Be Aware of Vibration in Workplace

Numbers of scientist believe that working in an uncomfortable/unusual position and workplace is risky. The effected work environment factor is vibration felt in the worker body. Industrial world has various vibration sources. Vibration is oscillation mechanically occurred because of periodical body movement, either static or not static.
Usually these vibrations are caused by tools or machines used to production process. Such vibration is known as mechanical vibration that is a vibration caused by the medium and tools of human activities. For example: vibration result from shovel, dumper, and dozer. Mechanical vibration consist several types. They are whole body vibration and tool-hand vibration. Whole body vibration is a vibration felt by whole body, for example, the vibration from production floor. Hand-arm vibration is only felt by part of body, for example, vibration felt in the hand of a worker when s/he uses a hand-drill.
We realize it or not, vibration felt by the operator body, in long- or short-term, can create risk for the operator. There are many health risks related to work environment (vibration). The common risk occurred, are: to decrease of working concentration, to stimulate fatigue, and to damage touch-neuron, thus decreasing sensitivity level of the operator to touch stimulation. Besides, it can decrease the balance of the workers and disorder of other parts of the body, such as eyes, nerves, and muscles. Since the operator is often in vibrated environment, the risk will be higher.
Whole body vibration particularly happens in lifting tools, for examples, trucks, lifting machines in the industry, farming tractors, etc. In addition to, vibration from heavy machines can be transferred to the whole body through the floor then the feet. The most important vibration is a vibration from chair to the feet then to the body. This vibration can create the appearance of resonance in parts of the body, thus the effect is mechanical. It leads to the damage of tissue cells or the disorder of body metabolism. In this case, mechanical effect can occur in tissues, and the stimulus of nerve receptor in the tissues.
In sit position, the whole body is admitted one unit of mass to vibration. In body position that is different with vibration flow, the transition of the vibration is varying. The content of the stomach in any body position can be regarded as one unit to a vibration to 9 Hz. However, in the higher frequency, the existence tools will follow its own vibration.
The impact of the vibration in the body depends on the tissues. It occurs in nature frequency, 3 – 9 Hz, for several unit of body, such as chest and stomach. While in high frequency, it can affect other tools with high nature frequency. Neck, head, and hip, have a good resonance to a vibration with frequency of 10 Hz. Strong vibration can create a very serious pain.
The eyes are the most effected part by mechanical vibration. In the frequency until 4 Hz, the eyes are still able to follow the vibration between the head and the target, while in the subsequent frequency; the eyes are not able to follow. So, in high frequency vision can be disturbed. Work disturbance by vibration is the result of the disturbance if hand movement and the decreased of vision sharpness.
Besides, there area works that use continuous vibrated tools. These tools can make disturbance and disorder as the result of mechanical vibration in the arms. Those disturbances are the disorder in blood circulation and neuron, and the damage in the joint and bones. The initial symptoms are pale face and rigidness in the ends of the fingers that occur repetitively and irregularly. The perturbation starts in the hand, then spread to the shoulders. An operator is very potential in loosing holding ability and muscle control.
Until now, there are many workers who do not realize the risk of the vibration in workplace. Even, for those who have already known the risks did not do something to prevent them. It can be seen from the performance of the operator so far. For example, drilling use hand-drill. Even though the frequency resulted is not big, but the impact will still effect the operator performance, moreover, if the work appears in long-term. The vibration will creep to the whole body of the operator. In some companies, I saw once a worker who drilled using hand-drill without gloves. Whereas the gloves are very useful to decreases the vibration effect to the operator. Thereby, they can decrease the vibration frequency felt by the operator. Perhaps, at that time, operator thought that he was used to feel the vibration. However, if the task was taken place for years, soon or later, the worker will experience the risk created by that vibration.
Written by : Eddy Harliono