Why are large concentrations of fluorides in natural waters considered dangerous?

Large concentrations of fluorides in natural waters are considered dangerous primarily due to their potential to cause bone disorders. Fluoride, in appropriate amounts, is beneficial for dental health, but excessive exposure can lead to conditions such as skeletal fluorosis. This disorder results from the accumulation of fluoride in the bones, leading to pain, joint stiffness, and skeletal deformities over time.

Bone disorders from high fluoride exposure occur because fluoride can interfere with the normal processes of bone remodeling, affecting the balance between the formation and resorption of bone tissue. This disruption can result in excessive fluoride deposits in the bones, compromising bone strength and quality.

While there are other health concerns associated with high fluoride levels, such as potential impacts on heart health, digestive issues, and skin rashes, the most significant and well-documented effects of excessive fluoride consumption are related to bone health. Therefore, the focus on bone disorders highlights the specific risks associated with high fluoride concentrations in water systems.