Investigation of pharmaceutical bioaccumulation in Daphnia sp. living in a wastewater treatment plant

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used pharmaceuticals. Their presence in natural waters is due to the low removal efficiency in conventional wastewater treatment plants (WWTPs). Interestingly, certain zooplankton species can survive the mixture of pollution and abnormal water conditions in WWTPs. In our study, for the first time, we tested the in-situ bioaccumulation of NSAIDs and their metabolites in Daphnia pulex, which were obtained in high numbers in one WWTP during the summer. It was found that diclofenac (DCF) and 4-hydroxy DCF were present in the studied clarifiers and ponds. Among these chemicals, only DCF was detected in daphnia. The bioaccumulation factor of DCF in daphnia was below 36 L kg−1ww and was lower than those obtained under experimental conditions for Daphnia magna. The tested daphnia adapted to chronic exposure to mixtures of drugs in μg L−1 level and could be implemented in biobased WWTPs. According to our data, there is a need to supplement the risk assessment of anthropogenic pollutants with in-situ cases to demonstrate the adaptation possibilities of wild-living organisms. [Display omitted] •Daphnia spending their lifetime in clarifiers of WWTPs were sampled.•From tested NSAIDs, diclofenac was the only tested drug found in daphnia.•The in-situ BAF of DCF was lower than the experimental values.•Suspended particles can be an source of drug in daphnia.•DCF was not bioaccumulate in wild-living daphnia.