A cross-sectional assessment of respiratory function and symptoms was p e ~o r m e d in 1985 on 409 male rubber workers and 172 unexposed control workers. A follow-up study in 311 of the original rubber workers was pe$ormed 6 years later, Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves. At the time of the initial study, significantly higher prevalences of all chronic respiratory symptoms, except for asthma, were found among the rubber workers cornpared to controls. Smokers had a significantly higher prevalence of most of the chronic respiratory symptoms compared with nonsmokers. A high prevalence of acute symptoms during the workshift was recorded among the rubber workers at both surveys. Rubber workers demonstrated significantly lower ventilatory capacity measurements compared to predicted. Ventilatory capacity measurements diminished significantly across the workshift, particularly FEF.50 and FEF2.5. Metaprotere-no1 inhaled at the end of the workshift significantly improved lung function in a small group of sensitive rubber workers. Annual lung function loss among both smokers and nonsmokers was in excess of predicted. Our data suggest that exposure to noxious agents in the rubber industry are associated with the development of acute and chronic respiratory impairment.