The National Radiation Protection Committee recommends permissible concentration of radium water for continuous use microcuries per cubic centimeter. This is equivalent to x per milliliter or curies per gram. Approximately the same v ured in curies per gram would apply to the total quantity of sumed. Thus, it is indicated from these studies that tap wa common foods used in the United States appear to be well wit the permissible limits for radium. Radiation Effects on Tobacco and Potato Plants. (UNCLASSIFIED) A species of tobacco was planted this year in the gamma field at Brookhaven National Laboratory. Resuits show that irradiatiog produced a moderately high rate of spontaneous tumors. In the ganma f3eld, the tumor-induction rate at fairly high dosage rates (300 r/day) Was greatly of a tumors have been recognized in animals for many years. Experiments on the effect of radiation on the "keeping" of potatoes were completed by Brookhaven National Laboratory A quantity of potatoes was secured and divided into five lots, which were given various radiation doses and the fifth kept greding procedures. At the final test period on August 15, t lot was essentially spoiled, whereas those that had been expos 20,000 r were still Grade A potatoes in all respects. Potatoe to about 50,000 r might be classed as Grade B potatoes, and th exposed at 80,000 r were also Grade E potatoes. What apparent is that, in late spring, potatoes tend to sprout and these sp release an enzyme responsible for the breakdown of the starch. are inhibited by relatively small doses of radiation, and cons the starch is not broken down. At the higher doses, apparenti is enough cellular destruction to cause a general breakdown ov period of time. Whether these explanations are correct or noth debatable, but there seems to be little doubt now that this is phenomenon, Since it was observed last year quite accidentally f nection with some other work, and the experiment this yeer was specifically to prove this point. typing of Blood Platelets. (UNCLASSIFIED) Discovery of g types for blood platelets was announced recently by the New England _ Medical Center at Boston, Massachusetts. Platelets are colcriebs, diskShaved bedies found in the blood of humans and all other mammalfb. They