How many smoke detectors would it require to pose a definite health hazard in an average 3 bedroom home of approximately 2000 sq.ft. and under what conditions? (These being equipped with Americium 241)

Asked by: Richard A. Morse


A reasonable amount of smoke detectors wouldn't pose any more of a risk from the radiation than you would get from natural sources such as radon, or solar radiation.

If you are going to pile each room to the rafters with smoke detectors you would increase the health risk.

One in each room is perfectly safe.

One reason americium 241 is used is because it's a mainly a pure alpha emitter. Alpha particles are low energy and are stopped by a piece of paper or the dead skin layer on your body. The only travel a short distance in air. In addition the source used is very small.

The only way you could increase your health risk is to eat the source.
Answered by: Scott Grasmick, B.A., Health Physicist, Bremerton, WA