Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada.
Aquat Toxicol. 2013 Oct 15;142-143:414-21. doi: 10.1016/j.aquatox.2013.09.003. Epub 2013 Sep 12.
Understanding the toxicity of oil sands process-affected water (OSPW) is a significant issue associated with the production of oil from the Alberta oil sands. OSPW is acutely and chronically toxic to organisms, including larvae of Chironomus dilutus. In this study, fresh OSPW ('WIP-OSPW') was collected from the West In-Pit settling pond and aged OSPW ('FE5-OSPW') was collected from the FE5 experimental reclamation pond, both of which are located on the Syncrude Canada Ltd. lease site near Fort McMurray, Alberta, Canada. Larvae of C. dilutus were exposed to a freshwater control, WIP-OSPW, or FE5-OSPW for 4 or 7 days and survival, growth, and markers of oxidative stress and endocrine disruption were assessed. Survival was not significantly different among treatment groups. Compared to masses of larvae exposed to freshwater, masses of larvae exposed to WIP-OSPW were 49% lesser on day 4 and 62% lesser on day 7. However, organisms exposed to FE5-OSPW did not have significantly lesser masses than controls. Abundances of transcripts of glutathione-s-transferase (gst), catalase (cat), and glutathione peroxidase (gpx), which are important for the response to oxidative stress, were significantly altered in larvae exposed to WIP-OSPW, but not FE5-OSPW, relative to controls. Peroxidation of lipids was greater in larvae exposed to WIP-OSPW, but not FE5-OSPW. Exposure to fresh OSPW might have caused endocrine disruption because abundances of transcripts of the steroid hormone receptors, ultraspiricle protein (usp), ecysteroid receptor (esr), and estrogen related receptor (err) were greater in larvae exposed to WIP-OSPW for 7 days, but not FE5-OSPW. These results suggest that lesser growth of larvae of C. dilutus exposed to fresh OSPW might be due to oxidative stress and disruption of endocrine processes, and that aging of OSPW attenuates these adverse effects.
了解油砂处理废水（OSPW）的毒性是与从阿尔伯塔省油砂中生产石油相关的一个重要问题。OSPW 对生物体具有急性和慢性毒性，包括摇蚊幼虫。在这项研究中，从西采坑沉降池采集新鲜 OSPW（“WIP-OSPW”），从 FE5 实验复垦池采集老化 OSPW（“FE5-OSPW”），这两个地点都位于加拿大阿尔伯塔省麦克默里堡附近的 Syncrude Canada Ltd. 租用地。将摇蚊幼虫暴露于淡水对照、WIP-OSPW 或 FE5-OSPW 中 4 或 7 天，并评估其存活率、生长情况以及氧化应激和内分泌干扰的标志物。处理组之间的存活率没有显著差异。与暴露于淡水的幼虫相比，暴露于 WIP-OSPW 的幼虫在第 4 天的体重减少了 49%，在第 7 天的体重减少了 62%。然而，暴露于 FE5-OSPW 的生物体的体重并没有比对照组显著减少。参与氧化应激反应的谷胱甘肽-S-转移酶（gst）、过氧化氢酶（cat）和谷胱甘肽过氧化物酶（gpx）的转录物丰度在暴露于 WIP-OSPW 的幼虫中显著改变，但在暴露于 FE5-OSPW 的幼虫中没有显著改变。暴露于 WIP-OSPW 的幼虫的脂质过氧化作用更大，但在暴露于 FE5-OSPW 的幼虫中没有。暴露于新鲜 OSPW 可能导致内分泌干扰，因为暴露于 WIP-OSPW 7 天的幼虫的类固醇激素受体、超微体蛋白（usp）、蜕皮激素受体（esr）和雌激素相关受体（err）的转录物丰度增加，但暴露于 FE5-OSPW 的幼虫的转录物丰度没有增加。这些结果表明，暴露于新鲜 OSPW 的摇蚊幼虫生长减缓可能是由于氧化应激和内分泌过程的破坏，而 OSPW 的老化减轻了这些不利影响。
