Beresford N A, Hosseini A, Brown J E, Cailes C, Beaugelin-Seiller K, Barnett C L, Copplestone D
Centre for Ecology & Hydrology Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP, UK.
J Radiol Prot. 2010 Jun;30(2):265-81. doi: 10.1088/0952-4746/30/2/S04. Epub 2010 Jun 9.
A number of models are being used to assess the potential environmental impact of releases of radioactivity. These often use a tiered assessment structure whose first tier is designed to be highly conservative and simple to use. An aim of using this initial tier is to identify sites of negligible concern and to remove them from further consideration with a high degree of confidence. In this paper we compare the screening assessment outputs of three freely available models. The outputs of these models varied considerably in terms of estimated risk quotient (RQ) and the radionuclide-organism combinations identified as being the most limiting. A number of factors are identified as contributing to this variability: values of transfer parameters (concentration ratios and K(d)) used; organisms considered; different input options and how these are utilised in the assessment; assumptions as regards secular equilibrium; geometries and exposure scenarios. This large variation in RQ values between models means that the level of confidence required by users is not achieved. We recommend that the factors contributing to the variation in screening assessments be subjected to further investigation so that they can be more fully understood and assessors (and those reviewing assessment outputs) can better justify and evaluate the results obtained.
有许多模型正在被用于评估放射性物质释放可能产生的环境影响。这些模型通常采用分层评估结构，其第一层设计得高度保守且易于使用。使用这一初始层级的目的是识别出关注度可忽略不计的场地，并以高度的信心将其排除在进一步考虑之外。在本文中，我们比较了三种免费可得模型的筛选评估结果。这些模型的结果在估计风险商（RQ）以及被确定为最具限制性的放射性核素 - 生物组合方面差异很大。已确定有若干因素导致了这种变异性：所使用的转移参数（浓度比和K(d)）值；所考虑的生物；不同的输入选项以及这些选项在评估中的使用方式；关于长期平衡的假设；几何形状和暴露情景。模型之间RQ值的这种巨大差异意味着未达到用户所需的置信水平。我们建议对导致筛选评估变异性的因素进行进一步研究，以便能更全面地理解这些因素，并且评估人员（以及审查评估结果的人员）能够更好地证明和评估所获得的结果。
