Factory performance evaluations of engineering controls for asphalt paving equipment

Effective dust control systems on concrete dowel drilling machinery

Rotary-type percussion dowel drilling machines, which drill horizontal holes in concrete pavement, have been documented to produce respirable crystalline silica concentrations above recommended exposure criteria. This places operators at potential risk for developing health effects from exposure. United States manufacturers of these machines offer optional dust control systems. The effectiveness of the dust control systems to reduce respirable dust concentrations on two types of drilling machines was evaluated under controlled conditions with the machines operating inside large tent structures in an effort to eliminate secondary exposure sources not related to the dowel-drilling operation. Area air samples were collected at breathing zone height at three locations around each machine. Through equal numbers of sampling rounds with the control systems randomly selected to be on or off, the control systems were found to significantly reduce respirable dust concentrations from a geometric mean of 54 mg per cubic meter to 3.0 mg per cubic meter on one machine and 57 mg per cubic meter to 5.3 mg per cubic meter on the other machine. This research shows that the dust control systems can dramatically reduce respirable dust concentrations by over 90% under controlled conditions. However, these systems need to be evaluated under actual work conditions to determine their effectiveness in reducing worker exposures to crystalline silica below hazardous levels.

The intervention research process in occupational safety and health: an overview from the National Occupational Research Agenda Intervention Effectiveness Research team

The goal of occupational safety and health intervention effectiveness research is to determine whether specific interventions work to prevent work-related injury and illness. But that is not the whole story. It is also important that the development and implementation of the intervention be evaluated. All three phases (development, implementation, and effectiveness) are central to a model of intervention research proposed by the National Occupational Research Agenda Intervention Effectiveness Research team. Areas for future research are also presented.