Effects of brewing conditions on infusible fluoride levels in tea and herbal products and probabilistic health risk assessment

Excessive ingestion of fluorides might adversely affect the health of humans. Hence, this study aimed to investigate the concentrations of infusible fluoride in five different types of tea and herbal products; additionally, the probabilistic health risks associated with the ingestion of fluoride in drinking tea and herbal products were estimated. The highest and lowest concentrations of infusible fluoride were detected in black and white tea, respectively. On average, the highest amount of infusible fluoride was extracted following a short brewing time of 5 min in the case of black tea (2.54 mg/L), herbal tea (0.40 mg/L), and white tea (0.21 mg/L). The level of infusible fluoride during brewing was inversely associated with the leaf size of the tea and herbal products. Furthermore, the type of water used influenced the release of infusible fluoride; purified water yielded lower amounts of infused fluoride. The findings of the probabilistic health risk assessment indicated that the consumption of black tea can increase the fluoride intake leading to chronic exposure. Thus, the health risk posed by fluoride intake from drinking tea needs to be evaluated in more details in the future. Appropriate measures for health risk mitigation need to be implemented to minimize the total body burden of fluorides in humans.