long term biological removal rate constant for juvenile Marshallese did not
agree with reported data.
This appears to occur because of the difference
in the age distribution of the juvenile data reported in NCRP report 52 and
that of the Marshallese juveniles.
The 137
Cs long term biological removal rate constant for the Marshallese
population is highly dependent on body mass.
This relationship is best de-
scribed by a simple logarithmic equation of the form
k= a+b In(m)
(2)
The coefficient of determination for this equation is 0.79 for females and 0.89
for males.
The regression coefficients a and b are respectively 19 and -3.9 for
males, and 16 and -2.6 for females.
The units for the quantities mass, m, and
biological rate constant, k, are kg and year! tespectively.
The impact of mass
on the rate constant is greatest for body masses less than 60 kilograms.
Similar results were reported in studies by Lloyd (L173) which related body mass
to biological half-life for 13766.
Several investigators have reported that 60c, exhibits a long term biclog~
ical removal rate constant for both inhaled insoluble cobalt (Jo65, $i64) and
CoCl administered orally or intravenously (Le72, 5m72).
These investigators
agree that the retention function for cobalt should have several compartments
whose retention is characterized by linear first order removal mechanisms.
For
ingestion, four and five compartment models have been postulated to describe the
retention of soluble CoCl.
Using the average of values reported by Smith (Sm 72) and rounding to
significant figures, the single intake retention function would be of the form
R(t) = 0.5e 174
4t
+ o.ge fe2* § Ole
-0.12t
+ 0.1
e 0 00087t
(3)