There is growing worry that drinking water can be affected by contaminants of emerging concern (CECs), potentially threatening human health. In this study, a wide range of CECs (n = 177), including pharmaceuticals, pesticides, perfluoroalkyl substances (PFASs) and other compounds, were analysed in raw water and in drinking water collected from drinking water treatment plants (DWTPs) in Europe and Asia (n = 13). The impact of human activities was reflected in large numbers of compounds detected (n = 115) and high variation in concentrations in the raw water (range 15-7995 ng L-1 for ∑177CECs). The variation was less pronounced in drinking water, with total concentration ranging from 35 to 919 ng L-1. Treatment efficiency was on average 65 ± 28%, with wide variation between different DWTPs. The DWTP with the highest ∑CEC concentrations in raw water had the most efficient treatment procedure (average treatment efficiency 89%), whereas the DWTP with the lowest ∑177CEC concentration in the raw water had the lowest average treatment efficiency (2.3%). Suspect screening was performed for 500 compounds ranked high as chemicals of concern for drinking water, using a prioritisation tool (SusTool). Overall, 208 features of interest were discovered and three were confirmed with reference standards. There was co-variation between removal efficiency in DWTPs for the target compounds and the suspected features detected using suspect screening, implying that removal of known contaminants can be used to predict overall removal of potential CECs for drinking water production. Our results can be of high value for DWTPs around the globe in their planning for future treatment strategies to meet the increasing concern about human exposure to unknown CECs present in their drinking water.

Aigües de Barcelona EMGCIA S A General Batet 1 7 08028 Barcelona Spain

Centre Asiatique de Recherche sur l'Eau Ho Chi Minh City University of Technology 268 Ly Thuong Kiet District 10; Vietnam National University of Ho Chi Minh City Linh Trung Ward Thu Duc District Ho Chi Minh City Vietnam

Department of Aquatic Sciences and Assessment Swedish University of Agricultural Sciences Box 7050 SE 750 07 Uppsala Sweden

Department of Aquatic Sciences and Assessment Swedish University of Agricultural Sciences Box 7050 SE 750 07 Uppsala Sweden; University of South Bohemia in Ceske Budejovice Faculty of Fisheries and Protection of Waters South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses Zatisi 728 2 CZ 389 25 Vodnany Czech Republic

Helmholtz Zentrum Geesthacht Institute of Coastal Research 21502 Geesthacht Germany

Key Laboratory of Yangtze River Water Environment Ministry of Education College of Environmental Science and Engineering Tongji University Shanghai 200092 China

KWR Water Research Institute 3430BB Nieuwegein The Netherlands

Lereti S p A Via Somigliana 10 22100 Como Italy

National Institute of Advanced Industrial Science and Technology 16 1 Onogawa Tsukuba Ibaraki 305 8569 Japan

Université Grenoble Alpes IRD CNRS Grenoble INP IGE 38 050 Grenoble France

Water Environmental and Food Chemistry Unit Carrer Jordi Girona 18 26 Barcelona 08034 Spain

Water Research Institute Italy

References provided by Crossref.org

Selected neonicotinoids and associated risk for aquatic organisms

Novel nontarget LC-HRMS-based approaches for evaluation of drinking water treatment