Is There a Correlation Between Nitrate Quantity in Drinking Water and the Prevalence of Social Issues in the Metropolitan Area of Tehran?

Background and ObjectivesRecent research by NGOs has revealed concerning nitrate levels in drinking water across all 22 districts of Tehran, amid conflicting reports from City Council officials and the Tehran Water and Waste Water Company regarding pollution. A preliminary study on groundwater in the U.S. demonstrated a strong link between nitrate levels and various societal issues. This study aims to investigate two key areas: the current nitrate levels in Tehrans drinking water and their compliance with safety standards set by organizations like the WHO and US EPA. It also seeks to determine if there is a correlation between nitrate levels in specific Tehran districts and societal problems similar to those observed in the U.S. Materials and MethodsSampling took place on November 6, 2022, using 50 mL clear polypropylene Falcon test tubes, which were prepared by rinsing with distilled water. Twenty-two residential sites in Tehrans districts were randomly chosen. Samples were collected within a 16-hour window, allowing the water to flow for 30 seconds before collection. The samples were immediately frozen at -4 degrees Celsius and analyzed 24 hours later for nitrate nitrogen using the colorimetric method (Brucine) as per U.S. EPA guidelines. The analysis was conducted at the Aryan Fan Azma laboratory using a portable DR 2800 spectrophotometer. Environmental conditions during testing included a temperature of 23.4 degrees Celsius and humidity of 18%. Statistical analyses were performed using the Shapiro-Wilk test, Kruskal-Wallis test, and hierarchical cluster analysis (HCA) with R and ApexChart.JS software, while heat maps were created using ArcGIS Pro. FindingsThe nitrate concentration measurements across Tehrans districts revealed levels exceeding the Maximum Contaminant Level (MCL) set by WHO in districts 9, 15, and 16, contradicting previous studies. Furthermore, a significant correlation was found between nitrate concentrations and various social issues, including rates of illiteracy, incidents of harassment by vagrants and drug addicts, feelings of insecurity at night, and the prevalence of vagrants and drug users. ConclusionThis research highlights a notable link between nitrate levels in drinking water and social challenges in Tehran. The correlation between high nitrate concentrations and various societal issues suggests a need for further investigation into this relationship. Additionally, these findings underscore the importance of integrating environmental and social health considerations into urban planning and public policy initiatives.