Radiological implications of inhaled 239Pu and 241Am in dusts at the former nuclear test site in Maralinga.
The biokinetics of 239Pu and 241Am present in three dust samples obtained from Maralinga were investigated after their deposition in the rat lung. Results were used as an experimental basis for assessing the radiological implications for human exposure. The transfer rates of these actinides to blood in the various dusts differed by 50-fold. The most transportable forms were compatible with a material that had 25% class W and 75% class Y characteristics. The doses per unit intake for adults, children, and infants exposed to an aerosol of 5 microns AMAD were calculated to be, respectively, 0.059, 0.076, and 0.140 mSv Bq-1. The corresponding doses for the least transportable forms were the same as those calculated for a class Y compound, namely 0.036, 0.049, and 0.096 mSv Bq-1. The behavior of the actinides in humans was predicted by combining the transfer rates to blood with mechanical clearance data obtained after volunteers had inhaled 85Sr or 88Y labeled fused aluminosilicate particles. The results suggested that monitoring of 241Am in the chest could be used to advantage for assessing intakes incurred by workers involved with any further decontamination procedures but would be of little practical value for assessing inadvertent public exposure. The paper includes comments on the relevance of the 1990 ICRP recommendations and the proposed new dosimetric model for the respiratory tract.
Stradling
G N
GN
National Radiological Protection Board, Chilton, Didcot, Oxon, United Kingdom.
Stather
J W
JW
Gray
S A
SA
Moody
J C
JC
Ellender
M
M
Pearce
M J
MJ
Collier
C G
CG
D000280:Administration, Inhalation; D000576:Americium / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D000818:Animals; D004391:Dust; D005260:Female; D008168:Lung / Q000378:metabolism*; D009689:Nuclear Warfare; D011005:Plutonium / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D011847:Radioactive Fallout; D051381:Rats; D013021:South Australia
D004391:Dust; D011847:Radioactive Fallout; D011005:Plutonium; D000576:Americium