W8 PM Ecotoxicology of Agrochemicals and Pharmaceuticals
Wednesday, 16 November 2005: 1:50 PM - 5:30 PM in 337-338

(DUS-1117-854768) Water and Sediment toxicity of selected pharmaceuticals and personal care products to benthic invertebrates.

Dussault, E¹, Balakrishnan, V², Sverko, E³, Solomon, K¹, Sibley, P¹, ¹ University of Guelph, Guelph, Ontario, Canada² National Water Research Institute, Aquatic Ecosystem Protection Research Branch, Environment Canada, Burlington, Ontario, Canada³ National Laboratory for Environmental Testing, Environment Canada, Burlington, Ontario, Canada

ABSTRACT- Aquatic sediments may represent an important matrix for the deposition and storage of pharmaceuticals and personal care products (PPCPs), yet the potential risks that these compounds pose to sediment-dwelling organisms are virtually unknown. In this study, we evaluated the acute toxicity of the anti-epileptic drug carbamazepine (CBZ), the lipid regulator atorvastatin (ATO), the antimicrobial triclosan (TCS) and the synthetic hormone ethinylestradiol (EE2), toward the midge Chironomus tentans and the freshwater shrimp Hyalella azteca, using standard 10-d acute toxicity tests. In water-only exposures, LC10 values varied between 0.2 and 28.6 mg.L^-1 for C. tentans, with TCS being the most toxic and CBZ the least toxic compound. H. azteca was generally more sensitive than C. tentans, with LC10 values ranging from 0.2 to 8.5 mg.L^-1. The relative toxicity ranking of the four compounds was the same as observed for C. tentans; however ATO was approximately 10 times more toxic to H. azteca compared to C. tentans, and approached the toxicity of TCS. Growth was generally a more sensitive indicator of toxicity than mortality, with EC10 values being 1.5-14.7 times lower than LC10 values. Experiments are currently under way to evaluate the acute toxicity of spiked sediments. Measured toxicity thresholds in water-only short-term tests were several orders of magnitude higher than current environmental concentrations, indicating that these compounds likely pose little risk to benthic invertebrates. However, studies to examine chronic responses to PPCPs, particularly effects on reproduction, endocrine disruption and behaviour, are poorly known and will be the subject of future testing.

Key words: pharmaceuticals and personal care products, benthic invertebrates, aquatic toxicity, sediment toxicity