Continuous bio-aerosol monitoring in a tropical environment using a UV fluorescence and light scattering instrument

This paper describes an instrument designed to achieve the continuous monitoring of ambient bio-aerosol concentrations. The instrument is a compact, relatively low-cost, UV aerosol spectrometer that monitors and classifies the ambient aerosol by simultaneously recording from individual airborne particles both a 2×2 fluorescence excitation-emission matrix and multi-angle spatial elastic scattering data. The former can indicate the possible presence of specific biological fluorophores within the particle whilst the latter provides an assessment of particle size and shape. Taken together, these parameters can facilitate discrimination between biological and non-biological particles and potentially allow classification of biological particle types. Example measurements are given illustrating magnitude and temporal fluctuations in the biological fraction of aerosol within the Borneo tropical rain forest.