Influence of wastewater discharge and seasonal variability on synthetic musk compounds in major Korean rivers

Abstract

Synthetic musk compounds (SMCs) are typical anthropogenic organic contaminants used as additives in many consumer products. They primarily enter aquatic environments through wastewater treatment plant (WWTP) discharge. However, the factors influencing their seasonal variation in riverine environments remain poorly understood. In this study, water samples were collected near WWTP discharge points from major Korean rivers to measure 12 SMCs using a gas chromatograph coupled to a tandem mass spectrometer. Among the SMCs analyzed, HHCB (Galaxolide), DPMI (Cashmeran), musk ketone (MK), and AHTN (Tonalide) were consistently detected in all samples, suggesting widely used SMCs in the aquatic environments. The highest SMC concentrations were observed in the Han River (mean: 229 ng/L), which flows through a highly populated urban area (Seoul), indicating the significant influence of WWTP discharge. Within the sampling locations in each river, the highest concentrations were found at locations closest to WWTPs, implying the importance of proximity to contamination sources in aquatic environments. SMC concentrations in river water were highest in winter and lowest in summer due to the dilution effects caused by heavy precipitation. Although the measured SMC concentrations remained below ecological threshold values, further research is necessary to evaluate the long-term impacts of exposure to pollutant mixtures on aquatic organisms.