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引言~(129)I是核裂变的副产物,因而是核动力发生站、核燃料重处理工厂和核废品贮存库的可能排出物。由于这种核素的物理半衰期长达1.57×10~7年,所以甲状腺从~(129)I所吸收的每单位活性剂量,极大地取决于甲状腺中碘的长期清除速率。为了估计这种长期清除函数(时间函数),对那些为了医学诊断目的已经接受这种核素,并志愿作为以后测量的个人做了甲状腺~(125)I的测量(物理半衰期60.14天)。许多研究者(由ICRP概括)已研究了甲状腺放射性碘从开始摄入到为期40～60天后的损失。这些足以计算~(131)I吸收剂量的数据,但是不足于去预测~(129)I的剂量,因为许多个体大于初始摄入的75%残留60天之久。长期存留研究的报道是少有的。Bordell和
INTRODUCTION ~ (129) I is a by-product of nuclear fission and is therefore a potential effluent from nuclear power stations, nuclear fuel refineries and nuclear waste repositories. Because of the physical half-life of this nuclide, which is as long as 1.57 × 10-7 years, the amount of active unit absorbed by thyroid from ~ (129) I greatly depends on the long-term iodine removal rate in thyroid. In order to estimate this long-term clearance function (time function), thyroid 125I measurements (physical half-lives of 60.14 days) were made for those who had already accepted this nuclide for medical diagnostic purposes and volunteered for later measurements. Many investigators (summarized by ICRP) have studied the loss of thyroid radioactive iodine from the initial intake for 40 to 60 days. These are sufficient data to calculate the ~ (131) I absorbed dose, but not enough to predict the dose of ~ (129) I since many individuals remain for more than 60% of the initial intake of 75%. Long-term survival studies are rare. Bordell and