Previous studies have reported conflicting data on baseline lung function, respiratory symptoms, and (cumulative) exposuretowooddust.Asimilarlysizedstudyamong652redcedar workers16 showed that pulmonary function variables were relatedtoexposuretodustbutnottodurationofemployment. A later 11 year follow up of the same cohort showed a significant association between decreases in lung function and time in three exposure groups was around 0.4 mg/m3.17 Among subsequent studies in medium size cohorts (n=100–200) several have found no overall relation between lung function variables and cumulative exposure index18–21 in similar exposure ranges,whereas others22 23 described increased respiratory symptoms and a reduction of spirometric indices in workers exposed to wood dust. Differences may be due to variations in wood type and handling, climatic conditions, misclassification of exposure, and confounding by exposure. In our study most workers were exposed to meranti,a tropical wood which is considered to be a softwood based on it density and hardness.1 Exposure to other types of wood known to induce asthma was excluded from this study. In some jobs coexposure to formaldehyde was present but a nested case-control study in workers in exposure category I (