Evaluation of microplastic pollution in a lotic ecosystem and its ecological risk

This study investigates the microplastics (MPs) pollution in Tigris River, assessing spatial and temporal variations in water and sediment. MPs presence was high during both seasons 3429.2 MPs/m³ (dry season) and 3363.2 MPs/m³ (wet season) in water, and 121.2 MPs/kg (wet season) and 123.2 MPs/kg (dry season) in sediment. MPs morphology mostly consisted of fibers and fragments, with sizes below 0.5 mm. Transparent and white were the most common colors, and they were primarily composed of polyethylene (PE) and polypropylene (PP). Ecological risk assessment, using the plastic hazard index (PHI), pollution load index (PLI), and potential ecological risk index (PERI), categorized the risk from danger to extreme danger based on PHI, while PLI and PERI indicated a minor risk. These findings provide initial evidence of microplastics pollution in the Tigris River's water and sediment, emphasizing the need for action by decision-makers to mitigate these risks.