ELF

In recent years, ELF fields have become a subjectof concern in computing applications where cathode-ray tube (CRT) displaysare used. These displays, typically used in desktop computerworkstations and television sets, generate electromagnetic fields because ofthe strong, fluctuating currents in the electron-beam deflectingcoils. The frequencies of these fields are on the order of a fewkilohertz or less. Some studies suggest that ELF fields mighthave detrimental health effects on humans exposed to them forlong periods of time. The claims vary from increased risk ofcancer to premature births and miscarriages. However, as of thiswriting, conclusive proof has yet to be obtained that ELF fieldsare harmful at the levels encountered by computer users.

The ELF fields surrounding a CRT display tend tobe stronger off the sides of the CRT than directly in front of itor behind it. The fields diminish rapidly in intensity withincreasing distance from the CRT. As a general rule, computerusers should sit at least 18 inches away from a CRT display.Side-by-side workstations should be at least five feet apart.These considerations are important for visual comfort and"breathing room" as much as for minimizing thepotential risk posed by ELF fields.

Read more about ELF: - Wikipedia has an entry about ELF fields. - U.S. Department of Labor's Occupational Safety & Health Administration agency explains current thinking on issues related to ELF fields.

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