Disinfection of selected Aspergillus spp. using ultraviolet germicidal irradiation.
OBJECTIVE
The efficacy of ultraviolet germicidal irradiation (UVGI) and the UVGI dose necessary to inactivate fungal spores on an agar surface for cultures of Aspergillus flavus and Aspergillus fumigatus were determined.


RESULTS
A four-chambered UVGI testing unit with a 9-W, Phillips, low pressure, mercury UVGI lamp in each chamber was used in this study. An aperture was adjusted to provide 50, 100, 150, and 200 micro W/cm2 of uniform flux to the surfaces of the Petri dish, resulting in a total UVGI dose to the surface of the Petri dishes ranging from 12 to 96 mJ/cm2. The UVGI dose necessary to inactivate 90% of the A. flavus and A. fumigatus was 35 and 54 mJ/cm2, respectively.


CONCLUSIONS
UVGI can be used to inactivate culturable fungal spores. Aspergillus flavus was more susceptible than A. fumigatus to UVGI.


CONCLUSIONS
These results may not be directly correlated to the effect of UVGI on airborne fungal spores, but they indicate that current technology may not be efficacious as a supplement to ventilation unless it can provide higher doses of UVGI to kill spores traveling through the irradiated zone.
Green
Christopher F
CF
Department of Civil and Environmental Engineering at the University of Cincinnati, OH 45221-0071, USA.
Scarpino
Pasquale V
PV
Jensen
Paul
P
Jensen
Nancy J
NJ
Gibbs
Shawn G
SG
D001231:Aspergillus flavus / Q000528:radiation effects*; D001232:Aspergillus fumigatus / Q000528:radiation effects*; D015169:Colony Count, Microbial; D004203:Disinfection / Q000295:instrumentation / Q000379:methods; D004307:Dose-Response Relationship, Radiation; D013172:Spores, Fungal / Q000528:radiation effects*; D014466:Ultraviolet Rays