A Prospective Study of Health Symptoms And<i>Aspergillus fumigatus</i>Spore Counts Near a Grass and Leaf Composting Facility

Aspergillus fumigatus (A. fumigatus), a fungus found in compost, is a respiratory allergen and can cause serious invasive disease in susceptible individuals. We conducted a study involving the collection of health symptom data and environmental monitoring data near a 40-acre grass and leaf composting facility. Analyses were based on symptom diary data from 63 individuals from the study area and 82 individuals from a reference area. Airborne A. fumigatus was not associated with increases in respiratory or irritative symptoms. Symptom incidence was associated with ragweed, ozone, temperature, and time since start of the study, although a tendency to report fewer symptoms as the study progressed may have confounded this result. Other features of the study design, including short-term spore count variability, lack of individual exposure data and gaps in the symptom diary data, complicated interpretation of the results. Although this study does not support an association between allergy and asthma symptom incidence and A. fumigatus spore levels, we could not assess the risk of unusual, but severe illnesses among very sensitive individuals.