Læknablaðið - 01.10.1968, Blaðsíða 57

LÆKNABLAÐIÐ
2i r>
EFFECTS OF ACUTE WHOLE BODY RADIATION
I r No detectable effect
lOr Very slight changes in lymphocytes
lOOr Slight depression of white blood cell count
Slight nausea and vomiting
lOOOr Severe depression of blood elements including platelets
Severe vomiting and diarrhea
Death within 20 days
lO.OOOr Immediate disorientation orcoma
Prompt death
Table 1.
Effects of given amounts of whole-body radiation arranged by orders
of magnitude.
penetrating, highly injurious alpha particles of radium and of
plutonium, as well as of other man-made elements; the
beta particles of radium and of many radioactive isotopes;
and the X-rays as well as tlie gamma rays ol' radium and
of still other isotopes. The heta particle is intermediate
in penetration and in damaging effect. The gamma and
X-rays tend to be more penetrating and hence can cause
extensive injury. In addition, the neutron, a parlicle having mass
hut not electric charge, formed by an atomic reactor or in the
hurst of an atomic homh, has great penetrating power, causes
extensive ionization in tissue and hence produces much injury
(Fig. 2).
A given physically-measured dose of radiation will vary in
its biologic effect with the character of the radiation, and this
relationship is expressed hy a factor called the relative hiologic
efficiency. In general, gamma or X-ray radiations are considered
to have a factor of 1; beta rays also liave a factor of 1, whereas
alpha rays luive a factor of 10, and neutrons, depcnding on their
characteristics and the object irradiated, a factor ranging from
3 to 20.
Most cells of the body, with the exception of germinal
epithelium, have great power to repair cells damaged hy radiation