Baby teeth find their way back to the laboratory

By Robert Kelly

May 29, 2008

Thousands of baby teeth, almost all collected from St. Louis-area residents in the 1950s and 1960s, will finally be used in a comprehensive study aimed at learning whether fallout from atomic bomb tests increased the cancer risk for Americans born in those Cold War years.

The nonprofit Radiation and Public Health Project in New York announced last week that a $15,000 donation from the Oregon Community Foundation of Portland, Ore., would allow the yearlong study to begin. The rest of the nearly $37,000 project cost is being covered by other private contributors, project officials said.

Almost 85,000 baby teeth left from a study conducted in the early 1960s at Washington Univ. will be used in the new study. They were uncovered in 2001 in an old ammunition bunker at the university's Tyson Research Center.

Each tooth is enclosed in a small envelope and clipped to a 3x5 card with basic information about the tooth donor. Most of them were born in the late 1950s or early 1960s and lived in the St. Louis area as children.

They were part of the St. Louis Baby Tooth Survey, in which nearly 300,000 area children sent their teeth to the Greater St. Louis Citizens Committee for Nuclear Information.

Scientists used the teeth to determine that children were absorbing radioactive fallout from nuclear bomb tests. Those findings helped lead to a 1963 treaty banning atmospheric tests of nuclear weapons.

Joseph Mangano, executive director of the Radiation and Public Health Project, said last week in a telephone interview from New York that his research group had had possession of the 85,000 teeth since 2001 but lacked the money until now to begin a full study of the cancer risk posed by the nuclear tests.

Now, he said, the research group will identify 100 tooth donors who later developed cancer, plus 200 healthy donors. A lab will then test their teeth for levels of strontium 90, a radioactive chemical found in bomb fallout and nuclear reactors.

If the teeth of donors with cancer have a higher average strontium 90 level, a link with the fallout would be suggested. Then the research group would proceed with a more detailed study, Mangano says. At the end of the one-year project, the researchers will submit an article to a medical journal for publication, he says.

"This actually extends the Washington Univ. study," he says. "We now have much more sophisticated machines to do the study."

The emergence of the Internet also allows the scientists to find many of the tooth donors from years ago and to question them about their health.

Mangano says it was especially important to focus the study on St. Louis, calling the city "probably the hardest-hit large American city by bomb fallout," based on official U.S. Public Health Service measurements of radiation in milk.

Scientists identified a "milk pathway" by which fallout from nuclear testing in the 1950s and 1960s contaminated pastures. Anyone who drank milk from cows that grazed there could have been exposed to radiation.

Mangano says the Washington Univ. study showed there was a rapid decline in strontium 90 in baby teeth collected after the nuclear test ban went into effect. But that study did not look at a potential link between cancer rates and fallout from the atomic bomb tests, he said.

"Our whole point is to try to determine the cancer risk to the baby boomers who were exposed to fallout," he says. "After 50 years, we still don't know much about that.

Mangano said that strontium 90 decayed over time, but that nearly three-eighths of the radioactive chemical originally found in the teeth could still be detected.

To read the rest of this story, go here, Baby tooth study to begin

SOURCE: St. Louis Post-Dispatch