Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China.
School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, China.
Environ Sci Technol. 2021 Jan 5;55(1):458-467. doi: 10.1021/acs.est.0c05664. Epub 2020 Dec 17.
Species sensitivity to neonicotinoids has been shown to be highly variable among aquatic invertebrates. Toxicokinetic and toxicodynamic (TKTD) models were constructed to mechanistically elucidate the susceptibility of to imidacloprid. was highly tolerant to single short-term exposure to imidacloprid (96-h LC50 of 8.47 μg/mL), but delayed and carry-over toxicity occurred under repeated pulse exposures. Kinetic distribution of imidacloprid between exoskeleton and soft tissues of was evaluated using a newly developed method. Approximately 84% imidacloprid was distributed to soft tissues but was rapidly depurated from the tissue ( of 1.2 h), resulting in low bioaccumulation and high tolerance. TKTD modeling also successfully simulated the survival of after pulsed exposures. The calculated recovery time was 45 d, indicating significant delayed and carry-over toxicity of the insecticide. While complete elimination of imidacloprid only took about 5 h (TK), slow damage recovery (45 d) caused slow organism recovery (TD). Consequently, although was tolerant to imidacloprid due to fast depuration from soft tissue, long damage recovery time significantly enhanced the toxicity under repeated pulse exposures. Our study highlights the necessity of integrating delayed and carry-over toxicity quantification in assessing the risk of neonicotinoids to aquatic invertebrates.
水生无脊椎动物对新烟碱类杀虫剂的敏感性具有高度的变异性。构建了毒代动力学和毒效动力学（TKTD）模型，以从机制上阐明对吡虫啉的敏感性。 对单一短期吡虫啉暴露（96 小时 LC50 为 8.47μg/mL）具有高度耐受性，但在重复脉冲暴露下会发生延迟和残留毒性。使用新开发的方法评估了吡虫啉在 体表和软组织之间的动力学分布。约 84%的吡虫啉分布在软组织中，但很快从组织中排泄（1.2 小时的半衰期），导致低生物积累和高耐受性。TKTD 模型还成功模拟了脉冲暴露后昆虫的存活情况。计算出的恢复时间为 45 天，表明杀虫剂具有明显的延迟和残留毒性。虽然完全消除吡虫啉只需要大约 5 小时（TK），但缓慢的损伤恢复（45 天）导致了生物体的缓慢恢复（TD）。因此，尽管由于从软组织中快速排泄，对吡虫啉具有耐受性，但长时间的损伤恢复时间会显著增加重复脉冲暴露下的毒性。本研究强调了在评估新烟碱类杀虫剂对水生无脊椎动物的风险时，需要综合考虑延迟和残留毒性的量化。
