Further Studies of Long-Term Ecological Effects of Exposure to Uranium.
Abstract
A third year of study of the ecological consequences of exposure of terrestrial ecosystems at the Los Alamos Scientific Laboratory to elevated soil concentrations of natural and depleted uranium was completed. A uranium analytical technique that uses instrumental epithermal neutron activation analysis was developed and tested. It provided more accurate and expeditious results for soil and biota samples that contain greater than 10-ng total uranium than did our other two techniques. Spatial variability in sampling for soil uranium distribution by a polar coordinate system was evaluated in randomly selected soil cores. Variations for surface (0- to 2.5-cm-deep) soils were 0.18 at 10 m from the detonation point and 0.96 at 50 m. Results were strongly influenced by past uranium dispersal patterns, variable leaching of uranium debris, and surface water runoff. A total surface (0- to 5-cm) soil uranium inventory within a 12.6-ha circle centered on the E-F detonation point was estimated to be 3000 kg when calculated by soil uranium concentration isopleths and 4500 kg when using annuli of a polar coordinate sampling system. Uranium concentrations in tissues of deer mice (Peromyscus maniculatus) and pocket gophers (Thomomys bottae) were sufficiently different to conclude that the greater bioavailability of uranium in the top few millimeters of soil at E-F Site, combined with the difference in grooming and food habits of the animals, resulted in greater contamination of deer mice than of pocket gophers. Invertebrate populations inhabiting areas of high and medium soil uranium concentrations at LASL sites were sampled by pitfall trapping and insect net sweeps.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1978
- Accession Number
- ADA060487
Entities
People
- Felix R. Miera Jr
- Wayne C. Hanson
Organizations
- Los Alamos National Laboratory