Plutonium Leaks in Japan: What Are the Real Dangers?

April 2nd, 2011

Plutonium Leaks in Japan

What are the real dangers?

Because of the Japan nuclear accidents, many people are reading about and becoming concerned about plutonium. The information below should serve to put your mind at ease about any risk we in the U.S. might have due to plutonium exposure.

Plutonium is a man made element created from uranium and used as a fuel in nuclear power plants.

External exposure to plutonium presents very little risk because it throws off weak alpha radiation that cannot penetrate our skin.

Ingestion of plutonium does not pose much of a risk either, because it passes through our GI tract, is poorly absorbed and is eliminated without doing harm.

Plutonium can be dangerous when it is inhaled and therefore circumvents the GI tract. Then it can remain in our systems for decades, exposing our cells/tissues/organs to radiation and substantial risk of cancer.

The risk of airborne plutonium coming from Japan is almost negligible because of the distance and the fact that plutonium is heavy and will fall to the ground.

External exposure to plutonium poses very little health risk, since plutonium isotopes emit alpha radiation, and almost no beta or gamma radiation.

Ingestion is not a significant hazard, because plutonium passing through the gastro-intestinal tract is poorly absorbed and is expelled from the body before it can do harm.

Internal exposure to plutonium is an extremely serious health hazard. It generally stays in the body for decades, exposing organs and tissues to radiation, and increasing the risk of cancer.

The main threat to humans comes from inhalation. While it is very difficult to create airborne dispersion of a heavy metal like plutonium, certain forms are a hazard. If inhaled, much of the material is immediately exhaled. Some however will be trapped and transferred, first to the blood and later to other parts of the body, notably the liver and bones. It is here that the deposited plutonium’s alpha radiation may eventually cause cancer, and generally stays in the body for decades.

How does plutonium get into the environment?

Plutonium was dispersed worldwide from atmospheric testing of nuclear weapons conducted during the 1950s and ‘60s. The fallout from these tests left very low concentrations of plutonium in soils around the world.

Nuclear weapons production and testing facilities (Hanford, WA; Savannah River, GA; Rocky Flats, CO; and The Nevada Test Site, in the United States, and Mayak and Semi Plafinsk in the former Soviet Union), also released small amounts. Some releases have occurred in accidents with nuclear weapons, the reentry of satellites that used Pu-238, and from the Chernobyl nuclear reactor accident.

How does plutonium change in the environment?

All isotopes of plutonium undergo radioactive decay. As plutonium decays, it releases radiation and forms other radioactive isotopes. For example, Pu-238 emits an alpha particle and becomes uranium-234; Pu-239 emits an alpha particle and becomes uranium-235.

This process happens slowly since the half-life of plutonium isotopes tend to be relatively long: Pu-238 has a half-life of 87.7 years; Pu-239 has a half-life is 24,100 years, and Pu-240 has a half-life of 6,560 years. The decay process continues until a stable, non-radioactive element is formed.

How do people come in contact with plutonium?

Residual plutonium from atmospheric nuclear weapons testing is dispersed widely in the environment. As a result, virtually everyone comes into contact with extremely small amounts of plutonium.

People who live near nuclear weapons production or testing sites may have increased exposure to plutonium, primarily through particles in the air, but possibly from water as well. Plants growing in contaminated soil can absorb small amounts of plutonium.

How does plutonium get into the body?

People may inhale plutonium as a contaminant in dust. It can also be ingested with food or water. Most people have extremely low ingestion and inhalation of plutonium. However, people who live near government weapons production or testing facilities may have increased exposure. Plutonium exposure external to the body poses very little health risk.

What does plutonium do once it gets into the body?

The stomach does not absorb plutonium very well, and most plutonium swallowed with food or water passes from the body through the feces. When inhaled, plutonium can remain in the lungs depending upon its particle size and how well the particular chemical form dissolves. The chemical forms that dissolve less easily may lodge in the lungs or move out with phlegm, and either be swallowed or spit out. But, the lungs may absorb chemical forms that dissolve more easily and pass them into the bloodstream.

Once in the bloodstream, plutonium moves throughout the body and into the bones, liver, or other body organs. Plutonium that reaches body organs generally stays in the body for decades and continues to expose the surrounding tissue to radiation.

Health Effects of Plutonium:

How can plutonium affect people’s health?

External exposure to plutonium poses very little health risk, since plutonium isotopes emit alpha radiation, and almost no beta or gamma radiation. In contrast, internal exposure to plutonium is an extremely serious health hazard. It generally stays in the body for decades, exposing organs and tissues to radiation, and increasing the risk of cancer. Plutonium is also a toxic metal, and may cause damage to the kidneys.

Is there a medical test to determine exposure to plutonium?

There are tests that can reliably measure the amount of plutonium in a urine sample, even at very low levels. Using these measurements, scientists can estimate the total amount of plutonium present in the body. Other tests can measure plutonium in soft tissues (such as body organs) and in feces, bones, and milk. However, these tests are not routinely available in a doctor’s office because they require special laboratory equipment.

Protecting People from Plutonium

What can I do to protect myself and my family from plutonium?

Since plutonium levels in the environment are very low, they pose little risk to most people. However, people who live near government weapons production or testing sites may have higher exposure.

Plutonium particles in dust are the greatest concern, because they pose the greatest health risk. People living near government weapons facilities can track radiation monitoring data made available by site personnel. If radiation levels rise, they should follow the radiation protection instructions given by site personnel.