Radsafers,
What has been said before by so many others is correct. The peak fallout did occur in 1963-1964 and therefore will make much more of an impact on teeth than the '50s fallout. Yes, there are other environmental measurements which will allow one to consider the amount of Sr-90 in the environment.
But, to get my own two cents worth in, I want to add the following. The peak fallout in the early 60s was not also higher in airborne concentrations but it was also higher in total deposition. And because these 100 megaton bombs put a lot of radionuclides into the stratosphere, it continued to wash out year after year for at least a decade. Just check the Battelle BARC (Battelle Airborne Radionuclide Concentrations) report for a long history of airborne concentrations for things like C-14, Pu-238/239 etc, Cs-137, Pb-210, Be-7, Sr-90. Sb-125, and the list goes on and on. It just didn't disappear over night.
Now, every group likes to have celebrities supporting their cause. Republicans and Democarats do it, so why not the TFP. However, we in the sciences do have not glamour personalities. We have, as Joe Friday used to say, "Just the facts m'am, just the facts."
So why do we continue to beat this dead horse? Well as I see it, if we do not speak out for rationality and science, who will? So, we as HPs and other radiation related scientists speak out when we see a innuendo and assertions being made without bothering to do the required background reading that is required for any scientific endeavor. And this has gotten way beyond pleading ignorance. This is the place to come for the answers. We will stand corrected if found to be wrong, such is the way of science. But at present the data are on our side and not that of the TFP.
If the TFP is claiming a synergistic effect between Sr-90 and other carcinogens, then they should so state along with some alternate hypotheses so that some sore of crucial experiment or set of measurements can be made. To concentrate on Sr-90 and to ignore the other radioactive elements such as Ra-226 in teeth is working with blinders on so you can see only what you want to see.
So, finally, my addition to this dialogue is that there is a much easier way to test for Sr-90 in teeth. Go straight to the cow's mouth where you can get a whole lot of teeth from most slaughter houses. Compare the Sr-90 in calf's teeth to that in cow's teeth. See what you get. Granted, this does not carry the psychological or emotional impact as baby teeth. This might make a great MS thesis project and could be done before the TFP gets any good results.
As I have stated earlier concerning Sr-90 in milk, we have not seen much of a decrease in Sr-90 over the years. Even though the fallout has decreased a lot, we still see about 1 pCi/l now as we did back in the 70s and 80s.
Kjell Johansen, PhD
Wisconsin Electric Power Co.
Point Beach Nuclear Plant
kjell.johansen@wepco.com or kajohans@powercom.net for private answers
As always, just my own thoughts on the matter.