Anderson T W
Can Med Assoc J. 1972 Jul 8;107(1):34-7.
Serum levels of calcium and magnesium were measured in two Ontario cities that differ widely in the hardness of their local water-supply. The hypothesis being tested was that residents of the city with the hard water-supply (and a low cardiovascular death-rate) would show relatively high serum levels of calcium and/or magnesium. In addition, a comparison was made of the cortical thickness of the second metacarpal bone in the two areas to see if there was any evidence of increased skeletal mineralization in the hard-water area. The results obtained did not support either of these hypotheses, but it is suggested that the failure to demonstrate differences in body-levels of calcium or magnesium may not be incompatible with one (or both) of these water-borne elements functioning as the "water-factor" in cardiovascular disease.
在安大略省的两个城市测量了血清钙和镁水平，这两个城市的当地供水硬度差异很大。正在检验的假设是，生活在供水硬度高（且心血管疾病死亡率低）城市的居民血清钙和/或镁水平相对较高。此外，还比较了这两个地区第二掌骨的皮质厚度，以查看在硬水地区是否有骨骼矿化增加的证据。所获得的结果并不支持这两个假设中的任何一个，但有人认为，未能证明钙或镁的身体水平存在差异，可能与这些水中元素之一（或两者）作为心血管疾病中的“水因子”发挥作用并不矛盾。
