A. The Bioaerosol Detection Problem

Improved real-time methods for characterizing airborne biological particles are needed. Here we review our e®orts in developing techniques for measuring the laser-induced °uorescence (total and spectrally dispersed) of individual airborne particles, and describe our present system which can measure °uorescence spectra of single micrometer-sized bioaerosol particles with good signal-to-noise. We demonstrate the capability of this system by showing measured spectra of a variety of airborne parti-cles generated in the laboratory from road dust, ammonium sulfate, Bacillus subtilis and other bacteria prepared under various conditions, allergens, cigarette smoke, chicken-house dust, etc. These spectra illustrate the capability of the system to distinguish between some biological and non-biological aerosols, and among several types of laboratory-generated biological aerosols. We suggest improvements needed to make our system ¯eldable