Zhang Rong, Zhang Wei, Liu Gao, Lin Kuangfei, Fu Rongbing
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, Shanghai, 200237, China.
School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China.
Environ Sci Pollut Res Int. 2016 Mar;23(5):4621-8. doi: 10.1007/s11356-015-5698-6. Epub 2015 Nov 3.
Lead (Pb) and decabromodiphenyl ether (BDE209) are main pollutants at electric waste (e-waste) recycling sites (EWRSs), and their joint toxicological effects have received extensive attention. Frequently, soil pollution at EWRSs usually results from the occurrence of repeated single or multiple pollution events, with continuous impacts on soil microorganisms. Therefore, a laboratory incubation study was conducted to determine Pb bioavailability and microbial toxicity in repeated Pb-polluted soil in the presence of BDE209 for the first time. We evaluated the impacts of repetitive exposure trials on chemical fractions of Pb, and the results showed that repeated single Pb pollution event resulted in an increase of carbonates fraction of Pb, which was different from one-off single Pb exposure. Moreover, one-off Pb-treated groups exhibited higher I R (reduced partition index) values on day 30 and all treatments remained the same I R level at the end of incubation period. The parameters of microbial toxicity were well reflected by soil enzymes. During the entire incubation, the dehydrogenase and urease activities were significantly inhibited by Pb (P < 0.01), and BDE209 supply could weaken the adverse influence. Additionally, significant correlations between available or metastable Pb and the two soil enzymes were clearly observed (P < 0.05 or 0.01). Such observations would provide useful information for ecological effects of Pb and BDE209 at EWRSs.
铅（Pb）和十溴二苯醚（BDE209）是电子垃圾回收场地（EWRSs）的主要污染物，它们的联合毒理学效应受到了广泛关注。通常情况下，EWRSs的土壤污染往往源于反复发生的单次或多次污染事件，对土壤微生物产生持续影响。因此，首次开展了一项实验室培养研究，以确定在存在BDE209的情况下，反复受铅污染土壤中铅的生物有效性和微生物毒性。我们评估了重复暴露试验对铅化学形态的影响，结果表明，单次铅污染事件的反复发生导致铅的碳酸盐形态增加，这与一次性单次铅暴露不同。此外，一次性铅处理组在第30天表现出较高的IR（还原分配指数）值，且在培养期结束时所有处理的IR水平保持相同。土壤酶很好地反映了微生物毒性参数。在整个培养过程中，脱氢酶和脲酶活性受到铅的显著抑制（P < 0.01），而BDE209的添加可减弱这种不利影响。此外，明显观察到有效态或亚稳态铅与两种土壤酶之间存在显著相关性（P < 0.05或0.01）。这些观察结果将为EWRSs中铅和BDE209的生态效应提供有用信息。
