There are labs that will evaluate dust, bacteria and mold spore samples.

Yes, tree rings can store information about nuclear tests. This is not my field of expertise, but I do know that wood ash is slightly radioactive due to naturally occurring isotopes. Coal ash is also slightly radioactive.

Forrest M. Mims III

There’s another question that has troubled me for a number of years, which I hope you can shed some light on:

Are trees that were alive during the time of atmospheric nuclear testing repositories for this form of radiation? And is there radioactivity present in the ashes of the wood when the tree is burned? We did a story on this for Pulse of the Planet in 1992 with a scientist named Stewart Farber, but I’ve never heard anything else about this matter. It this something that you’ve investigated?

Cheers;
Jim Metzner

The story is titled “Just ash with rain? Not so fast” and it opens with:

“The strange stuff that fell Tuesday, griming up windows and lining the pockets of carwash owners, has had the additional effect of setting up a sort of meteorological whodunit.

“Just what, some scientific sleuths want to know, commingled with the rain as it fell onto vehicles from San Antonio to Corpus Christi, from Austin to Houston?”

The story goes on to quote various weather people and includes this comment I gave them:

“Forrest Mims III, a science consultant and a freelance columnist for the Express-News, took a sample of the stuff from his window and put it under the microscope, forwarding some of his findings to TCEQ.

“‘There’s one black spore and there are three possible soot particles and everything else is dirt, dust, sand. I would say that it’s probably less than 1 percent smoke, and that’s being generous,’ he said.”

All in an all a rather intriguing story.

Forrest M. Mims III