Thyroid Study Finds No Link Between Hanford, Victims Research Unearths No Reason For Higher Death Rate

A decade-long study has found no link between Hanford’s Cold War-era radiation releases and the rate of thyroid disease among people living downwind.

But the study of 3,441 people in seven Eastern Washington counties did find slightly elevated levels of thyroid abnormalities and an unexplained death rate 20 percent higher than normal. The deaths were from birth defects and problems late in pregnancy or in the first week after birth.

But none of this increase was due to thyroid disease, researchers said.

The draft study was released Thursday in Richland after high-level briefings with U.S. Department of Energy officials and members of Congress in Washington, D.C.

The $18 million study was conducted by the Fred Hutchinson Cancer Research Center in Seattle for the U.S. Centers for Disease Control and Prevention.

The announcement by the CDC upset many in the Northwest who still believe Hanford caused their illnesses.

The thyroid study was funded by Congress after DOE admitted for the first time in 1986 that plutonium production at Hanford had extensively contaminated areas of Eastern Washington with iodine 131, a radioactive element that settles in the human thyroid gland and can cause a variety of health problems, including cancer.

The airborne radiation settled on grass, where it was eaten by cows and passed on to infants and children through milk.

A link between iodine-131 and thyroid disease has been found in several places where people were exposed to a mix of internal and external radiation:

In the Marshall Islands, where residents were exposed to fallout from H-bomb tests.

Among Utah schoolchildren exposed to fallout from nuclear bomb tests in Nevada.

And in the Ukraine, following the 1986 explosion of the Chernobyl nuclear reactor.

But it wasn’t found at Hanford, where the radiation dose was primarily internal from drinking contaminated milk and delivered to the thyroid gland over a long period, the three principal scientists who conducted the study said Thursday.

The mix of radioactive elements from Hanford was different than at the other nuclear sites, and the Hanford doses were lower than in the Marshall Islands or at Chernobyl, said endocrinologist Dr. Thomas Hamilton.

Also, people hit with radiation at Chernobyl and the Nevada Test Site got their doses quickly, while at Hanford they were spread out over time, Hamilton said.

“The exposure conditions are quite different for Hanford,” he said.

That still doesn’t answer why the Hanford study is such an anomaly compared with the other studies, said Tim Connor of the Northwest Environmental Education Foundation, an author on community epidemiology and chairman of a CDC advisory committee on nuclear health studies.

“There’s going to be a lot of anger among Hanford downwinders, who will see this as a message from the scientific community that invalidates their experience,” Connor said.

“We can’t use these studies to prove definitively whether individuals are injured,” he said. “It can’t be underscored enough: This doesn’t mean that Hanford emissions aren’t the cause.”

The anger from downwinders was immediate. At a public meeting Thursday night, study researchers faced a crowd of 80 mostly hostile people.

Sally Sanders of Kennewick, who has lost her mother and 52-year-old sister to thyroid cancer and whose brother also has the disease, faced the researchers with an American flag and a large sign that read, “I don’t believe it.”

“Three out of four of us. … I’m not satisfied with your study,” she daid.

Fred Hutchinson researchers Hamilton, epidemiologist Scott Davis and statistician Kenneth Kopecky said they are confident the study is accurate.

“This study was powerful in the number of people examined and in its design,” said Davis.

“If iodine-131 released from Hanford had caused anything, this study would have detected it,” he said.

The study does not, however, answer whether an individual’s case of thyroid disease is a result of Hanford radiation, Davis said. “People want to know what about me? We can’t answer that.”

The study is based on a group of 5,199 people born between 1940 and 1946 in Benton, Franklin, Adams, Walla Walla, Okanogan, Ferry and Stevens counties. Of this group, 94 percent were located and 3,441 agreed to participate.

They attended special clinics between 1992 and 1997 and also provided personal medical information to the researchers.

Of the original group of 5,199, some 541 had died. The researchers obtained death certificates for 502, which gave no indication that thyroid disease was responsible.

Even if some thyroid cancers were missed among these people, it’s unlikely that would have changed the study results, Davis said.

But the researchers, based in part on critical comments by reviewers that they didn’t look closely enough at those who had died, plan to review the mortality figures more closely.

A computer program developed by the Hanford Environmental Dose Reconstruction Project, an earlier government study to estimate radiation doses, was used to calculate a thyroid dose estimated for 3,193 participants.

Their doses ranged from 0 to 280 rads.

Nineteen confirmed cases of thyroid cancer were found among the study participants. However, the cancers were no more common among people with higher estimated radiation doses than among those with lower doses.

In addition, 249 participants had noncancerous thyroid nodules, 267 had hypothyroidism or auto-immune thyroid disease, and 34 had Graves Disease, which results in an overactive thyroid. However, none of these diseases could be correlated with radiation dose.

The researchers also took into account a dose for additional fallout from the Nevada Test Site. Residents of the inland West learned in 1997 in a new National Cancer Institute study that they’d been exposed to clouds of radiation from bomb tests in Nevada in the 1950s and early ‘60s.

“We did try to see if our Hanford results were affected (by bomb test fallout). We saw no evidence of that happening,” Kopecky said.

When they discovered the study was coming up with negative results, the Fred Hutchinson team was surprised. They conducted additional analysis to make sure they weren’t wrong, and other scientists also reviewed the results. The National Academy of Sciences also plans a review in February.

Dr. Paul Garbe, CDC scientific adviser for the study, said his agency will recommend further follow-up of the people the study examined. “It’s important to have continued access to them,” he said Thursday in Richland.

A medical monitoring program for 14,000 people exposed as children to Hanford’s releases - proposed by the Agency for Toxic Substances and Disease Registry - will probably be modified as a result of the Fred Hutchinson study, Garbe said. The agency has been mired in funding disputes with DOE for months.

But it’s important for the ATSDR program to go forward despite the negative findings in the CDC study, Garbe said.

“Some people will not believe the results of our study,” he said.

The ATSDR program will now likely focus on “risk communication and public education” with thyroid exams available for people who request them, he said.

Greg Thomas of ATSDR’s Seattle office said it’s even more important now for the monitoring program to proceed.

“We have a highly exposed population here,” Thomas said. “They’ll want to know what all this information means to them. One study doesn’t answer all the questions.”

This sidebar appeared with the story: FIND THE STUDY The study is available on the Internet. The Fred Hutchinson site: www.fhcrc.org/science/phs/htds/. The CDC site: www.cdc.gov/nceh. Public comments on the study can be made until April 1. They should be sent to CDC’s Radiation Studies Branch, Attention HTDS, mailstop F35, 4770 Buford Highway, Atlanta, GA 30341.