title: Mass balance of anti-influenza drugs discharged into the Yodo River system, Japan, under an influenza outbreak.
abstract: In February 2011, at the peak of an influenza outbreak, we performed a comprehensive analysis of the mass balances of four anti-influenza drugs-oseltamivir (OS), oseltamivir carboxylate (OC), amantadine (AMN), and zanamivir (ZAN)-in the urban area of the Yodo River system. This area includes three main river catchments (the Katsura, Uji, and Kidzu Rivers) and is home to 12 million people, about 10% of Japan's population. Water was sampled at six main rivers and 13 tributary sites and eight sewage treatment plants (STPs). We concluded that the STP effluents were the major sources of the anti-influenza drug load in the Yodo River system (68-94% of total mass fluxes). Extended measurement throughout the Yodo River system further showed only small fluctuations of the ratio of OS to OC from 0.2 to 0.3, suggesting that OS and its metabolite are environmentally stable. The results also clearly showed the importance of reducing the levels of anti-influenza drugs in the water environment by reducing their emission at STPs.
authors.affiliation: Research Center for Environmental Quality Management, Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga 520-0811, Japan. Electronic address: t.azuma@gly.oups.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Azuma
authors.forename: Norihide
authors.initials: N
authors.lastname: Nakada
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Yamashita
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D000547:Amantadine / Q000032:analysis; D000998:Antiviral Agents / Q000032:analysis*; D004196:Disease Outbreaks; D004784:Environmental Monitoring; D006801:Humans; D007251:Influenza, Human; D007564:Japan; D053139:Oseltamivir / Q000031:analogs & derivatives / Q000032:analysis; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000998:Antiviral Agents; D014874:Water Pollutants, Chemical; D053139:Oseltamivir; D000547:Amantadine; C535162:oseltamivir carboxylate
keywords: Environmental fate; Oseltamivir carboxylate; Relenza; River basin; Tamiflu; Zanamivir