Physics Department, Campus de Tafira, University of Las Palmas de Gran Canaria, Spain.
Physics Department, Campus de Tafira, University of Las Palmas de Gran Canaria, Spain.
Sci Total Environ. 2019 May 10;664:449-460. doi: 10.1016/j.scitotenv.2019.01.411. Epub 2019 Jan 31.
The Basic Safety Standard (BSS) Directive 2013/59/EURATOM of the European Union (EU) has stated the need for member states to establish national action plans to mitigate their general population's long-term risks of exposure to radon gas. Maps of radon-prone areas provide a useful tool for the development of such plans. This paper presents the maps of radon-prone areas in the Eastern Canary Islands (Gran Canaria, Fuerteventura and Lanzarote) obtained from assessment of Geogenic Radon Potential (GRP) distribution in the territory. GRP constitutes a magnitude that is contingent on both radon activity concentration and gas permeability of soils. An extensive campaign covering all geological formations of the Eastern Canary Islands was undertaken to locally sample these parameters. Geostatistical analysis of the spatial distribution of radon concentration in soils, permeability and GRP was performed on each of the islands, and the relationship between these magnitudes and the characteristic geological formations of the volcanic islands was investigated. Areas dominated by basic volcanic and plutonic rocks (originated by both recent and ancient volcanism) exhibit relatively low levels of radon in soils, and with the exception of specific cases of very high permeability, these areas are not classified as prone to radon risk according to international criteria. Areas in which intermediate or acidic volcanic and plutonic rocks predominate are characterised by greater radon activity concentration in soils, rendering them radon-prone. Given these results, Lanzarote is classified as an island with low radon risk all over its surface; Fuerteventura presents low-medium risk; and Gran Canaria contains extensive areas in the centre and north where the risk is medium or high. This classification is consistent with the risk maps obtained by National and European agencies from indoor radon measurements conducted on these islands.
欧盟的《基本安全标准指令 2013/59/EURATOM》规定，成员国需要制定国家行动计划，以减轻其民众长期接触氡气的风险。氡气易染地区的地图为制定此类计划提供了有用的工具。本文介绍了从评估领土内地质成因氡气潜力（GRP）分布中得出的东加那利群岛（大加那利岛、富埃特文图拉岛和兰萨罗特岛）的氡气易染地区地图。GRP 是一个与氡气活度浓度和土壤透气性都有关的量。在东加那利群岛的所有地质地层中进行了广泛的抽样，以评估这些参数。对每个岛屿的土壤中氡浓度、渗透性和 GRP 的空间分布进行了地质统计学分析，并研究了这些量与火山岛特征地质地层之间的关系。主要由基性火山岩和深成岩（由近期和远古火山作用形成）组成的地区，土壤中的氡含量相对较低，而且除了非常高透气性的特殊情况外，这些地区根据国际标准，不被归类为氡风险易染区。以中酸性火山岩和深成岩为主的地区，土壤中的氡活度浓度较高，属于氡气易染区。根据这些结果，兰萨罗特岛被归类为整个表面氡气风险低的岛屿；富埃特文图拉岛呈现中低风险；而大加那利岛中心和北部地区则存在中高风险。这种分类与从这些岛屿的室内氡测量结果得出的国家和欧洲机构的风险地图一致。
