Measures to reduce carpenters’ occupational exposure to mineral wool fibers and total dust while working indoors in Norway

Background: This study aimed to assess the effect of various measures in reducing the concentrations of total dust and mineral wool fibers carpenters are exposed to by one of the largest building contractors in Norway. Methods Personal samples, each taken over a 4-h to 9-h period of total dust (42) and mineral wool fiber (19) concentrations were collected from carpenters working indoors with insulation, steel studs, and drywall. Samples were collected for one week under normal cleaning procedures, then again for a week with additional cleaning measures. The results were analyzed using a linear mixed effects model. Results The time-weighted average (TWA) for total dust concentration ranged from 0.8 mg/m 3 to 9.2 mg/m 3 , with mean concentrations of total dust for the three exposure groups of 3.2 mg/m 3 , 2.0 mg/m 3, and 5.0 mg/m 3 for insulation, steel studs, and drywall, respectively. The TWA for mineral wool fiber concentrations ranged from 0.01 to 0.04 fibers/cm 3 . The differences in exposure among the groups were insignificant. No differences in the concentrations of total dust and mineral wool fibers were observed between the weeks with and without extra cleaning measures. However, no changes in carpenters’ cleaning habits were observed either. Only a few workers used personal respiratory protection. Conclusions Concentrations close to the limit for total dust were measured during drywall work. Dust reduction measures can potentially lower exposure concentrations while benefiting the construction industry financially. However, prior to implementing any dust reduction measures, knowledge of the potential health effects caused by exposure must be increased. Trial registration: This study is not a clinical trial and are not registered.