Occurrence and fate of pharmaceuticals and personal care products in river water, lake water, sewage effluent, tap water, and groundwater in Japan

Pharmaceuticals and personal care products (PPCPs) are widely detected in aquatic environments. However, recent studies on the environmental occurrence of currently used PPCPs in Japan are limited. In this study, a nationwide monitoring initiative focusing on PPCPs was undertaken to investigate the occurrence and fate of PPCPs in aquatic environments in Japan. A total of 700 samples were collected and analyzed from 2018 to 2022. Ninety-one PPCPs were detected in the analyzed samples. Three PPCPs (N, N-diethyl-meta-toluamide [DEET], salicylic acid, and crotamiton) were detected at particularly high frequencies, with a prevalence exceeding 99% of analyzed samples. Seasonal variations were observed for several PPCPs across multiple rivers, with concentrations generally increasing during fall/winter and decreasing during spring/summer (except DEET) throughout the sampling period. The detection frequencies and concentrations were higher in PPCPs with higher domestic prescription amounts. Some PPCPs, such as acetylsalicylic acid, exhibited low frequencies and concentrations despite high domestic prescription amounts, suggesting transformation into metabolites or degradates in the aquatic environment. The contribution of sewage treatment plant effluent to the PPCP concentrations in the environment was estimated by examining the correlation between each PPCP and sucralose concentration. Sewage effluents appeared to be a significant contributor to the majority of target PPCPs; however, DEET and certain other PPCPs may originate from alternate sources. This study is the first to provide a comprehensive assessment of the occurrence and fate of PPCPs in Japan's aquatic environment. Future research should assess the environmental and human health risks of these PPCPs and identify the occurrence of their metabolites or degradates in the aquatic environment.