Answer to Question #3704 Submitted to "Ask the Experts"

I have several small pieces of americium out of smoke alarms and was told by a science teacher that the dose is very low and shouldn't cause any ill effects as long as I didn't mess with it for long periods of time and only occasionally handle it. It is in a steel container inside a steel box. They are small, gold-colored discs about the size of a nail head. should I be concerned about having these?

The first thought that comes to my mind is that it is not a good idea to remove the ²⁴¹Am source from a smoke detector. The construction of smoke detectors is purposefully designed to minimize human contact with the ²⁴¹Am source. With the physical barriers (that is, the metallic chamber and the plastic case) no longer in place, you should exercise care when handling the sources. A number of Web sites provide interesting information on the ²⁴¹Am source used in smoke detectors (including the Oak Ridge Associated Universities site).

The NUREG-1717 report prepared by the Nuclear Regulatory Commission provides an estimate of the radiation dose received both during normal use of smoke detectors, as well as from accidental and misuse scenarios. The estimated annual effective dose to an individual from the presence of two smoke detectors located in a home is 0.001 mrem (quite trivial). NUREG-1717 also calculated the dose to a hypothetical teacher who removed the source from a smoke detector for classroom demonstrations—it was estimated to be less than 0.01 mrem (also trivial).

Finally, NUREG-1717 considered the radiation dose from the inadvertent ingestion of an ²⁴¹Am source from a smoke detector. While the report points out that this scenario is highly unlikely, it does state that ingestion of an ²⁴¹Am source has occurred during the manufacturing process—and that the estimated dose from this event was 600 mrem. While this is not a trivial dose, it is also not likely to result in any observable health effects. Please refer to the Health Physics Society position paper "Radiation Risk in Perspective" for more information on health risks from radiation doses.

In conclusion, one can expect a very minimal radiation dose from the infrequent handling of ²⁴¹Am sources that have been removed from smoke detectors. Nevertheless, one would be advised to take strong precautions to ensure that these sources are not inadvertently ingested.

Eric Abelquist, CHP, PhD