ریسک بهداشتی ناشی از مواجهه ارتعاش تمام بدن رانندگان لیفتراک در دو وضعیت دارای بار و بدون بار: مطالعه موردی در یک شرکت خودروسازی

Introduction: Fork-lifts are considered as one of the main sources of vibration at workplaces. Due to importance of the risks from exposure to vibration, the present study was aimed to investigate health risk due to exposure of fork-lift drivers to whole body vibration at two position with load and without load in an Automobile industry. Method: In this cross sectional study, the evaluation of whole body vibration exposure according to standard ISO 2631-1: 1997 was done for 33 drivers of fork-lift truck. All measurements were performed using 3-axis accelerometer in sitting position of operators on the move forklift for 20 minutes. Then, the effect of load on vibration exposure and health risk was determined by SPSS software (Version16.0) and the paired-samples t-test. Results: The frequency-weighted r.m.s acceleration values for x, y, and z direction (m/s2) in the “without load” condition were 0.0038, 0.63 and 0.93 m/s2, respectively, and in the “with load” was equal to 0.0027, 0.51, and 0.98 m/s2. The dominant direction of the r.m.s acceleration in both states was the z-axis. There was no statistically significant difference between the acceleration of the dominant axis and the 8-hour equivalent values in both with and without load (P>0.05). Conclusion: The evaluation of the dominant axis and 8-hour equivalent acceleration showed that in both states, the exposure values were higher than the daily exposure limit value. Moving forklift with load reduced the vibration exposure values in two x, y direction, but did not effect on the z axis and the resulting health risk.