Waste Burial Site, Los Alamos National Laboratory

Small mammals were sampled at two waste burial sites (Sites 1 and 2) at Area G, TA-54, and a control site outside Area G (Site 3) to identify radionuclides that are present within surface and subsurface soils at waste burial sites, to compare the amount of radionuclide uptake by small mammals at waste burial sites to a control site, and to identify the primary mode of contamination to small mammals, either through surface contact or ingestion/inhalation. Three composite samples of at least five animals per sample were collected at each site. Pelts and carcasses of each animal were separated and analyzed independently. Samples were analyzed for americium (Am), strontium (Sr), plutonium (Pu and Pu), total uranium (U), and examined by gamma spectroscopy (including cesium [Cs]). Significantly higher (parametric t-test at p = 0.05) levels of total U, Am, Pu, Pu, and potassium (K) were detected in pelts as compared to the carcasses of small mammals at TA-54. Concentrations of other measured radionuclides in carcasses were nearly equal to or exceeded the mean concentrations in the pelts. Our results show higher concentrations in pelts compared to carcasses which is similar to what has been found at waste burial/contaminated sites outside of Los Alamos National Laboratory. Site 1 had significantly higher (alpha = 0.05, P = 0.0095) total U concentrations in carcasses than Sites 2 and 3. Site 2 had significantly higher (alpha = 0.05, P = 0.0195) Pu concentrations in carcasses than either Site 1 or Site 3.