P-393 Evaluation of the Vibration Environments of the Hand-Arm System in a Worker Handling a Pneumatic Impact Wrench

Introduction Vibrations are important risk factors for musculoskeletal disorders. The objective of our study is to identify and measure the vibrations of the hand-arm system encountered during the handling of a pneumatic impact wrench by a worker at a port terminal in Morocco as well as to evaluate their possible harmful effects about health. Methods This metrological study is measuring the vibrations of the hand-arm system in a male worker who manipulates a pneumatic impact wrench to screw and unscrew the nuts of large caliber tires within a port terminal using a hand-arm system sensor connected to an analyzer. The measurements were carried out both on the right hand which supports the machine and ensures maximum operating effort and on the left hand which operates the device. Results At the level of the right hand, the weighted equivalent accelerations Ahv were of the order of 10.87 m/s² when unscrewing and 6.51 m/s² when screwing. On the left hand they were rated at 12.70 m/s² when unscrewing and 7.78 m/s² when screwing. The daily exposure levels Ahv (8) were 0.62 m/s² when unscrewing and 0.37 m/s² when screwing on the right as well as around 0.71 m/s² when unscrewing and 0.27 m/s² when screwing on the left. Discussion and conclusion The exposure levels found remain lower than the values triggering preventive action, this conclusion should not hinder the continuity of adequate occupational health care to early detect the harmful effects on health of these vibrations before the appearance of values which require the implementation of preventive actions.