Seabrook Katryna J, Winn Louise M, Brinkmann Markus, Adams Julie E, Canete Ashley, Xie Linna, Peng Hui, Robinson Stacey A, Orihel Diane M
School of Environmental Studies, Queen's University, Kingston, Ontario, Canada.
Department of Biomedical and Molecular Science, Queen's University, Kingston, Ontario, Canada.
Environ Toxicol Chem. 2025 Jul 31. doi: 10.1093/etojnl/vgaf178.
N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) is a widely used rubber antioxidant, entering aquatic ecosystems through roadway runoff of tire wear particles. A transformation product of 6PPD, 6PPD-quinone, has been detected in watersheds at concentrations acutely toxic to some salmonid fish species. We evaluated the toxicity of 6PPD to early-life stage largemouth bass (Micropterus nigricans) in a series of outdoor aquatic microcosm experiments. Wild-collected embryos were chronically exposed to 6PPD and its potential transformation products in natural lake water under ambient environmental conditions. In a preliminary 96-h experiment, 6PPD was toxic to largemouth bass embryos with a 96-h LC50 of 42.8 µg/L. Interestingly, we found that exposure to 6PPD-quinone did not cause mortality in largemouth bass embryos beyond concentrations of maximum solubility in water. To further investigate the developmental toxicity of 6PPD, largemouth bass were exposed to 6PPD (modelled time-weighted average concentrations ranging from 0.1-3.7 µg/L) for 10 d, which spanned the embryonic to yolk-sac larval life stages. Exposure to 6PPD decreased yolk sac absorption as well as increased the occurrence and severity of malformations compared to the solvent control. As the first toxicological assessment of 6PPD with largemouth bass, our findings provide an important first step in understanding how 6PPD affects the development of the early life stages under environmentally realistic conditions.
N-（1,3-二甲基丁基）-N'-苯基对苯二胺（6PPD）是一种广泛使用的橡胶抗氧化剂，通过轮胎磨损颗粒的道路径流进入水生生态系统。在流域中已检测到6PPD的一种转化产物6PPD-醌，其浓度对一些鲑科鱼类具有急性毒性。我们在一系列室外水生微宇宙实验中评估了6PPD对大口黑鲈（Micropterus nigricans）幼鱼期的毒性。野外采集的胚胎在环境条件下长期暴露于天然湖水中的6PPD及其潜在转化产物。在初步的96小时实验中，6PPD对大口黑鲈胚胎有毒，96小时半数致死浓度为42.8μg/L。有趣的是，我们发现暴露于6PPD-醌不会导致大口黑鲈胚胎死亡率超过其在水中的最大溶解度浓度。为了进一步研究6PPD的发育毒性，大口黑鲈暴露于6PPD（模拟时间加权平均浓度范围为0.1-3.7μg/L）10天，这涵盖了胚胎到卵黄囊幼体阶段。与溶剂对照相比，暴露于6PPD会降低卵黄囊吸收，并增加畸形的发生率和严重程度。作为对6PPD与大口黑鲈的首次毒理学评估，我们的研究结果为了解6PPD在环境现实条件下如何影响幼鱼期发育提供了重要的第一步。
