氚的内照射剂量转换系数研究

Study on Internal Dose Coefficient of Tritium

不同的生物动力学模型给出的氚的摄入量滞留函数和剂量转换系数存在明显的差别。Crawford-Brown模型在氚化学形态转化描述和年龄段剂量转换系数分析上具有独特优势,本文在比较不同模型研究进展的基础上,重点对Crawford-Brown模型进行计算,给出不同年龄段的氚滞留函数和剂量转换系数,并同其他模型计算结果进行了详细的比较。结果显示,除了成人摄入氚水情况,Crawford-Brown模型计算给出的不同年龄段人群摄入氚水和有机氚的剂量转换系数都会比ICRP模型的高。随着年龄的减小,氚水和有机氚的相互转换愈发明显,剂量转换系数上的差别愈发明显。成人氚水摄入量滞留函数的比较表明,几种模型在100d内的滞留函数曲线几乎完全相同,只在长期滞留项上存在显著差别。

Retention functions and dose coefficients derived from some biokinetic models vary a lot.Crawford-Brown model has the unique advantage of describing chemical forms transfer of tritium and analyzing dose coefficients of different age groups.In this article,several important biokinetic models of tritium were introduced.Crawford-Brown model was especially analyzed,age-specific dose coefficients were calculated and the results were discussed.The results show that HTO and OBT dose coefficients derived from Crawford-Brown model are larger than that from the ICRP model in all age groups except for the adult group.As the age is smaller,the difference of the two models is more obvious because of the transfer of HTO and OBT.The comparison in adult retention functions of HTO ingestion shows that retention functions in the first 100 d are almost exactly the same,while the long retention terms are significantly different.