fgr is interesting and gives some insight into how this bureaucratic world functions a couple of things i noted the table of p shows a good dozen elements including ca where the values changes by well over and order of magnitude from on model to the next the following summary on p says for about of radionuclides the differences are not substantial ie less than a factor of four that points out that none of these figures are derived from actual physical measurements but from computer models also there is no qualification on the uncertainty of these values as one would expect if it was a scientific test which it is not it's a model the magnitude of the changes and that fact that a factor of is seen as not substantial gives an idea of how reliable the number may or may not be i don't know what the exchange rate for k is but it is prsesent in signif icant amounts in the urine at concentrations that vary comparatively widely this would suggest i suppose that the body regulates k very closely disposingof excess amounts very rapidly perhaps someone should do a study by feeding reference bananas to his dots i have found this banana equivalent dose very useful in attempting to explain infinitesmal doses and corresponding infinitesmal risks to members of the public interestingly the anti nukes just hate this and severely critisize us for using such a deceptive concept would love to go into more detail but have to get back to our deadly human radiation experiments i e eating bananas considering the fact that the doe has officially stated that there is no safe dose of radiation my advice to you all is to stop eating immediately disclaimer neither lawrence livermore national laboratory the university of california nor the department of energy recommends eating bananas so it seems the advocates of this bed idea do regard it as a bit of an insider joke and take joy in using it to be provocative but if the k in a banana is times more potent than that already in muscle tissue there is still a substantial problem somewhere at least this is getting closer to understanding where it comes from and how it is calculated