Published ahead of print on June 30, 2004, doi:10.1164/rccm.200403-266OC
© 2004 American Thoracic Society doi: 10.1164/rccm.200403-266OC
Pulmonary Function and Exercise-associated Changes with Chronic Low-Level Paraquat ExposureDepartment of Epidemiology and Preventive Medicine, University of California Davis School of Medicine, Davis, California; Department of Internal Medicine, Texas Tech University Health Sciences Center, El Paso, Texas; and Respiratory Sciences Center, University of Arizona, Tucson, Arizona Correspondence and requests for reprints should be addressed to Marc B. Schenker, M.D., M.P.H., University of California, Davis, Department of Epidemiology and Preventive Medicine, One Shields Avenue, TB168, Davis, CA 95616. E-mail: mbschenker{at}ucdavis.edu The present study was undertaken to test the hypothesis that chronic, low-level paraquat exposure causes restrictive lung function with gas transfer impairment. Three hundred thirty-eight Costa Rican farm workers from banana, coffee, and palm oil farms completed a questionnaire, spirometry, and a test of single-breath carbon monoxide diffusing capacity. Subjects 40 years of age or older, without other medical risk factors, completed maximal cardiopulmonary exercise tests. Most (66.6%) were paraquat handlers; 24.8% of handlers and 27.3% of nonhandlers reported current cigarette smoking. In linear regression models, cumulative paraquat exposure was not an independent predictor of VA, carbon monoxide diffusing capacity, peak oxygen uptake, FVC, or oxygen pulse peak. However, the ventilatory equivalent for CO2, although within normal range, was significantly higher with increased cumulative paraquat exposure. Oxygen desaturation greater than 5% from rest to peak exercise had an odds ratio of 1.7 (95% confidence interval = 0.9–3.0) with the cumulative paraquat exposure index in models adjusted for age, weight, and smoking status. The association of paraquat exposure with ventilatory equivalent and oxygen desaturation suggests that paraquat may be associated with subclinical gas exchange abnormalities, but overall these findings are consistent with no clinically significant increases in interstitial thickening or restrictive lung disease among this population.
Key Words: agriculture • exercise test • interstitial lung disease • occupational exposure • respiratory function tests This article has been cited by other articles:
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