Effective half-life

Effective half-life

Effective half-life denotes the halving of radioactive material in a living organism by means of radioactive decay and biological excretion. A decay constant is needed to calculate the half-life. It is the sum of the biological and physical decay constants, as in the formula:

:{lambda_e} , = {lambda_p} , + {lambda_b} ,

With the decay constant it is possible to calculate the effective half-life using the formula:

:t_{1/2} = frac{ln (2)}{lambda_e}

The biological decay constant is often approximated as it is more difficult to accurately determine than the physical decay constant.

External links

* [http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/biohalf.html Biological Half-life]


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