Fluorescent lamps are another source of harmful electromagnetic fields in offices and work environments. Both fluorescent and incandescent lamps are harmful if the ceiling of the room is not enough high. Tall people get the most damage from the ceiling lamps.
The emissions of a fluorescent tube come from both the tube and the additional circuits required by the tube, like the starter and ballast. The latter is a quite strong source of alternating magnetic field at the frequency of the electric network (50 Hz or 60 Hz), because of its internal coil.
Many times we have heard people blaming fluorescent lamps because of the tube flickering, or the color of the light. Even if some people may be sensitive to these aspects, the biggest problem is that of electromagnetic field emitted by the lamp.
The compact fluorescent lamps (CFL) are like small fluorescent tubes curved and curled to enter in a smaller space. In addition the CFL have another electronic circuit that modifies the current inside them to make them brighter, consume less energy and live longer. The savings in energy consumption are a good thing, but unfortunately these circuits emit a lot of electromagnetic fields at many frequency bands, much more than the traditional fluorescent tubes.
The electric vibrations created by these circuits affect also the electric system of the house or office, the same vibrations are passed to the current in the electric wires and so reach every other electric appliances attached to the wall sockets. For example the electric noise of a compact fluorescent lamp passes through the cables and reappears at the computer monitor. However, even without this transmission, the electromagnetic emissions coming from the CFL circuits are harmful enough for everyone who stays in the office for many hours with the lights turned on.