Lung health in Alberta farmers.

Setting: A study conducted in the rural areas of two counties in east-central Alberta, Canada.

Objective: To investigate the relationship between lung health and dust exposure in farmers.

Design: A cross-sectional study of 781 farmers growing grain crops and raising livestock. Measurements included a questionnaire on respiratory symptoms, smoking habits and occupation, skin prick tests using common aeroallergens, and spirometry.

Results: Immediate skin reactivity to common aeroallergens was less prevalent in farmers with higher reported intensity of dust exposure. Respiratory symptoms suggestive of bronchitis had a significant dose-response relationship with the reported intensity of dust exposure. Respiratory symptoms consistent with bronchial responsiveness were significantly positively associated with cumulative dust exposure. There was a significant positive association between a physician's diagnosis of bronchitis and intensity of dust exposure. FEV1 and FEV1/FVC were significantly negatively associated with cumulative dust exposure. Ten years of exposure to a moderate dust level was associated with a deficit of 43 ml in the FEV1 and a deficit of 0.44% in the FEV1/FVC.

Conclusions: Despite evidence of worker selection related to dust exposure, these farmers experienced respiratory symptoms, respiratory conditions, and reduced lung function associated with reported occupational dust exposure.