The Associated Press State & Local Wire
Researcher says Hanford thyroid study was released too early
DATELINE: SPOKANE, WA
A recent study that found no connection between Hanford radiation releases and thyroid disease should not have been released before it underwent peer review, the study's lead researcher now says.
The admission by Dr. Scott Davis of the Seattle-based Fred Hutchinson Cancer Research Center follows harsh criticism of the research methods and findings since the study was released Jan. 28.
"I couldn't agree more that we should have waited" for a thorough review by other scientists, Davis told The Spokesman-Review newspaper in a story published Sunday.
Still, the epidemiologist said he stands behind the study's science.
"It's been very rough. There's been a lot of very negative reaction. We felt all along it was not in everyone's best interests to release a draft report," Davis said.
Critics say researchers overemphasized findings that show no link between radioactive iodine releases from the Hanford nuclear reservation in the 1940s and '50s and the incidence of thyroid disease among those living downwind.
Critics of the 10-year, $18 million study also contend contradictory data - including findings that incidence of thyroid disease among study subjects was higher than would be expected in an average population - was buried in the report by officials with the U.S. Centers for Disease Control and Prevention and their Seattle researchers.
The decision to release the study as a preliminary draft shortly after its completion last fall was made at CDC's Atlanta headquarters in response to public pressure, said Dr. Paul Garbe, director of epidemiology in the CDC's radiation studies branch.
The center released the draft after an internal review when the National Academy of Sciences said it would not review the document until it had been made public, Garbe said.
Lynn Stembridge, director of the Hanford Education Action League, a Spokane-based watchdog group, criticized the decision.
"It's a very sad commentary on what CDC hasn't learned about working with communities. You don't just pop a study out before it's peer-reviewed," she said.
The study examined the thyroid health of 3,441 people born between 1940 and 1946 in seven Eastern Washington counties. Those people were children when substantial amounts of Iodine-131 were released into the air around Hanford between 1944 and 1957 and carried by the wind toward the northeast.
Children are particularly susceptible to radioactive iodine, which concentrates in the thyroid gland. Researchers have found that downwinders who grew their own food and drank milk from a cow that grazed in the area were most likely to have ingested radioactive iodine from the Hanford releases.
Some scientists who reviewed the study after its release say they have found mathematical uncertainties in the radiation dose estimates. Those estimates were used in reaching the conclusion that no link exists between the radiation releases and thyroid disease.
The study researchers relied upon a previous Hanford study by Battelle's Pacific Northwest National Laboratory to assign doses to the people they examined, based on where the subjects lived as children. The Battelle estimates were produced for the 1994 Hanford Environmental Dose Reconstruction Project.
The project underestimated by nearly three times the Iodine-131 doses from Hanford after 1950, according to a recent critique by SENES Oak Ridge Inc.'s Center for Risk Analysis.
That review, dated Feb. 3, was presented recently to the National Academy of Sciences panel considering the CDC study.
Because the thyroid study's dose estimates have been questioned, most of the 3,441 thyroid-study doses will have to be recalculated, Garbe said.
Another problem concerns the higher-than-average thyroid disease rates in the study group.
"They can't account for all the thyroid disease they found," said Judith Jurji of Seattle, a Hanford downwinder who served on the study's advisory committee.
The CDC may schedule more community meetings to discuss the study, he said. It has already extended the public comment period deadline from April 1 to July 1. A final report is due by the end of the year.
--- Comments should be addressed to: CDC, Radiation Studies Branch (Attn: HTDS), 4770 Buford Highway NE, Atlanta GA 30341.