Spirometry, Impulse Oscillometry and Capnovolumetry in welders and healthy male subjects

Abstract

Welding processes emit fine and ultrafine aerosol particles which are potentially harmful to the lungs of welders. In the past, changes in lung function were mostly determined by conventional spirometry. In this study spirometry was combined with new techniques such as Impulse Oscillometry (IOS) and Capnovolumetry (CVS) in order to assess welding associated changes in lung function. 45 Male welders and 24 non-welders were investigated at two time points: before work shift (baseline) and after work shift. At baseline there were no differences between both study populations in spirometric, IOS, and CVS parameters. However, parameters of the flow-volume curve decreased with increasing long-term welding fume exposure (welding years). Airway resistances measured by IOS increased with welding years. IOS central airway resistance and several parameters of CVS increased during the work shift indicating airway narrowing and more inhomogeneous ventilation. In this study it has been shown that welding associated long-term and short-term effects could be detected in a population of welders, although exposure conditions were quite heterogeneous. The parameters of IOS and Capnovolumetry showed effects even more pronounced than conventional lung function parameters. Thus, these techniques may be considered as an additional tool for occupational medicine research.