Doyle John J, Ward J Evan, Mason Robert
University of Connecticut, Department of Marine Sciences, 1080 Shennecossett Road, Groton, CT 06340, USA.
Mar Environ Res. 2015 Sep;110:45-52. doi: 10.1016/j.marenvres.2015.07.020. Epub 2015 Jul 31.
The production rates of titanium dioxide (TiO2) nanoparticles for consumer products far exceed the pace at which research can determine the effects of these particles in the natural environment. Sedentary organisms such as suspension-feeding bivalves are particularly vulnerable to anthropogenic contaminants, such as nanoparticles, that enter coastal environments. The purpose of this work was to examine the ingestion, bioaccumulation, and depuration rates of TiO2 nanoparticles by two species of suspension-feeding bivalves, the blue mussel (Mytilus edulis) and the eastern oyster (Crassostrea virginica). Two representative TiO2 nanoparticles, UV-Titan M212 (Titan) and Aeroxide P25 (P25), were delivered to the animals either incorporated into marine snow or added directly to seawater at a concentration of 1.0 mg/L for exposure periods of 2 and 6 h. After feeding, the animals were transferred to filtered-seawater and allowed to depurate. Feces and tissues were collected at 0, 12, 24, 72, and 120 h, post-exposure, and analyzed for concentrations of titanium by inductively coupled plasma-mass spectrometry. Results indicated that the capture and ingestion (i.e., transfer to the gut) of TiO2 nanoparticles by both mussels and oysters was not dependent on the presence of marine snow, and weight-standardized clearance rates of bivalves exposed to TiO2 nanoparticles were not significantly different than those of unexposed control animals. Both species ingested about half of the nanoparticles to which they were exposed, and >90% of the nanoparticles were egested in feces within 12 h, post-exposure. The findings of this study demonstrate that mussels and oysters can readily ingest both Titan and P25 nanoparticles regardless of the form in which they are encountered, but depurate these materials over a short period of time. Importantly, bioaccumulation of Titan and P25 nanoparticles does not occur in mussels and oysters following exposures of up to 6 h.
消费品中二氧化钛（TiO₂）纳米颗粒的生产率远远超过了研究确定这些颗粒在自然环境中影响的速度。像悬浮取食双壳贝类这样的固着生物特别容易受到进入沿海环境的人为污染物（如纳米颗粒）的影响。这项工作的目的是研究两种悬浮取食双壳贝类，即蓝贻贝（Mytilus edulis）和美国牡蛎（Crassostrea virginica）对TiO₂纳米颗粒的摄取、生物累积和净化率。将两种具有代表性的TiO₂纳米颗粒，紫外-Titan M212（Titan）和氧化钛P25（P25），以掺入海雪的形式或直接以1.0 mg/L的浓度添加到海水中，投喂动物2小时和6小时。投喂后，将动物转移到过滤后的海水中使其净化。在暴露后0、12、24、72和120小时收集粪便和组织，并用电感耦合等离子体质谱法分析钛的浓度。结果表明，贻贝和牡蛎对TiO₂纳米颗粒的捕获和摄取（即转移到肠道）不依赖于海雪的存在，暴露于TiO₂纳米颗粒的双壳贝类的重量标准化清除率与未暴露的对照动物没有显著差异。两种贝类摄取了大约一半暴露于它们的纳米颗粒，并且在暴露后12小时内，超过90%的纳米颗粒随粪便排出。这项研究的结果表明，贻贝和牡蛎能够轻易摄取Titan和P25纳米颗粒，无论它们以何种形式被遇到，但会在短时间内净化这些物质。重要的是，在长达6小时的暴露后，贻贝和牡蛎中不会发生Titan和P25纳米颗粒的生物累积。
Zotero 插件