Radionuclides in pinon pine (Pinus edulis) nuts from Los Alamos National Laboratory lands and the dose from consumption

One of the dominant tree species growing within and around the eastern port ion of Los Alamos National Laboratory (LANL), Los Alamos, NM, lands is the pinon pine (Pinus edulis). Pinon pine is used for firewood, fence posts, an d building materials and is a source of nuts for food-the seeds are consume d by a wide variety of animals and are also gathered by people in the area and eaten raw or roasted. This study investigated the (1) concentration of H-3, Cs-137, Sr-90, U-tot, Pu-238, Pu-239,Pu-240, and Am-241 in soils (0- t o 12-in. [31 cm] depth underneath the tree), pinon pine shoots (PPS), and p inon pine nuts (PPN) collected from LANL lands and regional background (BG) locations, (2) committed effective dose equivalent (CEDE) from the ingesti on of nuts, and (3) soil to PPS to PPN concentration ratios (CRs). Most rad ionuclides, with the exception of 3H in soils, were not significantly highe r (p < 0.10) in soils, PPS, and PPN collected from LANL as compared to BG l ocations, and concentrations of most radionuclides in PPN from LANL have de creased over time. The maximum net CEDE (the CEDE plus two sigma minus BG) at the most conservative ingestion rate (10 Ib [4.5 kg]) was 0.0018 mrem (0 .018 mu Sv); this is far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem (1000 mu SV). Soil-to-nut CRs for most radionuclides were within the range of default val ues in the literature for common fruits and vegetables.