Fate of pentabrominated diphenyl ethers in soil: Abiotic sorption, plant uptake, and the impact of interspecific plant interactions
Fate of pentabrominated diphenyl ethers in soil: Abiotic sorption, plant uptake, and the impact of interspecific plant interactions
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DOI：
10.1021/es060776l
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发表时间：
2006-11-01
影响因子：
11.4
通讯作者：
Shann, Jodi R.
中科院分区：
文献类型：
--
作者：
Mueller, Kevin E.;Mueller-Spitz, Sabrina R.;Shann, Jodi R.
多溴联苯醚（PBDEs）是一种具有潜在危害性和持久性的环境污染物。尽管有证据表明土壤是多溴二苯醚的主要汇，但人们对它们在这种介质中的行为知之甚少。在表层土壤中添加了与环境相关的商用五溴二苯醚混合物（75微克/千克），并在种植和非种植处理中对三种同系物（BDE-47、BDE-99和BDE-100）的可提取性进行了为期10周的监测。在实验土壤中，每种同系物的可提取性迅速下降，这主要是由于土壤颗粒的非生物吸附作用，从消毒和干燥土壤中回收的多溴二苯醚很低就证明了这一点。西葫芦和萝卜的单一种植不会影响土壤中多溴二苯醚的回收。然而，多溴二苯醚从混合物种种植的回收率几乎是未种植和单一种植处理的8倍，表明种间植物相互作用可能会提高土壤中多溴二苯醚的生物有效性。两个物种之间的竞争性相互作用的证据显示，西葫芦植物的地上部生物量减少，在混合处理相对于盆只含有西葫芦。这两种植物的根和茎组织（< 5微克/千克（-1）植物组织）都积累了多溴二苯醚。西葫芦对多溴联苯醚的吸收量较高，多溴联苯醚向西葫芦枝条的转运具有同源物特异性。我们的研究结果表明，虽然非生物吸附可能会限制人类接触土壤中多溴二苯醚的可能性，但植物可能会通过吸收和转移多溴二苯醚进入地上组织以及提高土壤中的生物利用度来增加接触风险。
Polybrominated diphenyl ethers (PBDEs) are potentially harmful and persistent environmental pollutants. Despite evidence that soils are a major sink for PBDEs, little is known regarding their behavior in this medium. An environmentally relevant level of a commercial penta-BDE mixture (75 mu g kg(-1)) was added to topsoil, and the extractability of three congeners (BDE-47, -99, and -100) was monitored over 10 weeks in planted and unplanted treatments. The extractability of each congener decreased rapidly in the experimental soil due largely to abiotic sorption to soil particles, which was demonstrated by low PBDE recovery from sterilized and dry soils. Monoculture plantings of zucchini and radish did not affect the recovery of PBDEs from soil. However, PBDE recovery from mixed species plantings was nearly 8 times higher than that of unplanted and monoculture treatments, indicating that interspecific plant interactions may enhance PBDE bioavailablity in soil. Evidence for competitive interactions between the two species was revealed by reduced shoot biomass of zucchini plants in mixed treatments relative to pots containing only zucchini. Both plant species accumulated PBDEs in root and shoot tissue (< 5 mu g kg(-1) plant tissue). PBDE uptake was higher in zucchini, and translocation of PBDEs to zucchini shoots was congener-specific. Our results suggest that although abiotic sorption may limit the potential for human exposure to PBDEs in soil, plants may increase the exposure risk by taking up and translocating PBDEs into above ground tissues and by enhancing bioavailability in soil.