Spatiotemporal variations of 2,4-dichlorophenoxy acetic acid with the role of sugarcane industry and related human health risk assessments in the Shadegan International Wetland

2,4-Dichlorophenoxyacetic acid (2,4-D) is the most important pesticide widely used in Khuzestan province. This study aimed to determine the ecological risks assessment in fish, plant tissues, and trends in 2,4-D urinary biomarker concentration in humans of Shadegan International wetland, Iran. Sampling was carried out from three areas: freshwater, saltwater, and brackish water. The average concentration of 2,4-D at point 38, taken from the wetland’s northern parts, was 15.73 µg/L. In the lower regions, it reached 326 µg/L at point 25. From points 37 to 16, it was higher than the international standard. The increasing trend of 2,4-D concentration was observed from point 36 to the middle of the wetland. The non-carcinogenic risk through ingestion and skin contact for children and adults was 3E−3 and 1.5E−2, 2.1E−3, and 8.6E−5, respectively, and through fish, consumption was 7.1E−4 for both groups. HI values were below one (< 1), indicating no health risk. HQ values in the summer were more than one (> 1), indicating the high risk to aquatic organisms and human health. Graphical abstract