Mining Publication: Preventing Exposure to Whole-Body Vibration

Negative health effects of exposure to whole-body vibration are prevalent in the industrial world today, particularly in  mining where heavy earth-moving equipment and off-road vehicles are necessities. Heavy machinery produces whole-body vibration and mechanical shock exposure to equipment operators when operating on rough surfaces and under harsh conditions. This places a significant burden on the health and safety of exposed mine workers.

Whole-body vibration exposure commonly occurs when a person is in contact with a vibrating surface – for example, while sitting on a vibrating seat, standing on a vibrating floor or lying on a vibrating bed or mat. Seated people exposed to whole-body vibration are also often simultaneously exposed to local vibration of the head (i.e., from a headrest), the hands (i.e., from a steering wheel) and the feet (i.e., from the floor). Vibration may also enter the body from contact with the seat backrest.

The primary characteristics of whole- body vibration are vibration frequency, magnitude, direction and duration. Vibration frequency is expressed as the reciprocal of the period in hertz (Hz). Magnitude is expressed as displacement, velocity or acceleration. In relation to the human body, direction is expressed in terms of vertical (head to foot), side to side (right to left) and back to chest. Duration is time interval of the exposure.

Humans are not typically exposed to vibration as a static, periodic signal in the real world. Instead, exposures include many simultaneous waves of varying frequency, magnitude, direction and duration. Therefore, the effects of whole-body vibration on the body of a mine worker are complex and can be substantial.