U.S. Army Engineer Research and Development Center, Environmental Laboratory, Vicksburg, Mississippi 39180, USA.
Environ Health Perspect. 2010 Jan;118(1):49-54. doi: 10.1289/ehp.0901076.
The potential exists for laboratory personnel to be exposed to engineered carbon-based nanomaterials (CNMs) in studies aimed at producing conditions similar to those found in natural surface waters [e.g., presence of natural organic matter (NOM)].
The goal of this preliminary investigation was to assess the release of CNMs into the laboratory atmosphere during handling and sonication into environmentally relevant matrices.
We measured fullerenes (C60), underivatized multiwalled carbon nanotubes (raw MWCNT), hydroxylated MWCNT (MWCNT-OH), and carbon black (CB) in air as the nanomaterials were weighed, transferred to beakers filled with reconstituted freshwater, and sonicated in deionized water and reconstituted freshwater with and without NOM. Airborne nanomaterials emitted during processing were quantified using two hand-held particle counters that measure total particle number concentration per volume of air within the nanometer range (10-1,000 nm) and six specific size ranges (300-10,000 nm). Particle size and morphology were determined by transmission electron microscopy of air sample filters.
After correcting for background particle number concentrations, it was evident that increases in airborne particle number concentrations occurred for each nanomaterial except CB during weighing, with airborne particle number concentrations inversely related to particle size. Sonicating nanomaterial-spiked water resulted in increased airborne nanomaterials, most notably for MWCNT-OH in water with NOM and for CB.
Engineered nanomaterials can become airborne when mixed in solution by sonication, especially when nanomaterials are functionalized or in water containing NOM. This finding indicates that laboratory workers may be at increased risk of exposure to engineered nanomaterials.
在旨在产生类似于天然地表水条件的研究中，实验室人员有可能接触到经过工程设计的碳基纳米材料（CNM）[例如，存在天然有机物（NOM）]。
本初步研究的目的是评估在处理和超声进入环境相关基质过程中，CNM 释放到实验室空气中的情况。
我们在称重过程中测量了空气中的富勒烯（C60）、未衍生的多壁碳纳米管（原始 MWCNT）、羟基化 MWCNT（MWCNT-OH）和炭黑（CB），将其转移到装有再生成淡水的烧杯中，并在去离子水和含有或不含有 NOM 的再生成淡水中进行超声处理。使用两个手持式粒子计数器来量化处理过程中排放的空气传播纳米材料，这两个计数器可测量空气中每体积纳米范围内（10-1000nm）的总粒子数浓度以及六个特定粒径范围（300-10000nm）的总粒子数浓度。通过对空气样品过滤器的透射电子显微镜观察来确定颗粒的大小和形态。
在对背景粒子数浓度进行校正后，很明显，除了 CB 之外，在称重过程中，每种纳米材料的空气中粒子数浓度都会增加，而空气中粒子数浓度与粒径成反比。超声处理纳米材料加标水会导致空气中纳米材料增加，尤其是在含有 NOM 的水中的 MWCNT-OH 和 CB。
通过超声混合在溶液中时，工程纳米材料会成为空气传播的污染物，特别是当纳米材料官能化或在含有 NOM 的水中时。这一发现表明，实验室工作人员可能面临更高的接触工程纳米材料的风险。
