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You are the part-time local health director in a small community.
You are called with the news that an unknown person or group has
introduced radiologic material into the town’s water processing plant.
Radioactive iodine is found in the water. What do you do? What do
you tell your patients?
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As described in the previous chapter, terrorists could use nuclear
material in one of a half dozen scenarios: detonation of a nuclear
weapon, detonation of an IND, sabotage of a nuclear power facility,
or more probably, RPSs or RDDs. This chapter summarizes the known
health effects from exposure to nuclear materials.
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Although neither the detonation of a thermonuclear device, an
atomic bomb, nor an attack on a nuclear reactor would go unnoticed,
the use of RPSs and RDDs may not readily be detected as radioactivity
and cannot be detected by our senses. Exposure from an RPS or from
an RDD would only be known once symptoms of radiation-related illnesses
began or by detection using sensing devices such as a Geiger counter.
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Minimizing the health effects of radiation exposure is consequence
of three factors: time, distance, and barrier. There is a dose-dependent
relationship for the time of exposure and the amount of radiation
absorbed that directly impacts health effects. Similarly, exposure
decreases exponentially and proportionally to the distance from
a radiation source. Physical barriers, even if not leaded, provide
an effective shield. The denser the shielding, of course, the more
protection afforded.
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Radiation exposure comes from a wide range of natural and manmade
sources. Most naturally occurring atoms (e.g., thorium, uranium,
radium) that exist in the earth exist at thermodynamically low-energy
levels and are quite stable. The few that are unstable, (e.g., uranium)
attempt to become stable by releasing energy from their nuclei in
the form of radiation. There are internal body deposits of radiation
in living cells, including potassium-40, carbon-14, radium, and
others. External cosmic rays originate in outer space and exposure
to them increase twofold in mountainous regions, and even more at
jet aircraft altitudes. Human exposure to natural radiation is greater in
that area of the earth’s crust rich in radioactive elements.
X-rays from medical diagnostics and treatment are the largest source
of artificial ionizing radiation exposure. Additional exposures occur
from cigarettes, radioactive material in building materials or bedrock,
radon gas, and phosphate fertilizers. Production, regulatory, and
construction workers in the nuclear industry are exposed, although
stringent monitoring requirements are in place. Medical, emergency
response, and first-responder personnel may inadvertently be exposed
to radiation before they are aware that a nuclear terror event has
transpired.
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Radiation injuries result from three basic methods of exposure:
irradiation, external contamination, and internal contamination.
The location and severity of injury are influenced by these routes of
exposure. Irradiation is radiation exposure from an external source
without physical contact with the body. Irradiation from x-rays,
gamma rays, neutrons, or alpha or beta particles may be ...