Health risk assessment of nitrate and fluoride in bottled water: a case study of Iran

Bottled water use has become widespread in recent years. Many Iranian cities are located in regions with a hot and semi-hot climate, and the quality of drinking water is low in most of these areas. Nitrate and fluoride are chemical constituents of drinking water with significant health concerns since they can be harmful in concentrations higher than drinking water standards. This study aims to determine nitrate and fluoride concentrations in different bottled water brands in the study region; evaluate the non-carcinogenic health risks posed by nitrate and fluoride exposure via the ingestion of bottled water; and compare the measured nitrate and fluoride concentrations with the amounts reported on the bottle labels. Twenty bottled water brands were sampled, and their nitrate and fluoride amounts were determined using the spectrophotometry method. The results revealed that 100% of nitrate and 70% of fluoride in samples had concentrations greater than the levels reported on bottle labels. Minimum, maximum, and mean concentrations for nitrate were, respectively, 1.1, 28, and 8.37 mg/L, and for fluoride were 0.014, 2.36, and 0.63 mg/L. The hazard quotient (HQ) values due to nitrate intake were > 1 in 10% of the samples (n = 2) for both infants and children, indicating potential adverse non-carcinogenic health effects upon consumption. For fluoride intake, the potential adverse health effects (HQ > 1) for infants, children, teenagers, and adults were respectively high in 30, 20, 10, and 10% of the samples. For nitrate, the 95th centile for infants was 1.547, and for fluoride, it was 2.62, 2.19, 1.15, and 1 for infants, children, teenagers, and adults, respectively.