radiographic services. These radionuclides have long half-lives. Many of
these sources are mostly in metallic capsule form and the likelihood of dis-
persion is minimal. However, they can be available in liquid and powder
forms and potentially be used in dirty bombs, which can result in wide-
spread contamination in the surrounding areas of explosion. Because one
cannot see, taste, or feel radiations, excessive exposure can be received
unknowingly by people in the vicinity of the area.
Types of Radiation Exposure
Radiation exposure from radiation accidents can be localized and/or whole-
body type. The localized exposure may be caused by direct handling of or
close proximity to highly radioactive sources. The local injury includes ery-
thema, epilation, desquamation, ulceration, or blistering depending on the
level of exposure. The treatment of choice for localized injuries is the use
of antibiotic for infection and control of pain. In severe cases, amputation
or plastic surgery is warranted.
The whole-body exposure causes various acute radiation syndromes that
have been discussed earlier in this chapter. These syndromes include hemo-
poietic, gastrointestinal, and cerebrovascular syndromes depending on the
absorbed doses. Although cerebrovascular syndromes occur with 10,000
rem (100 Sv), and result in death, the hemopoietic and gastrointestinal syn-
dromes may be managed by bone marrow transplantation and other pro-
phylactic treatment.
When a RDD explodes, radioactive material may be airborne and cont-
aminate food and water. Internal contamination can occur from the inges-
tion of contaminated food and water, inhalation of the contaminated air,
and diffusion through the skin or wounds. The principle of the treatment of
internal contamination primarily involves dilution, displacement by non-
radioactive material, complex formation, and blockage. In the case of inter-
nal contamination with radioiodine (e.g., incidences of fallout from a
nuclear explosion or a nuclear reactor accident), both the NRC and FDA
have approved the use of potassium iodide (KI) as a preventive measure.
Such use of KI is intended to block the thyroid from trapping^131 I and it
should be taken before the exposure or within several hours of exposure.
The recommended daily dose is 130 mg of KI for adults, 65 mg for 3 to 18
yr old, 32 mg for children 1 month to 3 yr old, and 16 mg for infants less than
1 month old (Mettler and Voelz, 2002).
Outer garments such as clothing and shoes can be contaminated by
radioactivity from the explosion of a dirty bomb. Such contamination does
not constitute a medical emergency and most of it can be removed by taking
off these garments. Minor skin contamination can be eliminated by thor-
ough washing with water and detergent, and a shower, if appropriate. Skin
should not be abraded by a heavy brush, as this may facilitate internal
absorption. If an individual has a life-threatening condition in addition to
Dirty Bombs 261