Errors Found In Hanford Thyroid Disease Study, by Trisha Pritikin, January 2000

Errors Found In Hanford Thyroid Disease Study
by Trisha Pritikin*, January 2000

Hanford Study Sees No Harm proclaimed the New York Times headline of January 28, l999. The headlines in USA TODAY, December 15, l999 read, Errors Are Found In Radiation Review at Hanford Nuclear Site.

I started my day on the January 28, 1999 with the phone ringing off the hook with calls from national, Pacific Northwest, and local media asking me what I thought about this purported "No Harm" finding of the Hanford Thyroid Disease Study (HTDS). The HTDS was a nine-year, $18 million epidemiological study to assess the impact of the Hanford Nuclear Reservation offsite emissions of radioiodine (I-131) onto an unsuspecting public from the mid l940s to the late l950s. Hanford released approximately 900,000 curies of I-131 between l944 and l957, as a byproduct of plutonium production at the facility.

Since I was one of those exposed to Hanford’s I-131 as a child, when most vulnerable to uptake of the radioactive substance into my thyroid gland, I had followed the emissions study from its inception years ago. But I was not prepared for this unbelievable "no harm" conclusion of the HTDS researchers. The disturbing Hanford Study Sees No Harm headline appeared the New York Times just hours before the scheduled briefing in which I was to participate as a member of the Hanford Health Effects Subcommittee. Somehow, someone had leaked this tidbit from the Congressional briefing on HTDS which had taken place in Washington D.C. on January 27th, a day before the public and press were to know the results of this study.

As I spoke with NPR, national and local TV stations, and print media reporters -- not yet having seen the summary materials on HTDS published by the federal Centers for Disease Control and Prevention (CDC), and its contractor, the Fred Hutchinson Cancer Research Center (FHCRC) -- all I could say to this barrage of media seeking me out was "I am shocked by this conclusion. This does not reflect the reality of what has happened to those of us exposed to Hanford’s radioactive emissions." I went on to describe the fact that my entire family, exposed to Hanford’s radioiodine and other radionuclides, developed thyroid disease and cancer, and that I am the only member of my family who has survived.

A Downwinder's Burden - The Reality

My father, a nuclear engineer at the Hanford facility during years of I-131 (and other radionuclide) releases, had died of aggressive, metastatic thyroid cancer three years ago. He also had hypothyroidism. My mother, who had developed both hypothyroidism and hyperparathyroidism, was to be diagnosed (just two weeks after this pronouncement by the HTDS research team of no health impact from Hanford’s radioiodine) with malignant melanoma, which killed her in less than six weeks’ time. My older brother had died in l947, during years of Hanford radiation emissions, within the Hanford downwind area, part of an unexplained surge of neonatal deaths within the Hanford downwind area. Exposed to Hanford’s I-131 as a fetus, infant and child, I also have developed severe hypothyroidism and related health problems. Of note is that there is no history of thyroid disease anywhere in our extended family other than those of us who lived in the shadow of the Hanford nuclear facility during years of I-131 emissions. And we are not alone. An entire family devastated by thyroid disease and cancer. This story is repeated over and over amongst those of us who are Hanford "downwinders."

The Struggle To Correct An Erroneous Official Study

So began the struggle by a small group of determined Hanford-exposed citizens and activists to correct this surreal, unfathomable, purported "no harm" conclusion reached by HTDS researchers. This struggle involved confronting defensive HTDS research team members in public meetings, trying to reverse the harm being done by this "conclusion" which truly did not reflect the reality of the Hanford situation.

The HTDS summary materials given to the public and the media contained the following statement: "[T]hese results provide rather strong evidence that exposures at these levels to I-131 do not increase the risk of thyroid disease or hyperparathyroidism. These results should consequently provide a substantial degree of reassurance to the population exposed to Hanford radiation that the exposures are not likely to have affected their thyroid or parathyroid health [emphasis added]." In these public meetings, I repeatedly requested the FHCRC HTDS researchers to retract this offensive statement publicly. I asked, 'How could Hanford-exposed people like me possibly be told we should be reassured when our loved ones were dead of thyroid cancer, and when whole families without history of thyroid disorders had developed thyroid disease?" To me, their "no harm" statement insulted the suffering, the reality of those who had been subjected to involuntary radiation exposures.

The media, overall, was very supportive of our efforts, perhaps because it was clear to all concerned that something was definitely wrong with this "no harm" conclusion. Particularly, in light of the Chernobyl studies that brought forward facts that children exposed to I-131 from the Chernobyl nuclear disaster had statistically significant incidence of thyroid disease and thyroid cancer. This "no harm" conclusion of HTDS was inconsistent with other studies of radioiodine exposure and thyroid health harm. Something was definitely wrong with this picture.

