Update of EPA Office of Water activities related to fluoride

The U.S. EPA Maximum Contaminant Level Goal (MCLG) and Maximum Contaminant Level (MCL) for fluoride from National Public Water Systems were established in 1986 as 4 mg F/L. They were derived for protection against crippling skeletal fluorosis in adults. As a result of the 2003 review of EPS's drinking water regulations, the Agency funded a review of new data on fluoride health effects and exposure by the National Research Council (NRC). The NRC report recommended that severe dental fluorosis be considered as an adverse health effect because pitting of the tooth enamel reduced its protective function. Subsequent to the NRC report the EPA Office of Water conducted a dose-response analysis for severe dental fluorosis and a study of current population exposures to fluoride from drinking water, diet, toothpaste and other sources. The dose-response analysis utilized the study by Dean (1942) to identify the concentration in drinking water associated with a 0.5% prevalence of severe dental fluorosis among children. After adjusting for drinking water intakes, dietary fluoride, and body weights, a reference dose of 0.08 mg/kg/day was derived. The reference dose is expected to be protective for severe dental fluorosis during the period of enamel formation for permanent teeth. The exposure analysis indicated that some children younger than age 7 may be exposed to fluoride from all sources at levels that cause severe dental fluorosis. The EPA finding is supported by the increase in the levels of moderate and severe dental fluorosis within the U.S. population over the last several decades