The practice of removing fluoride from water is done to minimize the health conditions that can develop from overexposure to fluoride. While fluoride is added to drinking water in many areas, too much fluoride can actually create health problems, both in the mouth and the skeletal system. Even in areas where fluoride is not added to the water, the fluoride level may be high. As water travels downstream, it can pick up fluoride from rocks in streams and lakes.
Removing fluoride from water is somewhat controversial. Fluoride can reduce the development of dental caries, or cavities, when taken at the optimal level. The optimal amount is not well established however, and even if it were, it is nearly impossible to regulate the dosage given the way fluoride is supplemented into the water supply. A child that drinks a great deal of water will automatically consume more fluoride than the child who drinks less. This makes it difficult to determine whether the fluoride in a particular water system is too high.
Fluoride was originally added to drinking water and toothpaste to improve oral health. Fluoride halts enzymes that produce bacteria that secrete acid. These acid-producing bacteria can speed the development of dental caries. Fluoride was also believed to bond with calcium in the body to strengthen teeth. The science behind this is less established. While fluoride in moderate amounts may help strengthen teeth, too much actually leeches calcium from the body.
The primary reason that some individuals consider removing fluoride from water is to prevent fluorosis. Dental fluorosis is a condition where the teeth change appearance due to overexposure to fluoride. This condition develops in young children because the fluoride affects the appearance of teeth that are still developing. Teeth that are affected by fluorosis develop a chalky-white, blackened, mottled, or otherwise discolored appearance.
Skeletal fluorosis is a more serious condition that occurs when someone is overexposed to fluoride. It causes permanent damage to bones and joints. Symptoms of skeletal fluorosis include stomach and headaches, muscle weakness, and stiffness in the joints. Excessive fluoride intake can also impair the function of the thyroid gland.
Removing fluoride from water is a straightforward process. The adsorbtion method requires a filter made of material such as activated charcoal to run water through before using. The flocculation method requires adding alum to the water. The alum will bind with the fluoride, and both will settle out, sinking to the bottom of the container. When removing fluoride from water it is important to dispose of the byproducts carefully, as it will be an extremely concentrated form of fluoride, and should not be added back to the groundwater system.