国内都市域の水環境中における生活由来化学物質の環境実態解明及び生態リスク評価

抄録

Quantitative analysis of pharmaceuticals and personal care products (PPCPs) in three environmental medias (air, water, and sediment) were carried out via a network of regional environmental research institutes in five large cities (Tokyo, Nagoya, Hyogo, Osaka, and Fukuoka) in Japan. The study took place from FY2016 to FY2018 as a part of a risk assessment for aquatic organisms. Analysis data of water samples from the five cities were carried out at the Tokyo Metropolitan Research Institute for Environmental Protection. The risk assessment for aquatic organisms was carried out by comparing the sample data with the predicted no-effect concentrations (PNECs) gathered from various sources. Concentration levels of five chemicals (clarithromycin, erythromycin, diclofenac, carbamazepine, and triclosan) exceeded the PNECs in several water samples. Concentrations of antibiotics, such as clarithromycin, and antihistamines, such as fexofenadine, tended to be higher during January to February than during June to August. In contrast, concentrations of insect repellents such as N, N-diethyl-m-toluamide (DEET) tended to be higher during June to August than during January to February. The discharge sources of these chemicals would be effluents from plants, such as sewage treatment plants, that were not completely treated. Estimated PPCPs loads accumulated by inflow data of Tamagawa river were compared with measured load value in this study. For some of these chemicals, such as fexofenadine and diclofenac, estimated loads did not coincide with measured loads at sampling points along the Tamagawa River. These differences were thought to occur as the consumption of fexofenadine increased rapidly during the research period, and diclofenac photodegraded while flowing down the river.