Radiation Studies Branch
Psychological First Aid in Radiation Disasters


Conference of Radiation Control Program Directors (CRCPD)
an organization whose members represent state radiation protection programs. For more information, see the CRCPD website: http://www.crcpd.org.
Contamination (radioactive)
the deposition of unwanted radioactive material on the surfaces of structures, areas, objects, or people where it may be external or internal. See also decontamination.
the reduction or removal of radioactive contamination from a structure, area, object, or person.
Dirty bomb
a device designed to spread radioactive material by conventional explosives when the bomb explodes. A dirty bomb kills or injures people through the initial blast of the conventional explosive and spreads radioactive contamination over a potentially large area—hence the term “dirty.” Such bombs could be miniature devices or large truck bombs. A dirty bomb is much simpler to make than a true nuclear weapon. See also radiological dispersal device.
Dose (radiation)
the amount of radiation absorbed by a person’s body.
Exposure (radiation)
a measure of ionization in air caused by x-rays or gamma rays only. The unit of exposure most often used is the roentgen. See also contamination.
External exposure
exposure to radiation outside of the body.
Geiger counter
a radiation detection and measuring instrument consisting of a gas-filled tube containing electrodes, between which an electrical voltage but no current flows. When ionizing radiation passes through the tube, a short, intense pulse of current passes from the negative electrode to the positive electrode and is measured or counted. The number of pulses per second measures the intensity of the radiation field. Geiger counters are the most commonly used portable radiation detection instruments.
Prenatal radiation exposure
radiation exposure to an embryo or fetus while it is still in its mother’s womb.
energy moving in the form of particles or waves. Familiar forms of radiation are heat, light, radio waves, and microwaves. Ionizing radiation is a very high-energy form of electromagnetic radiation.
Radioactive contamination
the deposition of unwanted radioactive material on the surfaces of structures, areas, objects, or people. It can be airborne, external, or internal. See also contamination, decontamination.
Radioactive material
material that contains unstable (radioactive) atoms that give off radiation as they decay.
Radiological or radiologic
related to radioactive materials or radiation. The radiological sciences focus on the measurement and effects of radiation.
Radiological dispersal device (RDD)
a device that disperses radioactive material by conventional explosive or other mechanical means, such as a spray. See also dirty bomb.