Department of Animal Science, Michigan State University, 474 South Shaw Lane, East Lansing, MI 48824, United States.
Abt Associates, 1881 Ninth St., Ste 201, Boulder, CO 80302-5148, United States.
Ecotoxicol Environ Saf. 2017 Dec;146:91-97. doi: 10.1016/j.ecoenv.2017.03.045. Epub 2017 Apr 14.
Shorebirds were among birds exposed to Mississippi Canyon 252 (MC252) crude oil during the 2010 Deep Water Horizon (DWH) oil spill in the Gulf of Mexico. The western sandpiper (Calidris mauri) was chosen as one of four species for initial oral dosing studies conducted under Phase 2 of the avian toxicity studies for the DWH Natural Resource Damage Assessment (NRDA). Thirty western sandpipers were assigned to one of three treatment groups, 10 birds per group. The control group was sham gavaged and the treatment groups were gavaged with 1 or 5mL oil kg bw daily for 20 days. Periodic blood samples for hemoglobin measurements were collected during the trial. A final blood sample used to determine hemoglobin concentration in addition to complete blood counts, plasma clinical chemistries, haptoglobin concentration and plasma electrophoresis was collected when birds were euthanized and necropsied on day 21. Tissues were removed, weighed and processed for subsequent histopathological evaluation. There were numerical decreases in hemoglobin concentrations in oil-dosed birds over the 21-day trial, but values were not significantly different compared to controls on day 21. There were no significant differences between controls and oiled birds in complete blood counts, plasma chemistries, haptoglobin concentration, and plasma electrophoresis endpoints. Of the hepatic oxidative stress endpoints assessed, the total antioxidant capacity assessment (Trolox equivalents) for the control group was lower compared to the 1mL oil kg bw group. Absolute liver weights in the 5mL oil kg bw group were significantly greater compared to controls. While not conclusive, the numerical decrease in hemoglobin concentration and significant increase in absolute liver weight are consistent with exposure to oil. Histological changes in the adrenal gland could be considered a non-specific indicator of stress resulting from exposure to oil. It is possible that the quantity of oil absorbed was not sufficient to induce clearly evident hemolytic anemia or that the western sandpiper is relatively insensitive to ingested oil.
涉禽是在墨西哥湾 2010 年深海地平线（DWH）溢油事件中接触密西西比峡谷 252（MC252）原油的鸟类之一。西部滨鹬（Calidris mauri）被选为 DWH 自然资源损害评估（NRDA）鸟类毒性研究第二阶段初始口服剂量研究的四种物种之一。30 只西部滨鹬被分配到三个治疗组中的一个，每组 10 只鸟。对照组进行假灌胃，治疗组每天用 1 或 5mL 油/kgbw 灌胃 20 天。在试验期间定期采集血液样本进行血红蛋白测量。在第 21 天处死鸟类并进行尸检时，采集最后一个血液样本，除了血红蛋白浓度外，还用于全血细胞计数、血浆临床化学、触珠蛋白浓度和血浆电泳。采集组织、称重并进行随后的组织病理学评估。在 21 天的试验中，油处理组的血红蛋白浓度数值下降，但与对照组相比，第 21 天无显著差异。对照组和油处理组的全血细胞计数、血浆化学、触珠蛋白浓度和血浆电泳终点无显著差异。在所评估的肝氧化应激终点中，对照组的总抗氧化能力评估（Trolox 当量）低于 1mL 油/kgbw 组。5mL 油/kgbw 组的绝对肝重明显大于对照组。虽然没有结论性，但血红蛋白浓度的数值下降和绝对肝重的显著增加与接触油有关。肾上腺的组织学变化可被认为是暴露于油引起的应激的非特异性指标。可能是吸收的油量不足以引起明显的溶血性贫血，也可能是西部滨鹬对摄入的油相对不敏感。
