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Which natural processes release fluoride into groundwater?

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A labeled diagram of the periodic table entry for fluorine, showing its atomic number 9, symbol F, atomic weight 18.998, electron configuration, and indicating it is a halogen and a gas at room temperature. — fluorine Properties of fluorine.

Fluoride is released into groundwater primarily through the natural weathering and erosion of fluoride-containing minerals, such as apatite, cryolite, and calcium fluoride (also known as fluorite). These minerals are naturally present in rocks and soil, and as they break down over time, they release fluoride into the environment and surrounding water sources.12

The concentration of fluoride in groundwater varies significantly by geographic region, depending on local geologic features. In some areas, these natural processes can lead to fluoride levels that exceed 10 parts per million (ppm).2