Strontium-90 in Food and Bone From Fallout1
- C. S. Klusek2
The long-term, continuing study of fallout 90Sr in humans and the environment has provided basic information that is required to assess human exposure from 90Sr from nuclear tests. The current stratospheric inventory of 90Sr is very low and the rate of new input into the environment is exceeded by the rate of decay. However, because of its long physical and biological half-life, 90Sr continues to be one of the most persistent artificial radionuclides that reaches humans through ingestion. Quarterly sampling of 19 representative food items in New York and San Francisco since 1954 provides a record of the changes that occur in the relative contributions of 90Sr by the various food categories, as well as the changes in the total 90Sr intake to the diet in these typical Northern Hemisphere regions. The current intake of 0.18 Bq/d in New York has declined from maximum levels of 1.1 Bq/d in 1963 to 1964. The 90Sr content of San Francisco diets has been consistently lower than the New York level. The retention of dietary intake has been studied through the analysis of bone samples from long-term residents of the same cities. The measured concentration of 90Sr in adult bones in the USA is now 50% less than the peak concentrations of 85 Bq/kg Ca seen in 1965.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .