the Bikini Island options.

inhalation rate in pCi/da.

The Eneu

A mass

living pattern, therefore, has more

loading of 100 g/m? is at the high

flexibility for potential exposure via

end of the observed range for normal

other pathways without exceeding Fed-

open air aerosol measurements.

eral guidelines.

ever, since local resuspension created

How-

in the immediate vicinity of an indi-

INHALATION PATHWAY

vidual during his normal activities
No air sampling data were taken

Open

measurements, it appears reasonable,

field aerosols were measured to some

for lack of specific data, to use the

extent previously at Bikini Atoll. 8°27

higher number.

Because of the sparsity of data, how-

concentrations in the surface soils

ever,

(O to 5 cm) of Bikini and Eneu Islands

and also the lack of data on

The average 239, 2405,

resuspension processes in the atoll

are 9.3 and 1.4 pCi/g, respectively.

environment, the average concentra-

The pCi/day intake resulting from the

tions of Pu in the soil were used in a

above model is, therefore,

mass loading model to predict the

Bikini and 0.0028 for Eneu.

0.019 for

The doses resulting from inhalation

doses via the inhalation pathway.
This is the same approach used to

of 241,240, are listed in Table 10 for

evaluate the inhalation pathway at

the three critical organs:

Enewetak Ato11.28

and liver.

The mass loading concept may be

lung, bone,

The doses predicted on

Eneu are, of course,

less than those

more relevant for estimating the

predicted on Bikini Island.

potential dose via inhalation than

doses will be compared below with bone

‘open air aerosol measurements because

and whole body dose from other pathways.

is reflected in open air measurements.

in the soil on Bikini and Eneu is

Therefore, it is assumed that the con-

approximately 10 times that of

centration of Pu observed in the sur-

239, 2405, 3

face soil at Bikini and Eneu Islands

energy beta radiation (0,021 MeV maxi-

will remain the same in the respir-

mum) and a much shorter half life

able, resuspended surface material.

(14 yr) the integrated 30-, 50-, and

In addition, a mass loading of

70-yr doses from 24doy are more than

100 gsm and a breathing rate of

one-tenth less than those listed in

20 m>/da were used to develop the Pu

Table 10 for 239,240,

loas

be

LapeEct

Se

Xgl n tal

eee

ment may be significantly greater than

Two other isotopes must be consid24tn
ered in the inhalation pathway —
241 Pu
24.an.
and
The concentration of

at dniotaanee

These

Ans

Lehele

ek a

aer A oe Ped ae bo

ee

during the 1975 Bikini survey.

is probably greater than open air

the resuspended material created by a
person in his own immediate environ~

90099b8

-18-

However, because of low

Select target paragraph3