Baby teeth offer radioactive clues
By Gary Stoller, USA TODAY
A new study concludes that counties within 40 miles of six nuclear power plants have higher levels of radioactive strontium-90 than other counties in their states.
Strontium-90, a byproduct of uranium fission, is one of the pollutants emitted into the air by nuclear reactors. If inhaled or ingested, it collects in bones and tissue and increases the risks of cancer and leukemia, according to the Environmental Protection Agency.
The study, published this week in the journal The Science of the Total Environment, was done by the Radiation and Public Health Project (RPHP), a New York-based non-profit group that analyzes baby teeth for strontium-90. Baby teeth from counties near two nuclear plants in Florida and plants in California, New York, New Jersey and Pennsylvania were compared with baby teeth from other counties in the same states.
Nuclear power companies denounce the RPHP study. They and some scientists say RPHP's findings are not based on sound science. "I don't question finding strontium-90 in teeth, because there better be strontium-90 in teeth," says Ralph Andersen, chief health physicist for the Nuclear Energy Institute, which represents power plant owners and operators. "I question how they compare data. I fail to see a factual basis for their conclusions."
Everyone is exposed to small amounts of strontium-90, the EPA says, because it was widely dispersed into the environment and the food chain by above-ground nuclear weapons tests in the 1950s and 1960s. The Nuclear Regulatory Commission says strontium-90 also was released into the environment by weapons tests of the French and Chinese governments between 1970 and 1980 and by an accident at the Chernobyl nuclear power plant in the Ukraine in 1986.
The EPA wouldn't comment on the RPHP study and referred questions to the NRC. NRC spokeswoman Elizabeth Hayden says the agency won't comment until the study is reviewed by technical staff.
Joseph Mangano, one of five co-authors of the study, says RPHP takes no position on whether nuclear power plants should be allowed to operate. But its researchers "strongly suggest that the health risks of nuclear reactors should be given top priority in formulating policies for nuclear reactors."
The study looked at 2,089 teeth sent to the RPHP and analyzed by a radiochemistry laboratory in Ontario. It found that most counties near nuclear plants had strontium-90 levels that were 31% to 54% higher than counties farther away.
The highest levels were found in three counties near the Limerick power plant in Pottstown, Pa., and in three counties near the Indian Point nuclear facility in Buchanan, N.Y. Pottstown, the study notes, is "within 70 miles of 11 operating and two closed reactors, a concentration unmatched in the U.S."
The study says its most unexpected finding is that strontium-90 levels have steadily risen after decades of decline. Baby teeth of children born in 1994 to 1997 had nearly 50% higher strontium-90 concentration than those from children born in 1986 to 1989, the study found.
Nuclear experts and the federal government say strontium-90 levels should be dropping because above-ground atomic bomb tests stopped decades ago, below-ground tests and nuclear weapons production halted at least 12 years ago and nuclear fuels reprocessing ceased in the late 1970s.
"The only other source of strontium-90 that can explain this steady and dramatic rise in the 1990s is emissions from nuclear power reactors," the study says.
Robert Alvarez, an Energy Department senior policy adviser in the 1990s, says that conclusion is "too much of a leap, because of the need to factor in other multiple risk factors."
The EPA's Web site says, "People who live near or work in nuclear facilities may have increased exposure to strontium-90." But Patricia Milligan, NRC senior emergency preparedness specialist, says only a speck of strontium-90 is released each day from a nuclear plant.
The amount of strontium-90 released at every plant is less than limits established by the NRC and the EPA, says Stephen Klementowicz, the NRC's health physicist.
Alvarez, who is often critical of nuclear plant safety, isn't convinced RPHP has proved its case. But he says there may be a correlation between strontium-90 in baby teeth and childhood cancers.
RPHP is currently studying whether children with cancer have more strontium-90 in their teeth than other children, funded, in part, by a $25,000 allocation from New Jersey.