vs
17
Precipitation data from the Quarterly Health Physics Reports of
Atomic Energy of Canada, Limited.
|
,
The source of the elevated tritium in this table is the thermonuclear
_ testing carried out from 1952 through 1961.
Tritium from the more recent
thermonuclear tests has not yet appeared in precipitation samples.
There is some variation in the excretion pattern of tritium with age
following a single exposure.
This has no effect in the case cf continuous
exposure from the environment and the body burdens reflect the amount of
.
body water times the concentration in the environment.
The geographical pattern of tritium in precipitation in the United
States is available for 1963.
The data are shown in the following table.
Tritium in Precipitation-United States, 1963 Average
(U. S. Geological Survey Data)
~
Palmer, Alaska
Menlo Park, Calif. Salt Lake City
2950 Tritium Units
480
.
3670
Albuquerque
1870
Denver
Lincoln, Neb.
Madison, Wis.
Bismark
St. Louis
Baton Rouge
Boston
Washington
Ocala, Fla.
San Juan
3110
2280
2510
4370
1560
830
1410
1130
620
ako
Data from Stewart and Hoffman, Geological Survey Circular: 520 (1966)
Carbon-14
(Natural and Man-made)
Carbon-1h is produced in the atmosphere by cosmic-ray bombardment.
The
isotope has a long half-life (over 5000 years) and is mixed uniformly with
the carbon compounds of living matter to give an activity of about 6 pCci/gren