The incidence of fluorosis is correlative with the content of Fluoride, which comes from mother-rock and is related to petrogenic element in soil.

壤F与壤中造岩元素具显著正相关，主要来自于质。

The endemic fluorosis is a kind of endemia widely distributed in Ningxia, and this is strongly related to the special natural geochemical environment of Ningxia.

要是宁夏广泛分布的一种方，与宁夏特殊的原生球化学环境有密切关系。