Bioavailability of lead in contaminated soil depends on the nature of bioreceptor
Bioavailability of lead in contaminated soil depends on the nature of bioreceptor
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DOI：
10.1016/j.ecoenv.2011.11.045
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发表时间：
2012-04-01
影响因子：
6.8
通讯作者：
Naidu, Ravi
中科院分区：
文献类型：
--
作者：
Ming, Hui;He, WenXiang;Naidu, Ravi
通过化学、生物或生理方法对来自两个铅锌冶炼厂和一个射击场的长期铅 (Pb) 污染土壤以及新添加的对照土壤进行研究，以检验老化对 Pb 生物有效性的影响。对新鲜加铅的对照土壤进行蚯蚓毒性试验，观察蚯蚓的回避反应和死亡反应。同时，检查了由于老化而在加标土壤上可提取的铅部分，并进一步与基于生理学的体外生物可及性提取测试进行了比较。它们对加标土壤中蚯蚓种群的致死浓度 LC50 的差异随着土壤 pH 值的变化而变化很大。老化对毒性的强烈影响也反映在铅的可提取性上，与标记为 BC 的碱性土壤相比，酸性土壤（标记为 AC）中铅的可提取性要高得多。这表明，相对于碱性土壤，酸性土壤的总铅含量要低得多，才能实现对蚯蚓产生毒性的生物可利用部分。此外，衰老的影响还表明，生物可利用的铅显着下降，导致毒性降低。在铅浓度相对较低的长期污染土壤中进行的急性毒性试验中，蚯蚓体重显着减轻，表明其他金属或组合金属毒性也可能发挥重要作用。本研究表明，土壤特性和老化时间极大地影响了与生物受体相关的 Pb 的生物可利用分数。 (C) 2011 Elsevier Inc. 保留所有权利。
Long-term lead (Pb) contaminated soils from two lead-zinc smelters and a shooting range, along with freshly spiked control soil, were studied by means of chemical, biological or a physiological method to examine the effect of ageing on Pb bioavailability. The freshly Pb spiked control soil was subjected to an earthworm toxicity test to observe the avoidance and mortality response of the earthworms. Meanwhile, an extractable fraction of Pb on the spiked soil as a result of ageing was examined and further compared with physiologically based in vitro bioaccessibility extraction tests. Their differences in lethal concentration, LC50, to the earthworm population from spiked soils varied substantially as a function of soil pH. The strong effect of ageing on toxicity was also reflected in the extractability of Pb which was far greater in acidic soil, labelled AC, compared to the alkaline soil, labelled BC. This demonstrates that the bioavailable fraction causing toxicity to earthworms was achieved at a much lower total Pb content for acidic soils relative to alkaline soils. Moreover, the effect of ageing also exhibits that a marked decline in bioavailable Pb results in lowering toxicity. Significant amounts of weight loss in earthworms during an acute toxicity test in long-term contaminated soils at a relatively low Pb concentration suggested that other metal or combined metal toxicity may also play a significant role. This study demonstrates that the soil characteristics and ageing period greatly influence the bioavailable fraction of Pb which is related to the bioreceptor. (C) 2011 Elsevier Inc. All rights reserved.