Acute Changes in Lung Function in Farmers Exposed to Grain Dust

Abstract

As reported from previous cross-sectional studies, grain farmers have increased prevalence of respiratory symptoms and lower lung function values than do rural-dwelling, non-farming men (Dosman et al., 1987). A pilot study was conducted to determine acute changes in lung function in farmers exposed to high level of dust during shoveling cereal grain (composed of wheat, barley, oats, and canola seed) in a grain storage facility (granary). Twenty-two male grain farmers (mean age ± S.D., 39.8 ± 10.5 years) and 22 age-matched, non-exposed control subjects (39.7 ± 10.5 years) participated in the study. Grain farmers and control subjects were similar in height, weight, and smoking habits. Prior to shoveling grain in the granary, farmers completed a respiratory questionnaire and had spirometry measurements taken by a technician. Following shoveling grain, farmers had repeat spirometry and completed a questionnaire ascertaining acute symptoms. Two spirometry measurements were also made on control subjects. The mean time period between two spirometry measurements in control subjects (107.2 ± 38.5 min) was greater than was the mean time between measurements for men shoveling for grain (76.0 ± 29.8 min). The exposed grain farmers had a greater period change in lung function measurements in comparison to the control subjects. Similar results were observed after allowing for the differences in the time period between two sequential spirometry measurements in the grain farmers and control subjects. Mean acute respiratory symptom scores were significantly greater in the exposed grain farmers than in the control subjects. Further studies are required to examine the physiological mechanisms of changes in lung function in farmers acutely exposed to grain dust.