Assessment of Whole-Body Vibration Exposure in Mining Earth-moving Equipment and Other Vehicles Used in Surface Mining.

This study characterized whole-body vibration exposures in a set of vehicles that operate in open-pit mines and compared three different daily exposure parameters based on the ISO 2631-1:1997 and ISO 2631-5:2004 standards. Full-shift, 6 to 12-hour, continuous whole-body vibration measurements were collected from 11 representative types of vehicles in terms of hours of operation and number of vehicles used. For each type of vehicle, the exposure parameters (A(8), VDV(8), and Sed(8)) were calculated for each axis (x, y, and z), and in addition, shear or horizontal (∑xy) and vector sum (∑xyx) whole-body vibration exposure. Findings showed that: (i) substantially higher shear and vector sum whole-body vibration exposures indicated relatively high levels of exposure on the non-predominant axis; (ii) the predominant axis of exposure varied across the different type of vehicles; (iii) there were differences in whole-body vibration exposure parameters regarding the standards-based predictions of potentially adverse health outcomes (the impulsive exposure parameters VDV(8) and Sed(8) were higher and reduced acceptable vehicle operation times by one-half to two-thirds relative to A(8) exposures); and (iv) based on the predominant exposures and the time to reach daily vibration action limits, the operation of most mining vehicles would be limited to less than 8 hours a day. Differences in whole-body vibration exposure parameters impact the prediction of potentially adverse health outcomes and may introduce some uncertainty regarding how to best characterize a vehicle operator's actual exposure.