In The Fffects of Nuclear Weavons, it is noted that: » « «. internal sources of , . . beta particles, or soft (low-energy) gamma~ray emitters can dissipate their entire energy within a small, possibly sensitive, volume of body tissue thus causing considerahle damage." (51 7. 604-5) The implication of the above statement denotes an area ahout which there was much controversy during the discussion about radioactive fallout and its effects in the United States, exposure in terms of averages, e.q., Many scientists described dosage and the maximum permissable concentration (MPC) of strontium 90 allowable in the body of a worker in atomic industries, This is 1000 "Sunshine Units" which is 1000 micromicrocuries (ahbreviated as uuC--one millionth of a millionth of a curie, a small unit of radioactivity) per total weight of calcium in a person's body, 1000 grams of calcium in his bodv, Since the average person has it equals 1 uuC per gram, maximum permissible concentration for the general population working in atomic industry) hovever, (those not is 1/l0th of that, or 100 "Sunshine Units.” There are also other PC's for other radionuclides, does not indicate, The equivalent what this averaging is the fact that strontium, like other isotones, not only selectively concentrates in certain tissues or organs, but that its distribution in these areas is now alvavs uniform, This means that it is possible for a worker to have a total concentration in his tody or an organ of less than, or ecual to the MPC of strontium, but that because it is unevenly denosited, he may have high concentrations or “hot snots where the MPC" of 1 micromicrocurie gram of calcium is exceeded. (or 1/10 of a micromicrocurie) 90 Thus garwa and beta-emitters like Sr’, CS 2.137 and I . 131.. which for each ; selectively *The term MPC since that time has been changed to Recommended Permissible Corcentration (RPC), 101425