Japan (Continued) G/R.138 Correction to above report. (Corr.1) G/R.139 EXPERIMENTAL STUDIES ON THE DEVELOPMENT OF LEUKEMIAIN MICE WITH FREQUENT ADMINISTRATIONS OF SMALL DOSES OF SOME RADIOACTIVE ISOTOPES (P-32, Sr-89, Ce-144) The development of leukemia is described in three strains of mice in which the disease has not been observed under control conditions. Nine cases of leukemia have been observed among 46 animals surviving 21 weeks and longer following the first of repeated administrations of P* at three dose levels (0.1, 0.3, and 0.5 pc/g). Latent periods varied with total dose administered. Larger doses were more effective than small doses. The leukemias were primarily of the myaloid type. Radiostrontium (Sr*’) and radio-cerium (Ce!) were much less and practically ineffective in producing this disease in these animals. Sarcoma of bone was found in strontium-treated animals. It is concluded that leukemia is the result of severe damage to the haematopoietic tissues in the bone marrow and lymph nodes. There are many tables and figures, including results of radiochemical analyses of various bones at various intervals following injection. G/R.139 Correction to above report. G/R.140 EXPERIMENTAL STUDIES ON COLLOIDAL RADIOACTIVE CHROMIC (Corr.1) PHOSPHATE CrP"*0, Describes morphological observations on the liver of rats which were injected intravenously with various concentrations of colloidal suspensions (particle size 0.1-1.0 micron) of radioactive chromium phosphate (CrP%Q,). Even with high doses (7.5 pc/g) liver injury did not become manifest until 20 days after injection and correspondingly later with lower doses. Changes in the liver are described but not illustrated. They are greater in the liver than in other organs containing reticule-endothelial cells. The lesions are said to resemble those of virus hepatitis. Large doses of chromium phosphate also produce lesions in the bone marrow with concomitant changes in the peripheral blood. G/R.140 Correction to above report. (Corr.1) G/R.141 RADIOLOGICAL DATA IN JAPAN II-CONCENTRATIONS OF STRONTIUM 90, CAESIUM137, Pu-239 AND OTHERS IN VARIOUS MATERIALS ON EARTH’S SURFACE Contains data on concentration of Sr® in rain water, soil, foodstuffs, and human bone in Japan obtained by radiochemical analysis in some cases and by computation from the total beta activity in other cases. Besides Sr®, data on Cs, pu?) Zn Fe® and Cd!!3 are also included. G/R.141 Correction to above report. (Corr.1) G/R.161 A SENSITIVE METHOD FOR DETECTING THE EFFECT OF RADIATION UPON THE HUMAN BODY ‘ Discovery of a new extremely sensitive biological indicator of the ionizing radiation. The acute dose of 50 mr and even less results in changes of the phosphene threshold of the eye. Approximately linear ship between the effect and the logarithmas of the dose from 1 mr to effect of significant relation50 mr is derived. Summation of the effect of repeated exposure is found. G/R.168 AN ENUMERATION OF FUTURE Sr® CONCENTRATION IN FOODS AND BONE Gives amendments and corrections to the report G/R.137 based upon new available data. 184