Fusarium toxins and fungi associated with handling of grain on eight Finnish farms

Abstract

Farmers' exposure to airborne dust, fungi and possibly also to Fusarium toxins during the drying and milling of grain and feeding of cattle was studied on eight Finnish farms. Airborne viable and total spores were collected on polycarbonate filters. Spore concentrations and fungal flora were determined by cultivation and epifluorescence microscope counting. Eighteen airborne dust samples were taken on glass-fiber filters with a high-volume sampler, and biological toxicity was tested from those samples. In toxic dust samples, Fusarium toxins were analyzed with a gas chromatography-mass spectroscopy. Fungi and Fusarium toxins were also analyzed in ten grain samples collected from the farms during the air sampling. Yeasts, as well as species of Cladosporium, Penicillium, Aspergillus, Absidia and Fusarium occurred in the air at all three stages of grain handling. Airborne spore concentrations ranged from 103 to 10 6 cfu m −3 for viable fungi and from 10 5 to 10 7 spores m −3 for total spores; airborne dust concentrations varied from 0.04 to 81.1 mg m −3. Low deoxynivalenol concentrations (3 and 20 ng m −3) were found in two air samples collected during milling. Fusarium spp. were identified in eight grain samples, and DON concentrations of 0.004–11 mg kg −1 were detected in all samples analyzed. Although any conclusion on Finnish farmers' exposure to mycotoxins cannot be done on the basis of this small data, it can be assumed that toxigenic fungi and Fusarium toxins may occur in the air and inhalation exposure of farmers to Fusarium toxins is possible in agricultural environment.