Measurement of Fluoride ions concentration in a variety of black tea brands and their brews

Fluoride is one of the most well-known and useful substances to inhibit tooth decay and bone caries, but high doses of it can cause dental and skeletal fluorosis. Since tea and water contains fluoride, the present study was performed to measure fluoride concentration in drinking water and tea in Tehran in 2014 year. In this descriptive-analysis study, 25 types of Iranian and foreign brands of tea available in Tehran's market and 30 samples of drinking water from Tehran city were studied in 4 replications. The amount of fluoride in the tea and brewed tea samples within 3, 5 and 10 m and water samples after digestion were measured by fluoride ion selective electrode. Finally, the obtained data was analyzed by SPSS Ver. 18 software. The results indicated that the amounts of fluoride in different brands of tea, tea solution and water were 22.2-303.8 mg/kg, 0.2–2.37 mg/L and 0.95-0.012 mg/L, respectively. Also, the results showed that the amount of released fluoride in tea increases with the increase of brewing time. Therefore, after 3, 5 and 10 m, the average percentages of fluoride released in the tea solution were 31.88%, 53.34% and 78.08% respectively. Finally, it was found that daily consumption of five cups of the studied tea by children and adults may not lead to health problem. However, other sources of fluoride ions such as drinking water, etc should be taken into consideration to prevent the occurrence of skeletal and dental diseases.