Size Characteristics of Fungus Allergens in the Subtropical Climate

Aerodynamic size of fungus spores determines particle motion including settling under gravity, resuspension, and transport by air movement, and where fungus allergens are deposited in the human respiratory tract. Field investigation was conducted to evaluate size characteristics of ambient fungus spores in Taipei city by Andersen six-stage viable sampler in summer and winter seasons. It was found that the highest number of concentrations occurred at nighttime, with a concentration value above 1,700 CFU m-3, but decreased to a level of 450-600 CFU m-3 at daytime. Moreover, large numbers of fungus spores isolated were found to be in the size range of 2.1-3.3μm with a geometric mean diameter in the size range of 1.96-3.40μm. The significant concentration variations between daytime and nighttime samples were demonstrated because of a large number increase in the size range of 1.1-3.3 μm. In addition, size distributions of the yeasts were found to be remarkably different from those of Aspergillus and Penicillium spp. The observations of size differences among the important fungus allergens demonstrated that there might also be significant differences in their behavior and respiratory deposition.