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Carbon 14 and nuclear medicine

Question: Why is carbon14 useful in radioactive dating, but not as useful in nuclear medicine?


It is all to do with the emitted radiation and the half-life of the source.

Carbon 14 is a beta emitter with a half-life of 5570 years.

1. Beta particles have a short range in body tissue and so cannot penetrate far.
2. With a half-life of 5570 years if any is injected into your body it will only have decreased in strength by just over 1% during say 100 years of your life. Do you really want to walk around with an increased radioactivity level for that long??

Of course a small fraction of the carbon atoms in your body are carbon 14 so you are already radioactive!! Don't worry the activity level is very low.

© Keith Gibbs 2011