Many people are exposed to vibration in the workplace. Exposure to certain types of vibration can cause health effects that range from discomfort and interference with ability to perform work, to acute or chronic illness. There are two main types of vibration that you may be exposed to in the workplace: whole body vibration, which enters the body through a seat or the floor; and segmental vibration, which primarily affects one part of the body. The most common type of segmental vibration exposure is hand-arm vibration from the use of vibrating hand tools. In both whole-body and segmental vibration exposure, the health effects will depend on the characteristics of the vibration (including frequency, amplitude, and acceleration), the part of your body that is exposed, the daily exposure time, and the total number of years that you are exposed.
Manufacturers of tools recognize the risk associated with vibration and incorporate anti-vibration technology to minimize or eliminate the risks. Employers and employees who purchase or use equipment that may induce vibration are encouraged to consult the manufacturer specifications/instructions, or the supplier to ensure that appropriate measures are taken to eliminate or reduce the transmission of harmful levels of vibration to the body.
Who is at Risk?
If you regularly use vibrating hand-tools or equipment for long periods of time, you could be at risk of developing Hand-Arm Vibration Syndrome (HAVS). This condition is also known as Vibration-Induced White Finger, or Raynaud’s Phenomenon of Occupational Origin. You can receive vibration exposure from a variety of hand tools, such as chainsaws, jackhammers, and grinders. Hand-arm vibration exposure often takes place for 2 to 10 years before health effects become noticeable.
Exposure to whole-body vibration can take place when you are on any equipment, machinery, or structure that vibrates. Examples of people who are at risk of whole-body vibration exposure include bus drivers, farm and heavy equipment operators, and aircraft pilots.
In mild cases of HAVS, you may have occasional attacks where circulation to your fingers is reduced, you feel tingling or numbness in one or two of your fingers, and your finger tips turn white for a period of 30 to 60 minutes. Pain is usually experienced as circulation increases in your fingers, and colour and sensation return in your finger tips. Attacks are normally brought on by exposure to cold, damp conditions. With increased exposure to vibration over time, attacks become more severe and occur more often. In the most severe cases of HAVS, all fingers will be affected by persistent numbness, and although it is very uncommon, tissue damage can progress to a point where amputation is necessary.
Exposure to whole-body vibration over a long period of time can have a negative effect on the organs, muscles, circulatory system, and soft tissues of your body. Back pain and degenerative spinal disc diseases are the most common health problems experienced by those who are chronically exposed to whole-body vibration. Whole-body vibration exposure is also likely to increase temporary hearing loss during noise exposure.
Immediate health effects from whole-body vibration exposure can also occur, such as fatigue, insomnia, stomach aches, and headaches. People may experience motion sickness in sea, air, or land vehicles when vibration exposure occurs in the 0.1 to 0.6 Hz frequency range. Whole-body vibration exposure can also present safety risks. One example of a safety risk from acute vibration exposure is a driver becoming unable to grip a steering wheel while driving, and loosing control of a vehicle.
How Vibration is Measured
There are several types of instruments that can be used to measure vibration. A vibration measurement transducer, which is also known as an accelerometer, can be used to measure vibration that is typically in the range of 5 to 1500 Hz. A frequency analyzer is also used to determine the frequency of vibration. There are standards for measuring vibration that should be followed in order to obtain accurate results.
It is important to limit your exposure to vibration. Here are some good work practices for preventing HAVS:
Reduce vibration exposure to levels below the ACGIH TLVs®
Use anti-vibration tools as per manufacturers’ specifications/instructions
Maintain equipment to minimize vibration
Keep warm and dry
Use anti-vibration gloves
Complete periodic medical checkups
Use a light hand grip that is sufficient to operate the tool safely
Good work practices for minimizing whole-body vibration exposure include:
Using equipment, machinery, and vehicles that do not vibrate excessively
Providing vehicle operators with air-ride or suspended seats in order to isolate the operator from vibration
Mechanically isolating vibrating machines from the floor
Removing employees from exposure if possible – for example, using a video camera and electronics monitor and control machinery remotely, rather than in-person
Maintaining equipment to minimize unnecessary vibration
Avoiding lifting heavy objects or bending immediately following exposure
Using simple motions, with minimum rotation or twisting when exiting a vehicle