Environment Canada, Prairie & Northern Wildlife Research Centre, 115 Perimeter Rd., Saskatoon, SK, S7N 0X4, Canada.
J Toxicol Environ Health A. 2010;73(15):1058-73. doi: 10.1080/15287394.2010.481619.
Environmental contaminants are transported over great distances to Arctic ecosystems, where they can accumulate in wildlife. Whether contaminant concentrations in wildlife are sufficient to produce adverse effects remains poorly understood. Exposure to contaminants elevates oxidative stress with possible fitness consequences. The glaucous gull (Larus hyperboreus), an Arctic top predator, was used as a bioindicator for investigating relationships between contaminant levels (organochlorines and polychlorinated biphenyls [OC/PCB], mercury [Hg], and selenium [Se]) and measures of oxidative stress (glutathione [GSH] metabolism and lipid peroxidation) in Canadian Arctic ecosystems. Contaminant levels were low and associations between contaminant exposure and oxidative stress were weak. Nevertheless, glutathione peroxidase activity rose with increasing hepatic Se concentrations, levels of thiols declined as Hg and OC/PCB levels rose, and at one of the two study sites levels of lipid peroxidation were elevated with increasing levels of hepatic Hg. These results suggest the possibility of a deleterious effect of exposure to contaminants on gull physiology even at low contaminant exposures.
环境污染物被远距离运输到北极生态系统，并在那里积累在野生动物体内。野生动物体内的污染物浓度是否足以产生不良影响仍知之甚少。接触污染物会增加氧化应激，从而可能对适应性产生影响。北极地区的顶级掠食者——环嘴鸥（Larus hyperboreus）被用作生物指示剂，用于研究加拿大北极生态系统中污染物水平（有机氯和多氯联苯[OC/PCB]、汞[Hg]和硒[Se]）与氧化应激测量值（谷胱甘肽[GSH]代谢和脂质过氧化）之间的关系。污染物水平较低，污染物暴露与氧化应激之间的关联较弱。尽管如此，随着肝硒浓度的升高，谷胱甘肽过氧化物酶活性上升；随着 Hg 和 OC/PCB 水平的升高，巯基水平下降；在两个研究地点中的一个地点，随着肝 Hg 水平的升高，脂质过氧化水平升高。这些结果表明，即使在低污染物暴露水平下，接触污染物对海鸥生理也可能产生有害影响。
