1
PLUTONIUM
1. PUBLIC HEALTH STATEMENT
This public health statement tells you about plutonium and the effects of exposure to it.
The Environmental Protection Agency (EPA) identifies the most serious hazardous waste sites in the
nation. These sites are then placed on the National Priorities List (NPL) and are targeted for long-term
federal clean-up activities. Plutonium has been found in at least 16 of the 1,689 current or former NPL
sites. Although the total number of NPL sites evaluated for this substance is not known, strict regulations
make it unlikely that the number of sites at which plutonium is found would increase in the future as more
sites are evaluated. This information is important because these sites may be
sources of exposure and
exposure to this substance may be harmful.
When a substance is released from a large area, such as an industrial plant, or from a container, such as a
drum or bottle, it enters the environment. This release does not always lead to exposure. You are
normally exposed to a substance only when you come in contact with it. You
may be exposed by
breathing, eating, or drinking the substance, or by skin contact. However, since plutonium is radioactive,
you can also be exposed to its radiation if you are near it.
External exposure to radiation may occur from natural or man-made sources. Naturally occurring sources
of radiation are cosmic radiation from space or radioactive materials in soil or building materials. Man-
made sources of radioactive materials are found
in consumer products, industrial equipment, atom bomb
fallout, and to a smaller extent from hospital waste and nuclear reactors.
When you are exposed to plutonium, many factors will determine whether you will be harmed. These
factors include the dose (how much), the duration (how long), and how you come in contact with it. You
must also consider any other chemicals you
are exposed to and your age, sex, diet, family traits, lifestyle,
and state of health.
PLUTONIUM
2
1. PUBLIC HEALTH STATEMENT
1.1 WHAT IS PLUTONIUM?
Radioactive metal
Plutonium is a radioactive element. Pure plutonium is a silvery-white metal.
Most plutonium is found combined with other substances, for example,
plutonium dioxide (plutonium with oxygen) or plutonium nitrate (plutonium
with nitrogen and oxygen).
Plutonium is usually measured in terms of its radioactivity (curies or
becquerels). Both the curie (Ci) and the becquerel (Bq) tell us how much a
radioactive material decays every second.
Exists in various
forms called
isotopes
The most common plutonium isotope is plutonium-239.
Plutonium is not
stable
Each radioactive isotope of an element constantly gives off radiation, which
changes it into an isotope of a different element or a different isotope of the
same element. This process is called radioactive decay.
Plutonium-238 and plutonium-239 give off alpha particles (sometimes
referred to as alpha radiation) and transform into uranium-234 and
uranium-235, respectively.
The half-life is the time it takes for half of the
atoms of a radionuclide to
undergo radioactive decay and change it into a different isotope. The half-
life of plutonium-238 is 87.7 years. The half-life of plutonium-239 is
24,100 years. The half-life of plutonium-240 is 6,560 years.
Produced in
Very small amounts of plutonium occur naturally. Plutonium-239 and
nuclear power
plutonium-240 are formed in nuclear power plants when uranium-238
plants and used
captures neutrons. Plutonium is used to produce nuclear weapons.
in nuclear
weapons and
Plutonium-238 is used as a heat source in nuclear batteries to produce
batteries
electricity in devices such as unmanned spacecraft and interplanetary
probes.
More information about the properties and uses of plutonium can be found in Chapters 4, 5, and 6.
1.2 WHAT HAPPENS TO PLUTONIUM WHEN IT ENTERS THE ENVIRONMENT?
Released during
testing of
nuclear weapons
Plutonium released during atmospheric testing
of nuclear weapons, which
ended in 1980, is the source of most of the plutonium in the environment
worldwide. The plutonium released during these tests was deposited on land
and water. The small amount that remains in the atmosphere continues to be
deposited as it slowly settles out.
Plutonium is also released to the environment from research
facilities, waste
disposal, nuclear fuel reprocessing facilities, nuclear weapons production
facilities, and accidents at facilities where plutonium is used.
3
PLUTONIUM
1. PUBLIC HEALTH STATEMENT
Deposited in
water or soil
Plutonium can be transported in the atmosphere usually when it is attached to
particles in the air. It can be deposited on land or water by settling or by rain.
Plutonium can stick to particles in soil, sediment, and water.
Plutonium isotopes will undergo radioactive decay in the environment.
For more information on
plutonium in the environment, see Chapter 6.
1.3 HOW MIGHT I BE EXPOSED TO PLUTONIUM?
You may be exposed to plutonium by breathing air, drinking water, or eating food containing plutonium;
however, the levels of plutonium in air, water, soil, and food are very low.
Soil
Average plutonium levels in surface soil from fallout range from 0.01 to
0.1 picocuries (pCi) per gram of soil (1 picocurie equals one-trillionth [10
-12
]
of a curie).
Air
Plutonium concentrations in air are generally low. Baseline plutonium-239
concentrations in air ranging from 1.6x10
-6
to 3.8x10
-6
pCi per cubic meter of
air (pCi/m
3
) have been reported.
Workplace
Persons who work at nuclear fuel and weapons production
facilities have a
greater chance of being exposed than individuals in the general population.
Accident
You could be exposed to plutonium if there was an accidental release of
plutonium during use. It is very unlikely you would be exposed as the result
of a traffic accident or disposal. Plutonium transport containers are virtually
indestructible by accident or fire. The disposal site is deep underground and
away from the public.
Further information on how you might be exposed to plutonium is given in Chapter 6.