Simon S L, Graham J C
Nationwide Radiological Study, Majuro, Marshall Islands.
Health Phys. 1996 Oct;71(4):438-56. doi: 10.1097/00004032-199610000-00003.
Dose assessments, both retrospective and prospective, comprise one important function of a radiological study commissioned by the Republic of the Marshall Islands (RMI) government in late 1989. Estimating past or future exposure requires the synthesis of information from historical data, results from a recently completed field monitoring program, laboratory measurements, and some experimental studies. Most of the activities in the RMI to date have emphasized a pragmatic rather than theoretical approach. In particular, most of the recent effort has been expended on conducting an independent radiological monitoring program to determine the degree of deposition and the geographical extent of weapons test fallout over the nation. Contamination levels on 70% of the land mass of the Marshall Islands were unknown prior to 1994. The environmental radioactivity data play an integral role in both retrospective and prospective assessments. One recent use of dose assessment has been to interpret environmental measurements of radioactivity into annual doses that might be expected at every atoll. A second use for dose assessment has been to determine compliance with a dose action level for the rehabilitation of Rongelap Island. Careful examination of exposure pathways relevant to the island lifestyle has been necessary to accommodate these purposes. Examples of specific issues studied include defining traditional island diets as well as current day variations, sources of drinking water, uses of tropical plants including those consumed for food and for medicinal purposes, the nature and microvariability of plutonium particles in the soil and unusual pathways of exposure, e.g., that which might be associated with cooking and washing outdoors and inadvertent soil ingestion. A study on the prevalence of thyroid disease is also being conducted and the geographic pattern of disease may be useful as a bioindicator of the geographic pattern of exposure to radioiodine. Finally, an examination is underway of gummed film, fixed-instrument, and aerial survey data accumulated during the 1950's by the Health and Safety Laboratory of the U.S. AEC. This article gives an overview of these many different activities and a summary of recent dose assessments.
剂量评估，包括回顾性评估和前瞻性评估，是马绍尔群岛共和国（RMI）政府于1989年末委托开展的一项放射学研究的一项重要功能。估算过去或未来的暴露剂量需要综合历史数据信息、最近完成的实地监测项目结果、实验室测量数据以及一些实验研究结果。马绍尔群岛共和国迄今为止的大多数活动都强调务实而非理论方法。特别是，最近的大部分工作都用于开展一项独立的放射学监测项目，以确定全国武器试验沉降物的沉积程度和地理范围。在1994年之前，马绍尔群岛70%的陆地面积的污染水平是未知的。环境放射性数据在回顾性评估和前瞻性评估中都发挥着不可或缺的作用。剂量评估最近的一个用途是将环境放射性测量结果转化为每个环礁可能预期的年剂量。剂量评估的另一个用途是确定朗格拉普岛修复是否符合剂量行动水平。为实现这些目的，必须仔细研究与岛屿生活方式相关的暴露途径。所研究的具体问题示例包括界定传统岛屿饮食以及当前的变化、饮用水源、热带植物的用途（包括用于食物和药用的植物）、土壤中钚颗粒的性质和微观变异性以及不寻常的暴露途径，例如可能与户外烹饪和洗涤以及意外摄入土壤有关的途径。一项关于甲状腺疾病患病率的研究也正在进行，疾病的地理分布模式可能作为暴露于放射性碘的地理分布模式的生物指标。最后，正在对美国原子能委员会健康与安全实验室在20世纪50年代积累的胶卷、固定仪器和航空测量数据进行审查。本文概述了这些许多不同的活动，并总结了最近的剂量评估情况。
