Playing It Safe at Work : What About ELF? Carpal Tunnel Syndrome

by Food and Drug Administration (FDA)

(Page 2 of 2)

Rest occasionally during periods of intense concentration. The National Institute of Occupational Safety and Health recommends taking a 15-minute rest break every hour from highly demanding computer tasks. Don't forget to blink frequently to reduce dryness and irritation. Looking at a distant object can relax your eyes. Closing your eyes can also help.

Maintain a good viewing distance. Close viewing may cause focusing fatigue. Adjust the workstation so that keyboard, screen, and paper copy are an equal distance from the eyes with the screen slightly (about 20 degrees) below eye level. It is helpful to use a copyholder. A good viewing distance is 22 to 26 inches.

Talk to an eye-care professional about special glasses or an altered prescription. Some people may need special glasses for focusing at the intermediate distance that is neither as long a distance as prescriptions for nearsightedness usually encompass, nor a typical reading distance. This is particularly true if you wear reading glasses or bifocals. Tell your eye-care professional if you use a computer for long periods, and discuss any eye discomfort you have.

Keep the work environment free of dust. Dust can make the eyes tear, feel gritty, or turn red. Proper humidity and ventilation are important. There are cleaners available to remove dust from the screen.

What About ELF?

Another serious concern associated with VDTs is the extremely low frequency (ELF) electromagnetic fields they produce. Alternating only 60 times a second, the effects of these fields are at the center of a scientific controversy. Some studies of humans exposed to ELF radiation have suggested an association between this exposure and certain types of cancer. But the evidence is not clear. For example, other human studies do not show an increased cancer risk. Even those studies with positive results have not been able to accurately determine how much ELF radiation people in the studies received, making it difficult to determine the risk, if any. And animal experiments have thus far failed to show a cancer-causing effect.

Some studies have also raised the question of an increased risk of miscarriages and other problems during pregnancy among women exposed to ELF fields. The evidence for these effects is even more uncertain than that for cancer.

Although existing studies raise concern about the possibility of health effects from ELF radiation, the scientific evidence is not sufficient at present to warrant regulatory action by FDA. The agency believes that the most prudent course of action is for it to continue to monitor the research in this field and, in the meantime, to work with manufacturers to reduce levels of ELF radiation.

To address these concerns, some VDT manufacturers are beginning to produce terminals that emit less ELF radiation. In the meantime, some people may wish to reduce their exposure, despite the absence of scientific evidence pointing to a clear health hazard by taking three simple steps:

Turn off the VDT when not in use.

Position yourself approximately 22 to 28 inches (arm's length) from the screen when using the VDT. If possible, use an adjustable computer shelf so you can position the keyboard further from the screen. ELF emissions fall off drastically after a distance of 28 inches, so sitting at least that far from the screen will reduce exposure.

Position yourself approximately four feet from the sides and rear of other terminals. ELF emissions are greater from these parts of VDTs than from the front screen.

Carpal Tunnel Syndrome

VDTs have also spawned a rise in carpal tunnel syndrome, or repetitive motion injury. This hand condition results from performing the same motions for hours at a time, as when a terminal operator types continuously. The syndrome is named for the narrow tunnel in the wrist formed by ligament and bone. Tendons that enable the hand to close pass through the carpal tunnel. Injury to this part of the body can cause numbness or weakness, tingling and burning in the fingers and hands, or difficulty opening and closing hands. If the condition is not treated, permanent injury and loss of the use of the hand are possible.

The American Physical Therapy Association recommends several steps to prevent or alleviate the symptoms or carpal tunnel syndrome:

Keep wrists relaxed and straight, using only finger movements to strike the keys. Your typing table should be slightly higher than your elbows when your arms are held relaxed by your sides. Rest your elbows by your sides or support them with special arm rests now available on some office chairs. Relax your shoulders and keep them level.

Press keys with the minimum pressure necessary. Make sure the keyboard is kept clean and in good working order to minimize resistance.

Move your entire hand to press hard-to-reach keys rather than overextending your fingers. Use two hands if necessary to execute combination keystrokes, such as shifting to upper case.

Break up typing tasks with other activities — such as proofreading, filing, or telephone work — to rest fatigued muscles.

Protective Eyewear

For students and teachers, shop and science labs pose a danger of eye injuries from foreign objects. Some sports and hobbies can also pose a risk of eye injury. Chemicals or tools can damage unprotected eyes.

Although FDA regulates regular glasses, sunglasses and goggles, the Occupational Safety and Health Administration regulates job-related protective eye equipment. All major component parts of industrial-type eye protectors that conform with the OSHA standard are marked Z87, and the manufacturer's monogram is marked on each lens. Most states require Z87 eyewear for protection for certain occupations.

Choose protective eyewear to shield you from foreign objects, heat, chemicals, dust, and radiation. Safety glasses or goggles with side shields provide protection from frontal and side impact and are designed for such projects as woodworking. These are "primary protectors." For protection against severe hazards such as arc welding or furnace operations, face shields and welding helmets, called "secondary protectors," must be worn in addition to the safety glasses or goggles.

Our ability to identify deleterious health effects from advancing technology is evolving. As we attempt to keep pace with rapid workplace innovations, some basic safety rules can do much to minimize risk: Keep equipment in good working order, follow directions for use carefully, and use common sense when operating machines.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.