Reza Ali Fallahzadeh - Environmental Science and Technology Research Center, Department of Environmental Health Engineering, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
Seyed Ali Almodaresi - Department of GIS & RS, Engineering College, Yazd Branch, Islamic Azad University, Yazd, Iran.
Davoud Ghadirian - Environmental Science and Technology Research Center, Department of Environmental Health Engineering, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
Ahmad Fattahi - Department of Occupational Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.

Introduction: Several diseases, especially in infants such as some cancer and blue baby are related to the presence of nitrate in drinking water. The Environmental Protection Agency (EPA) specified the maximum contaminant level (MCL) of nitrate as 50 mg L-1 for regulated public water systems. This study aimed to evaluate the concentration of nitrate and to assess its probabilistic risk exposure in drinking water wells of Abarkouh city, Iran. Materials and Methods: The average annual nitrate level was studied from 18 wells around Abarkouh in 2017. The Hazard Quotient (HQ) was also investigated as health risk assessment and sensitivity analysis was carried out for effective variables.Results: Average concentration of nitrate was 27.57 ± 6.80 mg L-1 and all measured concentrations were below the permitted maximum standard (50 mg L-1) according to the National Standard of Iran. The HQ value for children and adults were more than 1 (1.81) and less than 1, respectively. In calculating HQ for children, the most important variable was the concentration of nitrate in drinking water.Conclusion: According to the results, children health is highly at risk in these areas and exposure to nitrate should be reduced for at-risk populations.

Nitrate, Geographic Information Systems, Risk Assessment, Drinking Water, Abarkouh City