Answer to Question #3391 Submitted to "Ask the Experts"

There is no good explanation as to why you get heart palpitations and why your wife gets headaches when you use the computer monitor. There is nothing in the output from any kind of a computer monitor that has been shown to definitely cause those symptoms in people or otherwise make them sick, although similar complaints are heard occasionally.

One suggestion that seems to have some merit is that cathode ray tube (CRT) type monitors are at least somewhat sensitive to 60 Hz magnetic fields produced by transformers and other devices connected to the power lines or even the power lines themselves. So if you have a CRT-type monitor and there are strong 60 Hz electromagnetic fields where it is located, the 60 Hz fluctuations of light from the display on the screen might cause the problems. A few years ago, when there was more concern about the extremely low frequency (ELF) fields from power lines, some power companies would check the 60 Hz (ELF) fields in homes for people but they may not still do that. If they do not, perhaps you can find some service with proper instrumentation who will. Before doing that, perhaps you should first try moving the monitor and computer to a different location in the house and see if that helps. Or, you can try replacing the CRT monitor with an LCD (liquid crystal display) monitor since it should not be sensitive to the ELF fields.

The observation that the monitor set off the smoke alarm with an ADT (an electronic security system) person as witness is unusual. Some ADT smoke alarms are hard wired into the house wiring so it sounds as if there may have been some type of electrical interference pulse transmitted through the house wiring that caused the alarm to go off but it is impossible to know without further testing with proper instrumentation. There should be nothing emitted by the monitor that would set off the smoke alarm. If it did emit enough smoke or vapors to set off the alarm, because some component got hot, the people around should certainly have smelled it and seen it. Conceivably the monitor might have emitted ionizing radiation that set off the alarm but, considering the design of today's CRT monitors, the alarm would probably have had to be close to the monitor and the display on the monitor probably would have been very bright. Again, further testing with the proper instrumentation would be necessary to determine if the monitor emits any significant ionizing radiation.

A more plausible explanation for your symptoms is that it really is the ergonomics (lighting causing glare, uncomfortable chair causing stress, etc.) that are the problem. They, of course, have nothing to do with the monitor's output or anything it emits. Still, moving the computer and monitor and changing the chair and the set up might help. Finally and perhaps the most important suggestion is for you and your wife to see your doctor(s) and get physical exams to be sure there are no medical explanations for your symptoms. In most cases there is no explanation that can be found, but it is most important to check for medical causes first.

Captain Edward F. Dawson, PhD, Regulatory Operations Officer, Electronic Products Branch/DOEB/OC/CDRH/FDA, US Public Health Service