TABLE Il
Factors for Converting Air Concentrations of Radioiodine
to Thyroid Dose via the Milk Pathway*
(mrem/yrper pCi/m?)
Age
I-129
Tyr
5830
4 yr
2400
14 yr
2040
Adult
2850**
*
°
1-130
I-13)
1-132
29.1
2665.
0.619
12.8
1100.
0.267
4.81
462.
3.75
379.
1-133
1
1-134
T-135
0.0624
8.30
41.3
0.0269
3.56
0.0968
16.0
0.00968
1.27
0.0747
12.3
0.00749
0.980
Assuming:
1} Grazing 365 days/yr. Factors for other grazing Seasons can
be obtained by multiplying tabulated values by fraction of
year during which cows graze.
2)
3)
4)
5)
6)
**
No other radioiodine intake by cow or person.
No decay between milking and consumption.
Consumption of 1 liter/day of milk.
All radioiodine is inorganic.
If only 2% of radioiodine is
in an inorganic form, then multiply DF's by (Z/100).
Ignoring long-term accumulation in soil, which for I-129
would add 1.3% in one year or 50% in 40 years.
Dose in first year.
Maximum dose rate after equilibrium is
reached between thyroid burden and intake rate would be 1.09
times this value.
Revised May 1976
J. K. Soldat