The Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, Texas, USA.
Environ Toxicol Chem. 2011 Aug;30(8):1885-91. doi: 10.1002/etc.576. Epub 2011 Jun 8.
Weathered crude oil in the Gulf of Mexico can result from oil spills such as the Deepwater Horizon incident that occurred on April 20, 2010 or from natural seeps. Adult waterbirds of the Gulf Coast region may become exposed to weathered crude oil while foraging, wading, or resting, and residues can then be transferred to nests, eggs, and hatchlings. Although the toxicity of many types of crude oil to avian embryos has been thoroughly studied, the effects of weathered crude oil on developing avian embryos are not well characterized. The objective of the present study was to examine embryotoxicity of weathered crude oil collected from the Gulf of Mexico in June 2010 using mallard ducks (Anas platyrhynchos) as a model species. Weathered crude oil was applied to fertilized mallard duck eggs by paintbrush in masses ranging from 0.1 to 99.9 mg on day 3 of incubation. Mortality occurred as early as day 7 and the conservatively derived median lethal application of weathered crude oil was 30.8 mg/egg (0.5 mg/g egg) or 30.7 µl/egg (0.5 µl/g egg). Body mass, liver and spleen mass, crown-rump and bill lengths, and frequency of deformities were not significantly different among hatchlings from oiled and control eggs. In comparison to published reports of fresh crude oil embryotoxicity, weathered crude oil was considerably less toxic. We conclude that avian toxicity varies according to the degree of crude oil weathering and the stage of embryonic development at the time of exposure. Results indicate bird eggs exposed to weathered crude oil from the Gulf of Mexico during summer 2010 may have had reduced hatching success.
墨西哥湾风化原油可能是由 2010 年 4 月 20 日发生的“深水地平线”事件等溢油事件造成的，也可能是由自然渗漏造成的。墨西哥湾沿海地区的成年水鸟在觅食、涉水或休息时可能会接触到风化原油，然后将残留物转移到巢、卵和雏鸟中。尽管许多类型的原油对鸟类胚胎的毒性已经进行了深入研究，但风化原油对发育中鸟类胚胎的影响尚未得到很好的描述。本研究的目的是使用绿头鸭（Anas platyrhynchos）作为模型物种，研究 2010 年 6 月从墨西哥湾采集的风化原油的胚胎毒性。风化原油通过画笔涂抹在受精的绿头鸭蛋上，孵化第 3 天的剂量范围为 0.1 至 99.9mg。死亡率早在第 7 天就出现了，保守推算的风化原油的致死中剂量为 30.8mg/卵（0.5mg/g 卵）或 30.7µl/卵（0.5µl/g 卵）。从油卵和对照卵孵出的雏鸟的体重、肝脾重量、头臀长和喙长以及畸形频率没有显著差异。与已发表的新鲜原油胚胎毒性报告相比，风化原油的毒性要小得多。我们得出的结论是，鸟类毒性根据原油风化的程度和暴露时胚胎发育的阶段而有所不同。结果表明，2010 年夏季暴露于墨西哥湾风化原油的鸟卵孵化成功率可能降低。
