IMPROVED METHODS FOR GENERATION, SAMPLING, AND RECOVERY OF BIOLOGICALAEROSOLS IN FILTER CHALLENGE TESTS

In preparation for filter efficiency tests and sampler comparison stud ies, methods of biological aerosol generation, sampling, and filter re covery were modified from previous studies. Methods described include (1) techniques for generating aerosols that reduced nuisance particles to negligible levels and increased the cell culturability of Mycobact erium abscessus by 30%, (2) sampling techniques that lowered the detec table range of biological particle size from 0.65 to 0.45 mu m and red uced the sampling flow from the chamber from 28.3 to 1.5 L/min, and (3 ) development of methods to remove culturable organisms from respirato r filter media. These methods were developed for filter challenge test s with M. abscessus and were applied to two other bacteria, They may a lso have application to a wider variety of organisms and bioaerosol as sessments.