Unstable Elements

recovered from old email

09/07/2001

Does radon come only from uranium? Shouldn't some come from thorium, which is more abundant than uranium? What isotopes of radon would be expected to seep up out of the ground? What are their decay products? Just in case you don't know all of this off hand, can you suggest a reference? - Jim N.

Somewhere I have a book that shows all the decay sequences of all the isotopes. It may be a government publication.

More of the radon found in people's house comes from the thorium decay sequence. Radon is the only one that is a hazard because it is the only gas. Thorium is around because it has chemistry similar to the stuff in clay. True clay however is not very permeable so it is less of a problem. In Houston there is much blue clay but it is not at the surface. So it is moist and mostly impermeable. The greatest problems come from clay and sand mixtures or shale, which is partially consolidated sediment. Shale is the problem is Western Pennsylvania where I used to live.

The most unstable element I have dealt with was a wife. - the pup