Production and Characterization of Air Suspendable, Dusts Containing Common Indoor Allergens for Inhalation Exposure Research

Controlled milling of natural source materials has led to establishment of an allergen carrier particle sample bank for common, indoor, allergen proteins. Allergen reference powders are obtained from controlled processing of spent dust mite culture, roach colony fras, and cat and dog fur samples from pet grooming establishments. Due to wide variations in parent material particle size, shape, hardness or tensile strength, different milling prescriptions are required to produce appreciable yields of suspendable particles in the 0.5 - 20 ?m size range with substantial mass fractions less than 12 ?m. Characterization data includes: mass fraction and number particle size distributions determined by optical scattering and inertial impactor methods; particle morphology as determined by scanning electron microscope examination; allergen concentrations determined by immuno-assay enzyme-linked analysis (ELISA); inhalation exposure risk analysis of the powders as reservoir dusts. Certified quartz powders (99% < 10 microns) and Bacillus Thuringiensis spores serve as reference powders.