Module 2 Biological Effects
1. Acute radiation doses
a. High doses of radiation received in a short period of time
EO5 Define the terms "acute
are called acute doses. The body's cell repair
dose" and "chronic dose."
mechanisms are not as effective for damage caused by an
Acute doses to the whole body
After an acute dose, damaged cells will be replaced by
new cells and the body will repair itself, although this
may take a number of months. Only in extreme cases,
such as with the Chernobyl firefighters (500 rem), would
the dose be so high as to make recovery unlikely.
Acute doses to only part of the body
1) X-ray machines
It is possible that radiation exposure may be limited to a
part of the body, such as the hands.
There have been accidents, particularly with X-ray
machines, in which individuals have exposed their
fingers to part of the intense radiation beam. In some of
these cases, individuals have received doses of millions
of mrem to their fingers, and some individuals have lost
their finger or fingers. It is important for individuals
who work with X-ray or similar equipment to be trained
in the safe use of this equipment.
2) Radiation therapy
a) Radiation therapy patients receive high doses of
radiation in a short period of time, but generally only to a
small portion of the body (not a whole body dose).
b) The skin and limited tissue of these patients may receive
significant doses, but doses to the region of a tumor are
many times higher.