And so the analysis began, by citizens and scientists alike, trying to determine how this study could come to such a surreal conclusion. Already, articles and letters to the editor were appearing in regional papers from members of the American Nuclear Society and their allies, portraying these conclusions of HTDS as final, irrefutable evidence that Hanford’s I-131 had caused no harm to those exposed.

One of the true scientific heroes in this effort is Dr. Owen Hoffman of SENES, Oak Ridge, Inc., Center for Risk Analysis. It was through the efforts of Dr. Hoffman that we were able to begin to understand what had gone wrong, and how to discuss the scientific fallacies of this study publicly. Dr. Hoffman was able to translate complex statistical concepts into understandable terms, thus empowering us to raise these issues of import with the HTDS researchers and the media.

And, thus empowered by Dr Hoffman and others, my colleague Tim Connor, an investigative journalist and Hanford activist for many decades, and I, armed with a letter of protest co-signed by more than 22 representatives of citizen groups from around the country, went to meet with Dr Dick Jackson, director of the National Center for Environmental Health of the Centers for Disease Control and Prevention. This letter raised serious concerns with regard to a number of scientific issues within HTDS and as to the communication and interpretation of the findings of this study by FHCRC and CDC to the public, Congress, and the media. These concerns included HTDS researchers’ presentation of this study as if it were conclusive proof of no thyroid or parathyroid impact from Hanford’s I-131 releases, that FHCRC exaggerated the statistical power of the study, and that the uncertainties in dose estimates and confounding NTS and global fallout I-131 doses were not specifically addressed for the HTDS cohort. The letter went on to discuss significant problems created by the information "blackout" which kept even those citizens who had been following the study throughout its history, from learning about the results of the preliminary draft of the study until we read about it in the New York Times on the morning of January 28.

We asked Dr. Jackson to support a precedent-setting extended review by the National Academies of Science (NAS) of HTDS, a review which would address both the scientific and communications aspects of HTDS. Dr. Jackson, to his credit, understood the importance of this review, and granted our request. This is one of the first such extended reviews to be carried out by NAS, initiated by concerned citizens, reviewing not just the typical scientific components and qualities of a study, but concentrating as well upon the way the study’s preliminary findings were communicated to the public, Congress, and the media. The "normal" NAS review of this type comprises only a review of the science.

The NAS, which is the entity reviewing HTDS, was chartered in l863. The NAS is one of the world’s most prominent scientific organizations. Its purpose is to advise the US Congress and federal agencies on scientific and technical matters. Its Board on Radiation Effects Research has played a leading role over the years in evaluating radiation health studies.

NAS Review Conclusions

The NAS committee released the results of its extended review of HTDS this December 12, l999, in a public meeting in Spokane, Washington, followed the next day by a briefing in Washington D.C. The conclusions reached by the NAS validated all of the arguments made by those of us who had "gone public" to contradict the misinformation portrayed by the HTDS research team. The headlines in USA TODAY, December 15, l999 read: "Errors Are Found In Radiation Review at Hanford Nuclear Site. "

This is truly a victory for Hanford and all downwinders, for people everywhere exposed to I-131 --- from US Department of Energy nuclear weapons facilites such as Hanford, Oak Ridge or the Idaho National Engineering Lab, or from nuclear weapons test sites such as the Nevada Test Site or Semipalatalinsk in Kazakhstan, or from nuclear accidents resulting in exposure due to global fallout. No longer can the HTDS be portrayed by US pro-nuclear factions and their allies as conclusive proof that I-131 does not cause thyroid cancer, thyroid disease and parathyroid disease.

The NAS committee concluded the following:

1. While the study itself was well designed, the study researchers reported the study’s findings as more conclusive than they really were purported to be.

The committee found that "shortcomings in the analytical and statistical methods used by the study’s investigators overestimated the ability to detect radiation effects, which means the study results are less definitive than had been reported." [NAS review report, 12/14/99, at page l] The failure by HTDS researchers to find a statistically significant relationship between increasing dose and frequency of thyroid disease was interpreted by the authors of HTDS as evidence of no effect (that is, that the negative findings were conclusive). Because there could be a true underlying effect that couldn’t be detected by this study, the results of the study were, at best inconclusive, rather than conclusive of no health impact from Hanford’s I-131 exposures, as portrayed by HTDS’ authors.

There are several important reasons why HTDS may have not picked up this underlying effect, and these are discussed within the other findings of the NAS review, discussed below.

2. Unlike conventional epidemiological studies, the HTDS researchers released their findings without sufficiently explaining the uncertainties involved in reconstructing radiation exposures from decades ago.

