monitor case is a 1000-microfarad capacitor, which holds more than enough electricity to
seriously harm you or worse, even when the monitor is off and unplugged.
Another safety ti pthat could save your life is that if you ignore these warnings and
insist on opening the monitor case to work on it, absolutely donotwear an ESD wrist
strap. If you do, you will become the grounding circuit for all of that stored electricity.Environmental Issues
There are two primary environmental issues involving PC monitors, specifically CRT
monitors.ThefirstissueisradiationemissionsandtheotherisdisposingofaCRTproperly.Electromagnetic Emissions
There is no debate as to whether a CRT emits small amounts of electromagnetic radiation
in what are called the Very Low Frequency (VLF) and Extremely Low Frequency (ELF)
ranges. The debate concerns whether this radiation is harmful.
Most VLF and ELF radiation, which is not a lethal variety like an X-ray or gamma ray,
is emitted from the back and sides of the monitor and through the screen. This radiation
does not carry far and is virtually nonexistent only a few feet from the monitor. The
general rule of thumb is that users sit an arm’s length from the monitor’s screen to protect
their eyes. If you impose this limit on the back and sides, everyone should be safe.
Noneoftheresearchperformedtodatehasfoundanyrealdanger,althoughmanyex-
perts believe there is still some danger, in being exposed to these radiations for extended
periods. The belief is that extended exposure at close range may increase a user’s risk for
cancer, leukemia, or abnormal pregnancies, miscarriages, or birth defects. The Swedish
government through its TCO environmental standards organization has instituted very
tough CRT emission standards, first in its MPR-II standards and with its latest series of
standards—TCO ‘92, TCO ‘95, and TCO ‘99. Although many manufacturers believe these
standards to be overly strict, they have complied. If you wish to buy a monitor that meets
the TCO standards, expect to pay a bit more for it. For more information on the TCO
personal computer standards, visitwww.tco-info.com.(^400) PC Hardware: A Beginner’s Guide