12. National Academy of Sciences/National Research Council, 1972. “The ROOT UPTAKE OF TRANSURANIC ELEMENTS Effects on Populations of Exposure to Low-Levels of Ionizing Radiation." Report of the Advisory Committee on the Blological Effects of Ionizing Radiations (BEIR). p. 12. 13, 14. Oakes, T. W., and K. BE. Shank. 1977. "Subsurface Investigation of Energy Systems Research Laboratory Site at the Oak Ridge National Laboratory." ORNL-TM-5695 (in press). Romney» E. M., A. Wallace, R. CG. Gilbert, and Jean E. Kinnear. 1976. "233 240py and 241am Contamination of Vegetation in Aged Fallout Areas." In: 491. 15. R. K. Schulz Department of Soils and Plant Nutrition University of California, Berkeley Transurantum Nuclides in the Environment. IAEA-SM-199. Schulz, R. K., G. A. Tompkins, and K. L. Babcock. Plutonium and Americium by Plants From Soils." tn the Enutromment. IAEA-SM-199. pp. 303-310, In: 1976. pp. 479- 16. Union Carbide Corporation--Nuclear Division. 1975. “Environmental Monitoring Report, USERDA Oak Ridge Facilities, 1974." UCC-ND-302. 17. Union Carbide Corporation--Nuclear Division. 18. United States Environmental Protection Agency, Office of Radiation Programs. 1975. Draft Environmental Statement for a Proposed Rule-making Action: Environmental Protection Requirements for Normal Operations of Activities in the Uranium Fuel Cycle. p. v. Also Published in Federal Register Vol. 40, No. 104, p. 23424. Subpart B. (190,10 (a) Standards for Normal 1976, ABSTRACT “Uptake of Transurantwn Nucltdes “Environmental Monitoring Report, USERDA Oak Ridge Facilities, 1975." Y¥/UB-4. The uptake of elements by plant roots is one of the important pathways of entry of many elements into the food chain of man. Data are cited showing plutonium concentration ratios, plant/soil, ranging from 10-10 to 10-3, Concentration ratios for americium range from 10-7? to 10+1. Limited experiments with curium and neptunium indicate that root uptake of curium 1s similar to that of americium and that plant uptake of neptunium is substantially Operations). larger than that of curium and americium. The extreme ranges of concentration ratios cited for plutonium and americium are due to a number of causes. Experimental conditions such as very intensive cropping will lead to abnormally high concentration ratios. In some experiments, addition of chelating agents markedly increased plant root uptake of transuranic elements. Particle size and composition of the source material influenced uptake of the transuranics by plants. Translo~ cation within the plant, and soil factors such as pH and organic matter content, all effect concentration ratios. . INTRODUCTION The purpose of this paper is to discuss the magnitude of (and some factors determining) plant root uptake of several transuranic elements. To date, a number of reviews have appeared in the literature on this subject. These reviews include those of Bernhardt and Eadie (1976); Brown (1976); Dahlman et al. (1976); Francis (1973); Price (1973). Since a number of reviews exist, and three of them are as recent as 1976, it is felt that it would be a duplication of effort to make an in-depth review of the published literature. Rather, this shall be an examination of some factors affecting plant uptake of transuranics along with a look at recent information on this subject. 321 320