By Donald E. Wasserman, Occupational Vibration Consultant
Have you ever personally experienced or watched a heavy equipment construction crew get tossed around by vibration; or a truck driver moving a heavy rig down the highway; or someone using a power hand-tool and observed the intense ripples of vibration motion beginning at the operator's hands, moving up through the forearms to the shoulders? Do you think this daily human exposure to vibration is harmless? Think again...because what you don't know about daily vibration exposure can seriously and irreversibly hurt those who are exposed!
In the USA alone there are some 8-10 million people who are regularly exposed each day to occupational vibration and many more world-wide. These vibration exposures are usually divided into two different major groups depending on the job.
One major exposure type is called Whole Body Vibration (WBV), or head-to-toe exposure, affecting truck, bus, heavy equipment, farm vehicle, fork-lift, railroad, and overhead crane operators, etc.
The second major exposure type is called Hand-Arm Vibration (HAV), or localized vibration exposure, mainly, but not exclusively, affecting people who regularly use all types of vibrating pneumatic, electrical, hydraulic, and gasoline powered hand-tools.
On rare occasions there can be daily "crossover exposures" between WBV and HAV, depending on the job. For example, in the case of certain hand-tool usage such as pneumatic pavement breakers or demolition type tools where the operator can choose either to grasp the tool with their hands extended away from their torso (HAV exposure) or letting the tool rest against their torso (WBV exposure) in an attempt to damp the vibration. Sometimes both WBV and HAV exposures occur simultaneously, such as in motorcycling or mountain bike use.