N. Ishigure et al., LUNG RETENTION OF PU FOLLOWING INHALATION OF PUO2 IN RATS MEASURED USING A WHOLE-BODY COUNTER, Journal of radiation research, 35(1), 1994, pp. 16-25
A lung retention function on the amount of PuO2 in rats was determined
. Five rats were exposed to polydisperse aerosols of PuO2 having a siz
e of 0.47 mu m activity median aerodynamic diameter. The initial lung
burden was between 1990 Bq and 2960 Bq. Instead of serial-sacrifice st
udy, in vivo counting of low energy L X-rays with thin NaI(Tl) scintil
lation detectors was used to follow the lung retention of Pu at variou
s intervals up to 468 days after inhalation. The calibration of this c
ounting system was made by measuring lung activity of rats sacrificed
for other experimental purposes. It was confirmed that the potential s
kin contamination and the Pu translocated to the other organs was not
counted at the present counting geometry. Our results showed that 77%
of PuO2 deposited deep in the lung was cleared with a half-time of 53
days, whereas the residual 23% stayed there for a longer period (a hal
f-time of 795 days).