McMaster M E, Evans M S, Alaee M, Muir D C G, Hewitt L M
National Water Research Institute, Environment Canada, Burlington, ON.
Environ Monit Assess. 2006 Feb;113(1-3):143-65. doi: 10.1007/s10661-005-9100-x.
In response to a number of recommendations following the Northern Rivers Basin Studies (NRBS) contaminant program, the Northern Rivers Ecosystem Initiative (NREI) focused considerable attention on assessing contaminants from specific sources including pulp mill effluents, atmospheric transport of mercury and the Alberta oil sands operations. NRBS identified a number of major contaminants of concern including polychlorinated biphenyls, dioxins and furans, mercury and various hydrocarbons. Together, the NRBS and the NREI studies have demonstrated major declines in the levels of dioxins and furans over the last decade as pulp and paper mills have changed their process and treatment strategies in response to new Federal regulations. Polychlorinated biphenyls however, continue to be a concern for the region as their levels have not declined in fish and sediments over the course of these studies. Higher levels in sediments downstream of Grande Prairie and Hinton were identified, but the source of these contaminants remains unknown. Chlorinated pesticides were also investigated, and although toxaphene, DDT and other chlorinated organic pesticides were detected in fish tissue, they were present at very low levels. Studies on the oil sands industry in northern Alberta demonstrated limited impacts on the Athabasca River to date, although studies did identify slight to moderate impacts of natural oil seeps on fish and benthic communities in tributary streams. NREI studies also identified endocrine active compounds in the three pulp and paper mill effluents tested, but endocrine disruptive effects in wild fish were minimal. Municipal sewage effluents also contain endocrine active compounds and it is recommended that monitoring continue around these point sources.
根据北河流域研究（NRBS）污染物项目之后的一系列建议，北河生态系统倡议（NREI）将大量注意力集中在评估特定来源的污染物上，包括纸浆厂废水、汞的大气传输以及艾伯塔省油砂作业。NRBS确定了一些主要关注的污染物，包括多氯联苯、二恶英和呋喃、汞以及各种碳氢化合物。总体而言，NRBS和NREI的研究表明，在过去十年中，随着纸浆和造纸厂根据新的联邦法规改变其工艺和处理策略，二恶英和呋喃的含量大幅下降。然而，多氯联苯仍然是该地区的一个问题，因为在这些研究过程中，鱼类和沉积物中的多氯联苯含量并未下降。在大草原城和欣顿下游的沉积物中发现了较高含量的多氯联苯，但这些污染物的来源仍然不明。还对氯化农药进行了调查，虽然在鱼组织中检测到了毒杀芬、滴滴涕和其他氯化有机农药，但它们的含量非常低。对艾伯塔省北部油砂行业的研究表明，迄今为止，对阿萨巴斯卡河的影响有限，尽管研究确实发现天然油渗漏对支流中的鱼类和底栖生物群落有轻微到中度的影响。NREI的研究还在测试的三家纸浆和造纸厂废水中发现了内分泌活性化合物，但对野生鱼类的内分泌干扰作用微乎其微。城市污水中也含有内分泌活性化合物，建议继续对这些排放源进行监测。
