No abstract

Data were obtained from the literature for gonad and body weights and for the Pu or Ce content of the gonads and body at death for several laboratory animal species, five human Pu injection cases, and 731 human adults exposed environmentally to Pu in fallout. Data for Pu concentration in gonads, liver, and bone samples of 59 male and five female occupational Pu cases (including four completely analyzed whole bodies) were obtained from the U.S. Transuranium Registry. A logarithmic function was used to relate fractional Pu or Ce concentration in testes and ovaries to body weight of the animals and to predict fractional Pu or Ce concentrations in human gonads, [Pu]G . PuB-1 = aBWb, where [Pu]G or [Ce]G is the nuclide concentration in gonads (Bq g-1 of wet weight), PuB or CeB is the nuclide content of the body at death, and BW is body weight (kg). The fractional Pu and Ce concentrations in both the testes and ovaries are inverse and nearly linear functions of body weight. The regression lines of fractional Pu or Ce concentration in testes and ovaries have similar slopes (b = -1.07 +/- 0.14); however, the nuclide concentrations (coefficient a) in ovaries are six times greater than in testes. Extrapolation of the animal data yielded fractional Pu concentrations in human testes and ovaries that agree with those calculated for the occupational cases and those recommended by the International Commission on Radiological Protection. The good agreement between the fractional concentrations of Pu and Ce in the testes and in the ovaries suggests that these data can be substituted in metabolic models of chemically similar elements for which gonadal data are scarce.

Since 1959, selected tissues from deceased humans have been examined for the presence of plutonium. The original purpose was to correlate plutonium body burden calculated from urine assay and actual burden determined by analysis of autopsy materials. The tissues have provided data on plutonium deposition in man resulting from general distribution of plutonium in the environment through global fallout and that resulting from plutonium fabrication or research and development operations.Lung, liver, kidney, lymph, and skeletal tissue are the principal materials examined. The analytical data, the significance of the findings, and the considerable uncertainties in the radiochemical analysis and calculations are discussed. The data will be completely evaluated in other Los Alamos Scientific Laboratory reports.The results are contained in the appendixes to this report. Median concentrations in the organs and tissues of a general population (not occupationally exposed) were (each number represents dis/min Pu per kg): liver,1.4; lung, 0.8; lymph nodes, 3.0; bone, 0.6; and kidney, 0.6. Plutonium concentration is generally higher in the tissues of those who have been occupationally exposed to plutonium; the concentration obviously depends upon the nature of the exposure and its severity am' lunation.

A review of the literature was carried out to investigate the following: the fraction of Pu in the body that was in the gonads; the necessity for a localization factor in calculating the genetic dose to humans; and the possibility that an unexpectedly high relative biological effectiveness (RBE) causing genetic effects could occur for alpha particles. Human autopsy data from both occupationally exposed persons and the public were relied on to determine the amount of Pu in the gonads. It was found that an average fraction of 3 X 10(-3) of the Pu in the body was in the ovaries and testes but there was a wide variation among individuals. While a localization factor over the average of 2.5-4 is needed to calculate the dose to the sensitive cells for rodents, no such factor is required for the human. Information on the RBE for various genetic effects shows RBEs for Pu alpha's about as would be expected from neutron irradiation. The usual quality factor applied in calculating dose equivalent is appropriate and may be conservative, particularly for females.