Aerobiology and Aeroallergens

Abstract

Aerobiology is the broad science of airborne substances of organic origin. In a more restrictive sense, allergists use the term to describe the study of aeroallergens. These may be divided into indoor and outdoor sources, although there is certainly overlap. Additionally, aeroallergens may be characterized as of plant or animal origin: plant sources predominate outdoors while animal sources are most relevant indoors. Allergenic proteins are carried on particles that range greatly in size. Soluble allergens may be found in submicronic droplets. Mold spores range from a few microns to over a hundred in length. Most pollen grains vary between ten to forty microns, although some may be larger. Particles that are five microns and smaller are easily respired into the smaller terminal bronchioles. The sources from which they are derived may be microscopic, as in the case of bacteria, some molds, or dust mites, or as large as horses or cows. The spectrum of aeroallergen sources is delineated in Figure 7–1.