土壤锑胁迫下赤子爱胜蚓在个体和细胞水平的毒性效应

随着锑(Sb)矿的开采，Sb及其化合物对矿区周围生物暴露风险增大，Sb污染研究在国内外日益受到重视. 为阐明矿区Sb污染土壤对周边生物的毒性效应，本文通过向人工土壤添加焦锑酸钾(KSbO₆H₆)模拟受污染土壤，分别探究了Sb对土壤无脊椎模式生物——赤子爱胜蚓(Eisenia fetida)存活、Sb富集、总蛋白、抗氧化系统酶、丙二醛(malondialdehyde, MDA)的影响，并利用生物标志物响应指数(biomarker response index, BRI)对Sb胁迫下蚯蚓的毒性效应进行综合评价. 结果表明:①蚯蚓死亡率与土壤Sb浓度和暴露时间剂量效应关系明显，经计算蚯蚓56 d LC₅₀为4 380.37 mg/kg. ②蚯蚓对Sb仅有少量吸收，最高处理组(12 800 mg/kg)在暴露56 d后Sb富集量仅为213 mg/kg. ③超氧化物歧化酶(superoxide dismutase, SOD)、过氧化物酶(peroxidase, POD)、MDA在暴露28 d内呈现先升高后降低的倒“U”型变化，过氧化氢酶(catalase, CAT)总体呈现“上升—下降—上升—下降”的变化趋势；总蛋白随时间和处理水平增加呈现不断下降趋势. ④在暴露期间共计24个含Sb处理组中，20个处理受到中等及以下水平健康影响，仅有4个处理组BRI小于2.5，属于严重健康影响. 研究显示，总蛋白、SOD、CAT、POD、MDA均对Sb比较敏感，Sb对赤子爱胜蚓的毒性效应不强，该研究结果可为我国土壤Sb污染提供关键毒理学数据. 

Toxicity of Soil Antimony to Eisenia fetida at Individual and Cellular Levels

With the exploitation of antimony (Sb) ore, the exposure risk of antimony and its compounds to organisms around the mining areas has increased, and antimony contamination studies have attracted more attention at home and abroad. To elucidate the toxic effects of contaminated soil in antimony mining areas on surrounding organisms, the effects of Sb were systematically evaluated by the soil invertebrate model organism earthworm (Eisenia fetida). The survival, antimony enrichment, total protein, antioxidant enzymes and malondialdehyde (MDA) of the earthworm were investigated by adding KSbO₆H₆ to artificial soil to simulate contaminated soil. And the biomarker response index (BRI) was used to evaluate the toxicity response of earthworms under antimony stress. The results showed that: (1) Earthworm mortality was significantly correlated with the dose effect of soil Sb concentration and exposure time, and the calculated the 56-day LC₅₀ was 4,380.37 mg/kg. (2) Limited uptake of Sb was observed, only 213 mg/kg was enriched in earthworms after 56 d exposure at the highest dose treatment 12,800 mg/kg. (3) Superoxide dismutase (SOD), peroxidase (POD) and MDA showed an inverted ‘U’ shaped change of increasing and then decreasing during 28 days of exposure, while catalase (CAT) showed an overall trend of ‘up-down-up-down’. Total protein decreased with the increase of exposure time and treatment level. (4) Among the 24 Sb-containing treatments during the exposure period, 20 treatments showed moderate or lower level of health effects, and only 4 treatments had a BRI of less than 2.5, which was considered as severe health effects. Overall, all five biomarkers were sensitive to Sb; the toxic effect of Sb on Eisenia fetida was not strong. The results of this study can provide key toxicological data for Sb contamination of soil.