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1H a/b/c - Pesticides, pharmaceuticals, perfluoroalkylated substances, antibiotics (WEP/12) Effects of mixtures of pharmaceuticals in the aquatic environment: Using cosms as assessment tools. Sanderson, Hans1, Sibley, Paul1, Mabury, Scott, 1 University of Guelph, Guelph, ON, Canada ABSTRACT- The potential environmental effects of pharmaceuticals released into aquatic ecosystems have typically been derived from single-species, acute laboratory bioassays on single compounds. However, exposures to these substances from human and agricultural inputs are usually chronic in nature and they are invariably to mixtures. In addition, although their mechanisms of action are well understood in mammals, their effects in other organisms such as invertebrates may not be known. Cosm bioassay allow the detection of direct or indirect effects of acute and chronic exposures to a large number of species at the same time and under more environmental realistic conditions. In several studies, probabilistically derived combinations of concentrations of pharmaceuticals were used to chronically (35-60 d) expose aquatic organisms in12,000 L microcosms. Mixtures consisted of ibuprofen, fluoxetine, and ciprofloxacin; as well as acetaminophen, sulfamethoxazole, caffeine, trimethoprim, sertraline, levofloxacin, atorvastatin, and carbamazepine. Effects on bacteria, phytoplankton, zooplankton, macrophytes, and fish were assessed over time through regular sampling. The principles behind the use of cosms and the assessment of mixtures of stressors in these systems will be discussed and some illustrative examples of the effects on organisms in several trophic levels will be presented. Key words: Microcosms, Mixtures, Effect assessment |
