Okada S, Momoshima N
Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka, Japan.
Health Phys. 1993 Dec;65(6):595-609. doi: 10.1097/00004032-199312000-00001.
Tritium has certain characteristics that present unique challenges for dosimetry and health-risk assessment. For example, in the gas form, tritium can diffuse through almost any container, including those made of steel, aluminum, and plastics. In the oxide form, tritium can generally not be detected by commonly used survey instruments. In the environment, tritium can be taken up by all hydrogen-containing molecules, distributing widely on a global scale. Tritium can be incorporated into humans through respiration, ingestion, and diffusion through skin. Its harmful effects are observed only when it is incorporated into the body. Several sources contribute to the inventory of tritium in our environment. These are 1) cosmic ray interaction with atmospheric molecules; 2) nuclear reactions in the earth's crust; 3) nuclear testing in the atmosphere during the 1950s and 1960s; 4) continuous release of tritium from nuclear power plants and tritium production facilities under normal operation; 5) incidental releases from these facilities; and 6) consumer products. An important future source will be nuclear fusion facilities expected to be developed for the purpose of electricity generation. The principal health physics problems associated with tritium are 1) the determination of the parameters for risk estimation with further reduction of their uncertainties (e.g., relative biological effectiveness and dose-rate dependency); 2) risk estimation from complex exposures to tritium in gas form, tritium in oxide form, tritium surface contamination, and other tritium-contaminated forms, with or without other ionizing radiations and/or nonionizing radiations; 3) the dose contributions of elemental tritium in the lung and from its oxidized tritium in the gastrointestinal tract; 4) prevention of tritium (in oxide form) intake and enhancement of tritium (oxide form) excretion from the human body; 5) precise health effects information for low-level tritium exposure; and 6) public acceptance of tritium leakage and waste disposal from reactors and fuel reprocessing plants.
氚具有某些特性，这些特性给剂量测定和健康风险评估带来了独特的挑战。例如，以气体形式存在时，氚几乎可以扩散穿过任何容器，包括由钢、铝和塑料制成的容器。以氧化物形式存在时，常用的检测仪器通常无法检测到氚。在环境中，氚可以被所有含氢分子吸收，在全球范围内广泛分布。氚可以通过呼吸、摄入以及经皮肤扩散进入人体。只有当它进入人体后才会观察到其有害影响。我们环境中氚的存量有几个来源。这些来源包括：1）宇宙射线与大气分子的相互作用；2）地壳中的核反应；3）20世纪50年代和60年代的大气层核试验；4）核电站和氚生产设施在正常运行期间持续释放氚；5）这些设施的意外释放；6）消费品。未来一个重要的来源将是预期为发电而开发的核聚变设施。与氚相关的主要健康物理问题包括：1）确定风险估计参数并进一步降低其不确定性（例如，相对生物效应和剂量率依赖性）；2）评估气态氚、氧化物形式的氚、氚表面污染以及其他受氚污染形式的复杂暴露所带来的风险，无论是否伴有其他电离辐射和/或非电离辐射；3）肺部元素氚及其在胃肠道中氧化氚的剂量贡献；4）防止人体摄入（氧化物形式的）氚并促进人体排出（氧化物形式的）氚；5）获取低水平氚暴露的确切健康影响信息；6）公众对反应堆和燃料后处理厂氚泄漏及废物处置的接受程度。
