Monitoring of Pharmaceutical and Personal Care Products in the Upper Reaches of the Yamato River System (Second Report)

Abstract

We investigated the concentrations of 17 pharmaceutical and personal care products (PPCPs) in Nara prefectural sewage treatment plants. Sewage samples were collected at sewage treatment plants in the same river basin on the same day as the river water survey date reported earlier. Results showed that, among the PPCPs investigated for this study, only trimethoprim, valsartan, and DEET had removal rates exceeding 50% in both winter and summer at sewage treatment plants, indicating that most other investigated PPCPs were discharged into the environment with little treatment. Large-scale sewage treatment plants in the same river basin had similar removal rates for PPCP that showed relatively high removal rates if their treatment systems were the same. Comparison of influents among seasons and among plants revealed seasonal differences in influent concentrations, even among cities in Japan. Local specificity was observed among plants within the same river basin and in the river water, suggesting the need to elucidate the actual state of PPCP influents in the respective regions. Furthermore, comparison of PPCP concentrations in effluent and river water showed that most substances were detected at higher concentrations in the effluent, but only valsartan and DEET were detected at higher concentrations in a specific river than in the effluent, so we revealed the presence of major sources of PPCP other than sewage treatment plants.