![[spacer]](/images/spacerbar.gif){kind=small}
Answer to Question #379 Submitted to "Ask the Experts"Category: Doses and Dose Calculations — Internal dose calculations The following question was answered by an expert in the appropriate field: Q
What is the biological half-life for 54Mn, 58Co, and 60Co? Thanks.
A
The biological half life for cobalt is complex. Half of the material entering the blood stream is assumed to go directly to excretion, 5% goes to the liver and the remaining 45% goes to other tissues where it assumed to be uniformly distributed. Of the cobalt that goes to any tissue fractions 0.6, 0.2, and 0.2 are assumed to be retained with half-lives of 6, 60, and 800 days respectively. The half life for material in the blood stream is 0.5 days.
Manganese: 35% of the material entering the blood stream goes to bone, where it is retained with a half-life of 40 days. Of the remainder, fractions 0.1 and 0.15 go to the liver and are retained with half-lives of 4 and 40 days, respectively, while fractions 0.2 and 0.2 are assumed to become uniformly distributed among other organs and tissues with half-lives of 4 and 40 days, respectively. The biological half-life is independent of the isotope. The effective half-life includes the radioactive decay but this will have little effect on the shorter half-lives given above. Gary Kramer, PhD
Answer posted on August 11, 2000. The information and material posted on this Web site is intended as general reference information only. Specific facts and circumstances may alter the concepts and applications of materials and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice specific to whatever facts and circumstances are presented in any given situation. Answers are correct at the time they are posted on the Web site. Be advised that over time, some requirements could change, new data could be made available, or Internet links could change. For answers that have been posted for several months or longer, please check the current status of the posted information prior to using the responses for specific applications.
|
||||||||||||||||||
