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Cytotoxicity assessment of some carbon nanotubes and related carbon nanoparticle aggregates and the implications for anthropogenic carbon nanotube aggregates in the environment.

Murr LE, Garza KM, Soto KF, Carrasco A, Powell TG, Ramirez DA, Guerrero PA, Lopez DA, Venzor J - Int J Environ Res Public Health (2005)

Bottom Line: Toxicological studies, while sparse, have been concerned with virtually uncharacterized, single wall carbon nanotubes, and the conclusions have been conflicting and uncertain.These results suggest a number of novel epidemiological and etiological avenues for asthma triggers and related respiratory or other environmental health effects, especially since indoor number concentrations for multiwall carbon nanotube aggregates is at least 10 times the outdoor concentration, and virtually all gas combustion processes are variously effective sources.These results also raise concerns for manufactured carbon nanotube aggregates, and related fullerene nanoparticles.

View Article: PubMed Central - PubMed

Affiliation: Department of Metallurgical and Materials Engineering, The University of Texas at El Paso, El Paso, Texas 79968, USA. fekberg@utep.edu

ABSTRACT
Nanotechnology and nanomaterials have become the new frontier world-wide over the past few years and prospects for the production and novel uses of large quantities of carbon nanotubes in particular are becoming an increasing reality. Correspondingly, the potential health risks for these and other nanoparticulate materials have been of considerable concern. Toxicological studies, while sparse, have been concerned with virtually uncharacterized, single wall carbon nanotubes, and the conclusions have been conflicting and uncertain. In this research we performed viability assays on a murine lung macrophage cell line to assess the comparative cytotoxicity of commercial, single wall carbon nanotubes (ropes) and two different multiwall carbon nanotube samples; utilizing chrysotile asbestos nanotubes and black carbon nanoaggregates as toxicity standards. These nanotube materials were completely characterized by transmission electron microscopy and observed to be aggregates ranging from 1 to 2 microm in mean diameter, with closed ends. The cytotoxicity data indicated a strong concentration relationship and toxicity for all the carbon nanotube materials relative to the asbestos nanotubes and black carbon. A commercial multiwall carbon nanotube aggregate exhibiting this significant cell response was observed to be identical in structure to multiwall carbon nanotube aggregates demonstrated to be ubiquitous in the environment, and especially in indoor environments, where natural gas or propane cooking stoves exist. Correspondingly, preliminary epidemiological data, although sparse, indicate a correlation between asthma incidence or classification, and exposure to gas stoves. These results suggest a number of novel epidemiological and etiological avenues for asthma triggers and related respiratory or other environmental health effects, especially since indoor number concentrations for multiwall carbon nanotube aggregates is at least 10 times the outdoor concentration, and virtually all gas combustion processes are variously effective sources. These results also raise concerns for manufactured carbon nanotube aggregates, and related fullerene nanoparticles.

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Related in: MedlinePlus

TEM bright-field images of SWCNT-1 and MWCNT-N carbon nanotube aggregates.(a) SWCNT-1 sample showing low-magnification view of typical nanostructure and complex aggregated morphology. The insert shows a magnified view of nanoropes and attached Fe catalyst nanoparticles.(b) MWCNT-N structure showing individual, kinked, aggregate structure of capped, multiwall carbon nanotubes and other fullerenic nanoforms. The insert shows a lower magnification view to provide an aggregate size context.
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f1-ijerph-02-00031: TEM bright-field images of SWCNT-1 and MWCNT-N carbon nanotube aggregates.(a) SWCNT-1 sample showing low-magnification view of typical nanostructure and complex aggregated morphology. The insert shows a magnified view of nanoropes and attached Fe catalyst nanoparticles.(b) MWCNT-N structure showing individual, kinked, aggregate structure of capped, multiwall carbon nanotubes and other fullerenic nanoforms. The insert shows a lower magnification view to provide an aggregate size context.

Mentions: Figure 1 compares the typical microstructures for the SWCNT-1 sample (Figure 1(a)) and MWCNT-N sample (Figure 1(b)). Figure 1(a) shows the SWCNT microstructure to consist of bundles or so-called ropes of single-wall carbon nanotubes which are aggregated with residual iron catalyst nanoparticles and other nanoparticle contamination especially observable in the magnified insert in Figure 1(a). These ropes form tangled aggregates which range in mean (or geometric) diameters from 2μm to 20 μm; with an average aggregate diameter of ~10 μm. The ropes are composed of several to tens of SWCNTS (arrow in Figure 1(a) insert) and range in thickness (or diameter) from 10 nm to about 50nm.


