Fluoride concentrations in water from four principal coastal plain aquifer systems, South Carolina
Ample supplies of ground water are available throughout most of the Coastal Plain of South Carolina, but in many places the fluoride concentrations far exceed (as high as 5.8 mg/L, milligrams per liter) the MCL (maximum concentration limit) established for drinking water by the EPA (U.S. Environmental Protection Agency) and SCDHEC (South Carolina Department of Health and Environmental Control). Fluoridation of drinking water for the prevention of dental caries is a well known practice in many parts of the country. Low concentrations of fluoride have an apparent beneficial effect whereas high concentrations may cause dental fluorosis (mottled teeth enamel) in young children. The recommended concentration of fluoride, as established by EPA (1975) in South Carolina ranges from 1.4 to about 2.4 mg/L depending on the daily air temperature (tables 1 and 2). A lower fluoride concentration in drinking water is considered optimum in areas of high air temperature because generally more water is consumed by individuals in these areas. The total fluoride intake in a warm area where the concentration is low, therefore, will be approximately the same as in a cooler area where the concentration is higher. However, it has been established by SCDHEC that the MCL for fluoride in public drinking water in the coastal areas will be 1.6 mg/L (R. Lewis Shaw, written commun., 1976).