Airborne pollen and spores in Melbourne

Abstract

The incidence, on exposed slides, of pollen grains and spores from the atmosphere of Melbourne is recorded. Observations over 4½ years show that 30 types of pollen appear regularly each year and few of these are in great abundance. The highest concentration of pollen is in the period August-December and the lowest concentration in the period Aprii-May. In eariy spring, pollen grains from conifers and deciduous trees are most numerous, and in later spring and summer those from grasses and plantains predominate. Variations in weather conditions produce variations in the duration and concentration of the pollen cloud, both annually and within the season. High concentrations of fungal spores, at times exceeding those of pollen grains, occur during late spring and early summer, but follow a less clearly defined seasonal pattern than the pollen cloud. Pollen normally transferred by insects may at times become airborne in significant concentration. Grass pollen, because of its presence in the air over a long period and its high concentration during the Melbourne pollinosis season, must be considered important in relation to seasonal allergy. Other types of pollen and fungal spores, which are in high concentration for a shorter period or in less quantity for a long period, may also contribute to allergic symptoms.