[thedoc (OP)]

Nuclear fallout from Cold War nuclear tests could help to identify poached ivory...

Read the whole story on our website by clicking here

 [chapter podcast=1000417 track=13.07.04/Naked_Scientists_Show_13.07.04_1000986.mp3] or Listen to the Story[/chapter] or [download as MP3]

[CliffordK]

Would the age of the animal also be a factor?  So, for example, a 70 year old animal would have formed at least part of the tusks before the end of WWII. 

[chris]

Interesting point! I've written to Mark to alert him to this; let's see what he says...

[alancalverd]

Intriguing story. You could presumably get a second handle on the date from strontium 90, which did not appear in the atmosphere at all before 1945, and has decreased since the end of atmospheric nuclear tests in the 1960's.

[chris]

Mark, the author of the news story, ran into difficulties with the forum anti-spam system, so he sent me this in reply to Clifford's comment:

As per the story >>This allowed them date any tissues formed after 1955 to within a year or so ...

So they only got accurate ages on tissue formed after that year. Here's how they do that (from the paper) >> “Maximum accuracy with respect to the known
age is achieved by using tissues that undergo little or no turnover. Samples collected from the proximal, or most recently formed, portion of the tissue can
be used to determine date of collection, which is often, but not always, death.”

cheers
mark

[CliffordK]

Thanks Chris,

So, if one recovered a whole tusk, one could date the end closest to the skull, and get a good estimate of when the animal died.

But, for example, I have some ivory beads, and Mom has an ivory chess set that was given to her as a gift. 

So, if I tried to sell the chess set, or necklace, one would want to determine that they were manufactured before the international ban on importing ivory (of course, non destructive methods of analysis would be good).  But, already in manufactured form, I would think it would be difficult to determine where in the tusk they were located.