Japan i 3 <r>> Thursday, November 18, 1954 POR-TMNEDIATSPREMASE Reports on Japanese researches in diverse fields of radiobiology were received by the international conference at this afternoon's session, and the morning was devoted to discussions of methods of decontaminating foods, water, laboratcry workers and laboratory instruments which have been contaminated with rudioactivity substances. Chairzan for the morning session was Dr, Fumio Yamasaki of the Japanese delegation; for the afternoon, fir. Merrill #Hisenbud of the United States delegation, hr, #isenbud opened the morning session with a report of findings from researches in methods of decontaminating water supplies for human consumption, He called attention particularly to extensive studies by Harvard University in the water supply reservoirs of Boston and Cambridge, Massachusetts, and Rochester, New York, and by Kensselaer Polytechnic Institute in the water supply of Troy, New York. In this case, the studies on the quantities of radioactive substances falling out and the amount of the same substances contained in the water were found to show that, because the natural forces, time and biological processes, quickly decont2aminate the water reservoirs, the amount of radioactive substance in the water supply was far below any level of hazard to human health, For even more rapid artificial decontamination the Atomic Energy Commission has studied various treatments. In experiments at Los Alamos, New l'exica, one process removed 95 percent of the radioactivity introduced into the water supply; at Boston 50 percent was removed by another. This was followed by an explanation of Japanese experiments, in which it was reported that if it is necessary to decontaminate drinking water in the home, considerable decontamination can be attained by using charcoal and sand as a filter. Dr, Tajima reported that, by using this method in the laboratory, 90 percent of the rudioactive substances in the water was found to be removed. Close attention was given to American and Japanese methods of keeping radioactivity away from the surfaces and equipment in radioactive laboratories, Dr. Harley saidthat absolute cleanliness is necessary in order tc make sure that the samples are correctly moasured. Step by step he described the procedures used in American laboratories and gave the names of detergent substances employed in washing solutions. He continually emphasized that accurate measurement was nossible only when all traces of radicactivity from previous work were removed from the laboratory and its equipment daily. Grore) i a MUPTEITICY AS Lt