Nair S K, Miller C W, Thiessen K M, Garger E K, Hoffman F O
SENES Oak Ridge Inc., Oak Ridge, TN 37830, USA.
Health Phys. 1997 Jan;72(1):77-85. doi: 10.1097/00004032-199701000-00010.
Following the 1986 Chernobyl event, large amounts of radioactive materials were deposited in nearby areas. Concentrations of various radionuclides were measured in air and surface soil. To study the resuspension of radioactive particulate, three different exposure situations were developed on the basis of the collected data under the auspices of the international BIOMOVS II (BIOspheric MOdel Validation Study) project. Modelers were asked to predict seasonal air concentrations and resuspension factors at several locations at different distances from Chernobyl for six successive years following the accident. Measurements of radionuclide deposition on topsoil were provided for each site along with information on soil, vegetation, land use, surface roughness, meteorology, and climate. In this paper, the three exposure situations are described, along with the initial data set provided to the modelers; two modeling approaches used to make the endpoint predictions are also presented. After the model predictions were submitted, the measured air concentrations and resuspension factors were released to the modelers. Generally, the predictions were well within an order of magnitude of the measured values. Time-dependent trends in predictions and measurements were in good agreement with one of the models, which (a) explicitly accounted for loss processes in soil and (b) used calibration to improve its predictive capabilities. Reasons for variations between predictions and measurements, suggestions for the improvement of models, and conclusions from the model validation study are presented.
1986年切尔诺贝利事件之后，大量放射性物质沉降在附近区域。对空气和表层土壤中的各种放射性核素浓度进行了测量。为研究放射性颗粒物的再悬浮情况，在国际BIOMOVS II（生物圈模型验证研究）项目的支持下，根据收集到的数据设计了三种不同的暴露情景。要求建模人员预测事故发生后的连续六年里，切尔诺贝利不同距离处若干地点的季节性空气浓度和再悬浮因子。为每个地点提供了表层土壤中放射性核素沉降的测量数据，以及有关土壤、植被、土地利用、地表粗糙度、气象和气候的信息。本文描述了这三种暴露情景以及提供给建模人员的初始数据集；还介绍了用于进行终点预测的两种建模方法。在提交模型预测结果之后，向建模人员公布了实测空气浓度和再悬浮因子。总体而言，预测值与测量值一般相差不超过一个数量级。预测值和测量值随时间的变化趋势与其中一个模型吻合良好，该模型（a）明确考虑了土壤中的损失过程，并且（b）通过校准提高了其预测能力。文中给出了预测值与测量值之间存在差异的原因、对模型改进的建议以及模型验证研究的结论。
