FRCG Quarry Sampling Summary Report
The FIELD GROUP developed a summary report of sampling results for noise and silica at 10 open surface mines. Samples were collected across all seasons for a year. Employees who had a potential for exposure to noise or silica dust were monitored. For all eight jobs monitored, the mean 8-hour noise exposure exceeded 85 dBA. The exposure of only groundsmen exceeded 90 dBA, although crusher mechanics had exposures approaching this limit. For silica exposure, only groundsmen had a mean exposure at the silica permissible exposure level of 10 mg/m3. Recommended controls included fitting heavy equipment with cabs and air conditioning, fitting generators with supply and exhaust air mufflers, upgrading conveyor belts to reduce the need for belt cleaning by a groundsman, soundproofing the crusher operator’s booth, and shifting groundsmen's work schedules to reduce their time near operating equipment.