Salmon P L, Henshaw D L, Keitch P A, Allen J E, Fews A P
H.H. Wills Physics Laboratory, Bristol University, United Kingdom.
Radiat Res. 1994 Oct;140(1):63-71.
The technique of alpha-particle spectroscopy by CR-39 type TASTRAK plastic has been used to study the depth distribution of natural alpha-particle emitters at the surface of human bone. The predominant component of this alpha-particle activity was 210Po supported by 210Pb, although a smaller activity of 226Ra was also detected. Autopsy samples of human femur and cranium were obtained from subjects age 63 to 86. Both cortical and trabecular surfaces were analyzed. The results indicate that 210Pb-supported 210Po is concentrated at the surfaces of human bone from elderly subjects, in a narrow band 3 microns deep or less, by a factor of about four. As a result, the alpha-particle dose to the nuclei of cells lining bone surfaces is around 1.8 times greater than that calculated for a uniform volume distribution. Polonium-210 activity indicates the distribution of 210Pb, and of stable lead, received by continuous intake throughout life at a very low level. A persistent bone surface concentration of lead and other osteotropic metals may be associated with the hypermineralized layer about 1 micron thick which occurs at the surface of resting bone mineral.
利用CR - 39型TASTRAK塑料进行α粒子光谱分析技术，研究了人体骨骼表面天然α粒子发射体的深度分布。这种α粒子活性的主要成分是由210Pb支持的210Po，不过也检测到了较小活性的226Ra。人体股骨和颅骨的尸检样本取自63至86岁的受试者。对皮质表面和小梁表面均进行了分析。结果表明，由210Pb支持的210Po集中在老年受试者的人体骨骼表面，在深度为3微米或更浅的窄带中，其浓度约为均匀体积分布时的四倍。因此，骨表面衬里细胞核所接受的α粒子剂量比按均匀体积分布计算的剂量大约高1.8倍。钋 - 210的活性表明了在整个生命过程中以极低水平持续摄入的210Pb以及稳定铅的分布情况。铅和其他亲骨性金属在骨表面的持续浓度可能与静止骨矿物质表面出现的约1微米厚的矿化过度层有关。
