Ra icta tia aE Ak ale TABLE OF CONTENTS TOXICITY OF RADIOELEMENTS 1 a “3 i8 25 32 38 Ly £43 49 53 Application of Cellulose Nitrate Films for Alpha Autoradiography of Bone ALAN CoLE, D. J. Simmons, HELEN Cummins, F. J. Conan, anp Jacop KaAstTNER The Concentration of Radium, Thorium, and Uranium by Tropical Algae D. N. Eperneton, 8. A.-Gorpon, M. M. THomMes, anp L. A. ALMopOvaAR Separation of Cesium and Rubidium by the Ferrocyanides of Copper, Zine and Zireonium D. N. Epaeineton, M. XI. THOMMES, AND L. I. HARRISON Recovery and Modification of Radiation-Induced Division Delay in Developing Sea Urchin Eggs PATRICIA FAILLA The Retention of Ba in Beagles J. E. Farnuam anp R. E. Rownanp 210Pb and #4°Po in Wood and the Circulation of Lead in Trees R. B. HottzMan anv F. H. Incewicz The Concentration of Lead in Human Bone R. B. Hotrzman, H. F. Lucas, Jr., anp F. H. Ibcewicz Non-Uniformity in the Retention of the Alkaline Earths in Animals and Man ELizABetH LLoyp OO ; Variations in the Surface Area and Volume of Bene in Cross Sections Taken from a Single Human Rib EvizaBETH Luoryp o , Concentrations of Trace Elements in Great Lakes Fishes a H. F. Lucas, Jr., D. N. Epaineron, anp P. J. CotBy 6 Natural Thorium in Human Bone. H. F. Lucas, Jr., D. N. EpGIncton, AND FRANK MArkKUN a9 58 A Model for the Remodeling and Exchange Rate Distributions in Adult Human Bone. Preliminary Report 76 Improved Construction of Radioactive Phantoms with Arbitrary Source Distribution $1 “Time-of-Flight’? Gamma-Ray Camera of Large Dimensions L. D. Marinecu, G. F. CLements, I. K. ABu-SaHumays, ano O. J. STEINGRABER Regularization Unfolding in Low y-Ray Activity Measurements. I. Evaluation for One-Dimensional Scanning ae G. F. CLEMENTE, L. D. MARINELLI, anp I. K. Apu-SHuMays 87 95 “ ~O7 J. H. MARSHALL Haroitp May, L. D. MaRriIne_Lui, anp Paut Hess Regularization Unfolding for Two Dimensions: Progress Report I. K. Asu-SHuMAys Metabolism of"Th Decay Series Radionuclides in Man and Other Animals Following Intravascular Administration of Thorotrast 116 R. M. Parr, H. F. Lucas, JR., anp M. L. Grrem Strain Differences in the Response of the Mouse Skeleton to External Beta Irradiation 120 The Development and Healing of Rickets in Rats. II. Studies with Tritiated Proline D. J. Siumons, R. Hakim, anp HELEN CuMMINS D. J. Simmons anp A. 8. Kunin METEOROLOGICAL STUDIES 130 133 135 142 144 Chicago Air Pollution System Model Experimental Studies J. E, Carson Chicago’s Air Pollution Incident Control Test, Summer 1968 J. E. Carson, R. J. Vorrusa, anp J. W. Lin Chicago Aircraft Sounding Program J. E. Carson anp D. M. NELson Project ITREX—A Cooperative Thunderstorm Tracer Experiment D. F. Gatz City of Chicago Pollution Incidents: Case Studies D. F. Garz anp E,. W. KiarPpenpacu ili