Iranian Journal of

Background and Objective: Increased untreated wastewater and unsustainable development of agriculture has deteriorated water quality of rivers. The aim of this study was to determine the quality of water in Gorganrud River basin using NSFWQI IRWQISC and Liou Pollution Index and compare them with the global standards. To do this, GIS software.was used
Materials and Methods: In this study, 5 sampling stations were selected based on standard criteria including land use type, accessibility and standard distributions along the river. 12 water quality parameters including dissolved oxygen, fecal coliform, pH, biochemical oxygen demand, chemical oxygen demand, temperature, organic phosphate, nitrate, ammonium, turbidity, total dissolved solids and electrical conductivity in river for one year were measured from June 2019 to May 2019 follwoing standard methods.
Results: The amount of phosphate and turbidity was increased along the river from station 2 to the mouth of the river. This was due to the presence of agricultural and municipal sewage. There was a significant difference in BOD, fecal coliforms and nitrates with those of the standard values. Water quality indicators showed the great effects of urban wastewater and human waste in the river area. The best quality was observed in Station 1 (75; Good Quality), which was less exposed to human activity and development. Based on the conformity of the results of the indicators with the terrestrial reality, the results of the IRWQIsc index (Iranian surface water quality) showed the best results due to compatibility to the land uses and the trend of variables.
Conclusion: The presence of urban sewage and unsustainable agricultural in the city of Gonbad Kavous is the most important reason for the decline in water quality (poor quality class). In this regard, a comprehensive management in water resources and environmental impact assessment is needed.

Background and Objective: Despite their high nutritional value, fruits and vegetables may pose a risk to public health due to nitrate accumulation. This study aimed to assess the health risks associated with dietary exposure to nitrates present in fruits and vegetables sold in produce markets of Shahre-Rey.
Materials and Methods: In this cross-sectional study, samples of apples, oranges, potatoes, onions, and both greenhouse- and field-grown tomatoes and cucumbers (n = 13, 12, 22, 18, 24, and 32, respectively) were collected during autumn and winter 2023 and spring and summer 2024. Nitrate concentrations were measured using a spectrophotometric method. The non-carcinogenic hazard quotient (HQ) was calculated based on the measured nitrate levels. In addition, using GBD data, the contribution of nitrate to the disease burden of colorectal cancer was estimated through YLL (Years of Life Lost), YLD (Years Lived with Disability), and DALY (Disability-Adjusted Life Years) indices.
Results: The mean nitrate concentration varied significantly across the products, with the highest level found in field cucumbers (294.06 mg/kg) and the lowest in apples (51.99 mg/kg). In some products, nitrate levels exceeded the permissible limits set by the Iranian national standard. The highest non-carcinogenic risk was observed in potatoes, with a mean HQ of 0.231. Potatoes also had the highest incidence rate of colorectal cancer (2.02 per 100,000 population), the greatest DALY (23.15), and the highest nitrate-related mortality. The mean DALY attributed to nitrate exposure was estimated at 107.38 for potatoes, 94.87 for onions, and 12.10 for greenhouse cucumbers.
Conclusion: Certain agricultural products, particularly potatoes and onions, are significant sources of dietary nitrate exposure and may contribute to an increased risk of colorectal cancer. Continuous monitoring and management of nitrate levels in these products are essential.