AIRWAY REACTIVITY IN WELDERS - A CONTROLLED PROSPECTIVE COHORT STUDY

In a 3-year survey, respiratory symptoms, spirometry, and methacholine reactivity were measured annually in welders (n = 51) and non-welder control subjects (n = 54) to determine whether welding-related symptom s are associated with accelerated decline in lung function or changes in airway reactivity. In the across-workshift study, maximal midexpira tory flow rate declined reversibly during a welding day, whereas 1-sec ond forced expiratory volume and forced vital capacity were unchanged. In the longitudinal study, the welders had signifi cantly more revers ible work-related symptoms of cough, phlegm, wheeze, and chest tightne ss than the non-welder shipyard control subjects. In this group of act ively working welders, across-workshift changes in midflow and reversi ble symptoms were related to the welding occupation, but evidence for chronic irreversible effects on spirometry or airway reactivity was no t seen over the 3 years of observation. The short period of observatio n was not optimal for detecting a chronic effect on lung function. Wor k practices and engineering controls may be successfully preventing ir reversible respiratory effects, but not mild reversible effects, in th is group Of welders.