Fathead Minnow Lifecycle Exposure to a Mixture of Six Common Pharmaceuticals and Triclosan

Fathead minnows were exposed for a lifecycle to environmentally-relevant concentrations of a mix of 6 common pharmaceuticals (salicylic acid, ibuprofen, acetaminophen, gemfibrozil, naproxen, and diclofenac) and one personal care product (triclosan). Nominal concentrations of these pharmaceuticals and personal care product (PPCPs) were 1,000, 300, 100, 30, and 10 ng/L. Mean measured concentrations of the 7 PPCPs in the highest fish exposure aquaria were: naproxen 793 ng/L, gemfibrozil 662 ng/L, diclofenac 331 ng/L, ibuprofen 217 ng/L, triclosan 115 ng/L, salicylic acid 67 ng/L, and acetaminophen (chemical analysis inconclusive, nominal 1,000 ng/L). Fish exposed for a lifecycle even to the highest concentrations of these 7 PPCP mixture (PPCP mix) showed no significant changes in growth and development compared to control fish. Length, weights, condition factors, liver weights and gonad weights of PPCPexposed fish were similar to water controls and solvent controls (0.000005 % ethanol v/v) controls. There were no effects of PPCP mix exposure on the external sex characteristics of the fish. PPCP mix exposed females had normal ovipositor sizes. Males exposed to the PPCP mix had normal tubercle indices. Fish exposed for a lifecycle even to the highest concentrations of these 7 PPCPs reproduced very well. Egg production was variable, and showed no dose-related effects. The only parameter that appeared to be affected by the PPCP mix was the percentage of larval deformities in F1, which showed a dose related increase up to 30 % of the highest concentration of the PPCP mix. Larvae from control fish had 4.7 % (water controls) and 3.2 % (solvent controls) deformities, compared to 9 % in the 100 ng/L (nominal) PPCP mix and 11 % deformities in 300 ng/L (nominal) PPCP mix. Mean measured concentrations of the seven PPCPs in the 300 ng/L (nominal) PPCP mix were: naproxen 227 ng/L, gemfibrozil 220 ng/L, diclofenac 113 ng/L ibuprofen 72 ng/L, triclosan 54 ng/L, salicylic acid 63 ng/L, and acetaminophen (chemical analysis inconclusive, nominal 300 ng/L). The study is important as it shows that long-term exposure to environmentally-relevant concentrations of 7 PPCPs most often detected in Canadian MWWEs does not appear to affect fathead minnow survival, growth, or reproduction, although it may cause slight increases in deformities in the F1 generation.