Ecotoxicological effects of ketoprofen and fluoxetine

The effects of fluoxetine (antidepressant) and ketoprofen (analgesic) on aquatic ecosystems are largely unknown, particularly as a mixture. This work aimed at determining the effect of sublethal concentrations of both compounds and their mixture on aquatic communities at a microcosm scale. Several physicochemical parameters were monitored to estimate functional alterations in the ecosystem, while benchmark organisms (Daphnia magna, Lemna sp.) and the sequencing of 16S/18S rRNA genes permitted to determine effects on specific populations and changes in community composition, respectively. Disturbances were more clearly observed after 14 d, and overall, the microcosms containing fluoxetine (alone or in combination with ketoprofen) produced major alterations on most physicochemical and biological variables, compared to the microcosm containing only ketoprofen, which suffered less dramatic changes. Differences in nitrogen-species suggest alterations in the N-cycle due to the presence of fluoxetine; similarly, all pharmaceutical-containing systems decreased the brood rate in D. magna, while individual compounds inhibited the growth in Lemna sp. The structure of micro-eukaryotic communities was altered in the fluoxetine-containing systems, whereas the structure of bacterial communities was affected to a greater extent by the mixture. The disruptions to the equilibrium of the microcosm demonstrate the ecological risk these compounds pose to aquatic ecosystems.