Boecker B, Hall R, Inn K, Lawrence J, Ziemer P, Eisele G, Wachholz B, Burr W
Lovelace Inhalation Toxicology Research Institute, Albuquerque, NM 87185.
Health Phys. 1991;60 Suppl 1:45-100.
This report was prepared by a working group established by the Oak Ridge Associated Universities (ORAU) for the purpose of assessing the current capabilities of bioassay methods that can be used to determine the occurrence and magnitude of a previous internal deposition of one or more radionuclides. The first five sections discuss general features of the use of in-vitro bioassay samples to achieve this purpose. The remainder of the report is focused on the possible use of urine bioassay procedures to detect and quantify internal depositions of radionuclides that may have occurred in United States occupation troops in Hiroshima or Nagasaki, Japan, prior to 1 July 1946, or to personnel who participated in atmospheric nuclear weapons tests conducted between 1945 and 1962. Theoretical calculations were made to estimate the quantities of various radionuclides produced in a 20-kiloton (kt) nuclear detonation that might still be present in measurable quantities in people today if they were exposed 25 to 40 y ago. Two radionuclides that emerged as good choices for this type of bioassay analysis were 90Sr, which emits beta particles, and 239,240Pu, which emits alpha particles. The current status and future prospects of chemical procedures for analyzing in-vitro urine bioassay samples for these two radionuclides were examined to determine the minimum amounts that could be detected with current methods and how much one might expect the sensitivity of detection to improve in the near future. Most routine 239,240Pu bioassay analyses involve detection by alpha spectrometry. The current minimum detectable amount (MDA) is about 0.74 mBq L-1 (20 fCi L-1), but this could be lowered to 74 muBq L-1 (2 fCi L-1). An MDA of 0.74 mBq L-1 (20 fCi L-1) is adequate for routine bioassay analyses but is too high to detect most uptakes of 239,240Pu that may have occurred 25 to 40 y ago. Methods under development that are or can be much more sensitive and have lower MDAs than alpha spectrometry for 239Pu are fission track analysis and mass spectrometry. Currently, the fission track analysis method has an MDA of about 19 muBq L-1), and this may eventually be lowered to 1.9 muBq L-1 (0.005 fCi L-1). The current MDA for 239Pu by mass spectrometry is about 7.4 mBq L-1 (200 fCi L-1), but the potential exists that it could be lowered to a value of about 0.37 muBq L-1 (0.01 fCi L-1).(ABSTRACT TRUNCATED AT 400 WORDS)
本报告由橡树岭联合大学（ORAU）成立的一个工作组编写，目的是评估生物测定方法的当前能力，这些方法可用于确定一种或多种放射性核素先前体内沉积的发生情况和程度。前五节讨论了使用体外生物测定样本实现这一目的的一般特征。报告的其余部分重点关注尿液生物测定程序用于检测和量化1946年7月1日前可能在日本广岛或长崎的美国占领军，或1945年至1962年期间参与大气层核武器试验的人员体内可能发生的放射性核素体内沉积的可能性。进行了理论计算，以估计在一次20千吨（kt）核爆炸中产生的各种放射性核素的量，如果人们在25至40年前受到照射，如今这些放射性核素可能仍以可测量的量存在。对于这类生物测定分析，出现的两种很好的放射性核素选择是发射β粒子的90Sr和发射α粒子的239,240Pu。研究了用于分析这两种放射性核素的体外尿液生物测定样本的化学程序的现状和未来前景，以确定当前方法能够检测到的最小量，以及预计在不久的将来检测灵敏度可能提高多少。大多数常规的239,240Pu生物测定分析涉及通过α能谱法进行检测。当前的最低可检测量（MDA）约为0.74 mBq L-1（20 fCi L-1），但这一数值可降至74 μBq L-1（2 fCi L-1）。0.74 mBq L-1（20 fCi L-1）的MDA对于常规生物测定分析是足够的，但对于检测25至40年前可能发生的大多数239,240Pu摄取量来说太高了。正在开发的比239Pu的α能谱法更灵敏且MDA更低的方法是裂变径迹分析和质谱分析。目前，裂变径迹分析方法的MDA约为19 μBq L-1，最终可能降至1.9 μBq L-1（0.005 fCi L-1）。通过质谱分析测定239Pu的当前MDA约为7.4 mBq L-1（200 fCi L-1），但有可能降至约0.37 μBq L-1（0.01 fCi L-1）。（摘要截至于400字）
