Long- and short-term variability of airborne bovine epithelial antigen concentrations in cowsheds.

We have previously demonstrated an association between the level of specific airborne animal-derived dusts in animal houses and farmers' humoral responses. These findings suggested that allergenic dusts may be able to cause a response in a concentration-dependent manner. In order to determine the reliability of a single measurement for the evaluation of general levels of dust, we studied the long- and short-term variability of airborne bovine epithelial antigen (BEA) concentrations in cowsheds. It was found that individual cowsheds seem to have characteristic levels of BEA in the air; some cowsheds tend to have consistently high concentrations of BEA, whereas in other cowsheds BEA concentrations tend to be low. Thus, single determinations do appear to reflect the general level of BEA in cowsheds. These findings corroborate the previously observed association between the levels of airborne-specific dusts based on single determinations and farmers' humoral responses.