R4 PM Effects and Risk Assessment of Pharmaceutical and Other Emerging Wastewater Contaminants in Aquatic Systems
Thursday, 17 November 2005: 1:50 PM - 5:30 PM in Ballroom 4
(BRI-1117-726542) Reproductive effects of the pharmaceutical fluoxetine on a native freshwater mussel.
Bringolf, R.1, Cope, W.1, Heltsley, R.2, Eads, C.3, Shea, D.1, 1 Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, NC, USA2 Hollings Marine Laboratory, National Institute of Standards and Technology, Charleston, SC, USA3 College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
ABSTRACT- Recently, widespread occurrence of fluoxetine and other pharmaceuticals and personal care products (PPCPs) has been reported in surface waters of the United States and elsewhere; however, impacts of PPCPs on aquatic organisms are largely unknown. Fluoxetine is the active ingredient in the prescription anti-depressant drug ProzacTM, which acts as a selective serotonin reuptake inhibitor (SSRI) to increase serotonin levels at nerve synapses. Serotonin has previously been used to induce parturition/spawning in some bivalves. To determine the potential of fluoxetine to disrupt native freshwater mussel reproduction, we exposed gravid adult female eastern elliptio (Elliptio complanata) mussels to fluoxetine at target concentrations of 0, 0.03, 0.3, 3.0, 30, 300, and 3000 
g/L for 96 h in static-renewal tests. We used serotonin as a positive control and methiothepin, an inhibitor of serotonin pathways, as a confirmatory agent of pathway effects. Time to glochidia release, glochidia maturity and viability, and the number of glochidia released (fecundity) were measured. Fluoxetine exposure concentrations were analyzed by liquid chromatography/mass spectroscopy (LC-MS) to confirm exposure concentrations. Time to glochidial release was variable among the fluoxetine treatment groups, but was generally inversely related to exposure concentration. No glochidia were released by mussels in the control group in < 72 h; however, some mussels in each fluoxetine treatment, including low, environmentally relevant concentrations, released glochidia in < 24 hours. The average number of glochidia released was variable, but was generally positively correlated with fluoxetine exposure concentration. Released glochidia were predominantly immature, indicating that fluoxetine induced parturition in gravid mussels. Implications for population-level effects will be discussed. Additional studies of the endocrine and reproductive effects of fluoxetine on ripe adult male mussels are needed.
Key words: fluoxetine, reproduction, mussel, pharmaceutical