Particulate Matter, Endotoxin, and Worker Respiratory Health on Large Californian Dairies

摘要

Objective: To assess respiratory exposures and lung function in a cross-sectional study of California dairy workers. Methods: Exposure of 205 dairy and 45 control (vegetable processing) workers to particulate matter and endotoxin was monitored. Pre- and postshift spirometry and interviews were conducted. Results: Geometric mean inhalable and PM2.5 concentrations were 812 and 35.3 mu g/m(3) versus 481.9 and 19.6 mu g/m(3), respectively, for dairy and control workers. Endotoxin concentrations were 329 EU/m(3) or 1122 pmol/m(3) and 13.5 EU/m(3) or 110 pmol/m(3), respectively, for dairy and control workers. In a mixed-effects model, forced vital capacity decreased across a work shift by 24.5 mL (95% confidence interval, -44.7 to -4.3; P = 0.018) with log(10) (total endotoxin) and by 22.0 mL (95% confidence interval, -43.2 to -0.08; P = 0.042) per hour worked. Conclusions: Modern California dairy endotoxin exposures and shift length were associated with a mild acute decrease in forced vital capacity.