Measurements of airborne aflatoxins during the handling of contaminated corn

Abstract

Samples of airborne dust generated during the handling' of aflatoxin-contaminated corn were collected and analyzed to assess potential exposures of farmers and other agricultural workers to these mycotoxins. Using high volume total dust samplers and a high volume Andersen sampler, downwind dust samples were collected on glass fiber filters when contaminated corn was transferred by augers from a storage bin into a wagon and back into the storage bin. The aflatoxin B₁ content of the 15 dust samples ranged from 12.5 to 204.3 ppb, with an average of 138 ppb; the aflatoxin B₂ content ranged from 1.1 to 41.6 ppb, with an average of 24.6 ppb. The B₁ and B₂ levels of contamination in the bulk corn were 223.9 and 17.5 ppb, respectively. The gravimetric dust concentration in the air ranged from 7 mg/m³ to 417 mg/m³. The samples taken with an Andersen sampler indicate the dust is relatively coarse with only approximately 17% less than 7 µm. An analysis of the dust from each stage showed higher levels of aflatoxins in the larger first-stage particles than in the finer particles on the succeeding stages. The results of this study indicate that the dust generated when handling contaminated commodities also may be contaminated and represent a potential inhalation hazard. This fact, coupled with the extreme toxicity and carcinogenicity previously demonstrated in animal studies, suggests that appropriate measures be taken to prevent worker exposure during handling of contaminated materials.