Fluoride occurs naturally in groundwater because it is a component of several different minerals in soil and bedrock. The amount of fluoride we consume is important because the benefits of low levels of exposure are outweighed by adverse effects at high levels. Dietary fluoride, in the right amount, promotes the development of strong permanent teeth. For this reason, fluoride is considered most beneficial for children less than 12 years of age. However, too much fluoride can cause teeth to discolor and weaken; a condition dentists call "dental fluorosis". Fluoride can also affect bone development.
The National Academy of Sciences most recent report on fluoride (March, 2006) stated that the existing drinking water standard from USEPA (4 milligrams per liter; a.k.a., mg/L or ppm) is too high. In general, levels in drinking water should be kept to 1 ppm or less to avoid overdose. This is especially the case because of other important sources of fluoride; including, toothpaste, mouth rinses, fluoride drops, and tea.
The extent to which fluoride in Connecticut groundwater contributes to the incidence of dental fluorosis is likely low in most cases. However, because fluoride concentrations in Connecticut groundwater have not been extensively surveyed, it is possible that localized areas of high fluoride exist. Fluoride has no smell or taste. Testing is therefore the only way to confirm that your well water does not contain excessive amounts of fluoride. You should let your dentist know the results of your fluoride well test. If your well water has fluoride levels near 1 ppm, your children will likely not need fluoride supplements to promote dental health.
For more information, call the Environmental And Occupational Health Section of the Connecticut Department of Health, at 860-509-7742.