Course:SPPH381B/TermProject/Tylenol -Alex Kitt/Transportation/Whole Body Vibrations

Whole Body Vibration

Whole body vibration (WBV) is caused by constant, low-frequency vehicular shaking that is transferred to the driver when sitting. Certain frequencies cause resonance with individual organs and the body as a whole, causing greater vibration in the person. It causes numerous health effects, including: lumbago; nerve damage; issues of the bladder, abdomen, and lungs; fatigue and reduced motor functions caused by muscle contraction in response to vibrations.

To measure vibration, a triaxial accelerometer is placed on the driver’s seat, which measures movement in the x, y, and z planes . While there are no legal limits for exposure to WBV, WorkSafeBC provides suggested levels .

The values of the dominant, frequency-weighted (rms), component acceleration of for triaxial accelerometer and their effects for 4- and 8-hour driving shifts are given below:

Duration	No clear effects	Caution	Health risks likely
4 hours	Less than 0.6	0.6 to 1.1	Greater than 1.1
8 hours	Less than 0.5	0.5 to 0.9	Greater than 0.9

In the US, 8 million people are affected by occupational vibrations, and of these 6.8 million people are specifically exposed to WBV .

Controls

Elimination

Unfortunately, the only way to prevent WBV in drivers is to replace the mode of transportation, but WBV is also associated with other types of transportation. However, using larger trucks that can transport more cargo could reduce the number of workers needed.

Substitution

Since WBV is exacerbated by poor road conditions, selecting a driving route which utilizes the best-paved roads may mitigate WBV.

Engineering

One effective engineering control for WBV is to use new vehicles and technologies and to install vibration dampeners. Vibration dampeners include hydraulic dampeners and shock absorbers attached to the driver’s seat. However, for proper functioning these need to be adjusted to the correct weight , .

A relatively new technology, called electromagnetically active (EM-active) seats, has shown significant improvements in preventing WBV. The EM-active seat reduces vibrations by using a microprocessor-controlled actuator .

Properly set tire pressure and vehicle suspension may also aid in mitigating the effects of WVB ,.

Administrative

Employers should ensure that workers are given adequate breaks to exit the vehicle and stretch, as well as ensure that employees drive at a reasonable speed (as higher speeds increase WVB). Employers should also train employees in proper mirror adjustment, so that drivers are aware of potholes and obstacles that may cause the vehicle to jolt. Equipment should also be monitored and maintained, to ensure engineering controls are fully functional.

Furthermore, ensuring workers take frequent breaks to stretch, as well as shifting workers around (if they can perform jobs other than driving as well), may reduce the long-term effects of WBV.