Occurrence and fate of selected anticancer, antimicrobial, and psychotropic pharmaceuticals in an urban river in a subcatchment of the Yodo River basin, Japan

Abstract

Pollution status of six anticancer agents in the river water and effluents of sewage treatment plants (STPs) in Japan was surveyed with comparative analysis of the levels of four microbial and one psychotropic pharmaceuticals widely used for therapeutic medication. The area of survey is located in the Kanzaki-Ai River basin which is a major subcatchment of the Yodo River basin and is centered on a highly populated area that includes the middle and downstream reaches of the Yodo River. Selected cancer agents were bicalutamide, capecitabine, cyclophosphamide, doxifluridine, tamoxifen, and tegafur. A combination of strong anion solid-phase extraction cartridge under pH 11 for adsorption and optimization of liquid chromatography-tandem mass spectroscopy (LC-MS/MS) system was necessary to ensure high recovery rates (63-124% for river water and 52-115% for STP effluent). The year-round survey of these compounds in four seasons showed that all anticancer compounds were detected at median concentrations ranged from not detected to 32 ng/L in the river water and from not detected to 245 ng/L in the effluents of sewage treatment plants not using ozonation. In the case of bicalutamide (an active antiandrogen used to treat prostate cancer), the maximum concentration detected was 254 ng/L in river water and 1032 ng/L in non-ozonated sewage treatment plant effluents. Based on the mass balance, sewage treatment plants were the primary sources of anticancer compounds as well as the other pharmaceuticals in the river, and the attenuation effect of the river water was small. Ozonation at sewage treatment plants was effective in removing these compounds. To the best of our knowledge, this study is the first to report the existence of bicalutamide, doxifluridine, and tegafur in the river environment.

Distribution of Anticancer Drugs in River Waters and Sediments of the Yodo River Basin, Japan

“…The properties of the STPs including treatment process are shown in Table 1 [35]. Annual flow rates and BOD (biological oxygen demand, mg/L) at the sampling sites in the Kanzaki-Ai River basin are listed in Table 2 [30,36]. Stainless-steel pails were used to collect water samples, while a stainless-steel bottom sampler was used for river sediment samples collected at R5 (Suita Bridge) and R6 (Hirakata Bridge).…”

“…Figure 1. Locations of sampling sites in the Kanzaki-Ai River basin (reproduced from [30]). (Information of the sampling sites of S1-S3 are shown in Table 1, while those of a combined group of R1-R6 and T1-T4 are shown in Table 2.).…”

“…Table 1. Information of sewage treatment plants (STPs) located in the Kanzaki-Ai River basin ( Figure 1) (reproduced from the data in [30]). Step AO + Ozonation CAS: Conventional activated sludge; AO: Anaerobic/aerobic; A2O: Anaerobic/anoxic/aerobic.…”

“…Step AO + Ozonation CAS: Conventional activated sludge; AO: Anaerobic/aerobic; A2O: Anaerobic/anoxic/aerobic. [30]). (Information of the sampling sites of S1-S3 are shown in Table 1, while those of a combined group of R1-R6 and T1-T4 are shown in Table 2.).…”

“…At present, the pollution aspect of anticancer drugs in Japan has been analyzed only in the very limited area surrounding the Yodo River since 2009 [13,[28][29][30][31]. Their occurrence in the river water and sediments, including from hospital and sewage treatment effluents [13,28,32], their fate after discharge [31], and their attenuation properties [29,30], were reported in a separate fashion. The time has come to make an overview of the status of anticancer drugs in the environmental water of the Yodo River basin.…”