Samples collected from the river Avon (UK) were analyzed for group A and B CECs, and Olifants River (SA) samples were analyzed for group A CECs (table ). River samples from the UK had a total of 45 and 13 CECs above quantifiable limits from groups A and B, respectively. Metformin was recorded in the highest concentrations (1359 ± 83 ng L -1 ) in the river Avon. Previous work done on this river has also reported high levels of metformin ranging from 2000-3000 ng L -1 . The reasoning for why this CEC is so high, has been attributed to its extensive usage in the treatment of type-2 diabetes, and for the lack of metabolism in the body . The UV filter 4benzophenone, commonly found in sunscreens and cosmetic products, was also reported in high levels (299 ± 18 ng L -1 ). Its presence here is likely from a mixture of release from sewage discharge and from washed off skin from recreational activities (the river is popular among open water swimming).