Does Carbon Black Disaggregate in Lung Fluid? A Critical Assessment
Does Carbon Black Disaggregate in Lung Fluid? A Critical Assessment
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DOI：
10.1021/tx300160z
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发表时间：
2012-10-01
影响因子：
4.1
通讯作者：
McCunney, Robert J.
中科院分区：
文献类型：
--
作者：
Levy, Len;Chaudhuri, Ishrat S.;McCunney, Robert J.
炭黑是工业生产的几乎纯的元素碳的颗粒形式。炭黑的基本结构单元是（1）初级颗粒，具有限定的物理边界的微小物质块;（2）聚集体，强结合或熔融颗粒的集合;和（3）附聚物，弱结合聚集体的集合。工业炭黑是在一个封闭的反应器中生产的，其中初级颗粒形成聚集体，这些聚集体成为炭黑的不可分割的实体。这些聚集体然后形成附聚物，附聚物是商业中炭黑的典型形式。炭黑通常在体外和体内颗粒毒理学研究中用作参比纳米颗粒。毒理学研究经常报告初级颗粒的尺寸，但很少报告聚集体或附聚物的尺寸。在许多情况下，似乎对炭黑通常不作为初级颗粒存在而是作为聚集体和附聚物存在的事实存在有限的理解。此外，许多毒理学研究操纵炭黑颗粒以分散它们，使得在这些毒理学研究中使用的炭黑的形式可能与在工作场所环境中可能遇到的形式显著不同。由于炭黑的主要接触途径是吸入，因此出现了吸入的炭黑在与肺液接触时是否会解聚或分解成较小的聚集体或初级颗粒的问题。这个问题涉及到对较小颗粒可能存在其他危害的关注，例如它们转移到肺部以外的组织和器官的能力以及通过血脑屏障的能力。本评估的目的是审查现有文献中关于炭黑在与肺液接触时是否解聚或解聚成较小聚集体或初级颗粒的证据。基于对商业炭黑的物理特性和各种毒理学研究的审查，商业生产的炭黑与肺液接触似乎不太可能解聚或解聚成较小的聚集体或初级颗粒。
Carbon black is an industrially produced particulate form of nearly pure elemental carbon. The basic building blocks of carbon black are (1) primary particles, minute pieces of matter with defined physical boundaries; (2) aggregates, collections of strongly bound or fused particles; and (3) agglomerates, collections of weakly bound aggregates. Industrial carbon black is produced within a closed reactor where the primary particles form aggregates, which become the indivisible entities of carbon black. These aggregates then form agglomerates, which are the typical form of carbon black in commerce. Carbon black is often used in in vitro and in vivo particle toxicology investigations as a reference nanoparticle. The toxicology studies often report the sizes of the primary particles but rarely the sizes of the aggregates or agglomerates. It appears in many cases that there is a limited understanding of the fact that carbon black typically does not exist as primary particles but instead exists as aggregates and agglomerates. Moreover, many toxicology studies manipulate carbon black particles in order to disperse them so that the form of carbon black used in these toxicology studies may be substantially different from the form that may be encountered in the workplace environment. Since the main exposure route for carbon black is inhalation, the question arose as to whether inhaled carbon black may deagglomerate or disaggregate to either smaller aggregates or primary particles when in contact with lung fluids. This question relates to the concern that there may be additional hazards of smaller particles, such as their ability to translocate to tissues and organs beyond the lung and the ability to pass through the blood-brain barrier. The purpose of this assessment is to review the existing literature for evidence as to whether carbon black deagglomerates or disaggregates into smaller aggregates or primary particles when in contact with lung fluid. On the basis of a review of the physical characteristics of commercial carbon black and various toxicology studies, it appears that commercially produced carbon black in contact with lung fluid is unlikely to deagglomerate or disaggregate into smaller aggregates or primary particles.