| Whole-body-Vibration (WBV) exposure levels experienced by transport truck operators were investigated to determine whether their exposure exceeded the ISO standards. A second purpose of the study was to determine which truck characteristics predicted the levels of WBV exposures experienced. Predictor variables included road condition, truck type, driver experience, truck mileage, and seat type. Tests were conducted on four major highways. During each trip 5-minute random samples were taken during each 30-minutes of travel time at speeds greater than 80 km/hr. The dominant axis for which the vibration acted was the z-axis.; Results indicated operators were not at increased risk of adverse health effects from daily exposures when compared to ISO 2631-1 (1997) WBV standards and the ACGIH TLV (2000) guidelines. Significant regression models predicting the frequency weighted RMS accelerations for the x (F(5,97) = 8.63, p < 0.01), y (F(5,97) = 7.74, p < 0.01), z (F(5,61) = 9.83, p < 0.01) axes and the vector sum of the orthogonal axes (F(5,61) = 13.89, p < 0.01) were observed. Road was a significant predictor (p < 0.01) for all 3 axes and the vector sum of the axes, while truck type was a significant predictor (p < 0.01) in the z-axis and vector sum frequency weighted RMS accelerations. No other predictor variables were significantly related to the levels of WBV experienced by operators. Future WBV research should explore seasonal driving conditions, vehicles with greater age differences, a wider variety of seating conditions and suspension systems and team driver situations. |
