The authors in the present paper contend that the fluorine which leads to the endemic fluorosis has polyphyletic origins, including: (1) high-fluorine rocks such as claystone, coal and shale;

• 高氟含量的岩石粘土岩、煤、页岩等是氟的初始来源体；高氟含量土壤是氟第二个层次的来源；