Workers who perform concrete drilling are exposed to hazardous levels of noise, force, vibration and airborne silica dust. Reducing the risks associated with those hazards is the focus of a study by Dr. David Rempel, a member of CPWR's research consortium, and his research team at the University of California.

Using a specially designed test bench (right) the researchers have conducted experiments using a common rotary hammer and carbide-tipped bit to isolate the effect of drill bit wear on worker exposure to these hazards. The tests found that bit wear reduced worker productivity -- holes took longer to drill -- while increasing the drill operator's exposure to silica dust, noise, force and vibration. Looked at another way, by swapping out worn bits promptly for sharp new ones, contractors can increase productivity while better protecting workers from occupational health hazards.

The results have been published in a series of journal articles. Click on the links below for a one-page summary of the key findings:

• Carbide-tipped Bit Wear Patterns and Productivity with Concrete Drilling (Wear, 2017)
• Effect of Bit Wear on Hammer Drill Handle Vibration and Productivity (Journal of Occupational and Environmental Hygiene, 2017)
• The Effects of Bit Wear on Respirable Silica Dust, Noise and Productivity: A Hammer Drill Bench Study (Annals of Work Exposures and Health, 2017)