In the contributed papers session, Wong, Noshkin, and Jokela of Lawrence Livermore Laboratory demonstrated that data obtained through use of the MICE samples (Mn O, Impregnated Cartridge Extraction) can be compared in certain respects with a radiochemical coprecipitation method for the radiochemical separation of transuranic elements. The sampler was developed by Wong to preconcentrate in the field (Enewetak) low-level plutonium and other radionuclides from fresh and salt waters, with subsequent plutonium analysis of the Mn O» cartridges, A schematic for the collection of water samples is included in their report. Alpha autoradiography accomplished by Buddemeier, Bierman, and Gatrousis, Lawrence Livermore Laboratory, with Kodak LR~115, Type II cellulose nitrate alpha track detection film was studied to determine usefulness of the film in environmental plutonium soil sample analysis. Results indicated that alpha track detectors could be useful in analysis of amounts and distributions of activity in small samples such as aerosol filters, specific soil or sediment size fractions, and certain biological subsamples; for screening samples for limitation of numbers of radiochemical analyses; and for research into the statistical basis for environmental sampling design. White of Los Alamos Scientific Laboratory discussed the statistical estimation of expected values of environmental pollutants with lognormal and gamma distributions. Tests conducted indicated that the arithmetic mean provides an unbiased estimate of expected value, and that the achieved coverage of the confidence interval is greater than 75 percent for coefficients of variation less than two. Using barley plants, Wallace, Mueller, and Romney of UCLA investigated whether varying americium-241 concentrations in yolo loam soil would cause variance in the uptake and concentration in the plant, and what effect the addition of chelate would have on any such variance. Results indicated that 24/Am in plants was directly proportional to that in soil at all concentrations with DTPA. The uptake of americium from soil decreased slightly (about three times) without DTPA as the soil concentration of 741am was increased tenfold. G.I. absorption of actinide elements is greater in fasted animals than in those on regular diets, according to Weiss and Walburg of the Comparative Animal Research Laboratory, University of Tennessee. Cerium-144 (L1II) chloride was given to fasted and nonfasting mice in efforts to evaluate differences reported in animal experiments measuring G.I. absorption. Weiss and Walburg recommend that better absorption data would be obtained using animals on regular feed and a more normal gut transit time for absorption and complexing of most heavy metallic elements. Bernhardt, Bliss, and Eadie, EPA (Office of Radiation Programs), Las Vegas, reported on results of EPA samples taken in a project conducted by Rockwell International; Colorado Department of Health; Jefferson County (Colo.) Department of Health; and the EPA. The samples were 746

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