Ecotoxicological Effects Of CuO Nanoparticles On Benthic Macroinvertebrate Bellamya Aeroginosa

With the increasing production and industrial application of all kinds ofnanomaterials, engineered nanoparticles （ENPs） have been released to the environment,which will greatly increase the chances of human and ecological system being exposedto ENPs. Due to its large surface area, ENPs can strongly adsorb the coexistingpollutants, so this adsorption will not only change environmental behaviors of pollutants,but also influence environmental behavior of ENPs. ENPs have posed a new threat toenvironment and human health. CuO-NPs are a kind of important nanomaterials withwide applications. At present, little is known regarding ecotoxicological effects ofCuO-NPs to freshwater benthic organisms and joint effects between CuO-NPs and otherpollutants.The comparative ecotoxicological effects of CuO-NPs and CuO-MPs, the changeof ecotoxicological effects of typical persistent toxic substances at the presence ofCuO-NPs, and potential effects of organic matter in the sediment on CuO-NPsecotoxicity in Bellamya aeruginosa were investigated through sediment bioassay vianatural sediments artificially spiked with CuO-NPs, heavy metal Pb and new pollutantsBDE-47to explore the ecotoxicological effect patterns of CuO-NPs in sediments on B.aeruginosa, the interaction characteristics of CuO-NPs with these persistent toxicsubstances and the effect patterns of sediment properties on ecotoxicological effects ofCuO-NPs. The results showed that bioaccumulation of CuO-NPs in the hepatopancreas,gonad and muscle in B. aeruginosa was higher than that of CuO-MPs during theshort-term exposure （<14d）, but lower than that of CuO-MPs during long-termexposure （28d）. The order of bioaccumulation ability to Cu is hepatopancreas> gonad> muscle. During short-or intermediate-term （<14d） exposure, the inhibitive effects ofCuO-NPs on ATPase and SOD activities were higher than that of CuO-MPs, but lowerthan that of CuO-MPs during long-term exposure （28d）, the inhibitive effects ofCuO-NPs on CAT were higher than that of CuO-MPs. During long-term exposure （28d）, in the presence of CuO-NPs, low concentration (<125μg·g^-1) of Pb markedlylowered activities of ATPase, SOD and CAT, and hence enhanced the toxicity onhepatopancreas, whereas, high concentration (500μg·g^-1) of Pb significantly increasedtheir activities, and hence reduced the toxicity on hepatopancreas. In the presence ofCuO-NPs, BDE-47had no effect on ATPase and SOD activities during long-termexposure （28d）, low concentration (<160ng·g^-1) of BDE-47significantly increasedSOD activities, and hence reduced the toxicity on hepatopancreas, the relatively highconcentration (>640ng·g^-1) of BDE-47significantly reduced SOD activities, and henceenhanced toxicity. Under the relatively high concentration (>180μg·g^-1) of CuO-NPsstress the toxicity of CuO-NPs to hepatopancreas enhanced with increasing levels of humic acid.The above results suggest that the bioaccumulation of CuO-NPs and CuO-MPs arerelated to exposure duration. The presence of CuO-NPs is antagonistic to the toxicitiesof Pb and BDE-47in B. aeruginosa. High concentration (>0.1g·g^-1) of humic acid inthe sediments will enhance the toxicity of CuO-NPs to B. aeruginosa. In conclusion, theecotoxicological effects of CuO-NPs on benthic macroinvertebrate are complicated.When assessing ecological risks of CuO-NPs, it is not only its own toxicity should beconsidered, but also the effects of exposure duration and environmental mediumproperties, and other coexisting pollutants to its toxicity should be involved.The results of this study will be of important scientific value to reveal aquaticecotoxicological mechanisms and reasonably evaluate potential ecological risks ofCuO-NPs to aquatic ecosystems, and also can provide scientific basis anddecision-making consultation for risk management of these kinds of substances.