Answer to Question #410 Submitted to "Ask the Experts"

What are some items in a common household that over time may cause radiation poisoning (for example, microwaves, T.V.s, monitors)? Is there a hazard or is it so small that we should not be concerned with it?

Thanks.

There are a number of common items found in a typical household, or owned or possessed by a member of the public, that contain small amounts of radioactive material. These include, for example, (1) topaz gemstones that have been irradiated in a reactor to improve their appearance, (2) timepieces containing tritium, (3) smoke detectors containing ²⁴¹Am, (4) glass lenses in eyeglasses or sunglasses containing uranium and thorium, (5) thorium mantles used in gas lanterns, (6) magnetrons containing thorium used in microwave ovens, (7) electric lamps containing thorium in the filament, and (8) television faceplates and automotive glass containing thorium. Other consumer products were used in the past but are no longer marketed extensively. These include, for example, (1) electron tubes containing various radionuclides, (2) dental products containing uranium, (3) germicidal lamps and sunlamps containing thorium, and (4) glazed ceramic tableware and glassware containing uranium.

The U.S. Nuclear Regulatory Commission allows the use of these (and many other) items containing small amounts of radioactive material based on analyses which show that the radiation hazards to the public are very small and that the benefits of allowed uses of the items far outweigh the hazards. For further information, the interested reader is referred to Report No. 95 of the National Council on Radiation Protection and Measurements (NCRP), titled Radiation Exposure of the U.S. Population from Consumer Products and Miscellaneous Sources.

David Kocher

Editor's Note: NCRP Reports may be ordered from the NCRP Web site.