The Effect of Sampling Time and Flow Rates on the Bioefficiency of Three Fungal Spore Sampling Methods

ABSTRACT

The influences of sampling time and flow rates on total recovery rate of airborne fungal spores were evaluated in the laboratory test chamber by three sampling methods: AGI-30 all-glass impingers, the Nuclepore filtration and elution method, and the gelatin filters. In the test system, a Pitt-3 generator was used to generate the spores of Penicillium citrinum. The real-time number concentration of fungal spores was measured by a TSI aerodynamic particle sizer to determine the total recovery. The results demonstrated that total recovery of spores collected by the AGI-30 impinger was in the range of 4% to 24%. Moreover, the average total recoveries of spores collected by Nuclepore and gelatin filters were found to be in the range of 50% to 75%, and 50% to 90%, respectively. The observed low total recovery for the AGI-30 impinger may be due primarily to the biological stress during sampling process. The relative survival of fungal spores collected in AGI-30 impingers became lower as the sampling time and flow rates increased. However, no significant influences of sampling time and flow rates on the total recovery of both the Nuclepore filtration and gelatin-filter methods were observed. In conclusion, it was found that filtration methods could perform much better than impingers for sampling airborne fungal spores.