School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, New South Wales, Australia.
CSIRO Land and Water, Lucas Heights, New South Wales, Australia.
Environ Toxicol Chem. 2021 May;40(5):1266-1278. doi: 10.1002/etc.4971. Epub 2021 Mar 10.
The geographical shift of nickel mining to small island countries of the Southeast Asia and Melanesia region has produced a need to assess the environmental risk associated with increased sediment nickel exposure to benthic estuarine/marine biota. Chemical measurements of nickel concentration and potential bioavailability, including the use of diffusive gradients in thin films (DGT), were compared to effects on 10-d reproduction of the epibenthic estuarine/marine amphipod Melita plumulosa in nickel-spiked sediments and field-contaminated sediments with different characteristics. The 10% effect concentrations (EC10s) for amphipod reproduction ranged from 280 to 690 mg/kg total recoverable nickel, from 110 to 380 mg/kg dilute acid-extractable nickel, and from 34 to 87 μg Ni/m /h DGT-labile nickel flux. Nickel bioavailability was lower in sediments with greater total organic carbon, clay content, and percentage of fine particles. Measurements of DGT-labile nickel flux at the sediment-water interface integrated exposure to nickel from porewater, overlying water, and ingested sediment exposure pathways and were found to have the strongest relationship with the biological response. At most, there was a 29% reduction in 10-d M. plumulosa reproduction relative to the control when exposed to nickel from field-contaminated sediments collected from nickel laterite mining regions of New Caledonia. The DGT technique can be used as a complementary tool to measure the bioavailability of nickel in estuarine/marine sediments, especially sediments that are in nickel laterite mining regions where there are no or few toxicity data available for determining biological effects on local species. Based on the combined data set of the 3 nickel-spiked sediments a DGT-labile nickel EC10 threshold of 50 (30-69) μg Ni/m /h was determined. Environ Toxicol Chem 2021;40:1266-1278. © 2020 SETAC.
镍矿向东南亚和美拉尼西亚小岛屿国家的地理转移，产生了评估与底栖河口/海洋生物体内增加的镍沉积物暴露相关的环境风险的需求。镍浓度和潜在生物利用度的化学测量，包括使用薄膜扩散梯度（DGT），与在镍加标沉积物和具有不同特征的现场污染沉积物中，对 10 天繁殖的腹足类河口/海洋桡足类 Melita plumulosa 的影响进行了比较。桡足类繁殖的 10%效应浓度（EC10）范围为 280 至 690 mg/kg 总可回收镍，110 至 380 mg/kg 稀酸可提取镍，34 至 87μgNi/m /h DGT 不稳定镍通量。总有机碳、粘土含量和细颗粒百分比较大的沉积物中，镍的生物利用度较低。在沉积物-水界面测量的 DGT 不稳定镍通量综合了从孔隙水、上覆水和摄入沉积物暴露途径中暴露的镍，并发现与生物反应的关系最强。与对照相比，当从新喀里多尼亚镍红土矿开采区采集的现场污染沉积物中暴露于镍时，M. plumulosa 在 10 天内的繁殖减少了 29%。DGT 技术可作为一种补充工具，用于测量河口/海洋沉积物中镍的生物利用度，特别是在镍红土矿开采区的沉积物中，这些地区几乎没有或没有可用于确定对当地物种的生物影响的毒性数据。基于 3 个镍加标沉积物的综合数据集，确定了 DGT 不稳定镍 EC10 阈值为 50（30-69）μgNi/m /h。Environ Toxicol Chem 2021;40:1266-1278。 © 2020 SETAC。
