Bølviken B
Section of Hydrogeology and Geochemistry, Geological Survey of Norway, Trondheim, N-7491, Norway.
Med Hypotheses. 2000 Dec;55(6):513-6. doi: 10.1054/mehy.2000.1107.
Earlier comparisons of epidemiological and geochemical maps of China disclosed associations between high mortality rates from nasopharyngeal carcinoma (NPC) and low contents of magnesium in the soil. More recent work has shown that high rates of NPC are also associated with high levels of uranium and thorium in the soil. These latest findings are consistent with the earlier ones, since uranium and thorium occur predominantly in acid rocks poor in magnesium. Uranium and thorium are radioactive, and their progeny include radioactive elements such as radium and radon. Whether or not naturally occurring radioactive elements could be risk factors in NPC should, therefore, be further investigated. Direct carcinogenic properties of radon are well known, but in connection with NPC possibilities for reactivation of virus by natural ionizing radiation should also be considered.
早期对中国流行病学地图和地球化学地图的比较揭示了鼻咽癌（NPC）高死亡率与土壤中低镁含量之间的关联。最近的研究表明，鼻咽癌的高发病率也与土壤中高水平的铀和钍有关。这些最新发现与早期的发现一致，因为铀和钍主要存在于贫镁的酸性岩石中。铀和钍具有放射性，它们的子体包括镭和氡等放射性元素。因此，天然存在的放射性元素是否可能是鼻咽癌的危险因素应进一步研究。氡的直接致癌特性是众所周知的，但对于鼻咽癌，还应考虑天然电离辐射使病毒重新激活的可能性。
