Life-Cycle Exposure of Fathead Minnows to a Mixture of Six Common Pharmaceuticals and Triclosan

Abstract

Fathead minnows were exposed for a life cycle to environmentally relevant concentrations of a mixture of six common pharmaceuticals and one personal care product (nominal concentrations: 1,000, 300, 100, 30, or 10 ng/L). Mean measured concentrations of each chemical in the highest fish exposure aquaria were: naproxen 793 ng/L, gemfibrozil 662 ng/L, diclofenac 331 ng/L, ibuprophen 217 ng/L, triclosan 115 ng/L, salicylic acid 67 ng/L, and acetaminophen (chemical analysis inconclusive, nominal 1000 ng/L). Fish exposed for a life cycle even to the highest concentrations of the six pharmaceuticals and personal care product (PPCP) mixture showed no significant changes in growth and development compared to control. Length, weights, condition factors, liver weights, and gonad weights of PPCP-exposed fish were similar to water and solvent controls (0.000005% ethanol v/v). There were no marked effects of PPCP mixture exposure on external sex characteristics of the fish or on egg production. The only parameter that appeared to be affected was percent larval deformities in F1, which showed a significant increase in the 100- and 300-ng/L (nominal) PPCP mixture. Larvae from control fish had 4.7% (water controls) and 3.4% (solvent controls) deformities, compared to 9.3% in the 100-ng/L (nominal) PPCP mixture and 9.2% deformities in the 300-ng/L (nominal) PPCP mixture. Chronic exposure to environmentally relevant concentrations of seven PPCP most often detected in Canadian municipal wastewater effluents (MWWE) did not appear to affect fathead minnow survival, growth, or egg production, although it produced quantitative increases in deformities in the F1 generation.

Acknowledgements

We are grateful for generous funding for this project from Health Canada and the Canadian Environmental Protection Act (CEPA). Technical assistance of Beverley R. Blunt and Virginia Palabricia is greatly appreciated.

Permission to publish this article has been granted to the publisher by the authors and Environment Canada.