Quantitative Studies of Fungus Spores in the Air

Abstract

Daily samples of outdoor air from June 1953-55, using a slit sampler, showed that fungus spores were present throughout the year. Exposure length was 30 min. and the spore deposit was read under high power. The spores were definitely seasonal in occurrence, with wide daily variations. Total numbers in summer ranged from 50 to 1300/ft3 and from 5 to 50/ft3 in winter. Cladosporium was the commonest fungus present with numbers of 25 to 1000/ft3 in summer and 1 to 15/ft3 in winter. Ustilago chlamydospores were present all year, with a peak in June at harvest time. Numbers ranged from 3 to 415/ft3 in summer and 1 to 10/ft3 in winter. Alternaria spores also were seasonal, with numbers in the summer from 2 to 98/ft3 Puccinia urediniospores were present only in June, with numbers from 1 to 12/ft3. Yeasts, Fusarium, and basidiospores were most numerous following rains. Spores of Helminthosporium, Cercospora, Penicillium (or Aspergillus), Septoria, Stemphylium, Sporormia, Pleospora, Venturia-like, Leptosphaeria-like, Curvularia, Erysiphe, Heterosporium, Nigrospora-like, Cephalothecium, Sordaria-like, and Monilia-like chains were found occasionally. Many unidentified spores, especially one-celled, also were present. Hyphal fragments were present throughout the year in numbers ranging from 2 to 53/ft3.