Toxicity and bioaccumulation of ethofumesate enantiomers in earthworm Eisenia fetida
Volume 112, October 2014, Pages 163–169
• Peng Xu, Yinghuan Wang, Yanfeng Zhang, Jianzhong Li, Huili Wang
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing RD 18, Beijing 100085, China
Corresponding author. Tel.: +86 1062849385; fax: +86 1062946988.
• The acute toxicity of ethofumesate enantiomers to earthworm was enantioselective.
• The bioavailability of ethofumesate was determined using accumulation kinetics.
• The elimination of ethofumesate in earthworm was fast with a half life of 1.8 d.
• A linear relationship between Log BSAFs and Log Kow was observed.
• The elimination rate of some pesticides was independent of the Kow.
Earthworms represent an important food source for many vertebrates and as a result, predators may encounter toxic effects via the food chain from consumption of contaminated worms. Therefore, including an assessment of xenobiotic to worms in risk assessment procedures is advisable. Here we studied the acute toxicity, bioaccumulation and elimination of ethofumesate enantiomers in earthworm, Eisenia fetida, in a soil. A slight difference in toxicity to earthworm between two enantiomers was found, and the calculated LC50values for (+)-, rac- and (−)-ethofumesate were 4.51, 5.93 and 7.98 μg/cm2, respectively, indicating that the acute toxicity of ethofumesate enantiomers was enantioselective. Earthworm can uptake ethofumesate but the bioaccumulation curve did not reach the steady state. In the elimination experiment, the concentrations of ethofumesate in earthworm declined following a first-order decay model with a short half life of 1.8 d. The bioaccumulation and elimination of ethofumesate in earthworm were both nonenantioselective. In combination with other studies, a linear relationship between Log BSAFs and Log Kow was observed, and the Log BSAFs increased with increasing Log Kow. But the elimination rate did not show any correlation with theKow value.