Huel G, Thomazeau R, Derriennic F, Lazar P
Rev Epidemiol Sante Publique. 1978;26(5):381-90.
In Alsace (France) drinking water is supplied from two different sources. This situation is favourable to study the effects on human health of various water characteristics, among which hardness. However it would be misleading to consider the 947 towns or villages as independent units of observation because of their geographical adjacencies. An aggregation algorithm of these units has been set up. It consists in a progressive regrouping of adjacent areas, similar "enough" from the point of view of the parameters studied, the aim of the procedure being to get final areas with contrasted values of water characteristics. This partition is then used to compute rank correlation coefficients between water parameters and various mortality rates. With this method, no significant correlation was found between water hardness and mortality, in spite of the existence of a sharp gradient of hardness.
在法国阿尔萨斯地区，饮用水来自两个不同的水源。这种情况有利于研究各种水的特性对人体健康的影响，其中包括水的硬度。然而，由于这些城镇或村庄地理位置相邻，将其视为独立的观察单位可能会产生误导。因此，已建立了这些单位的聚合算法。该算法包括对相邻区域进行逐步重新分组，从所研究参数的角度来看，这些区域足够相似，该过程的目的是获得水特性值具有对比性的最终区域。然后，利用这种划分来计算水参数与各种死亡率之间的等级相关系数。采用这种方法，尽管水硬度存在明显梯度，但未发现水硬度与死亡率之间存在显著相关性。
