AEROBIOLOGICAL SAMPLING METHODS FROM AIRCRAFT

Abstract

Three methods are described for sampling airborne bacteria and fungi from. aircraft. These methods were designed for use in aircraft flying at speeds about 200 m.p.h. The first is a qualitative method for use in a B-29 aircraft, with a sampling tube to hold a Petri dish 12 in. in front of the nose, yet permit loading and unloading from the interior. In the second and third methods, which are quantitative, the samplers are located inside the aircraft and air is brought to them by rubber hose connected to 1 in. aluminum elbows in a side window; the sampled air leaves the aircraft by another set of hose and elbows. The second sampling method uses a G.E. Electrostatic Bacterial Air Sampler located in an aluminum sampling chamber 18 in. × 18 in. × 18 in The third method utilizes filters made from glass wool and lens paper discs mounted in brass hose couplings. Numbers of organisms were calculated on a cubic foot basis from colonies which developed on nutrient media. In the second method, the organisms were precipitated directly on the agar surface; in the third method, however, the filters were shaken in sterile water and aliquot portions cultured in agar plates. For studying the numbers of fungous spores, silicone slides were substituted for agar in Petri plates exposed in the G.E. sampler. Typical results are given for the two quantitative methods.