While there has been much discussion over the last 25 or so years about the validity of the theory of electromagnetic frequency (emf) and possible health risks with regard to waterbed heaters, the jury is still out. It has been established in the scientific community that there is a definite existence of emf, but it varies widely in intensity from appliances to wiring to just about every electronic product used today. Associated health risks have never been proven.
What are electromagnetic fields?
Electrical currents are what causes electromagnetic fields. Common household current is alternating current (AC), which reverses its direction (its charge) then switches back. A complete cycle per second is one hertz (Hz). For example, if your waterbed heater operates at 60 Hz, then its current changes direction 60 times per second. This cycle creates electric and magnetic fields at the same frequency. The fields created by power lines that distribute power throughout the country are power frequency fields. These currents are nearly everywhere we live. It exists in cars, trains, elevators, massage chairs, tv's and video terminals, just to name a few. Emf is ubiquitous throughout our society.
Most waterbed heaters manufactured today are low emf, or emf reduced, thus minimizing exposure. For those who wish to exercise extra caution, a timer can be used to run the heater when waterbeds are not in use. This we will recommend during pregnancies just to remain on the safe side. A waterbed mattress will usually not require heat in the summer months or warm climates for many of us, though some will disagree. Again, this issue is only theory. Generally, scientists on both sides say they are dealing at most with rare diseases and an increased risk that is almost infinitesimal, especially compared with life's other everyday risks.
No scientific data support definitive answers to questions about the existence or nonexistence of health risks related to wood frame waterbed heaters or softside waterbed heaters and electromagnetic fields. More research to produce more reliable information is needed before any conclusions can be drawn.