六种热带淡水物种被用来评估澳大利亚北部世界遗产地区附近铀矿的矿井水的毒性。该矿潜在关注的主要污染物是美国,Mg,Mn,和总氨氮(TAN)。进行了直接毒性评估,以评估已建立的针对单个污染物的特定地点指导值是否对作为混合物存在的污染物具有保护作用。计算污染物的金属形态,以确定哪些是毒性的主要贡献者,其中84%至96%的Mg以自由离子形式预测为Mg2+,76-92%的Mn预测为Mn2+。铀,Al,和铜被预测与富里酸强烈结合。铀,Mg,Mn,将Cu和Cu掺入浓度添加或独立作用混合物毒性模型中,以将每种水中观察到的毒性与预测的毒性进行比较。对于>90%的数据,矿井水毒性小于浓度添加模型预测。除一种情况外,毒性大于预期的情况伴随着单个金属指导值的超标(即,aMg浓度在指导值的10%以内)。这表明美国现有的个别水质指导值,Mg,Mn,TAN将充分保护矿山下游的生态系统。环境毒物化学2021;40:2334-2346。©2021澳大利亚联邦。环境毒理学和化学©2021SETAC。
Six tropical freshwater species were used to assess the toxicity of mine waters from a
uranium mine adjacent to a World Heritage area in northern Australia. Key contaminants of potential concern for the mine were U, Mg, Mn, and total ammonia nitrogen (TAN). Direct toxicity assessments were carried out to assess whether the established site-specific
guideline values for individual contaminants would be protective with the contaminants occurring as mixtures. Metal speciation was calculated for contaminants to determine which were the major contributors of toxicity, with 84 to 96% of Mg predicted in the free-ion form as Mg2+ , and 76 to 92% of Mn predicted as Mn2+ .
Uranium, Al, and Cu were predicted to be strongly bound to fulvic acid.
Uranium, Mg, Mn, and Cu were incorporated into concentration addition or independent action mixture toxicity models to compare the observed toxicity in each of the waters with predicted toxicity. For >90% of the data, mine-water toxicity was less than predicted by the concentration addition model. Instances where toxicity was greater than predicted were accompanied by exceedances of individual metal guideline values in all but one case (i.e., a Mg concentration within 10% of the
guideline value). This indicates that existing individual water quality guideline values for U, Mg, Mn, and TAN would adequately protect ecosystems downstream of the mine. Environ Toxicol Chem 2021;40:2334-2346. © 2021 Commonwealth of Australia. Environmental Toxicology and Chemistry © 2021 SETAC.