Banana equivalent dose

One BED is often correlated to 10−7 sievert (0.1 μSv); however, in practice, this dose is not cumulative, as the potassium in foods is excreted in urine to maintain homeostasis.

The origins of the concept are uncertain, but one early mention can be found on the RadSafe nuclear safety mailing list in 1995, where Gary Mansfield of the Lawrence Livermore National Laboratory mentions that he has found the "banana equivalent dose" to be "very useful in attempting to explain infinitesimal doses (and corresponding infinitesimal risks) to members of the public".

[a][5] Plants naturally contain radioactive carbon-14 (14C), but in a banana containing 15 grams of carbon this would give off only about 3 to 5 low-energy beta rays per second.

According to the US Environmental Protection Agency (EPA), isotopically pure potassium-40 will give a committed dose equivalent of 5.02 nSv over 50 years per becquerel ingested by an average adult.

[2][11] It follows that the additional radiation exposure due to eating a banana lasts only for a few hours after ingestion, i.e. the time it takes for the normal potassium content of the body to be restored by the kidneys.

[20][21] The process of drying and then smoking the solid matter concentrates those radionuclides further, creating in essence technologically enhanced naturally occurring radioactive material.