Boreal lakes with soft water and low buffering capacity are susceptible to excess ion loading resulting from metal mining. The impact of two Finish mining sites in downstream lakes was assessed with a chronic sediment toxicity test using a laboratory-reared freshwater Lumbriculus variegatus (Oligochaeta). The test organisms were exposed to mining-contaminated natural lake sediments and hypolimnion water (HLW) or artificial freshwater (AFW) as overlying water in two independent experimental setups. In both test setups, growth and reproduction of L. variegatus were lower in sediments from the lakes receiving high amount of mining effluents from the mines nearby. In the biomining site, the main contaminants in the recipient lakes were the ore metals Ni and Zn, while in the lakes affected by the conventional underground mine, they were Cu and Zn. These metals accumulated in L. variegatus especially in the setup with natural HLW above the sediment. Growth and reproduction were lower in the HLW than in the AFW setup. The mining-contaminated sediments did not support optimum growth or reproduction of L. variegatus in comparison to the local reference sediments. Decline of pH in the unbuffered natural sediments brought up challenges in the assessment of metal-contaminated lake sediments with high sulfur content, and a need to develop new tools for their risk assessment.

具有软水和低缓冲能力的北方湖泊易受金属开采产生的过量离子负荷的影响。使用实验室饲养的淡水豆荚兰（Oligochaeta），通过慢性沉积物毒性测试评估了下游湖泊两个Finish采矿场的影响。在两个独立的实验装置中，将测试生物暴露于受采矿污染的天然湖沉积物和次生水（HLW）或人工淡水（AFW）作为上覆水。在两种测试设置中，变异乳杆菌的生长和繁殖湖泊沉积物中的沉积物含量较低，从附近矿山接收大量采矿废水。在生物采矿区，接收者湖泊中的主要污染物是矿石金属Ni和Zn，而在受常规地下矿山影响的湖泊中，它们的主要污染物是Cu和Zn。这些金属尤其在具有天然高放废物的沉积物上方的百日草中积累。HLW中的生长和繁殖低于AFW中的生长和繁殖。受到采矿污染的沉积物不支持美洲乳杆菌的最佳生长或繁殖。与当地参考沉积物相比。未缓冲的天然沉积物中pH的下降给评估含硫量高的金属污染的湖沉积物带来了挑战，并且需要开发新的风险评估工具。