[ RadSafe ] NY Times-Study of Baby Teeth Sees Radiation Effects

Roger Helbig rhelbig at sfo.com
Mon Dec 13 23:35:01 CST 2010

This reporter could stand some education on Mangano and Sherman - sorry to
see that this hit the NY Times - 




has link to e-mail this reporter




December 13, 2010
Study of Baby Teeth Sees Radiation Effects
Men who grew up in the St. Louis area in the early 1960s and died of cancer
by middle age had more than twice as much radioactive strontium in their
baby teeth as men born in the same area at the same time who are still
living, according to a study based on teeth collected years ago by
Washington University in St. Louis.

The study, published on Dec. 1 in The International Journal of Health
Services, analyzed baby teeth collected during the era when the United
States and the Soviet Union were conducting nuclear bomb tests in the
atmosphere. The study seeks to help scientists determine the health effects
of small radiation doses, and to say how many people died from bomb fallout.
There is very little reliable data on the relationship of radiation to
cancer at low doses, so scientists instead use extrapolations from higher
doses, which introduces large uncertainties into their calculations.

The study implies that deaths from bomb fallout globally run into the "many
thousands," said the authors, Joseph J. Mangano and Dr. Janette D. Sherman,
both of the Radiation and Public Health Project, nonprofit research group
based in New York.

However, a scientist with long experience in the issue, Kevin D. Crowley,
the senior board director of the Nuclear and Radiation Studies Board at the
National Research Council, urged caution in interpreting the findings.

"It sounds like the best you could do is say this is an association," he
said. "An association is not necessarily causative."

R. William Field, an epidemiologist at the University of Iowa, praised the
authors for exploring the association between fallout in teeth and cancer,
but he that said the sample size was too small and that the study had other
limitations. He called for follow-ups.

The study's authors had previously tried to link strontium in the teeth of
children growing up near nuclear power plants to releases from those plants,
but those findings have not met with much scientific acceptance. Strontium
levels in a person's body may have more to do with where the person's food
was farmed than with where the person lives. In addition, the Nuclear
Regulatory Commission calculated that the doses from radioactive strontium
in the environment add only about 0.3 percent to the average American's
background exposure.

But this study tries to link differences in tooth contamination more
directly with health outcomes. The study measured the ratio of calcium, a
basic building block of teeth and bones, to strontium 90, which is absorbed
just as calcium is. The authors said they were using strontium as a proxy
for all long-lived fallout components, and they picked boys born in a period
when there was a lull in atmospheric testing, so that the boys' exposure to
short-lived radioactive materials, in utero or in the first few months of
life, was minimized. They limited their research to boys because men seldom
change their names and thus were easier to trace.

The authors found that among 3,000 tooth donors, born in 1959, 1960 or the
first half of 1961, 84 had died, 12 of those from cancer. The authors
selected two "control" cases, people still living, for each of those who had
died. The controls were born in the same county, within 40 days of the
person who later died. The study compared incisors with incisors, and molars
with molars.

The people who would later die of cancer had an average of 7.0 picocuries of
per gram of tooth; the control cases, who have never had cancer, had an
average of 3.1 picocuries per gram.

But the picture is not completely clear. Measurements of the teeth of people
who later had cancer but survived it did not show strontium levels markedly
different from those who had never had cancer, according to the study. One
reason may be that those nonfatal cancers were often polyps and melanomas
not related to radiation.

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