Colborn T
World Wildlife Fund, Washington, D.C.
J Toxicol Environ Health. 1991 Aug;33(4):395-453. doi: 10.1080/15287399109531537.
Historical data are provided to support the hypothesis that organochlorine chemicals introduced into the Great Lakes ecosystem following World War II are the cause of reproductive loss among bald eagles (Haliaeetus leucocephalus) in the basin. This is supported with data on concurrent population fluxes of extrabasin North American bald eagle populations and the European white-tailed sea eagle (Haliaeetus albicillus) where the same chemicals were produced and released. Organochlorine chemicals appear as a unique stress on Great Lakes bald eagle populations when compared with stresses on successful populations of bald eagles continentwide. Shoreline birds bear significantly higher concentrations of these persistent toxics than inland birds. Association between contaminated prey and elevated concentrations of PCBs, DDT, and DDE in Great Lakes bald eagles are presented. A fledging ratio is used to support the hypothesis that maternal prezygotic exposure affects the viability of embryos and chicks. The ratio of the mean number of fledglings per successful territory to the mean number of fledglings per active territory, when the numerator is greater than 1.4, provides an index of exposure to contaminants by parental animals and affected offspring. When the ratio is greater than 2, parental exposure to organochlorine chemicals should be considered. The adverse effects of prezygotic exposure to the same contaminants in other animal species dependent upon Great Lakes fish, and extrabasin bald eagle populations dependent upon contaminated fish, provide consistency to the argument. The mechanism of action of the organochlorine chemicals further strengthens the causal argument indicting DDT, DDE, and PCBs. A strong association between DDT/DDE and bald eagle reproductive success is provided. However, the role of PCBs is not ruled out. Only data for total PCB concentrations in bald eagle tissue are available, and until specific PCB congeners are quantified there will be uncertainty concerning PCB's role in the Great Lakes bald eagle's lack of success.
二战后引入五大湖生态系统的有机氯化学物质是该流域白头海雕（Haliaeetus leucocephalus）繁殖能力下降的原因。北美流域外白头海雕种群以及欧洲白尾海雕（Haliaeetus albicillus）同期种群变化的数据支持了这一假设，这些地区也生产和释放了相同的化学物质。与全大陆白头海雕成功种群所面临的压力相比，有机氯化学物质似乎是五大湖白头海雕种群所面临的一种独特压力。滨岸鸟类体内这些持久性有毒物质的浓度明显高于内陆鸟类。文中呈现了五大湖白头海雕体内受污染猎物与多氯联苯、滴滴涕和滴滴伊浓度升高之间的关联。雏鸟羽化率被用来支持母体合子前暴露会影响胚胎和雏鸟生存能力这一假设。当每个成功领地的雏鸟平均数量与每个活跃领地的雏鸟平均数量之比（分子大于1.4时），可提供亲代动物和受影响后代接触污染物的指标。当该比值大于2时，应考虑亲代接触有机氯化学物质的情况。其他依赖五大湖鱼类的动物物种以及依赖受污染鱼类的流域外白头海雕种群，合子前暴露于相同污染物所产生的不利影响，为这一观点提供了一致性。有机氯化学物质的作用机制进一步强化了指向滴滴涕、滴滴伊和多氯联苯的因果论证。文中给出了滴滴涕/滴滴伊与白头海雕繁殖成功率之间的紧密关联。然而，多氯联苯的作用并未被排除。目前仅有白头海雕组织中多氯联苯总浓度的数据，在特定多氯联苯同系物被量化之前，多氯联苯在五大湖白头海雕繁殖失败中所起的作用仍存在不确定性。
