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Re: More on baby teeth
When I think of radioactivity in Florida, I think of radium from "phosphate lands". Considering the discussions regarding analytical techniques, I have to wonder how much of the activity is coming from one radium isotope or another, or their decay products.
>>> Jim Hardeman <Jim_Hardeman@mail.dnr.state.ga.us> 05/03/00 09:02AM >>>
Colleagues -
Please take a look at the following excerpts from 2 press releases from the Radiation Public Health Project regarding the Tooth Fairy project. The full press releases can be found at www.rphp.org. Your thoughts?
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10/21/99 Press Release in Manhattan re: Sr-90 in baby teeth:
"The new higher-than-expected levels of radiation were found in 515 teeth measured thus far, most of them for children born in the states of New York, New Jersey and Florida. Many of the areas where teeth were collected are near nuclear power plants with a history of unusually large radiation releases. Strontium-90, a man-made element that was first introduced into nature as a byproduct of atomic bomb tests, is also produced by fission in nuclear reactors. It enters the body through drinking water and food, concentrating in bones and teeth.
The largest majority of teeth analyzed by the RPHP researchers were from the 1979-92 period and contained Strontium-90 in the range of 1.1 - 2.0 picocuries per gram of calcium. A few of the teeth were found to have reached levels as high as 16 or 17 picocuries per gram calcium. Baby teeth from the middle 1950's that were tested in a St. Louis-based teeth study contained approximately similar average concentrations. "
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11/22/99 Press Release in Miami, FL re: Sr-90 in baby teeth:
"Cancer-causing radioactive Strontium-90 (Sr-90) has been found in the teeth of children born in the 1980's at levels equal to those of the middle 1950's when the U.S. and the former Soviet Union were conducting routine aboveground nuclear bomb tests.
Among 476 teeth tested, the highest levels of radioactive Strontium-90 were found in South Florida children's teeth, reported Drs. Jay Gould and Ernest Sternglass, directors of the Radiation and Public Health Project (RPHP). Today, RPHP released the initial Florida results of an ongoing study of radiation levels in baby teeth (the "Tooth Fairy Project").
The highest levels of radioactive Strontium-90 were found in 39 South Florida teeth from Miami-Dade County, which had an average of 3.0 picocuries per gram of calcium, compared to an overall average of 1.5 picocuries for all teeth measured. Florida baby teeth had two times the radiation levels found in teeth from other states. Furthermore, the few teeth that reached peak levels as high as 16 or 17 picocuries per gram calcium were from the Miami, Florida, area."
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Hmm ... assuming for the moment (despite having no definitive evidence of this) that this Sr-90 is of recent origin, given the demographics of the Miami area, is it possible that this Sr-90 might have originated in another country? Just another little twist.
I would also note that in the Miami press release, it appears that a simple arithmetic average is being used to describe a decidedly "non-normal" distribution, as the Manhattan press release clearly indicates that most values are in the 1.1-2.0 pCi/g range ... with a few in the 16-17 pCi/g range. This either indicates a skewed distribution (such as a log-normal), or that you're actually looking at two separate distributions.
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Jim Hardeman
Jim_Hardeman@mail.dnr.state.ga.us
!
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