While the NAS committee emphasized that the HTDS appears to have been well designed, the weakest link is the dosimetry (which is the method of estimating individual exposure and radiation dose). The dose estimates which were assigned to members of the group (cohort) of exposed people studied were recreated using mathematical models involving input from study participants (and their mothers, if available) with regard to their recollections of approximately how much milk study participants drank some 50+ years ago. The milk pathway is one of the primary means by which radioiodine is ingested, and is a particular concern with infants and children. The radioiodine deposits on pasture grass, the cows or goats eat the contaminated grass, and then, the radioiodine is ingested by humans as the milk is consumed. Children uptake far more radioiodine than adults in this manner, because they often consume a greater quantity of milk than adults, because their thyroids are smaller and more vulnerable than those of adults, and because of a faster metabolism than that of adults.

Therefore, the estimated doses which were being correlated to incidence of thyroid and parathyroid disease within the HTDS study group were reconstructed from memories of milk intake years ago, and then based upon mathematical modeling of wind patterns, fallout of the radioiodine from rain, and deposition of radioiodine. These estimated Hanford doses were further confounded by the additional exposures of people within the HTDS cohort to Nevada Test Site radioiodine (from atomic bomb tests in the l950s and l960s) which was often a very substantial contributor to dose, and by fallout from global sources and the Marshall Islands Test of l954 (Test Bravo) in which fallout travelled west to east, depositing upon the Hanford exposure area as well. These confounding doses were not given detailed consideration by HTDS. An example of just how such an issue should be addressed is shown by the exemplary study performed by SENES Oak Ridge, Inc. Center for Risk Analysis, which was the first of its kind to estimate the cumulative I-131 dose received from Oak Ridge and Nevada Test Site I-131 exposures, within "uncertainty ranges" (that is, within a range of possible doses one may have received once age, diet and location are taken into account), and providing exposed populations with their estimated risk of health outcomes from these exposures. The HTDS did not deal in this way with specificity with these confounding exposures received by member of the HTDS study group.

The amount of I-131 Hanford released after mid-l951 also were more than likely underestimated, raising the total curies released from about 750,000 to more than 900,000. Revision of the amount released would have a significant effect on the dose estimates for those who were considered within HTDS to have received low doses as compared to the higher peak releases of l945-46.

3. The NAS committee found that the statistical power of the HTDS was not as high as claimed by the HTDS researchers.

The NAS committee found that the statistical power calculations made by the HTDS researchers made inadequate allowance for imprecision in the dose estimates. Due to this factor, the committee concluded that HTDS did not have as much statistical power to detect radiation effects as the investigators claimed.

4. The committee found that in media and public briefings on HTDS, the investigators failed to pay sufficient attention to the health concerns of the audience, and that HTDS investigators and CDC officials should have offered more balanced, and possibly alternative, interpretations of the findings and discussed their implications for individuals.

This last conclusion of the NAS committee is so well reflected in the actions of one Hanford-exposed person in attendance at the public briefing held in the Hanford area, on the evening of January 28, l999. Throughout the entire several-hour briefing, this woman held up a hand painted sign, reading "I DONT BELIEVE YOU."

Victory Comes After Tireless Efforts

The battle to expose the truth of the Hanford situation began on the morning of January 28, l999, and ended in the afternoon of December 12, l999, with the public briefing on the results of the NAS review of HTDS. The battle ended with the headline in USA TODAY, December 15, l999, Errors Are Found In Radiation Review at Hanford Nuclear Site. The tireless efforts of a small group of activists succeeded and the HTDS study can no longer be portrayed as conclusive proof of no health impact from Hanford I-131.

The HTDS study may actually turn out, upon follow-up, to be looked upon as a study portraying a slightly positive association between exposure and health. The purported "no impact" message had been echoed by conservative forces to rebut exposed communities concerns. Uncorrected, this "no impact" message was beginning to be used to nullify the public’s concerns about Nevada Test Site radioiodine exposures, exposures of radioiodine from local sites such as the Idaho National Engineering Lab (INEEL), in Oak Ridge, and exposures at other sites where I-131 was emitted as a byproduct nuclear weapons production.

This is a truly welcomed victory for everyone. It is an especially important victory for "downwinders" including all who have been exposed anywhere in the US from the Nevada Test Site to the Department of Energy nuclear weapons research and production facilities. Downwinders face hurdles trying to get even the most minimal medical screening or medical care; even to get relief through the justice system; and all the while we bury our loved ones and hope that we are not, indeed, the sacrificial minority we have sometimes been deemed.

* The author, Trisha Pritikin is from the US Pacific Northwest, a downwinder, activist, and an attorney presently based in northern California who is working for the rights of downwinders. Messages to Trisha Pritikin can be directed through the Nuclear Age Peace Foundation email address: wagingpeace@napf.org