Background: We tried to examine the small airway diseases which can be found early, in workers exposed to inorganic dusts. This is measured in normal breath by using the impulse oscillometry (IOS).
Conclusion:We could find out that 15 Hz, 20 Hz, and 35 Hz values of reactance were significantly influenced by pneumoconiosis. When usefulness and reproducibility to carry out the IOS are considered, it is thought that in future work will be required to draw the reference values for normal Korean persons.