United States of America (Continued) G/R.73 MAXIMUM PERMISSIBLE RADIATION EXPOSURES TO MAN A preliminary statement of the U. S. National Committee on Radiation Protection and Measurement. The recommendations given by the Committee in NBS Handbook 59 have been revised and the maximum permissible dose-levels have been lowered. The concept of “accumulated” dose for occupational conditions differs from the ICRP recommendations of 1956. For the whole population an annual additional exposure of 2.5 times the exposure from natural radiation sources is allowed. G/R.74 GONADAL DOSE PRODUCED BY THE MEDICAL USE OF X-RAYS A survey of diagnostic X-ray exposure with an attempt to estimate the genetically significant dose in the United States. The estimate has been made under the assumption that patients undergoing X-ray examinations have a normal child expectancy. The authors have assumed that the genetically significant dose can then be evaluated as approximately equal to the average gonad dosefor patients below the age of 30. Using exposure data which are considered fairly representa tive of American practice they arrive at 130-140 mrem/year and 50 mrem/year as being the most probable and the minimum figure respectively. G/R.75 SUMMARY OF CURRENT AND PROPOSED PROGRAMS OF RESEARCHIN THE U.S.A. RELATED TO RADIATION GENETICS A survey by investigator and title of current and proposed programs of research in the U.S.A. related to radiation genetics. G/R.91 STRONTIUM-90 IN MAN Radiochemical analysis of Sr* in human bone have been reported. The values are in accord with the predicted levels based on fallout measurements and fractionation through the food chains. G/R.93 SUMMARY OF ANALYTICAL RESULTS FROM THE HASL STRONTIUM PROGRAM JULY THROUGH DECEMBER 1956 Summarizes data on samples collected by the U. S. A. fallout network since September 1955 up to September 1956. In addition, it summarizes the data of the samples collected for the strontium program during the period July to December 1956. G/R.94 ENVIRONMENTAL RADON CONCENTRATIONS —AN INTERIM REPORT Preliminary data showing ambient concentrations of radon in the Metropolitan New York area are presented. An attempt has been made to define the variability of concentration of radon in the general atmosphere with location, time, and weather conditions. Samples have been analyzed from the outdoor air, inside of buildings, and above and below the surface of the ground. Comparisons with the data obtained by other investigators are also shown. G/R.95 THE RADIUM CONTENTOF SOIL, WATER, FOOD, AND HUMANS-—-REPORTED VALUES G/R.96 MARINE BIOLOGY -EFFECTS OF RADIATION —A SELECTED BIBLIOGRAPHY 24 references concerning investigation on the distribution and metabolism of fission products in marine organisms. G/R.97 SEA DISPOSAL OPERATION Some atomic energy activities in the United States have been disposing of radioactive wastes at selected ocean disposal sites since as early as 1946. It is the purpose of this report to describe the extent of these disposal operations including a summary of types of packaging used and of places where the wastes are dumped. The status of related oceanographic research (1956) is briefly touched upon. 200 Set asst