seal leaks.


RESULTS
The percentage of filter penetration ranged from 20% to nearly 100% for submicrometer-sized particles. In comparison, a dust-mist-fume respirator used in industrial settings had significantly less penetration through its filter medium. When the surgical masks had artificially induced face-seal leaks, the concentration of submicrometer-sized particles inside the mask increased slightly; in contrast, the more protective dust-mist-fume respirator showed a fourfold increase in aerosol penetration into the mask with an artificial leak 4 mm in diameter.


CONCLUSIONS
We conclude that the protection provided by surgical masks may be insufficient in environments containing potentially hazardous submicrometer-sized aerosols.
Weber
A
A
Department of Environmental Health, University of Cincinnati, OH.
Willeke
K
K
Marchioni
R
R
Myojo
T
T
McKay
R
R
Donnelly
J
J
Liebhaber
F
F
D000336:Aerosols; D005069:Evaluation Studies as Topic; D005374:Filtration; D006801:Humans; D017053:Infection Control; D017758:Infectious Disease Transmission, Patient-to-Professional / Q000517:prevention & control*; D008397:Masks / Q000592:standards*; D010316:Particle Size; D010564:Personnel, Hospital
D000336:Aerosols