The validity of soil toxicity databases for predicting ecological impacts in the field is rarely explored. The present study was set up to test whether laboratory toxicity data and the combined concepts of metal availability and mixture toxicity can predict ecological impact in mining‐affected soils. Metal and As contamination gradients were sampled approximately 5 different mines in Mexico where plant cover and abundances exhibited clear dose‐related responses. Soils were analyzed for total and isotopically exchangeable (labile) concentrations of Ni, Cu, Cd, Pb, and As and for soil properties affecting the availability of these elements. Six different indices of toxic doses were compared to evaluate their accuracy in describing the field response expressed as relative abundance and cover. Each index was based on a different method to calculate the sum of toxic units (TUs) in soil, with 1 toxic unit equal to the concentration of the element in soil yielding 50% adverse effect on plants with median sensitivity as recorded in a recent database of salt‐spiked soils. Toxic concentrations in the mine‐impacted soils were dominated by Zn and As. In the field, 50% reduced cover or abundance was found at 10 to 13 TUs if these were based on total soil concentrations and thresholds derived from freshly spiked soils, indicating a largely overestimated toxic effect. If thresholds were corrected for differences in availability among freshly spiked soils and spiked and laboratory‐aged soils, the overestimation of field toxicity was 5‐ to 6‐fold, irrespective of the consideration of soil properties. Finally, the TU calculated only with labile metals and As overestimated the field toxicity by factors 1.1 to 1.6 (95% confidence interval 1–7; i.e., rather accurate and indicating some Zn–As antagonism as confirmed in experimental studies). That latter index of dose yielded a bell‐shaped response on species richness peaking at approximately 1.6 TU. Overall, the present study shows that the current toxicity databases of metals can predict the impact of metal contamination on plant communities within factor 2, expressing the dose as soil‐labile concentrations and using the concentration addition concept in these mixed polluted environments. Environ Toxicol Chem 2020;39:1826–1838. © 2020 SETAC

中文翻译：

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验证使用毒性数据库预测受多金属开采影响的土壤中植物的覆盖率和生物多样性。

很少探讨土壤毒性数据库在预测田间生态影响方面的有效性。本研究旨在测试实验室毒性数据以及金属有效性和混合物毒性的综合概念是否可以预测受采矿影响的土壤中的生态影响。在墨西哥大约5个不同的矿山中采样了金属和砷污染梯度，这些矿山的植物覆盖度和丰度表现出明显的剂量相关响应。分析了土壤中Ni，Cu，Cd，Pb和As的总和同位素可交换（不稳定）浓度，以及影响这些元素有效性的土壤特性。比较了六个不同的毒性剂量指标，以评估它们在描述以相对丰度和覆盖率表示的田间响应方面的准确性。（TUs）在土壤中的毒性单位为1，等于土壤中元素的浓度，对盐敏感性土壤的最新数据库中记录的中度敏感性植物产生50％的不利影响。地雷影响土壤中的有毒浓度主要是锌和砷。在田间，如果以总土壤浓度和刚加标土壤的阈值为基础，则在10到13 TU时发现覆盖率或丰度降低了50％，表明毒性效应大大高估了。如果对新加标土壤，加标土壤和实验室老化土壤之间的有效性差异进行阈值校正，则无论考虑土壤特性如何，对田间毒性的高估都为5至6倍。最后，TU仅以不稳定金属计算，As以1.1至1.6的系数高估了田间毒性（95％置信区间1–7；即相当准确，并表明了实验研究证实的某些Zn-As拮抗作用）。后者的剂量指数对物种丰富度呈钟形响应，峰值约为1.6 TU。总体而言，本研究表明，目前的金属毒性数据库可以预测因子2内金属污染对植物群落的影响，将剂量表示为土壤不稳定的浓度，并在这些混合污染的环境中使用浓度增加的概念。2020年《环境毒理学》； 39：1826-1838。©2020 SETAC