Fluoride concentration of bottled water and tap water in Tehran, Iran

BACKGROUND AND AIMS: As a result of poor quality of public water supply in many countries, people have recently turned to bottled water consumption, the fluoride content of which is not generally consistent among different brands. This study sought to measure the fluoride concentration of public water supply in comparison with commercial brands of min-eral bottled water available in Tehran, Iran. MATERIALS AND METHODS: Eight different brands of locally produced bottled mineral water and samples of tap water were evaluated for fluoride content. All samples were collected in five equal containers in two summer and winter seasons. The fluoride content in part per million (ppm) was determined using a fluoride Ion Selective Electrode. The data were ana-lyzed using two-way ANOVA. For comparison of the fluoride content between three different brands of bottled water, one-way ANOVA was employed. Sample t-test was used to compare the label and laboratory values of bottled water. RESULTS: The highest concentration of fluoride in a bottled water brand was found to be 0.409 ppm with a pH of 6.67 in summer. There was a significant difference between the mean fluoride level of tap water (0.229 ± 0.079 ppm) and bottled water (0.111 ± 0.122 ppm) (P < 0.001). The measured fluoride concentrations of bottled water were significantly lower than those printed on the labels (P < 0.001). CONCLUSION: Our findings revealed that the mean fluoride level of both bottled and tap water samples evaluated is con-siderably lower than accepted standards.