Triclosan (TCS) is used as an antimicrobial agent and has been widely dispersed and
detected in the aquatic environment. However, it remains uncertain whether TCS is
genotoxic or not. In this study, the acute toxicity of TCS in goldfish (
Carassius
auratus
) was studied. Then, based on the results for acute toxicity, other
goldfish were exposed to various concentrations of TCS (control, DMSO control, and 1/4,
1/2, and 1/8 LC
50
) for 14 days, and the effects on genetic toxicity were
evaluated using micronucleus (MN) and nuclear abnormalities (NA) frequencies in peripheral
blood and the comet assay in the liver of the goldfish. In addition, malondialdehyde
(MDA), reduced glutathione (GSH), catalase (CAT), and total antioxidant capacity (T-AOC)
in the liver were assayed to evaluate oxidative stress and the possible mechanism of
genotoxicity. The 96 h median lethal concentration of TCS was 1111.9
µ
g/l. After 14 days of exposure, the MN and NA frequencies were
significantly increased in peripheral blood of the TCS-treated groups compared with the
solvent control, and the comet tail moment and MDA in the liver in the highest dose of TCS
groups were also significantly high. Meanwhile, an evident change in GSH, CAT, and T-AOC
of the liver was found as the TCS exposure concentration increased. The results showed
that TCS caused oxidative stress and a genotoxic response in goldfish, suggesting that it
presents a potential ecotoxicological risk to aquatic ecosystems.