沉积物中人工纳米颗粒对BDE-47生态毒性的影响

为评价淡水沉积物中人工纳米颗粒对持久性有机污染物生态毒性的影响,以底栖动物铜锈环棱螺为受试生物,采用沉积物慢性生物测试研究了非毒性浓度的不同管径多壁碳纳米管(MWCNTs)和两种金属氧化物纳米颗粒(三氧化二铝纳米颗粒Al₂O₃-NPs和二氧化钛纳米颗粒TiO₂-NPs)存在条件下不同浓度2, 2', 4, 4'-四溴联苯醚(BDE-47)对铜锈环棱螺肝胰脏超氧化物歧化酶(SOD)、谷胱甘肽-S-转移酶(GST)活性和丙二醛(MDA)含量的影响.结果表明,两种管径大小的MWCNTs不影响低浓度(100 ng·g^-1) BDE-47对铜锈环棱螺的毒性,但显著降低较高浓度(500、2000 ng·g^-1)BDE-47对铜锈环棱螺的毒性,小管径MWCNTs对BDE-47毒性的影响稍大于大管径MWCNTs;Al₂O₃-NPs和TiO₂-NPs对低浓度BDE-47的毒性没有影响,但显著增加较高浓度BDE-47对铜锈环棱螺的毒性,TiO₂-NPs对BDE-47毒性的影响略大于非毒性浓度Al₂O₃-NPs.这表明,沉积物中不同种类和类型的纳米颗粒对有机污染物生态毒性的影响存在明显差异.

Impact of Engineered Nanoparticles on Ecotoxicity of BDE-47 in Sediments

The extensive industrial applications of engineered nanoparticles(NPs) have caused concerns regarding their potential impact on human and environmental health. They may affect the bioavailability and ecotoxicity of other coexisting pollutants in the environment. This study was conducted to evaluate the ecotoxicity of persistent organic pollutant, 2, 2', 4, 4'-tetrabromodiphenyl ether(BDE-47) in the presence of multi-walled carbon nanotubes(MWCNTs), Al₂O₃ naoparticles(Al₂O₃-NPs), and TiO₂ naoparticles(TiO₂-NPs) at non-toxic concentrations in sediments. Superoxide dismutase(SOD) and glutathione-S-transferase(GST) activities and malondialdehyde(MDA) content in the hepatopancreas of Bellamya aeroginosa were examined following chronic sediment bioassay. Results showed that MWCNTs with different tube diameters had no effects on the toxicity of low concentrations of BDE-47(100 ng·g^-1) to B. aeroginosa, but significantly decreased the toxicity of high concentration of BDE-47(500, 2000 ng·g^-1). Such effects were slightly greater in MWCN with small tube diameters than that with large tube diameters. Both Al₂O₃-NPs and TiO₂-NPs did not show effects on the toxicity of low concentration of BDE-47 to B. aeroginosa, but significantly increased the toxicity of relatively high concentration of BDE-47. Such effects of TiO₂-NPs were slightly greater than those of Al₂O₃-NPs. These results indicate that different types and varieties of NPs have distinct effects on the ecotoxicity of coexisting organic pollutants in sediments, which is also dependent on the concentrations of coexisting pollutants.