Ainsbury Elizabeth A, Moquet Jayne, Rothkamm Kai, Darroudi Firouz, Vozilova Alexandra, Degteva Marina, Azizova Tamara V, Lloyd David C, Harrison John
Public Health England (PHE) CRCE, Chilton, Didcot, Oxfordshire OX11 0RQ, UK
Public Health England (PHE) CRCE, Chilton, Didcot, Oxfordshire OX11 0RQ, UK.
Radiat Prot Dosimetry. 2014 Jun;159(1-4):26-33. doi: 10.1093/rpd/ncu118. Epub 2014 Apr 15.
The fluorescence in situ hybridisation (FISH) technique is now well established for retrospective dosimetry in cases of external radiation exposure that occurred many years ago. However, the question remains as to whether FISH provides valid estimates of cumulative red bone marrow radiation doses in cases of incorporation of radionuclides or combined external and internal exposures. This question has arisen in connection with the interpretation of results of dose assessments for epidemiological studies of plutonium workers at the Russian Mayak plant and of members of the public exposed to strontium radioisotopes and external radiation as a result of discharges from Mayak to the Techa River. Exposures to penetrating external radiation result in fairly uniform irradiation of body tissues, and hence similar doses to all tissues, for which FISH dosimetry can provide a reliable measure of this whole body dose. However, intakes of radionuclides into the body by inhalation or ingestion may result in retention in specific organs and tissues, so that the distribution of dose is highly heterogeneous. For radionuclides emitting short-range radiations (e.g. alpha particles), this heterogeneity can apply to dose delivery within tissues and between cells within tissues. In this paper, an attempt is made to address the question of what FISH measures in such circumstances by considering evidence regarding the origin and lifetime dynamics of lymphocyte subsets in the human body in relation to the localised delivery of dose from the internal emitters (90)Sr and (239)Pu, which are of particular interest for the Southern Urals Mayak and Techa River populations, and for which most evidence is available in these populations. It is concluded that the FISH translocation assay can be usefully applied for detecting internal and combined external gamma and internal doses from internally deposited (90)Sr, albeit with fairly large uncertainties. The same may be true of (239)Pu, as well as other radionuclides, although much work remains to be done to establish dose-response relationships.
荧光原位杂交（FISH）技术现已广泛应用于多年前发生的外照射情况下的回顾性剂量测定。然而，对于放射性核素摄入或外照射与内照射联合作用的情况，FISH是否能有效估算累积红骨髓辐射剂量仍是个问题。这个问题是在解释俄罗斯马亚克工厂钚作业工人以及因马亚克向捷恰河排放而受到锶放射性同位素和外照射的公众剂量评估结果时出现的。穿透性外照射会使身体组织受到相当均匀的照射，因此所有组织的剂量相似，对于这种全身剂量，FISH剂量测定可以提供可靠的测量。然而，放射性核素通过吸入或摄入进入人体后可能会滞留在特定器官和组织中，从而导致剂量分布高度不均匀。对于发射短程辐射的放射性核素（如α粒子）而言，这种不均匀性可适用于组织内以及组织内细胞间的剂量传递。在本文中，我们试图通过考虑有关人体淋巴细胞亚群的起源和寿命动态的证据来解决这一问题，这些证据与来自内照射源（90）Sr和（239）Pu的局部剂量传递有关，这两种核素对南乌拉尔马亚克和捷恰河地区人群尤为重要，且这些人群有最多相关证据。得出的结论是，FISH易位分析可有效地用于检测来自体内沉积（90）Sr的内照射剂量以及外照射γ剂量与内照射剂量的联合剂量，尽管存在相当大的不确定性。对于（239）Pu以及其他放射性核素可能也是如此，不过要建立剂量反应关系仍有许多工作要做。
