Concentration of nitrate, nitrite and fluoride in drinking water and bottled water in Semnan city

The safety of drinking water is one of the critical indexes concerning to health and hygiene of a society. Monitoring and controlling qualitative indices of water is of great importance. Therefore, this study aimed to investigate the quality of bottled water and urban drinking water in Semnan city with regard to the concentration of pollutant ions of nitrite and nitrate as well as the concentration of fluoride which possesses nutritional value and compare them with the Standards of Iran and the world. This research was performed in 30 samples of drinking water and 150 samples of bottled water (with 15 different brand names) collected from Semnan, Iran. The concentration of nitrite, nitrate and fluoride ions were measured using Ion chromatography. The results indicated that the volume of nitrite was 0 mg/ml in all the examined samples and the average content of nitrate was 1.316 to 11.75 mg/ml in bottled water and 7.27 mg/ml in drinking water. Moreover, the average content of fluoride was 0.214 and 0.254 mg/ml in bottled water and drink water respectively. The content of nitrate and nitrite ions was in accordance with the standards of Iran and the world. However, the higher content of nitrate in four brands of bottled water compared to the samples of drinking water could be an alarm for contamination of bottled water. The content of fluoride ion is lower than allowed maximum and minimum. Due to the lower content of fluoride than that of allowable minimum (0.5 mg/ml) and regarding the significance of fluoride in dental diseases, this issue must be seriously considered in water fortification programs.