Background: Generally every different machines which are implemented in industries, agriculture and transport systems exposed human to excessive vibration. The produced vibration can reduce comfort and productivity and also cause adverse effect on human health and safety. Long term human exposure to high vibration levels may lead to physiological disorders.

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Material and methods: This paper presents the results of an experimental study which is done on 584 students of Tehran University of medical sciences. The data was gathered by interview and a validated questionnaire. In this study the stimulus was produced by a calibrated 3 axis vibrated seat. The voltage of stimuli was 90 and 95 V in two different frequencies of 20 and 25 Hz in two axis of x and y. During exposure the transferred whole body vibration was monitored by a calibrated whole body vibration meter.

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Finding: The results of this investigation showed that whole body vibration effect on mental disorder is significantly higher among female compared with that of in male. The disorder induced by frequency of 25 Hz was three times higher than that of produced by 20 Hz. The frequency of mental disorders was increased by rising vibration acceleration. It was also found that taller people are slightly less sensitive to the range of tested frequencies and acceleration compared with of shorter one.

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Conclusion: A significant relation between height and mental disorders was found in this study which can be used on whole body vibration exposure management.