This report dated May 16, 2011, was released June 21, 2011.
Title of report: Critical review of any new evidence on the hazard profile, health effects, and human exposure to fluoride and the fluoridating agents of drinking water
Opinion to be cited as:
SCHER, Opinion on critical review of any new evidence on the hazard profile, health effects, and human exposure to fluoride and the fluoridating agents of drinking water – 16 May 2011.
Fluoride is not an essential element for human growth and development, and for most organisms in the environment.
A large variation in naturally occurring fluoride in drinking water is observed in EU Member States ranging from 0.1 to 8.0 mg/L. Fluoridation of drinking water is recommended in some EU Member States, and hexafluorosilicic acid and hexafluorosilicates are the most commonly used agents in drinking water fluoridation. These compounds are rapidly and completely hydrolyzed to the fluoride ion. No residual fluorosilicate intermediates have been reported. Thus, the main substance of relevance to be evaluated is the fluoride ion (F-).
Systemic exposure to fluoride through drinking water is associated with an increased risk of dental and bone fluorosis in a dose-response manner without a detectable threshold. Limited evidence from epidemiological studies points towards other adverse health effects following systemic fluoride exposure, e.g. carcinogenicity, developmental neurotoxicity and reproductive toxicity; however the application of the general rules of the weight-of-evidence approach indicates that these observations cannot be unequivocally substantiated.
The total exposure to fluoride was estimated for infants, children, and adults from all sources of fluoride, e.g. water based beverages, food, dietary supplements, and the use of toothpaste. Contribution from other sources is limited except for occupational exposure to dust from fluoride containing minerals.
The upper tolerable intake level (UL), as established by EFSA, was exceeded only in the worst case scenario for adults and children older than 15 years of age at a daily consumption of 2.8 L of drinking water, and for children (6-15 years of age) consuming more than 1.5 L of drinking water when the level of fluoride in the water is above 3 mg/L. For younger children (1-6 years of age) the UL was exceeded when consuming more than 1 L of water at 0.8 mg fluoride/L (mandatory fluoridation level in Ireland) and assuming the worst case scenario for other sources. For infants up to 6 months old receiving infant formula, if the water fluoride level is higher than 0.8 mg/L, the intake of fluoride exceeds 0.1 mg/kg/day, and this level is 100 times higher than the level found in breast milk (less than 0.001 mg/kg/day).
The cariostatic effect of topical fluoride application, e.g. fluoridated toothpaste, is to maintain a continuous level of fluoride in the oral cavity. Scientific evidence for the protective effect of topical fluoride application is strong, while the respective data for systemic application via drinking water are less convincing. No obvious advantage appears in favour of water fluoridation as compared with topical application of fluoride. However, an advantage in favour of water fluoridation is that caries prevention may reach disadvantaged children from the lower socioeconomic groups.
In several environmental scenarios it was found that exposure of environmental organisms to levels of fluoride used for fluoridation of drinking water is not expected to lead to unacceptable risks to the environment.