Spatial distribution and ecological risk assessment of pharmaceuticals and personal care products across China's coastal waters.

Pharmaceuticals and Personal Care Products (PPCPs) constitute water pollutants of emerging concern due to their extensive occurrence and potential ecological impacts. In this nationwide-scale study of China's coastal systems, we integrated high-resolution spatial analysis (288 water samples across four marine regions) with multivariate source apportionment to reveal the distribution, drivers, and risks of 30 antibiotics and 14 other PPCPs. Antibiotics ranged from N.D. to 564 ng/L (sulfonamides dominant), while other PPCPs spanned N.D.-961 ng/L (phenoxy carboxylic acids predominant). Spatial patterns showed clear north-south gradients and region-specific source patterns, with southern China identified as a dominant emission hotspot via riverine and groundwater pathways. Structural equation modeling (SEM) indicated that different combinations of socio-economic factors and water quality parameters directly influenced the distribution of PPCPs in coastal seawater environments. Risk quotient (RQ) analysis using predicted no-effect concentrations (PNECs) showed medium to high ecological and resistance risks in many coastal cities. This study establishes a comprehensive integrated framework linking socio-economic drivers, hydrological pathways, and ecological risks for coastal PPCPs, providing critical insights for marine emerging pollutants management.