Maggio Stephanie A, Jenkins Jeffrey J
Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon, USA.
Environ Toxicol Chem. 2022 Apr;41(4):1054-1065. doi: 10.1002/etc.5283. Epub 2022 Feb 1.
Chlorpyrifos, a broad-spectrum neurotoxic organophosphate insecticide, is subject to atmospheric and hydrolytic transport from application sites to aquatic ecosystems. Across the landscape, concentrations in surface water can vary spatially and temporally according to seasonal use practices. Standardized bioassays can provide a screening-level understanding of aquatic receptor acute and chronic toxicity. However, these bioassays do not address ecologically relevant exposure patterns that may impact fitness and survival within and across generations. The aim of the present study was to evaluate the utility of a second-tier, screening-level methodology employing Daphnia magna multi- and transgenerational bioassays spanning four generations to investigate the effect of variable chronic chlorpyrifos exposure. The multigenerational assay consisted of continuous chlorpyrifos exposure across four consecutive 21-day bioassays using progeny from the previous assay for each successive generation. In the transgenerational assay, only the parent (F0) generation was exposed. For both assays, survival and reproduction were assessed across treatments and generations. Results indicated that (1) following continuous chlorpyrifos exposure at ecologically relevant concentrations to four generations of D. magna, the highest treatment showed an apparent tolerance response for both survival and reproductive success in the F3 generation, and (2) chlorpyrifos exposure to the F0 generation did not result in treatment effects in the unexposed F1, F2, and F3 generations in the apical endpoints of survival and reproduction. Employing a suite of acute and chronic bioassays, including chronic exposures spanning multiple generations, allows for a more robust screening-level evaluation of the potential impact of chlorpyrifos on aquatic receptors for variable periods of exposure. Environ Toxicol Chem 2022;41:1054-1065. © 2021 SETAC.
毒死蜱是一种具有广谱神经毒性的有机磷酸酯类杀虫剂，会通过大气和水解作用从施药地点传输至水生生态系统。在整个区域内，地表水的浓度会根据季节性使用情况在空间和时间上发生变化。标准化生物测定可提供对水生受体急性和慢性毒性的筛查水平的了解。然而，这些生物测定并未考虑可能影响代内和代际健康及生存的生态相关暴露模式。本研究的目的是评估一种二级筛查水平方法的实用性，该方法采用大型溞多代和跨代生物测定，跨越四代来研究可变慢性毒死蜱暴露的影响。多代测定包括在连续四个21天的生物测定中持续暴露于毒死蜱，每一代都使用上一代的后代。在跨代测定中，仅亲代（F0）代暴露。对于这两种测定，均评估了各处理和各代的生存和繁殖情况。结果表明：（1）在生态相关浓度下将毒死蜱连续暴露于四代大型溞后，最高处理组在F3代的生存和繁殖成功方面均表现出明显的耐受反应；（2）毒死蜱暴露于F0代并未在未暴露的F1、F2和F3代的生存和繁殖等关键终点产生处理效应。采用一系列急性和慢性生物测定，包括跨多代的慢性暴露，能够对毒死蜱在不同暴露时间段对水生受体的潜在影响进行更有力的筛查水平评估。《环境毒理学与化学》2022年；41：1054 - 1065。© 2021 SETAC。
