The embryonic and postembryonic developmental toxicity of imidazolium-based ionic liquids on Physa acuta

The embryonic and postembryonic developmental toxicity of imidazolium-based ionic liquids (ILs) to the snail Physa acuta was evaluated in this study. The results of embryonic toxicity tests showed that lower concentrations of 1-octyl-3-methylimidazolium bromide ([C(8)mim]Br) (1.5 and 2.1 mg/L) inhibited the hatching rate of snail embryos, and partial snails hatched normally and died, while all of the treated embryos died when the exposure concentration was higher than 4.16 mg/L, at which IL caused the deformation, death, and decay of snail embryos. Statistical analyses revealed obvious differences in the hatching rates between three developmental stages in the 2.1 and 2.94 mg/L groups, indicating that the veliger stage is more sensitive to [C(8)mim]Br exposure than the blastula and gastrula stages. Furthermore, the 96 h LC50 values of [C(8)mim]Br on the tested snails at three developmental stages (juvenile, subadult, and adult) were 70.83 +/- 2.99, 97.59 +/- 4.05, and 109.3 +/- 2.22 mg/L, respectively, indicating that young snails were more sensitive to [C(8)mim]Br toxicity than adults. In addition, the 96 h LC50 values of ILs with different alkyl chain lengths, that is, [C(12)mim], [C(10)mim], [C(8)mim], and [C(6)mim], in adult snails were 1.35 +/- 0.24, 8.96 +/- 5.66, 109.3 +/- 4, and 359.6 +/- 11.6 mg/L, respectively, suggesting that longer alkyl chains can increase the toxicity of imidazolium ILs on snails. (c) 2012 Wiley Periodicals, Inc. Environ Toxicol 29: 697-704, 2014.