Steven Starr, implications of radioactive cesium contamination — Part I


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The Implications of The Massive Contamination of Japan With Radioactive Cesium
Steven Starr

Senior Scientist, Physicians for Social Responsibility
Director, University of Missouri, Clinical Laboratory Science Program
Helen Caldicott Foundation Fukushima Symposium
New York Academy of Medicine, 11 March 2013

Biographical Sketch of Steven Starr
Bibliography of Recently Published Works

from TUC Radio’s 10-part Fukushima Symposium Mini-Series
Recordings from March 11 and 12, 2013

Broadcast quality mp3 of the 30 minute program is here: <> (20.8 MB)

( PDF format )


Thank you very much. It’s a pleasure to be here today. A large number of highly radioactive isotopes released by the destruction of the Fukushima Daiichi nuclear power plant grossly contaminated the Japanese mainland. Most of these radionuclides had short half lives which meant they would essentially disappear in a matter of days or months. For many of those who were exposed to them there will be major health consequences.

However, there were some radioactive elements that will not rapidly disappear. And it is these long-lived radionuclides that will remain to negatively affect the health of all complex life forms that are exposed to them.


Chief among them is Cesium-137, which has taken on special significance because it is has proven to be the most abundant of the long-lived radionuclides that has remained in the environment following the nuclear disasters at Chernobyl and Fukushima. It has a 30 year radioactive half life which is why it persists in the environment. Scientists now believe that it will be 180 to 320 years before the Cesium-137 around the destroyed Chernobyl reactor actually disappears from the environment.

Cesium is water soluble and quickly makes its way into soils and waters. It is in the same atomic family as potassium and it mimics it, acting as a macronutrient. It quickly becomes ubiquitous in contaminated ecosystems.

It is distributed by the catastrophic accidents at nuclear power plants because large quantities of volatile radioactive cesium build up inside the fuel rods of nuclear reactors. Thus any accident at a nuclear reactor that causes the fuel rods to rupture, melt, or burn will cause the release of highly radioactive cesium gas.

Long-lived radionuclides such as Cesium-137 are something new to us as a species. They did not exist on Earth in any appreciable quantities during the entire evolution of complex life. Although they are invisible to our senses they are millions of times more poisonous than most of the common poisons we are familiar with. They cause cancer, leukemia, genetic mutations, birth defects, malformations, and abortions at concentrations almost below human recognition and comprehension. They are lethal at the atomic or molecular level.

They emit radiation, invisible forms of matter and energy that we might compare to fire, because radiation burns and destroys human tissue. But unlike the fire of fossil fuels, the nuclear fire that issues forth from radioactive elements cannot be extinguished. It is not a fire that can be scattered or suffocated because it burns at the atomic level—it comes from the disintegration of single atoms.

Thus, radioactivity is a term which indicates how many radioactive atoms are disintegrating in a time period. We measure the intensity of radioactivity by the rate of the disintegrations and the energy they produce.


One Becquerel is equal to one atomic disintegration per second.

One Curie is defined as that amount of any radioactive material that will decay at a rate of 37 billion disintegrations per second.

So one Curie equals 37 billion Becquerels.


Sometimes these man-made radionuclides are compared to naturally occurring radionuclides, such as Potassium-40, which is always found in bananas and other fruits. However this is a false comparison since naturally occurring radioactive elements are very weakly radioactive. In the lab chart the radioactivity is described as the “specific activity”. Note that Potassium-40 has a specific activity of 71 ten millionths of a Curie per gram. Compare that to the 88 Curies per gram for Cesium-137. This is like comparing a stick of dynamite to an atomic bomb.

Highly-radioactive fission products such as Cesium-137 and Strontium-90 emit 10 to 20 million times more radiation per unit volume than does Potassium-40. So which one of these would you rather have in your bananas?

