Liu Kou, Chen Lin, Zhang Wei, Lin Kuangfei, Zhao Li
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, Shanghai, 200237, China.
Ecotoxicology. 2015 Mar;24(2):301-8. doi: 10.1007/s10646-014-1378-4. Epub 2014 Nov 6.
Lead (Pb) and decabromodiphenyl ether (BDE209) are the main contaminants at e-waste recycling sites, and their potential toxicological effects on terrestrial organisms have received extensive attention. However, the impacts on the oxidative perturbations and hydroxyl radical (·OH) generation in earthworms of exposure to the two chemicals remain almost unknown. Therefore, indoor incubation tests were performed on control and contaminated soil samples to determine the effects of Pb in earthworms Eisenia fetida in the presence of BDE209 through the use of several biomarkers in microcosms. The results have demonstrated that the addition of BDE209 (1 or 10 mg kg(-1)) decreased the enzymatic activities [superoxide dismutase, catalase (CAT), peroxidase] and total antioxidant capacity (T-AOC) compared with exposure to BDE209 alone (50, 250 or 500 mg kg(-1)). Electron paramagnetic resonance spectra indicated that ·OH radicals in earthworms were significantly induced by Pb in the presence of BDE209. The changing pattern of malondialdehyde (MDA) contents was accordant with that of ·OH intensity suggested that reactive oxygen species might lead to cellular lipid peroxidation. Furthermore, CAT exhibited more sensitive response to single Pb exposure than the other biomarkers, while T-AOC, ·OH and MDA might be three most sensitive biomarkers in earthworms after simultaneous exposure to Pb and BDE209. The results of these observations suggested that oxidative stress appeared in E. fetida, and it may play an important role in inducing the Pb and BDE209 toxicity to earthworms.
铅（Pb）和十溴二苯醚（BDE209）是电子垃圾回收站的主要污染物，它们对陆生生物的潜在毒理学影响已受到广泛关注。然而，这两种化学物质暴露对蚯蚓体内氧化扰动和羟基自由基（·OH）生成的影响几乎仍不为人知。因此，通过在微观世界中使用几种生物标志物，对对照土壤样品和受污染土壤样品进行了室内培养试验，以确定在存在BDE209的情况下铅对赤子爱胜蚓的影响。结果表明，与单独暴露于BDE209（50、250或500 mg kg⁻¹）相比，添加BDE209（1或10 mg kg⁻¹）会降低酶活性[超氧化物歧化酶、过氧化氢酶（CAT）、过氧化物酶]和总抗氧化能力（T-AOC）。电子顺磁共振光谱表明，在存在BDE209的情况下，铅会显著诱导蚯蚓体内的·OH自由基。丙二醛（MDA）含量的变化模式与·OH强度的变化模式一致，表明活性氧可能导致细胞脂质过氧化。此外，与其他生物标志物相比，CAT对单一铅暴露表现出更敏感的反应，而T-AOC、·OH和MDA可能是同时暴露于铅和BDE209后蚯蚓体内最敏感的三种生物标志物。这些观察结果表明，赤子爱胜蚓出现了氧化应激，并且它可能在诱导铅和BDE209对蚯蚓的毒性方面发挥重要作用。
