Evaluation of fluoride concentrations in bottled drinking water in the western region of Saudi Arabia

Background: Fluoride levels in bottled water from local sources in the western region of Saudi Arabia pose a significant public health concern due to discrepancies between actual and labeled concentrations. This study examined fluoride concentrations in commercially available bottled water, focusing on differences between measured and labeled values and variations among sources. Methods: This cross-sectional study was conducted from September 2024 to February 2025, during which water samples were collected from both local and international sources in the western region of Saudi Arabia. The ion-selective electrode method was used for fluoride analysis. Sample preparation included shaking each bottle for homogeneity and extracting a 10 mL aliquot for analysis. Fluoride concentrations ranging from 0.1 to 3.0 mg/L were used to create a standard calibration curve. Results: A total of 110 brands were analyzed: 49 (44.5%) from wells, 30 (27.3%) were desalinated, 15 (13.6%) from springs, 11 (10%) from natural sources, and 5 (4.5%) from nurseries. Most samples were from Saudi Arabia (n = 90, 81.8%), and 20 samples (18.2%) were from international sources. The fluoride concentrations ranged from 0.000 to 1.460 ppm, with an average of 0.928 ppm. Significant discrepancies were found between the measured and labeled fluoride levels and among the different water sources (p < 0.001). The spring water had the highest concentration at approximately 1.4 ppm, whereas the nursery water had the lowest fluoride concentration of approximately 0.7 ppm. Saudi bottled waters had fluoride levels ranging from 0.70 to 1.50 ppm, which were significantly higher than those from the USA (0.1–0.3 ppm; p = 0.008) and Europe (0.2–0.5 ppm; p = 0.003). Conclusions: This study revealed significant differences in fluoride levels, with Saudi bottled waters generally having higher concentrations than international brands.