I think it's measured in milligauss
Gauss (unit) - Wikipedia, the free encyclopedia
Ambient emr that is.
And no lol. It's perfectly safe. The earth emits a constant amount of emr on the magnitude of several thousand times more than most home appliances (although it's more prevalent near fault lines and is largely dilute). Research from NASA indicates that without the natural EMR on earth we often have trouble with equilibrium and may experience nausea. Thus, astronauts are equipped with strong magnets when they go to space.
Anyways. No I don't think you are in any danger. Using a cell phone is probably more likely to give you cancer than a spinning magnet. Remember ALL electric motors work on the same principle of inverting magnetic fields. A toy car or electric fan probably emits the same amount of EMR.
From the wiki article:
One thing you should explain to your mother is that there are many frequencies of electromagnetic radiation.
They span from low frequency infrared to UV
to X-Ray to Gamma. Two of them are carcinogenic. Gamma radiation will not hurt you. It will go right through you and cook you if in high enough doses. The term "radiation" is tossed around too lightly. Any type of dispersed energy that doesn't require a physical medium to travel in can be called radiation.
The "radio-active" radiation people talk about is really free neutrons and protons. That is what comes from nuclear reactors. As heavy material decays it sends off neutrons and protons and when they collide with our cells, to put things simply, mess them up at the molecular level.
Energy =/= radio-active particles.
The frequencies at which most our appliances operate are not dangerous. Suffice to say it is pretty well proven that super-high doses of certain radio frequencies aren't good for you...But considering that many of us have probably spent a good while next to an electric fan (which operates on the same principle as the motor in the filter) you are in no danger of radiation poisoning. Finally, about hairloss. Ask your doctor about it. It could be something else.