Baron Paul A, Deye Gregory J, Chen Bean T, Schwegler-Berry Diane E, Shvedova Anna A, Castranova Vincent
National Institute for Occupational Safety and Health, Cincinnati, Ohio 45226, USA.
Inhal Toxicol. 2008 Jun;20(8):751-60. doi: 10.1080/08958370801975303.
Single-walled carbon nanotubes (SWCNT) are being produced in increasing quantities because of high interest in applications resulting from their unique properties. Because of potential respiratory exposures during production and handling, inhalation studies are needed to determine potential toxicity. A generation system was designed to produce respirable aerosol at 5 mg/m(3) for a 1-wk animal (mouse) exposure. The starting material used in these experiments was as-produced powder from the high pressure carbon monoxide method that was sieved to number 6 mesh (< 2.3 mm). An acoustic feeder system was developed that handled the SWCNT powder without causing compaction of the material. The feed rate was adjustable, allowing output concentrations as high as 25 mg/m(3). The powder particles were reduced in size using a mill that produced high shear forces, tearing the agglomerates apart. The resulting aerosol was size-separated using a settling chamber and two cyclones to produce a respirable aerosol. The mass output efficiency of the entire system for producing a respirable aerosol from bulk material was estimated to be about 10%.
由于单壁碳纳米管（SWCNT）因其独特性能在应用方面备受关注，其产量正在不断增加。鉴于在生产和处理过程中可能存在呼吸道暴露风险，因此需要通过吸入研究来确定其潜在毒性。设计了一种生成系统，以5毫克/立方米的浓度产生可吸入气溶胶，用于对动物（小鼠）进行为期1周的暴露实验。这些实验中使用的起始材料是通过高压一氧化碳法制备的原状粉末，经过筛选至6目筛（<2.3毫米）。开发了一种声学进料系统，该系统在处理SWCNT粉末时不会导致材料压实。进料速率可调，可产生高达25毫克/立方米的输出浓度。使用产生高剪切力的研磨机将粉末颗粒尺寸减小，使团聚物分离。通过沉降室和两个旋风分离器对产生的气溶胶进行粒度分离，以产生可吸入气溶胶。整个系统从散装材料生产可吸入气溶胶的质量输出效率估计约为10%。
