(2)
Conducting surveys of leakage or exposure to radioactive sources.
(3)
Enforcing the standing operating procedures (SOPs).
b. Surveillance Programs.
(1) Physical. A complete physical should be given periodically with
particular attention given to any specific complaint. A specific complaint may be an
indication of too much exposure to radiation.
(2) Bioassay for radioisotopes. This test is performed if it is suspected that
an individual has been overexposed to radiation. For example, suppose an individual
has been working in a laboratory around radioactive material. There is a possibility that
he has been exposed to too much radiation. A blood sample is taken and put in a
machine which counts the amount of radioactivity. That amount is compared to the
standard amount.
(3) Film badge program. This program is a way of tracking the amount of
radiation an individual working with or around radiation accumulates. The individual is
given a badge on which his assigned number appears. The badge measures the
amount of radiation his body receives each day. Periodically, the badge is checked to
see whether the accumulated amount of radiation the person has received is normal or
excessive. If he has received too much radiation, there may be a leak in the equipment
which must be fixed. Suppose this person leaves this job and works in an area without
radiation. After a year, he returns to a job in an area where there is radiation. He puts
on his badge again, and the badge continues to record the radiation his body is
receiving. This amount of radiation is added to the total amount of the previous
radiation.
c. Methods to Reduce Exposure.
(1) Time. Keep the length of time personnel are exposed to radiation to a
minimum. The total radiation dose equals the radiation dose per hour times the
exposure time. Keep the exposure time for each individual as low as possible.
(2) Distance. The farther away a person is from the radiation source, the
better (see formula). If you move twice the distance away from the radiation source,
your exposure is lowered to one-fourth. Move three times the distance away, and your
exposure is reduced to one-ninth as much as before. Remember, then, that moving
even a small distance away, 10 or 20 feet, reduces exposure considerably.
1
EXPOSURE = ---------------------
(distance) 2
MD0587
2-9