Occurrence of emerging and persistent organic pollutants in the rivers Cam, Ouse and Thames, UK

The widespread occurrence of new and emerging and persistent organic pollutants (NEPs and POPs) in surface water poses a risk to drinking water supply and consequently human health. The aim of this work was to investigate the occurrence and potential transport of 42 target NEPs and POPs (including per-and polyfluoroalkyl substances (PFAS), pharmaceuticals, pesticides and bisphenols) along the rural and urban environments of three rivers in England. The type and concentrations of pollutants varied between the sampling days and points. Two pharmaceuticals (diclofenac and ibuprofen), two pesticides (diethyl-meta-toluamide (DEET) and prosulfocarb) and a range of PFAS were detected above the method detection limit. The observed PFAS include restricted perfluorooctanoic acid (PFOA), and perfluorooctanesulfonic acid (PFOS) and a newer generation substitute 6:2 fluorotelomer sulfonate (6:2 FTS). The levels of PFOS and diclofenac observed in all studied rivers exceeded the European environmental quality standard (EQS). PFOS and diclofenac high detection frequency in the river Ouse suggests their persistence and potential to contaminate connecting tributaries. An assessment of the ecological risk of prosulfocarb levels in the samples from river Ouse, using the risk quotient method, showed a potential risk to algae, planktonic crustaceans, and fish. Our results suggest that the presence of 12 NEPs and POPs, could potentially be influenced by anthropogenic activities across urban and rural environments of the studied rivers. The study highlights the need for continuous monitoring of restricted and new-generation chemicals in the surface waters to understand their impact on the ecosystem and public health.