EVERYDAY ACTIVITIES AND VARIATION OF FUNGAL SPORE CONCENTRATIONS IN INDOOR AIR

The effects of some everyday activities on concentrations of airborne fungal spores in Finnish home environments were examined to provide basic information needed to evaluate the importance of varying levels of fungal spores in the air. The activities studied were opening of a cellar door, handling of different organic materials, resuspension of spores as a result of cleaning activities and transport of spores on clothes and pets, Airborne spores were sampled using six-stage impactors and surface samples were taken from the materials used in the experiments with sterile swabs or with a vacuum cleaner. Most of the activities had an obvious effect on the spore counts. However, vacuum cleaning, humidifying of house plants and baking caused no marked changes in the spore concentration. The short-term activities studied in a house explain most of the wide variation previously observed in fungal spore concentrations in indoor air. These activities have to be taken into account when designing sampling strategies for airborne fungi, in evaluation of the microbial quality of indoor air and when making comparisons with recommended values.