Pediatric emergency medicine trisk 1978 1978
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possible—whole body and local injury. A high dose of penetrating radiation over
a short period of time to a large portion of the body (i.e., whole-body radiation)
causes the acute radiation syndrome. Large doses of radiation over a short period
of time to a small portion of the body cause a local radiation injury. Analogous
medical situations would be whole-body radiation as conditioning for bone
marrow transplantation and localized radiation therapy for breast cancer. The
signs and symptoms of the acute radiation syndrome ( Table 90.13 ) begin to
appear after whole-body radiation doses of approximately 1 Gy. Organs with
rapidly dividing cells such as bone marrow and GI tract lining are the most
susceptible to radiation damage. The amount of damage that occurs is dependent
both on the dose and on the dose rate, for example, a dose of 1 Gy/min would
probably cause symptoms but 1 Gy at a dose rate of 10 mGy/day for 100 days
would likely be asymptomatic. Acute doses of about 4 Gy may be lethal in
approximately 50% of people if they do not receive medical treatment. With
maximum medical treatment, the dose of radiation that will kill 50% of people
may be as low as 6 Gy.
