电离辐射的原发和继发效应及危害评价

Primary and secondary effects induced by ionizing radiation and their hazard evaluation

射线在与物质发生原发作用的同时,产生次级电子和辐射。一定能量的次级电子和辐射可在组织中穿行一定距离,具有与原发作用部位以外的物质发生次级电离和激发的能力。原发辐射作用诱导产生的辐射毒素(一类具有高溶蛋白、溶脂和溶碳水化合物性质的糖蛋白)也可借血液和体液循环输送到远离原发作用的部位,诱导类似原发辐射作用的效应。因此,辐射诱导的效应既可发生在射线作用的原始部位,也可发生在远离原始作用部位的地方。辐射效应包括原发效应和继发效应,低剂量辐射效应评价既要观察早期效应,更应关注远期效应,既要注意离体细胞和整体动物实验结果,更要注重人群流行病学调查结果。

Ionizing radiation interacts with material meanwhile secondary electrons and radiation are produced. The secondary electrons and the radiation with certain energy can travel within the organization and have secondary ability producing ionizing or excitation when interacted with materials. In addition, the radiation toxins （glycoproteins with high enzymatic activity including high proteolytic, lipidolytic and carbohydratelytic properties） produced by primary radiation effect can be transferred through blood and fluid circulation to the place far away from the primary site of radiation interaction and induce effect similar to the primary radiation. It is visible that the effect induced by radiation can occur in both sites of the rays primarily hitting and the sites far away from the original. Both primary and secondary effects can be induced in different places. Radiation hazard evaluation of low dose exposure should not only see the early radiation effects but also consider the late effects induced by radiation and should not only pay attention to results from somatic cells and whole animal experiments and more should pay attention to the results from epidemiological survey of population.