The Monitoring and Health Risk Assessment of Nitrate in Drinking Water in the Rural and Urban Areas of Tabriz, Iran

Background: The present study aimed to estimate the health risk of nitrate concentration (NO3-) in the drinking water of Tabriz, Iran. Methods: This descriptive, cross-sectional study was conducted on the drinking water samples collected from Tabriz city during 2016-2017. The concentration of NO3- was measured in 190 drinking water samples at the water and wastewater laboratory of the provincial health center using spectrophotometry. Results: The mean concentration of NO3- (nitrate ion) in the drinking water of the urban and rural districts was estimated at 14.6 ± 12.8 and 13.1 ± 12.8 mg/l, respectively, which is below the national standard of Iran and the World Health Organization (WHO) guidelines. In addition, the mean hazard quotient (HQ) for the four age groups of infants, children, adolescents, and adults was less than one in the urban and rural areas, while the HQ values for children were more than one in 15.20% of the urban and 10.7% of the rural samples. Conclusion: The non-carcinogenic risk of NO3- in drinking water does not threaten the exposed populations, while children are presumably at the risk of NO3-. Therefore, the continuous control of NO3- concentration is recommended to prevent the possible risks in the consumers, especially children.