Braune Birgit M, Mallory Mark L, Grant Gilchrist H, Letcher Robert J, Drouillard Ken G
Environment Canada, National Wildlife Research Centre, Carleton University, Ottawa, Ontario, Canada K1A 0H3.
Sci Total Environ. 2007 Jun 1;378(3):403-17. doi: 10.1016/j.scitotenv.2007.03.003. Epub 2007 Apr 5.
The ivory gull (Pagophila eburnea) is a circumpolar marine bird which has recently been listed as an endangered species in Canada. To determine whether contaminants may be playing a role in the population decline of this species, ivory gull eggs collected in 1976, 1987 and 2004 from Seymour Island in the Canadian Arctic were analyzed for organochlorines, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and non-ortho PCBs. This study also provides the first account of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs) and polybrominated biphenyls (PBBs) in ivory gulls. The most quantitatively abundant legacy organochlorines found in the ivory gull eggs were p,p'-DDE, SigmaPCB and oxychlordane. Concentrations of the organochlorines analyzed either decreased or showed little change between 1976 and 2004. Concentrations of SigmaPCDD in ivory gull eggs were greater than SigmaPCDF, and the non-ortho PCBs (primarily PCB-126) contributed the largest fraction to the total TEQ value in all years sampled. Concentrations of PCDDs, PCDFs and SigmaTEQ decreased from 1976 to 2004. In contrast, concentrations of the PBDEs steadily increased between 1976 and 2004 driven primarily by increases in BDE-47. Although concentrations of the persistent chlorinated compounds (i.e. organochlorine pesticides, PCBs, PCDDs, PCDFs) reported in this study were below published toxicological threshold values for eggs of wild birds, we cannot rule out the possibility of synergistic/additive, sublethal effects. Very few studies have been carried out to evaluate the exposure-effect relationship of the persistent brominated compounds in avian species. Given the scarcity of information on toxicity threshold levels for PBBs and PBDEs in avian species, coupled with the trend toward increasing concentrations in ivory gulls, continued monitoring and further toxicological studies of these compounds are warranted.
象牙鸥（Pagophila eburnea）是一种环北极海鸟，最近在加拿大被列为濒危物种。为了确定污染物是否可能在该物种的种群数量下降中起作用，对1976年、1987年和2004年从加拿大北极地区的西摩岛采集的象牙鸥蛋进行了有机氯、多氯二苯并对二恶英（PCDDs）、二苯并呋喃（PCDFs）和非邻位多氯联苯的分析。本研究还首次报道了象牙鸥体内的多溴二苯醚（PBDEs）、六溴环十二烷（HBCDs）和多溴联苯（PBBs）。在象牙鸥蛋中发现的数量上最丰富的遗留有机氯是p,p'-DDE、总多氯联苯（SigmaPCB）和氧化氯丹。1976年至2004年间，所分析的有机氯浓度要么下降，要么变化不大。象牙鸥蛋中总多氯二苯并对二恶英（SigmaPCDD）的浓度高于总多氯二苯并呋喃（SigmaPCDF），并且在所有采样年份中，非邻位多氯联苯（主要是PCB-126）在总毒性当量（TEQ）值中所占比例最大。1976年至2004年间，多氯二苯并对二恶英、多氯二苯并呋喃和总毒性当量（SigmaTEQ）的浓度下降。相比之下，1976年至2004年间，多溴二苯醚的浓度主要因BDE-47的增加而稳步上升。尽管本研究中报告的持久性氯化化合物（即有机氯农药、多氯联苯、多氯二苯并对二恶英、多氯二苯并呋喃）的浓度低于已公布的野生鸟类蛋的毒理学阈值，但我们不能排除协同/相加、亚致死效应的可能性。很少有研究评估持久性溴化化合物在鸟类中的暴露-效应关系。鉴于关于鸟类中多溴联苯和多溴二苯醚毒性阈值水平的信息匮乏，再加上象牙鸥体内浓度呈上升趋势，因此有必要对这些化合物继续进行监测和进一步的毒理学研究。
