Assessment of human exposure to airborne fungi in agricultural confinements: personal inhalable sampling versus stationary sampling.

Accurate exposure assessment to airborne fungi in agricultural environments is essential for estimating the associated occupational health hazards of workers. The objective of this pilot study was to compare personal and stationary sampling for assessing farmers' exposure to airborne fungi in 3 different agricultural confinements located in Ohio, USA (hog farm, dairy farm, and grain farm), using Button Personal Inhalable Samplers. Personal exposures were measured with samplers worn by 3 subjects (each carrying 2 samplers) during 3 types of activities, including animal feeding in the hog farm, cleaning and animal handling in the dairy farm, and soybean unloading and handling in the grain farm. Simultaneously, the stationary measurements were performed using 5 static Button Samplers and 1 revolving Button Sampler. The study showed that the total concentration of airborne fungi ranged from 1.4 x 10(4)-1.2 x 10(5) spores m(-3) in 3 confinements. Grain unloading and handling activity generated highest concentrations of airborne fungi compared to the other 2 activities. Prevalent airborne fungi belonged to Cladosporium, Aspergillus/Penicillium, Ascospores, smut spores, Epicoccum, Alternaria, and Basidiospores. Lower coefficients of variations were observed for the fungal concentrations measured by personal samplers (7-12%) compared to the concentrations measured by stationary samplers (27-37%). No statistically significant difference was observed between the stationary and personal measurement data for the total concentrations of airborne fungi (p > 0.05). Revolving stationary and static stationary Button Samplers demonstrated similar performance characteristics for the collection of airborne fungi. This reflects the low sensitivity of the sampler's efficiency to the wind speed and direction. The results indicate that personal exposure of agricultural workers in confinements may be adequately assessed by placing several Button Samplers simultaneously operating in a static stationary mode throughout the work site.