Environmental Research Institute of the Supervising Scientist, Darwin, Northern Territory, Australia.
Environ Toxicol Chem. 2022 Nov;41(11):2808-2821. doi: 10.1002/etc.5470. Epub 2022 Oct 11.
Copper (Cu) is a contaminant of potential concern for a uranium mine whose receiving waters are in the World Heritage-listed Kakadu National Park in northern Australia. The physicochemical characteristics of the freshwaters in this region enhance metal bioavailability and toxicity. Seven tropical species were used to assess the chronic toxicity of Cu in extremely soft freshwater from a creek upstream of the mine. Sensitivity to Cu was as follows: Moinodaphnia macleayi > Chlorella sp. > Velesunio sp. > Hydra viridissima > Amerianna cumingi > Lemna aequinoctialis > Mogurnda mogurnda. The 10% effect concentrations (EC10s) ranged from 1.0 µg/L Cu for the cladoceran Moinodaphnia macleayi to 9.6 µg/L for the fish M. mogurnda. The EC50s ranged from 6.6 µg/L Cu for the mussel Velesunio sp. to 22.5 µg/L Cu for M. mogurnda. Geochemical modeling predicted Cu to be strongly bound to fulvic acid (80%-99%) and of low bioavailability (0.02%-11.5%) under these conditions. Protective concentrations (PCs) were derived from a species sensitivity distribution for the local biota. The 99% PC (PC99), PC95, PC90, and PC80 values were 0.5, 0.8, 1.0, and 1.5 µg/L Cu, respectively. These threshold values suggest that the current Australian and New Zealand default national 99% protection guideline value for Cu (1.0 µg/L) would not provide adequate protection in freshwaters of low hardness, particularly for this area of high conservation value. The continuous criterion concentration predicted by the Cu biotic ligand model for conditions of low pH (6.1), low dissolved organic carbon (2.5 mg/L), low hardness (3.3 mg/L), and 27 °C was 0.48 µg/L Cu, comparable with the PC99. Consideration of the natural water quality conditions of a site is paramount for protective water quality guidelines. Environ Toxicol Chem 2022;41:2808-2821. © 2022 Commonwealth of Australia. Environmental Toxicology and Chemistry © 2022 SETAC.
铜 (Cu) 是澳大利亚北部列入世界遗产名录的卡卡杜国家公园内一座铀矿的潜在关注污染物。该地区淡水的物理化学特性增强了金属的生物利用度和毒性。七种热带物种被用于评估来自矿区上游溪流的极软水体内 Cu 的慢性毒性。对 Cu 的敏感性如下：大型溞（Moinodaphnia macleayi）>绿球藻（Chlorella sp.）>Velesunio sp. >水螅（Hydra viridissima）>美洲鱒（Amerianna cumingi）>浮萍（Lemna aequinoctialis）>贻贝（Mogurnda mogurnda）。10%效应浓度（EC10）范围为 1.0 µg/L Cu，针对的是有甲类壳的大型溞（Moinodaphnia macleayi），鱼类（M. mogurnda）则为 9.6 µg/L Cu。EC50 范围为 6.6 µg/L Cu，针对的是贻贝（Velesunio sp.），22.5 µg/L Cu 针对的是鱼类（M. mogurnda）。在这些条件下，地球化学模型预测 Cu 将与富里酸强烈结合（80%-99%），生物利用度低（0.02%-11.5%）。保护浓度（PC）是从当地生物群的物种敏感性分布中得出的。99%置信度保护浓度（PC99）、PC95、PC90 和 PC80 值分别为 0.5、0.8、1.0 和 1.5 µg/L Cu。这些阈值表明，目前澳大利亚和新西兰对 Cu 的默认国家 99%保护指导值（1.0 µg/L）在低硬度的淡水中不会提供充分的保护，特别是对高保护价值的地区。在 pH 值低（6.1）、溶解有机碳低（2.5 mg/L）、硬度低（3.3 mg/L）和 27°C 的条件下，Cu 生物配体模型预测的连续临界浓度为 0.48 µg/L Cu，与 PC99 相当。考虑到地点的自然水质条件对于保护水质指南至关重要。环境毒理学与化学 2022;41:2808-2821. © 2022 英联邦澳大利亚。环境毒理学与化学 2022©SETAC。
