Ecological Risk Assessment of Pharmaceuticals and Personal Care Products in the Water Environment of 15 Cities in Japan

<jats:title>Abstract</jats:title> <jats:p>To assess the ecological risk of pharmaceuticals and personal care products (PPCPs) to the water environment of several cities in Japan, major local environmental research institutes, a private company, and an academic institution launched a joint research project in 2019. Under this initiative, local environmental research institutes surveyed the concentrations of 46 types of PPCPs at 59 points distributed across 15 cities in Japan. IDEA Consultants, Inc. calculated the unknown values of predicted no-effect concentration (PNEC) of six chemicals (telmisartan, candesartan, fexofenadine, diphenhydramine, diphenyl sulfone, and ketotifen) through bioassay experiments on aquatic organisms. Among the researched chemicals, the concentrations of clarithromycin, 14-hydroxyclarithromycin, erythromycin, diclofenac, carbamazepine, and telmisartan exceeded the PNEC in at least one sampling point. However, ozone treatment removed most of these chemicals, except for certain phosphate ester flame retardants. The mass balance of chemicals in the Tamagawa River flowing through Tokyo Prefecture was calculated by multiplying the concentration of each chemical with the flow rate at each sampling point in the river. The measured load of most chemicals at each sampling point of the Tamagawa River coincided to a certain extent with the cumulative load accumulated from the tributaries and sewage treatment plants to the uppermost point (Nagata Bridge). However, the measured load of diclofenac was significantly smaller than the estimated values at each sampling point, suggesting that diclofenac photodegrades while flowing down the river.</jats:p>