|
|
Radiation is all around us, occurring naturally in the environment.
We are always exposed to radiation from:
- radon in the air
- uranium, radium and thorium in the earth
- cosmic rays from outer space and the sun
- radioactive potassium in our food and water
- naturally occuring radioactive material within our own bodies.
This is commonly called "naturally-occurring background radiation."
|
TYPES OF IONIZING RADIATION
| |
Alpha
|
Alpha particles can be shielded by a sheet of paper or by human skin.
If alpha emitters are inhaled, ingested, or enter the body through a cut, they can cause cancer.
| |
Beta
|
Beta radiation can be stopped by a shield like aluminum foil or wood.
If beta emitters are inhaled, ingested, or enter the body through a cut, they can cause cancer.
| |
Gamma
|
Gamma rays (and x-rays) are a very penetrating type of radiation.
Protection from gamma rays requires heavy shielding [e.g., lead, steel, depleted uranium (DU)].
This type of radiation can cause cancer and, in high doses, Acute Radiation Syndrome (ARS) even if the source is outside the body.
| |
Neutrons
|
Neutron radiation can be shielded by water, plastic, borated metals, and concrete.
Neutrons are subatomic particles emitted during the spontaneous fission of uranium and plutonium and from nuclear reactors.
Neutron radiation like gamma radiation is highly penetrating and carcinogenic; however, it has a relative biological effectiveness (RBE) twice that of gamma radiation.
|
|
