A field study was conducted to comparatively evaluate the dust control technologies on three track mounted, rock drilling rigs. Video exposure monitoring was used as the primary assessment tool to identify exposure variations from rig to rig and to determine which drilling activities contributed to or reduced exposures. Each rig was equipped with progressively more sophisticated engineering controls to reduce dust emissions. The first was an Ingersoll-Rand Crawlair CM350 that used water to suppresses dust emissions. The second rig was a Tamrock Zoomtrak DHH850 that used water and a dust collection system to suppress dust emissions. The third rig was a Fuwakawa 150 that used the same type of engineering controls as the Tamrock, but was also equipped with an enclosed, ventilated operator cab. As the level of engineering control increase, the worker exposure to dust decreased. The cost for a new Crawlair rig ranged from 70,000 to 80,000 dollars. This was the slowest rig, and resulted in the highest exposures. The Tamrock rig ranged in price from 190,000 to 200,000 dollars, was roughly 30 to 40% faster than the Crawlair, and had a decreased exposure. The new Fuwakawa rig ranged in price from 400,000 to 410,000 dollars, and was roughly 40 to 50% faster than the Crawlair, and resulted in the lowest exposure. Video exposure monitoring demonstrated that some brief worker activities increased exposures. It also showed that small particles were resuspended at the cartridge filtration dump. The video technique served as a good qualitative tool to assess occupational exposures, rather than as a quantitative tool, given the limitations of direct reading instrumentation.