b. Industrial Radiation.
(1) Nondestructive testing is a widely used technique in industry. An
example of this is the x-ray cabinet used in airports to examine the contents of hand
(2) Commodities manufacture. Many items, like the lensatic compass,
contain radioactive material. Frequently, items that glow in the dark do so because
they contain radioactive material.
c. Fallout from atmospheric testing of nuclear weapons also contributes to the
radiation we receive.
d. Nuclear power effluents contain some radioactive materials. They are
controlled by the Nuclear Regulatory Commission and monitored by the Environmental
e. Consumer Products. Some consumer products we use daily contain
radioisotopes or produce radiation.
(1) Color television sets have an amplifier that produces low energy x-rays.
These amplifiers are shielded to protect the consumer.
(2) Some smoke detectors use radioactive material in their operation. This
source is well sealed and of very low activity.
2-4. MACHINE-PRODUCED RADIATION SOURCES
a. Although there are a number of different machines designed to produce
ionizing radiation, the one most commonly found, particularly in a medical facility, is the
x-ray machine. X-ray machines play an important role in medical diagnosis and for this
reason they are abundant. A medical center may have as many as 25 to 100 separate
x-ray or fluoroscopy units.
b. X-rays, visible light, and gamma rays are all electromagnetic waves because
they consist of oscillating electric and magnetic fields. These electromagnetic
content. Electromagnetic radiations create wavelike disturbances in space similar to
the disturbances created if a stone is dropped into the center of a pool of water. A
series of crests and troughs are formed and these constitute an electromagnetic wave.
The distance between any two successive crests or troughs is known as the
wavelength (λ). In a vacuum, all EMR travel at the speed of light (3 x 1010 centimeters
/second). The number of waves (crests) passing a certain point per unit time is referred
to as the frequency (ν). The frequency will decrease as the distance between crests