and a discussion of the efficiency of this method being included. In this discussion a lower limit for the average value of the radon content in the period of 37 x 107!8 curie/cm! is obtained. A diurnal variation in the radon content was found which showed principal and secondary minima, the principal at about 12 to 14 hr N.Z.M.T. and the secondaryat 20 to 21 hr N.Z.M.T. The effect of wind speed on the radioactive content is shown and some indications obtained regarding the influences of wind direction, barometric pressure, and rainfall. From the results, approximate upper limits for the amount of fission product activity present in relation to the amount of natural radioactivity in the atmosphere atthis locality have been obtained. 15. Clayton, C. G. RADIOACTIVE CONTAMINATION OF FOODS FROM FALLOUT AS A SOURCE OF ERROR IN SOME ANIMAL EXPERIMENTS. Nature 179, 829-30 (1957). Radioactivity in control animals since 1956 has increased so as to vitiate experiments. The activity of foods used was measured. The counts are given for rat cubes, milk, peas, sugar, flour, cabbage, carrot, cauliflower, salt, semolina, and water. The high count of the cabbage is probably from Cs!*" present at 4 micromicrocuries per gram. 16. Cockcroft, John. RADIOACTIVE POLLUTION FROM NUCLEAR EXPLOSIONS. Smokeless Air 25, 192-96 (Summer 1955). Because it produces 100 to 1000 times more radioactive material than an atomic bomb, the hydrogen bomb is the most important source of radioactive material. If a hydrogen bomb is exploded on the ground millions of tons of soil, ranging in size from 0.02 in diameter down to 0.001 inches, will be mixed with the radioactive products, the larger particles settling near the scene of the blast, and the remainder dispersing in the stratosphere —above 50,000 feet. In the case of an air burst practically all of the radioactivity will go into the stratosphere and from there be deposited uniformly. The author calculates that the contribution of radioactivity from weapons tests is small, considerably less than the radiation exposure received from natural sources of radioactivity, if the tests continue at the present level. However, in the case of a full-scale hydrogen bomb war, the hemisphere contamination would correspond to a dose of about 25 r which could be damaging to future generations. Operation of nuclear plants for power, although sources of large amounts of radiation, can be controlled to minimize the radiation levels to the population. The major source of such contamination, radioactive wastes, can be handled through separation of the more hazardous strontium and cesium from the bulk of the wastes, storage of the residue for about 10 years followed by controlled release, and utilization of the separated cesium and strontium as by-product materials pending development of more satisfactory methods of handling and disposal. 17. Comar, C. L., Trum, Bernard F., Kuhn, U. S. G., Wasserman, R. H., Nold, M. M., and Schooley, J.C. THYROID RADIOACTIVITY AFTER NUCLEAR WEAPONS TESTS. Science 126, 16-19 (1957). 18. Cronkite, E. P., Bond, V. P., and Dunham, C. L. SOME EFFECTS OF IONIZING RADIATION ON HUMAN BEINGS. STUDY OF ACCIDENTAL DEPOSIT OF RADIOACTIVE MATERIAL ON INHABITED PACIFIC ISLANDS FOLLOWING DETONATION OF THERMONUCLEAR DEVICE. 7:22/TID-5338. 106p. Washington, U. S. Government Printing Office. Catalogue No. Y3.At $1.25. This report concerns the Marshallese and Americans accidentally exposed to radiation from fallout following the explosion of March 1, 1954, and includes a discussion of radiation injury in the human being. Radiation surveys of the areas revealed injurious radiation levels on inhabited atolls and evacuation was ordered immediately. The degree of radiation injury was assessed as quickly as possible, and appropriate care and study of the injured was instituted without delay. The initial data have been supple mented by field surveys 6 and 24 months after the original investigation. The results of this work are summarized. 19. Crosthwait, L.B. WELLINGTON. 382-4 (1955). MEASUREMENT OF ATMOSPHERIC AND RADIOACTIVITY AT New Zealand Journal of Science and Technology, Section B 37, No. 3, 159