Objectives: As the findings on changes in pulmonary function of welder
s have been inconsistent, this study aimed to analyze respiratory symp
toms and pulmonary function among welders and controls with particular
emphasis on small airways dysfunction. Methods: Cross-sectional analy
sis, using spirometry and a standardized questionnaire, was used to ev
aluate 521 participants, 166 of whom (64 welders and 102 controls) wer
e evaluated for pulmonary symptoms, occupational inhalative exposures,
leisure time activities, and anamnestic data. Results: The welders re
ported more pulmonary symptoms than the controls. They exhibited a dec
reased mean expiratory flow (MEF) at 25% and 50% of vital capacity (ME
F25, MEF50) while the other parameters tested (forced vital capacity,
forced expiratory volume in Is) were unchanged compared with the contr
ols. Multivariate regression analysis revealed that smoking explained
the observed variance; only in MEF25 the duration of welding exposure
had a significant influence on this parameter. Conclusions: The signif
icantly reduced flow values among the welders compared with the contro
ls indicates the presence of small airways disease. Differences in smo
king habits accounted for more than double the differences in MEF25 th
an did chronic welding fume exposure, confirming the role of the forme
r as the main risk factor leading to the decline in lung function. Lon
gitudinal studies are needed to evaluate the long-term effects of chro
nic welding fume exposure, in particular with a view to identifying es
pecially susceptible workers.