Skip to main content

TMI Cancer Study: Radiation, Health and Questionable Claims

Researchers at the Penn State College of Medicine recently published a study claiming that analysis of thyroid tumors showed tissue differences, based on where the patient lived. People who lived near Three Mile Island at the time of the 1979 accident had tumors more likely to have come from radiation exposure than people who developed thyroid cancer while living elsewhere, according to the researchers.

Science is advanced by experts who publish new findings, and readers who then evaluate the conclusions and how they fit into the existing body of knowledge. We welcome all contributions to knowledge. But scientific studies should be read with care, so their claims can be understood, and so we can determine how the findings fit with what was previously understood. And these findings don’t fit.

Three Mile Island
Three Mile Island Nuclear Generating Station

Despite what a reader might assume from a news headline, this paper does not assert that Three Mile Island is the cause of any cancers. It goes off in a new direction, in ways that may not be obvious to a reader unfamiliar with previous work in the area.

The scientific consensus is that examination of a tumor, and its DNA, does not conclusively tell you what caused the tumor to develop. The other is that extensive work, in scientific and engineering disciplines far distant from medical science, has concluded the amount of radioactive material released from the reactor building during the Three Mile Island accident in March, 1979, was very small, and that doses to people in the region were minuscule, adding a tiny increment to the natural background exposure.

To be sure, the researchers made only limited claims. They did not say anything, for example, about whether that part of Pennsylvania saw any increase in thyroid cases. (Other studies show that it didn’t.)

They wisely pointed to some shortcomings of their study: Small sample size, and among the sample tumor material that they could gather, the inability to definitively analyze the genetics of some of the material. There were only 15 people in what they called the “at risk” group. They couched their conclusions with conditional terms like “may” and “likely,” but called for more study.

But one basic problem is that you cannot look at a tissue sample and say that radiation was the cause of the tumor. The human thyroid is potentially vulnerable because the thyroid naturally concentrates iodine that is present in the environment, and reactors create a form of iodine that is radioactive. There are some publications suggesting that some of the genetic mutations that are discernible in tumors are more prevalent in people who have been exposed to very large amounts of radioactive iodine. But this is not generally accepted as definite.

Plus, experience has shown that radioactive iodine is only likely to cause cancer in one category of people: children. Even among A-Bomb survivors, the group that had excess thyroid tumors was 21 and under. Tumors in this study were taken from people in the Three Mile Island area with an average age of 28.

There is another problem with the sample, in addition to its small size. All the patients in the sample were treated in only one facility, in Hershey. There are many other facilities which would treat thyroid cancer. And people living in the area did not always stay there; they would leave the area (to go to college etc.). So the “at risk” population is not well defined.

Perhaps most important of all, the maximum possible doses in the Three Mile Island area were approximately 1,000 times smaller than those we believe can cause cancer, because releases of iodine were very small. The Penn State researchers did not make any statement about the level of dose.

The above is a guest post from Jerry Hiatt, senior project manager of radiation and materials safety at NEI.


Popular posts from this blog

Making Clouds for a Living

Donell Banks works at Southern Nuclear’s Plant Vogtle units 3 and 4 as a shift supervisor in Operations, but is in the process of transitioning to his newly appointed role as the daily work controls manager. He has been in the nuclear energy industry for about 11 years.

I love what I do because I have the unique opportunity to help shape the direction and influence the culture for the future of nuclear power in the United States. Every single day presents a new challenge, but I wouldn't have it any other way. As a shift supervisor, I was primarily responsible for managing the development of procedures and programs to support operation of the first new nuclear units in the United States in more than 30 years. As the daily work controls manager, I will be responsible for oversight of the execution and scheduling of daily work to ensure organizational readiness to operate the new units.

I envision a nuclear energy industry that leverages the technology of today to improve efficiency…

Why America Needs the MOX Facility

If Isaiah had been a nuclear engineer, he’d have loved this project. And the Trump Administration should too, despite the proposal to eliminate it in the FY 2018 budget.

The project is a massive factory near Aiken, S.C., that will take plutonium from the government’s arsenal and turn it into fuel for civilian power reactors. The plutonium, made by the United States during the Cold War in a competition with the Soviet Union, is now surplus, and the United States and the Russian Federation jointly agreed to reduce their stocks, to reduce the chance of its use in weapons. Over two thousand construction workers, technicians and engineers are at work to enable the transformation.

Carrying Isaiah’s “swords into plowshares” vision into the nuclear field did not originate with plutonium. In 1993, the United States and Russia began a 20-year program to take weapons-grade uranium out of the Russian inventory, dilute it to levels appropriate for civilian power plants, and then use it to produce…

Nuclear: Energy for All Political Seasons

The electoral college will soon confirm a surprise election result, Donald Trump. However, in the electricity world, there are fewer surprises – physics and economics will continue to apply, and Republicans and Democrats are going to find a lot to like about nuclear energy over the next four years.

In a Trump administration, the carbon conversation is going to be less prominent. But the nuclear value proposition is still there. We bring steady jobs to rural areas, including in the Rust Belt, which put Donald Trump in office. Nuclear plants keep the surrounding communities vibrant.

We hold down electricity costs for the whole economy. We provide energy diversity, reducing the risk of disruption. We are a critical part of America’s industrial infrastructure, and the importance of infrastructure is something that President-Elect Trump has stressed.

One of our infrastructure challenges is natural gas pipelines, which have gotten more congested as extremely low gas prices have pulled m…