Meeting Abstract
P3.104 Monday, Jan. 6 15:30 Acute and chronic effects of naproxen and its photodegradants on southern toad tadpoles TURNER, S.E.*; BROWN, J.B.; RAMIREZ, J.N.; CORY, W.C.; WELCH, A.M.; College of Charleston; College of Charleston; College of Charleston; College of Charleston; College of Charleston seturner@g.cofc.edu
Pharmaceutical pollution is an emerging environmental issue. Many pharmaceuticals pass through the body and are not completely removed during wastewater treatment, leading to the release of these compounds into the environment. The nonsteroidal anti-inflammatory drug naproxen is a widely used over-the-counter medication in the US and has been detected in natural waterways around the world. When exposed to sunlight, naproxen is converted into two related compounds. These photodegradants are predicted to be more toxic than naproxen because they have lower polarity. We tested the acute and chronic toxicity of naproxen and its two degradants using tadpoles of the southern toad (Anaxyrus terrestris). Amphibians are important components of freshwater ecosystems and may be particularly sensitive to pollutants due to their permeable skin. Acute toxicity was measured as median lethal concentration at 96 hours. The acute toxicity of naproxen was similar to that of its first degradant, but the second degradant was markedly more toxic. In the chronic toxicity tests, tadpoles were exposed to each compound at half of the median lethal concentration determined in the acute tests, through metamorphosis in a static renewal experiment. After 15 days of exposure, tadpoles exposed to either of the two degradants showed significant reductions in survival and growth, while those exposed to naproxen were not affected. Results at metamorphosis will also be presented. These tests suggest that photodegradation of naproxen in the environment may increase risk to freshwater organisms. With increasing concern about pharmaceutical pollution, more attention should be paid to degradation products of pharmaceuticals, which can be both more toxic and more environmentally persistent than the original compounds.
