In The Fffects of Nuclear Wearvons, it is noted that: tk . . . internal sources of . .. beta particles, or soft (low-enercy) gamma-ray emitters can dissinate their entire energy within a small, possibly sensitive, volume of body tissue thus causing considerable damage." (51 np. 604-5) The implication of the above statement denotes an area about which there was much controversy during the discussion about radioactive fallout and its effects in the United States. Many scientists described dosage and exposure in terms of averages, e.q., 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 (abbreviated as uuC--one millionth of a millionth of a curie, a small unit of radioactivity) per total weight of calcium ina person's body. Since the average person has 1000 grams of calcium in his body, it equals 1 uu per gram, The equivalent Maximum permissible concentration for the general population (those not working in atomic industry) is 1/l0th of that, or 100 “Sunshine Units." There are also other MPC's for other radionuclides. does not indicate, hovever, What this averaging is the fact that strontium, like other isotones not only sclectively concentrates in certain tissues or organs, its distribution in these areas is now always uniform, but that This means that it is possible for a worker to have a total concentration in his hody or an ordan of less than, or equal to the MPC of strontium, hut that because it is unevenly deposited, he may have high concentrations or “hot spots" where the “APC” of Ll micromicrocurie (or 1/10 of a micromicrocurie) for each gram of calcium is exceeded, Thus gamma and heta-emitters like er, cst37 ana 1 131 . . whjch selectively *The term MPC since that time has been changed to Recommended Permissible Concentration (RPC), 2] Cg 0285