Cytotoxicity assessment of some carbon nanotubes and related carbon nanoparticle aggregates and the implications for anthropogenic carbon nanotube aggregates in the environment.

Murr LE, Garza KM, Soto KF, Carrasco A, Powell TG, Ramirez DA, Guerrero PA, Lopez DA, Venzor J - Int J Environ Res Public Health (2005)

TEM bright-field images of SWCNT-1 and MWCNT-N carbon nanotube aggregates.(a) SWCNT-1 sample showing low-magnification view of typical nanostructure and complex aggregated morphology. The insert shows a magnified view of nanoropes and attached Fe catalyst nanoparticles.(b) MWCNT-N structure showing individual, kinked, aggregate structure of capped, multiwall carbon nanotubes and other fullerenic nanoforms. The insert shows a lower magnification view to provide an aggregate size context.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3814694&req=5

f1-ijerph-02-00031: TEM bright-field images of SWCNT-1 and MWCNT-N carbon nanotube aggregates.(a) SWCNT-1 sample showing low-magnification view of typical nanostructure and complex aggregated morphology. The insert shows a magnified view of nanoropes and attached Fe catalyst nanoparticles.(b) MWCNT-N structure showing individual, kinked, aggregate structure of capped, multiwall carbon nanotubes and other fullerenic nanoforms. The insert shows a lower magnification view to provide an aggregate size context.
Mentions: Figure 1 compares the typical microstructures for the SWCNT-1 sample (Figure 1(a)) and MWCNT-N sample (Figure 1(b)). Figure 1(a) shows the SWCNT microstructure to consist of bundles or so-called ropes of single-wall carbon nanotubes which are aggregated with residual iron catalyst nanoparticles and other nanoparticle contamination especially observable in the magnified insert in Figure 1(a). These ropes form tangled aggregates which range in mean (or geometric) diameters from 2μm to 20 μm; with an average aggregate diameter of ~10 μm. The ropes are composed of several to tens of SWCNTS (arrow in Figure 1(a) insert) and range in thickness (or diameter) from 10 nm to about 50nm.

Bottom Line: Toxicological studies, while sparse, have been concerned with virtually uncharacterized, single wall carbon nanotubes, and the conclusions have been conflicting and uncertain.These results suggest a number of novel epidemiological and etiological avenues for asthma triggers and related respiratory or other environmental health effects, especially since indoor number concentrations for multiwall carbon nanotube aggregates is at least 10 times the outdoor concentration, and virtually all gas combustion processes are variously effective sources.These results also raise concerns for manufactured carbon nanotube aggregates, and related fullerene nanoparticles.

View Article: PubMed Central - PubMed

Affiliation: Department of Metallurgical and Materials Engineering, The University of Texas at El Paso, El Paso, Texas 79968, USA. fekberg@utep.edu

ABSTRACT
Nanotechnology and nanomaterials have become the new frontier world-wide over the past few years and prospects for the production and novel uses of large quantities of carbon nanotubes in particular are becoming an increasing reality. Correspondingly, the potential health risks for these and other nanoparticulate materials have been of considerable concern. Toxicological studies, while sparse, have been concerned with virtually uncharacterized, single wall carbon nanotubes, and the conclusions have been conflicting and uncertain. In this research we performed viability assays on a murine lung macrophage cell line to assess the comparative cytotoxicity of commercial, single wall carbon nanotubes (ropes) and two different multiwall carbon nanotube samples; utilizing chrysotile asbestos nanotubes and black carbon nanoaggregates as toxicity standards. These nanotube materials were completely characterized by transmission electron microscopy and observed to be aggregates ranging from 1 to 2 microm in mean diameter, with closed ends. The cytotoxicity data indicated a strong concentration relationship and toxicity for all the carbon nanotube materials relative to the asbestos nanotubes and black carbon. A commercial multiwall carbon nanotube aggregate exhibiting this significant cell response was observed to be identical in structure to multiwall carbon nanotube aggregates demonstrated to be ubiquitous in the environment, and especially in indoor environments, where natural gas or propane cooking stoves exist. Correspondingly, preliminary epidemiological data, although sparse, indicate a correlation between asthma incidence or classification, and exposure to gas stoves. These results suggest a number of novel epidemiological and etiological avenues for asthma triggers and related respiratory or other environmental health effects, especially since indoor number concentrations for multiwall carbon nanotube aggregates is at least 10 times the outdoor concentration, and virtually all gas combustion processes are variously effective sources. These results also raise concerns for manufactured carbon nanotube aggregates, and related fullerene nanoparticles.

Show MeSH
Related in: MedlinePlus