ACCELERATED LUNG-FUNCTION DECLINE IN SWINE CONFINEMENT WORKERS

We conducted a longitudinal study to determine the annual rate decline in pulmonary function measurements in male swine confinement workers, For comparison, a grain farming group and a nonfarming rural-dwelling control group were also chosen for the longitudinal study. Two hundre d seventeen swine confinement workers, 218 grain farmers, and 179 nonf arming control subjects had valid pulmonary function measurements at t he baseline observation conducted in 1900 to 1991 and at the second ob servation conducted in 1994 to 1995, The swine confinement workers wer e younger (mean age=38.3+/-11.7 [SD] years) than the nonfarming contro l subjects (42.6+/-10.4 years) and the grain farmers (44.5+/-11.9 year s), When stratified by age, nonfarming control subjects had the lowest mean annual rate decline in FEV1 and FVC in all age categories, The s wine confinement workers had the largest annual rate decline in FEV1 a nd FVC, and this was most obvious in the middle age categories, After controlling for age, height, smoking, and baseline pulmonary function, swine confinement workers had excess annual decline of 26.1 mt in FEV 1 (p=0.0005), 33.5 mt in FVC (p=0.0002), and 42.0 mL/s in forced expir atory flow between 25% and 75% of FVC (FEF25-75%) (p=0.02) over nonfar ming control subjects, Grain farmers had excess annual decline of 16.4 mt in FEV1 (p=0.03), 26.7 mt in FVC (p=0.002), and 11.2 mL/s in FEF25 -75% (p=0.38) over control subjects, These findings suggest that worke rs engaged in the swine industry and grain farmers appear prone to acc elerated yearly losses in lung function and may therefore be at risk f or the future development of chronic airflow limitation.