Whereas the greatest risk from internally deposited transuranic elements has classically involved the Iung, liver, and bone (Thompson et al., 1972,) deposition of Pu and other actinides in mammalian gonads has been documented. Richmond and Thomas (1975) in their review reported the fraction of administered burden of Pu for rats and mice gonads to range from 4.3 x 107-5 to 9.8 x 107%. These values are comparable to values reported for soft tissues other than lung, liver, and bone when differences in sex, mode of introduction, and form of the elements administered are considered. Smith et al. (1976) reported comparable levels of Pu in male and female gonads when 237py and 233pyu citrate were injected interperitoneally. Because testes are heavier than ovaries, ovaries had a greater Pu burden than testes on a weight basis. Excretion rate in females was also higher than males by a factor of 2.7 within the first 24 hours post-injection, The uptake of Pu by the placenta and fetus has been demonstrated (Finkel, 1947; Sikov and Mahlum, 1968; Moskalev et al., 1969; Ovcharenko, 1972). The percentage of stillborn litters, as well as the number of stiliborn young in viable litters, increased following intravenous administration of 0.016 pCi/g Pu (Finkel, 1947). In addition, a lower incidence of conception was seen. These findings are supported by the work of Sikov and Mahlum (1968). Ovarian damage in mice has been reported with large doses of 30 wCi/kg Pu (Bloom, 1948). Testes mass was reduced 58% 18 weeks after an intravenous injection of 10 uCi/kg 739Pu citrate (Beechey et al., 1975). This reduction was attributed to germ cell death corresponding to a 51% reduction in epididymal sperm count. In addition, the authors reported a 5% increase in spermhead abnormalities. Green et al. (1975, 1976} reported nonhomogenous distribution of Pu in testes of mice, Plutonium was concentrated in the interstitial tissues outside the seminiferous tubules resulting in an increased dose to stem cells when compared to the average dose calculated for whole testes. These data indicate a high potential risk to genetic material which may result in depression of spermatogenesis, ovarian damage, and reduced fecundity. FIELD STUDIES The dynamics of transuranic elements in natural environments have been reviewed by Romney and Davis (1972), Price (1973), and Bennett (1974) and was the subject of two major recent symposia (Hanford, 1972; and IAEA Symposium in San Francisco, 1972). Romey et at. (1970) collected small animals over a tenyear pertod from contaminated sites at NTS. Tissue samples from Kangaroo rats (Dipodomys merrtami and D. miecrops) were polled to provide sufficient material for plutonium analysis. Their results were reported in DPM per sample; hence, intertissue comparisons are difficult, and their work cannot be directly compared to later investigations. They concluded that the relatively high levels of Pu found in the GI tract, which was probably due to ingestion of soil particles, indicated an additional pathway of uptake besides inhalation. | The importance of ingestion as a primary route of entry of residual Pu was further emphasized by Romney and Davis (1972). Paglia (1968) reported on hematopathologic surveys of Kangaroo rats in Pu contaminated and uncontaminated study areas of NTS. Blood cell depressions were noted in rats from some 390 to be determined. contaminated areas, but a physiological significance remains showed the Kangaroo rats from areas of highest Pu contamination (720 mg/m?) Hakonson and highest Pu body burdens and greatest blood cell depressions. the event after Johnson (1973) in their survey of the Trinity Site 2? years Concentration tissues. found considerable variability in levels of Pu in rodent tissues and was of Pu in rodent lungs was generally higher than for other distance from similar for that determined for soils and grass in relation to ions in the ground zero. They concluded that the relatively high concentrat biological lungs suggest resuspension as the most important mechanism in In a similar investigation in liquid waste redistribution of plutonium. for plutonium disposal areas of LASL, Hakonson ef al. (1973) collected rodents one sample station analysis. Plutonium concentrations in animal tissues at and pelt samples had as much as three orders of magnitude variation, with lung they suggested having highest mean Pu concentrations. Based on these data, In by animals. that resuspension of sedimentation was main route of Pu uptake concentraaddition, a rather low discrimination rate was reported. Plutonium ion of hide tions of liver and carcass were from 107! to 10-2 the concentrat hispidis) in and lungs. McClendon et al. (1975) sampled cotton rats (Sigmodon Based on the vicinity of the Savannah River Plant, Aiken, South Carolina. Pu in soil and 8 adult rat samples, concentation ratios of Pu in animals to levels of plutonium vegetation were from 10-2 to 10-!, respectively. Similar noted that, in general, were found in juvenile and immature rats. Little (1976) agreed with earlier data from rodents collected at the Rocky Flats facility . The small mammal 3 ecological investigations with two noteworthy exceptions ion level (10 internal and extemal tissues were at about the same contaminat He of magnitude. nCi/g dry), and bone tissue was the lowest by 1-2 orders to soil Pu, although suggested that contamination of small mammais was related mammal tissue and soil clear relationships between Pu concentrations in small or He concluded that a biologically available Pu compound were not clear. and external particle size distribution accounted for the similar internal inhalation Plutonium uptake was attributed to a combination of tissue burdens. y in tissue burdens. and ingestion. The result was a high degree of variabilit and Bradley, 1974; Moor Plutonium concentrations in small mammals of NTS (Moor those from other research et al., 1976) reflect somewhat different results than particularly Littie sites. Whereas data from Hakonson and Johnson (1973) and and external tissues (1976) indicate that contamination levels of internal NTS were from were similar, internal tissue (carcasses) of small mammals from In addition, one to three orders of magnitude lower than external tissues. and vegetasoil in Pu concentration factors, or the ratio of Pu in tissue to Residual Pu contamination tion, were from one to two orders of magnitude lower. higher than at the NTS area, however, was from one to two erders of magnitude or Trinity Sites (Tables Rocky Flats and five to six higher than Savannah River 1 and 2). NTS: In way of summarizing the results of our study in Area 11-C, 1. burdens, Pu and Whereas there is a high degree of variability in tissue Pu levels of Am levels in small mammals appear to be related to residual Tissue burdens of small mammals from a High Activity soil and vegetation. a Low Activity study plot were significantly higher (P<.01) than from study plot (Table 2). 391