The effect of domestic water filters on water fluoride content

Tap Water Filtration and Purification Usage and their Impact on the Concentrations of Fluoride and Other Minerals - A Community-based Study

OBJECTIVE

This study investigated the prevalence of water filtration and purification system (WFPS) use among residents of central Indiana (USA) and determined the effects of WFPS on the concentrations of fluoride, calcium, magnesium, potassium, and sodium in tap water.

METHODS

A census-based questionnaire collected data on demographics, water use, and water sources. Participants were also asked to provide water samples from their tap water or the WFPS they used. Water samples were analyzed using ion-specific electrodes (fluoride) and atomic absorption spectrometry (metals). Mineral concentration comparisons between water sources used nonparametric tests; questionnaire associations were testing using correlations, chi-square tests, and nonparametric tests.

RESULTS

One hundred and one participants completed the study, of which 71% used some type of WFPS. Blacks were less likely to use WFPS than Asian or White participants (p = 0.045). Those with bachelor's degrees or higher were more likely to use WFPS (p = 0.003). The most used WFPS were pitcher filters (31%), water softeners (21%), reverse osmosis systems (11%), faucet-mounted filters (4%), and whole-house carbon filters (1%). Reverse osmosis systems resulted in the lowest mineral concentrations (median, ppm; F-0.08, Ca-2.30, Mg-0.46, Na-4.60, P-0.35). Pitcher filters were largely comparable to unfiltered tap water. Water softeners resulted in the highest sodium concentrations (78.40 ppm).

CONCLUSION

A large proportion of study participants use WFPS, with pitcher filters being the most common. Reverse osmosis systems had the most significant impact on reducing mineral levels in tap water, while pitcher filters do not adversely affect mineral concentrations.

CLINICAL SIGNIFICANCE

Understanding how different WFPS affect the various minerals in tap water is essential for helping consumers in choosing the right system and for oral care providers to guide patients on water consumption and the need for fluoride supplementation, especially for those at high risk of dental caries.

Maintaining Good Oral Health With Fluoridated Water

Community water fluoridation (CWF) has been a public health measure against tooth decay since 1945. Strong evidence supports the use of CWF in reduction in caries risk in the pediatric population, and numerous studies also show benefit in adults. CWF remains an important contributor to oral health despite the availability and widespread use of other fluoride-containing dental products. The efficacy, safety, and optimal use of CWF will be discussed.