Determinants of respirable crystalline silica exposure in construction in western Canada.

This article focuses on task-based exposure to respirable crystalline silica (RCS) among construction workers in Alberta, British Columbia (BC), and Manitoba, Canada, based on 373 samples collected from 70 worksites across 44 companies between 2015 and 2020. The overall geometric mean (GM) RCS exposure was 0.045 mg/m³, exceeding the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) of 0.025 mg/m³, with the highest exposures observed in demolition and breaking tasks. A multivariable regression model identified province, task type, work environment, construction material, sampling duration, and use of engineering controls as significant predictors of exposure, explaining 42% of variability; working outdoors and using controls such as local exhaust ventilation and wetting were associated with lower exposures. Despite some regional differences, determinants of exposure were similar across provinces, highlighting ongoing risks and the need for improved exposure control measures in the Canadian construction industry.