Assessing Diazinon Pollution in the Three Major Rivers Flowing into the Caspian Sea (Iran)

The aim of this study was to investigate the seasonal and spatial variations in concentrations a widely used organophosphorous pesticide (OPP), diazinon, associated risk posed by OPP surface water from three largest rivers located northern province Iran: Haraz, Talar Babolrood rivers. These are agriculture Mazandaran, exposed high doses organophosphorus pesticides, especially diazinon. concentration diazinon determined using gas chromatography, while potential elucidated Risk Quotient (RQ) calculated for general (RQm) worst-case (RQex) scenarios. obtained results demonstrated that average ranged 41 ± 76 ng/L River 57 116 Haraz River, 76.5 145 with significant difference noted between summer autumn seasons all For some stations, is higher than standard guidelines Australian/New Zealand Guidelines Fresh Marine Water Quality (FMWQ) United States Criteria Maximum Concentration (CMC). RQs indicated medium RQm = 0.73 RQex 2.27, River; 1.02 2.49 1.35 4.54 River. overall exposure defined have (RQm > 1); however, sampling revealed 1), had < 1). not only elevated studied but most importantly aquatic organisms wellbeing whole river ecosystem. current showed development implementation appropriate standards regulations toward countries such as Iran required reduce pollution levels risks related pesticide.