NTS during the cascade impactor run was
measured to be 70 ug/m>,
Such derived values must, of course,
be used with a great deal of discretion.
They are based on simple model systems
air, and do not consider the additional
problems of resuspension of material
from contaminated clothing or the resuspension of materia! which has been transferred to homes,
Healy”° has
which are believed to be generally con-
considered these and
servative, but individual situations can be
other problems, and has provided tables
tions.
tion levels and home transfer levels.
of "decision levels" for surface contamina-
imagined which could exceed the predic-
A
decision level is based upon National
Other Considerations
Council on Radiation Protection and
The above calculations relate only to
Measurements (NCRP) recommended
the resuspended air activity in ambient
dose limitations,
Because the derivations
~
Table 152.
Decision levels 26 for soluble
239
Pu, and their equivalent in soil mass
based upon the "acceptable soil concentration" from Table 151.
Pathway
Decision level
A.
Direct personal contamination
2x 107° nCi/em?
Direct inhalation®
0.2 nCi/em”
Direct ingestion?
8X 1074 uci
Skin absorption*®
B.
1aSS equivalent
1x 1075 atom?
0.2 g/cm2
0.8¢
Transfer (to homes) levels
Resuspension®
0.01 .Ci/day
10 g/day
Direct inhalation
0.01 wCi/day
Direct ingestion
100 pCi/day
10 g/day
Skin absorption
0.03 pCi/day
30 g/day
10° g/day
aun,
gs
.
.
"The contamination level on clothing and skin that could result in inhalation of air
at the MPC, for the public.
burhe contamination level on skin or clothing that could result in ingestion of a
quantity of radioactive material equivalent to the ingestion of water at the MPC,
for an individual in the public.
“"The total quantity of radioactive material maintained on the skin for 24 h/day that
could result in absorption of a quantity equal to that which would be absorbed from
the Gi tract if water at the MPC. for "soluble" isotopes for an individual in the
public were ingest
Guthe amount transferred per day that could result in air concentrations due to
resuspension in a medium-sized home averaging at the MPC. for an individual in
the public. uZ&