Radionuclides in soil and water near a low-level disposal site and potential ecological and human health impacts.

Material Disposal Area G is the primary low-level radioactive waste disposal site at Los Alamos National Laboratory, New Mexico, and is adjacent to Pueblo of San Ildefonso lands. Pueblo residents and Los Alamos scientists are concerned about radiological doses resulting from uptake of Area G radionuclides by mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus), then consumption of deer and elk meat by humans. Tissue samples were collected from deer and elk accidentally killed near Area G and were analyzed for 3H, 90Sr, total U, 238Pu, 239,240Pu, 241Am, and 137Cs. These data were used to estimate human doses based on meat consumption of 23 kg y(-1). Human doses were also modeled using RESRAD, and dose rates to deer and elk were estimated with a screening model. Dose estimates to humans from tissue consumption were 2.9 x 10(-3) mSv y(-1) and 1.6 x 10(-3) mSv y(-1) from deer and elk, respectively, and RESRAD dose estimates were of the same order of magnitude. Estimated dose rates to deer and elk were 2.1 x 10(-4) mGy d(-1) and 4.7 x 10(-4) mGy d(-1), respectively. All estimated doses were significantly less than established exposure limits or guidelines.