- 33 —™ >
--
?
o
Laskin, et al, indicate a significant carcinogenic response
din the lung at 1400
of lung tissue °.
rem, suggesting a comparable sensitivity
Geesaman indicates that the tissue repair
time in the lung is of the order of one year’.
It therefore
seems appropriate, but not necessarily conservative, to accept
as guidance that this enhanced cancer risk occurs when particles
irradiate the surrounding lung tissue at a dose rate of 1000
rem/yr or more.
TABLE IV
Particle Activity and Size to Give a Dose of
.
1000 rem/year to the Surrounding Lung Tissue
“
Particle.
Activity
“°
(pCi) -
3/4 max inflated
1/2 max inflated
58
9
Particle Diameter (u)”
239
—**"%pu0,
«238 Pud2
(138 alveoli)
0.14
0.8
0.12
(
0.07
0.6
0.09
0.02
0.4
0.06 |
68 alveoli)
Closest 20 alveoli
56/
Laskin,
57/
Gecsaman,
58/
Ibid
59¢/
Based unen specific activity given by Langham, W.H.,
Op.
cit.,
Pp.
ét al, Op.
7.
cit.
Donald P., UCRL-50387, Op. cit.,
P.
ll.