Organic selenium species in waters and sediments: Production by algae and fate

硒（Se）是目前北美重要的无机污染物。它是从一些主要的工业过程中意外排放到水生环境中的，包括燃煤发电厂、炼油厂和各种类型的采矿作业（如煤、金和铀）。在一些接收环境中，有关注的生态毒理学效应所产生的硒排放，导致许多目前的工业赞助的环境硒研究。与此同时，美国环境保护署和加拿大环境部正在重新评估其目前的环境硒标准。对硒排放量增加的主要关切是，它会在水生生物体内生物积累，并可能导致水生鸟类和捕食性鱼类（如鸭和鳟鱼）的生殖影响（例如生育力降低、死胎和后代畸形），最终可能危及整个当地种群的生存。有机硒物种经常被引用的生物积累和生态毒性的硒，但从来没有被确定性地测量外的生物体。拟议的研究计划的目标是一劳永逸地确定，如果某些离散的有机硒物种和有机硒化合物，这是经常假设在地球化学模型和生态毒理学评估，实际上存在于环境沃茨和沉积物（如果是这样，在什么相对和绝对浓度）。为此，将允许藻类在受控条件下与硒相互作用，并确定在代谢和衰变过程中释放的硒的形式。

Selenium (Se) is an inorganic contaminant of high current importance in North America. It is discharged accidentally into the aquatic environment from some major industrial processes, including coal-fired power plants, petroleum refineries and various types of mining operations (e.g. coal, gold and uranium). In some receiving environments, there is concern about ecotoxicological effects arising from Se discharges, leading to numerous current industrially-sponsored environmental Se studies. At the same time, the US Environmental Protection Agency and Environment Canada are re-evaluating their current ambient Se criteria. The main concern about elevated Se discharges is that it bioaccumulates in aquatic organisms, and may lead to reproductive effects (e.g. reduced fertility, stillbirth and deformities in offspring) in aquatic birds and predatory fish, such as ducks and trout, which may ultimately endanger the survival of entire local populations. Organic Se species are often invoked in the bioaccumulation and ecotoxicity of Se, but have never been measured conclusively outside of organisms. The goal of the proposed research program is to determine once and for all if certain discrete organo-Se species and groups of organic Se compounds, which are frequently postulated in biogeochemical models and ecotoxicological assessments, actually exist in ambient waters and sediments (and, if so, at what relative and absolute concentrations). For this purpose, algae will be allowed to interact with Se under controlled conditions, and the forms of SE released during metabolism and decay will be determined.