To the Editor:<br>Farm work may result in exposure to microbial bioaerosols. In agriculture, average airborne concentrations of fungal conidia are several orders of magnitude higher than in nonagricultural, indoor environments without water damage.1 We used data from Iowa and North Carolina farmers to explore associations between farming activities and fungal sensitization.<br><br>We analyzed serum samples from a neurobehavioral substudy of 677 male private pesticide applicators in the Agricultural Health Study (AHS).2 Blood was collected in 2006-2008 from male pesticide applicators who had completed all AHS interviews. Blood samples were not available for the whole cohort. Individuals were excluded if they had never been a farmer or had neurologic diseases; women were excluded because of their low prevalence in the cohort (<3%).2 Participants in the substudy were similar to the cohort as a whole with regard to farm history (Hoppin et al, 2012, unpublished data). The study was approved by institutional review boards of the University of Iowa, the National Institutes of Health, and its contractors. ...
