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VII.
RADSOCESIUM
Sumnary
It
Cestum-137 is the significant cesium isotope in radioactive fallout.
ts a beta and gamma emitter with a 30-year physical half-life.
Since it is
similar to potassium in its metabolism, 137Cs fs distributed throughout the
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soft tissues of the body.
Its relatively uniform distribution throughout soft
“tissues brings about a declining whole-body exposure that its relatively short-
lived, since I37Cs is not retained in the body for long periods of time.
It
easfly moves through food chains and has been the subject of many radioecological tnvestigations.
Cesium-i37 was not appreciated as a significant fallout
dose canponent until {it was found to be present in people in the mid-1950s.
Environmental Pathways
The first report of cesium-137 in people came after its presence was noted
in measurements of whole-body radivactivity by gamma spectranetry (Miller and
Marinell{, 1956).
The persistence of '37Cs in the human body despite its
relatively short biological half-life was explained by continued exposure via
the diet; 137¢s was present jin meat and milk powders.
The presence of
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137Cg in people and tn various foods and its relation to 40% was reported
by Anderson et al. (1957) who calculated that the significant contributors to
dietary 137cs were dairy products. Dairy products and meat were considered
to be the primary sources of fallout I37e5, while inhalatton and ingestion
of drinking water were safd to contribute minimally to the 137cs houy burden
(Langham and Anderson, 1959).
The extent to which body burdens of 137Cs reflect dfetary inout was
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best exemplified in two human populations who were at the end of the