Article Text
Abstract
Introduction Silicosis is being increasingly reported among young stonemasons in the artificial stone (AS) benchtop fabrication and installation industry.
Objectives To identify metrics of exposure that predict risk of work-related respiratory ill-health among these stonemasons.
Methods Respiratory health screening which included a job and exposure history, a chest x-ray (CXR), a respiratory health questionnaire and gas transfer testing, were offered to stonemasons in Victoria Australia.
Results Workers typically reported a variety of tasks, including cleaning and labouring, which made exposure assessment complex. We estimated the relative respirable crystalline silica exposure intensity of each job from the proportion of time using AS and doing dry work (work without water suppression). The average intensity of exposure for up to five jobs was calculated. Cumulative exposure was calculated as the sum of the work duration multiplied by intensity for each job. Stone bench installers and factory machinists (other than CNC operators) were the most likely to report dry work with AS, and so had a greater average intensity of exposure. Exposure intensity and cumulative exposure were associated with increased odds of an ILO CXR category of ≥1 and with dyspnoea. Exposure duration was also associated with increasing ILO CXR profusion category. In multivariate analyses of health outcomes, only job type was associated with the ILO category. For both most recent and longest duration job type, factory machinists were more likely to have a CXR ILO category ≥1 than the lowest-exposed job group.
Conclusions This suggests that intensity of exposure estimated from the proportion of time dry cutting and proportion of time working on AS can predict risk of adverse respiratory outcomes for workers in this industry.