SHORT-TERM RESPIRATORY-FUNCTION CHANGES IN RELATION TO WORKSHIFT WELDING FUME EXPOSURES

The forced vital capacity (FVC), the forced expiratory volume in one second (FEV1) and the transfer factor for the lung (TL) were measured before and after the 8-h work shift in groups of welders and non-welder controls in a shipyard. For each subject, full-shift average concentrations of welding fume constituents were evaluated. On the average, the lung function indices in both groups of welders and controls decreased from morning through afternoon. The welders demonstrated more reduction in the indices than the control group. In general, there was no significant association between the acute changes in the lung function and the daily amount of exposure to welding fume constituents or the welding environmental factors. However, the overall difference of mean diurnal variations in TL between the groups working under different ventilation condition was significant (P < 0.01). On the average, welders who did not use any ventilation system showed maximum reductin in TL value. Acute reduction of FEV1 was positively correlated (P < 0. 05) with the levels of iron oxide produced during welding.