自然界中，许多矿物都含有一定量的氟元素，因而水源中不同程度含有氟离子．一般情况下，水中氟离子浓度比较低，含量不大于0．3毫克／升，但是在有些水源中，例如海陆交替相地层的氟富集区、干旱半干旱的富氟盐渍止低洼地区、山区等，一般也含有较高的氟．其中含氟超过2毫米／ In nature, many minerals contain a certain amount of fluorine, so the water source contains fluoride ions in varying degrees. In general, the concentration of fluoride ion in the water is relatively low, and the content is not more than 0.3 mg/L. However, in some water sources, such as the fluorine-enriched areas in the sea-land alternating layers, the arid and semi-drought fluoride-rich saline and low-lying areas, Mountain areas, etc., generally also contain high fluoride. Which contains more than 2 mm of fluorine /