Renaud Philippe, Pourcelot Laurent, Métivier Jean-Michel, Morello Marcel
Institut de Radioprotection et de Sûreté Nucléaire (Health Physics and Nuclear Safety Institute), CE Cadarache, Bat 153, 13108 Saint-Paul-Lez-Durance Cedex, France.
Sci Total Environ. 2003 Jun 20;309(1-3):257-64. doi: 10.1016/S0048-9697(03)00049-4.
We observed the relationship between present-day 137Cs surface activity and the rainfall in May 1986 to establish a relevant map of 137Cs deposition over eastern France. This study was performed in an area of the lower Rhône valley where clayey soils are assumed to trap caesium efficiently. Based on the rainwater/airborne activity ratio deduced from this relationship, we verified that present-day activities, measured in clayey soils of this type, are relatively representative of the initial depositions. The interlocked contaminated areas of the resulting map can be related to rainfall occurrences, as is the case for all countries affected by the Chernobyl fallout. This map can be reasonably compared with those obtained for countries bordering France in terms of both activity levels and extent of homogeneous activity areas. Lastly, we demonstrate that it would not be possible to produce a coherent map of initial fallout by extending the campaign over the whole of the eastern territory based on present-day soil activity measurements alone. Hence, only the relationship between 137Cs deposition and the rainfall of the first week of May 1986 can be used to construct a map depicting the Chernobyl fallout over eastern France.
我们观测了当前 137Cs 表面活度与 1986 年 5 月降雨量之间的关系，以绘制法国东部 137Cs 沉积的相关地图。本研究在罗纳河谷下游地区进行，该地区的黏土土壤被认为能有效捕获铯。基于从这种关系推导出的雨水/大气活度比，我们证实了在这类黏土土壤中测量的当前活度相对代表了初始沉积量。所得地图中相互关联的污染区域与降雨情况相关，受切尔诺贝利沉降影响的所有国家都是如此。就活度水平和均匀活度区域范围而言，该地图可与法国周边国家获得的地图进行合理比较。最后，我们证明仅基于当前土壤活度测量将活动扩展至整个东部地区，不可能绘制出连贯的初始沉降地图。因此，只有 137Cs 沉积与 1986 年 5 月第一周降雨量之间的关系可用于绘制描绘法国东部切尔诺贝利沉降的地图。
