Originally Posted by Jake Longhorn
... Most people including regulators are very uneducated* about smoke detectors. Household ionizing smoke detectors contain radioactive Americium-241...
Greetings and welcome aboard the CF, Jake.
* Indeed - and bananas kill!
Ionization chamber smoke detectors do contain a very small amount of Americium-241 [source of alpha particles], which does expose people to about 1/100 of a millirem of radiation per year.
This is well below the natural background radiation level of about 360 millirems a year.
The U.S. National Council on Radiation Protection & Measurements estimates that household smoke detector use causes a radiation dose of 9-50 nSv (nanosievert) per year.
To put this in perspective, the dose received from eating a banana is about 100 nSv, the dose of a typical person in the U.S. from natural and manmade background sources is about 3.6 mSv per year, and a lethal full-body dose is about 5 Sv.