Gilbert R O, Engel D W, Anspaugh L R
Computational Sciences Department, Pacific Northwest Laboratory, Richland, WA 99352.
Sci Total Environ. 1989 Sep;85:53-62. doi: 10.1016/0048-9697(89)90304-5.
In this paper, estimates are obtained of the fraction of ingested 239+240Pu, 238Pu, 241Am and 137Cs transferred to blood, muscle, liver, kidney, femur, vertebra, and gonads of a reproducing herd of 17 beef cattle, individuals of which grazed within fenced enclosures for up to 1064 days under natural conditions with no supplemental feeding at an arid site contaminated 16 years previously with transuranic radionuclides. The estimated geometric mean (GM) GI-to-blood fractional transfer of 238Pu (0.0001) was about 20 times larger than the estimated transfer of 239+240Pu (0.000005), while the estimated transfer of 241Am (0.00001) was about 2 times larger than that of 239+240Pu. These GM GI-to-blood transfers were smaller than the GI-to-blood transfer value of 0.001 recommended by the International Commission on Radiological Protection (ICRP) for humans exposed via food chains or occupationally from unknown mixtures or compounds of plutonium and americium. Statistical tests indicated significantly (p less than 0.05) larger GI-to-tissue transfers of (1) 238Pu as compared to 239+240Pu for all tissues examined, (2) of 238Pu as compared to 241Am for muscle, liver, femur, and vertebra, and (3) of 241Am as compared to 239+240Pu for blood serum, femur, and kidney. The estimated GM fractional transfers of 137Cs from GI to muscle and liver were 0.03 (n = 8) and 0.001 (n = 3), respectively, assuming a 50-day biological half-time of 137Cs in cattle tissue.
本文给出了17头繁殖期肉牛摄入的239+240钚、238钚、241镅和137铯转移至血液、肌肉、肝脏、肾脏、股骨、椎骨和性腺的份额估计值。这些肉牛个体在自然条件下于围栏内放牧长达1064天，在一个16年前被超铀放射性核素污染的干旱场地，未进行补充饲喂。238钚从胃肠道到血液的估计几何平均（GM）转移份额（0.0001）约为239+240钚估计转移份额（0.000005）的20倍，而241镅的估计转移份额（0.00001）约为239+240钚的2倍。这些从胃肠道到血液的GM转移份额小于国际放射防护委员会（ICRP）针对通过食物链或职业途径接触未知钚和镅混合物或化合物的人类所推荐的0.001的胃肠道到血液转移值。统计检验表明，对于所有检测组织，（1）238钚从胃肠道到组织的转移显著（p小于0.05）大于2,39+240钚；（2）对于肌肉、肝脏、股骨和椎骨，238钚从胃肠道到组织的转移大于241镅；（3）对于血清、股骨和肾脏，241镅从胃肠道到组织的转移大于239+240钚。假设137铯在牛组织中的生物半衰期为50天，137铯从胃肠道到肌肉和肝脏的估计GM转移份额分别为0.03（n = 8）和0.001（n = 3）。
