Distribution characteristics and ecological risks of typical emerging contaminants in inflowing rivers: a case study of Tianjin

This study provides a detailed analysis of the distribution characteristics and ecological risks of emerging contaminants in five major inflowing rivers in Tianjin. Samples were collected during the wet season in 2023 and the dry season in 2024 and 15 typical emerging contaminants in the region were quantitatively analyzed using high-performance liquid chromatography-mass spectrometry (HPLC-MS). The results indicate that the concentration and risk quotient (RQ) of these emerging contaminants show significant differences between the hydrological periods. Pharmaceuticals and personal care products (PPCPs) exhibited higher RQ values in the wet season compared to the dry season, while pesticides showed lower risks in the wet season due to dilution effect of rainfall. Risk assessments indicated that the RQ values of certain emerging contaminants exceeded safety thresholds in specific areas, indicating high ecological risks. This study highlights the importance of developing differentiated pollution management strategies based on hydrological changes and provides scientific evidence for environmental protection and pollution control in Tianjin and similar regions.