Predictors of longitudinal changes in pulmonary function among swine confinement workers

Pulmonary function

Swine confinement workers have an increased prevalence of respiratory symptoms and reduced pulmonary function test values compared with grain farmers and nonfarmers. An increase in airways responsiveness and across-shift decrements in pulmonary function have been reported in swine workers. Associations between longitudinal decline in lung function and air contaminants have been observed among swine confinement workers .In a recent longitudinal study, we found accelerated annual decline in forced expired volume in 1 s (FEV 1) and forced vital capacity (FVC) among swine confinement workers versus nonswine farming subjects . There have been reports relating these airways responses to the indoor air environment of swine confinement units. The ambient air in these units includes varying levels of dusts, microbes, ammonia and endotoxins. A recent study reported a dose-response relationship between across-shift changes in lung function in swine farmers, and endotoxin and ammonia levels in the confinement units . Across-shift changes in FEV 1 and levels of indoor airborne environmental contaminants have been significantly associated with longitudinal changes in FEV1. We report the results of our investigations on the relationship between shift change and longitudinal decline in lung function measurements, and between environmental exposure to air contaminants and longitudinal decline in lung function measurements among swine confinement workers in Canada.