Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Fallout strontium-90 and cesium-137 in northern Alaskan ecosystems during 1959--1970

Thesis/Dissertation ·
DOI:https://doi.org/10.2172/4425152· OSTI ID:4425152
 [1]
  1. Colorado State Univ., Fort Collins, CO (United States)
Cycling routes, rates of transport, and resultant concentrations of the fallout radionuclides 90Sr and 137Cs in northern Alaskan ecosystems were defined during the period 1959 to 1970. Radiochemical analysis of extensive samples of biota and whole-body counting of 137Cs in Eskimo and Indian ethnic groups were related to ecological principles, especially the concept of trophic niche, which elucidated the observed patterns of radionuclide concentrations. Experiments involving Sr and Cs radioisotopes applied to natural Cladonia-- Cetraria lichen carpets yielded effective half-times of 1.O to 1.6 years for Sr and more than 10 years for Cs. Direct and indirect estimates of 131Cs half-times in Eskimos on a caribou meat diet were made by dietary manipulation and by relating dietary 137Cs intake and resultant change between periodic whole body counts. Effective half- times of 70 days for adults (more than 21 years old) and minors (14 to 20 years old) and of 45 days for children (less than 14 years old) were found. Suitable mathematical models were used to compute lichen forage ingestion rates of free- ranging adult caribou (4.5 to 5.0 kg dry weight per day), caribou meat ingestion rates of Anaktuvuk Pass residents (up to 2 kg wet weight per day for men), and 90Sr body burdens of Anaktuvuk Pass residents during the period 1952 to 1968 (maximum value of 8 nCi in adult males during late 1966 to early 1967). Special emphasis was made of cultural influences upon the food-gathering patterns of the native peoples studied. Culture change, especially in the form of food stamps, welfare payments, acquisition of snowmobiles, and improved housing was documented throughout the study and noticeably reduced the radionuclide accumulations. Total radiation dose rates to the Anaktuvuk Pass adult population were estimated to be about 100 mrad/year from natural sources, 60 to 140 mrad/year from 137Cs body burdens, and 20 to 130 mrad/year from 90Sr body burdens.
Research Organization:
Colorado State Univ., Fort Collins, CO (United States)
Sponsoring Organization:
US Atomic Energy Commission (AEC)
NSA Number:
NSA-29-000402
OSTI ID:
4425152
Report Number(s):
COO--2122-12
Country of Publication:
United States
Language:
English