Comparison between ISO 2631-1 comfort prediction equations and self-reported comfort values during occupational exposure to whole-body vehicular vibration

Abstract

It is important to understand whole body vibration (WBV) since it affects comfort and is important in worker health and performance. Although discomfort can be subjectively evaluated, the ISO 2631-1 standard predicts discomfort based on vibration magnitudes, frequencies and durations. The objective of this study was to determine whether the ISO 2631-1 prediction method produces similar results to self-reported discomfort levels during routine heavy machinery operations in the field. While working under normal conditions, 6 df seat-pan vibration data were recorded in construction, mining, and forestry vehicles. At 5-minute intervals, operators rated their discomfort based on the preceding minute of vibration exposure. Discomfort was predicted from the vibration total value for each corresponding one-minute vibration profile. Each industry showed consistent trends between the predicted and self-reported discomfort; however, there were different relationships between industries. Construction showed a weak positive relationship (r2=0.09) between predicted and self-reported discomfort values, whereas both forestry and mining showed no relationship. The predicted discomfort levels did not accurately represent self-reported discomfort; this is similar to some previous studies, but contrasts with other studies. This variability may be due to discrepancies with the prediction equations, or perhaps due to additional factors being incorporated into self-reported comfort measures, such as temperature, noise, and fatigue.