Cs-137 10 million times more radioactive than Potassium-40

It is in fact the amount of Cesium-137 deposited per square kilometer of land that defines the degree to which an area is classified as being too radioactive to work or live. One may get an idea of the extreme toxicity of Cesium-137 by considering how little of it is required to make a large area of land uninhabitable.

Chernobyl: Cs-137 contamination

The lands that were grossly contaminated by the destruction of the Chernobyl nuclear power plant are classified by the number of Curies of radiation per square kilometer. There were 3840 square miles of land contaminated with 15 to 40 Curies of radiation per square kilometer. These lands are considered strict radiation dose-control zones.

Chernobyl: Cs-137 contamination
High Resolution Map Detail

The 1100 square mile uninhabitable exclusion zone that surrounds the destroyed Chernobyl reactor has greater than 40 Curies of radioactivity per square kilometer. For those more familiar with square miles, that would be 104 Curies per square mile.

Consider again that one gram of Cesium-137 has 88 Curies of radioactivity.

Thus, as little as one third of a gram of Cesium-137, made into microparticles and distributed as a smoke or gas over an area of one square kilometer, will make that square kilometer uninhabitable.

2 grams of Cs-137 - less than the weight of a US dime, distributed evenly over CentralPark, would make it a radioactive exclusion zone

Less than two grams of Cesium-137, a piece smaller than an American dime, if made into microparticles and evenly distributed as a radioactive gas over an area of one square mile, will turn that square mile into an uninhabitable radioactive exclusion zone. Central Park in New York City can be made uninhabitable by 2 grams of microparticles of Cesium-137. Hard to believe, isn’t it?

Remember, these nuclear poisons are lethal at the atomic level. There are as many atoms in one gram of Cesium-137 as there are grains of sand in all the beaches of the world. That’s 1021 atoms—10 to the 21st power. 1480 trillion of them or 1.48 times 10 to the 12th power are disintegrating every second, releasing invisible nuclear energy. So this works out to about one and a half million disintegrations per second per square meter. We can see how this works then.

150 million Curies Cs-137 in the spent fuel at Indian Point. Sources: Reconstruction and Analysis of Cesium-137 Fallout Deposition Patterns in the Marshall Islands, U.S. Centers for Disease Control, 2000; National Council on Radiation Protection and Measurement, Cesium-137 in the Environment, Report No. 154, September 2007, Table 3.1,; Nuclear Energy Institute, Spent Nuclear Fuel at U.S. Reactors, December 2011,; and U.S. NRC, Characteristics for the Representative Commercial Spent Fuel Assembly for Preclosure Normal Operations, May 2007, Table 16.

Note the immense inventories of Cesium-137: 150 million Curies that are located in the nearby spent fuel pool at Indian Point Nuclear Power Plant which is about 40 miles from here by road and less than that as the radioactive cloud flies. Many of the 104 US commercial nuclear reactors and power plants have more than 100 million Curies of Cesium-137 in their spent fuel pools. This is many times more than in the spent pools at Fukushima.

So now that we have some idea of the extreme toxicity of Cesium-137, let’s look at the extent of the contamination of the Japanese mainland.

Fukushima Explosion, March 11, 2011

It is now known that the reactors 1, 2, and 3 at Fukushima Daiichi all melted down and melted through the steel reactor vessels within a few days following the earthquake and tsunami of March 11, 2011. This was not made public by either TEPCO or the Japanese government for two months.

Editor‘s note: this transcript was created from the broadcast quality audio recording program featuring Steven Starr produced by Maria Gilardin in her Fukushima Symposium Mini Series on TUC Radio. Starting with the PDF file in the March 11 Documents tab of <>, the text below was fashioned using Maria’s Introduction and Mr. Starr’s actual presentation. (All highlighted text in the original PDF – e.g., underlining, italics, bold – is represented below as underlined text.) The slides were generated from copy generously provided by Mr. Starr. I am grateful for the assistance of Steven Starr and Maria Gilardin in assembling this presentation.