Carbon nanotubes and nanocrystals in methane combustion and the environmental implications

Murr, L. E.; Bang, John J.; López, Daniel; Guerrero, P. A.; Esquivel, E. V.; Choudhuri, Ahsan; Subramanya, Mahesh; Morandi, Maria T.; Holian, Andrij

doi:10.1023/b:jmsc.0000017787.53545.b7

Cited by 23 publications

(12 citation statements)

References 12 publications

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“…MWCNTs and carbonaceous nanoparticles (Figures 6C-6F) were also observed in outdoor airborne particulate matter collected in El Paso (Texas) and Houston (Murr et al, 2004b). The aggregates were similar in structure to those collected indoors except that the outdoor particulate matter also included agglomerates with other common atmospheric mineral nanocrystals, such as silica.…”

Section: Multiwall Carbon Nanotubes In the Outdoor Environmentmentioning

confidence: 71%

“…MWCNTs and fullerene-like nanocrystal forms were also observed in numerous particle aggregates in a sample of ancient ice obtained from an ice core at the Greenland ice cap Murr et al, 2004b). The ice sample, from a core drilled 1646 feet deep, was dated to roughly 10,000 years old (placing it in the Neolithic Stone Age).…”

Section: Multiwall Carbon Nanotubes Were Combustion Products Of Anciementioning

confidence: 96%

“…from Fuel-Gas Burning Activities Indoors In fact, MWCNTs and other fullerene-related multi-layer shell structures were observed in samples collected from the effluent stream of co-flowed flames of methane and air (Figures 6A and 6B) (Murr et al, 2004b). Bang et al (2004) also found MWCNTs and carbonaceous nanoparticles in aggregates of particulate matter collected from propane or natural gas (containing 96% methane) flames generated by typical kitchen stoves; the aggregates had sizes ranging from 0.4 to 2 µm, putting them in the respirable range.…”

Section: Formation Of Multiwall Carbon Nanotubesmentioning

confidence: 99%

“…The ice sample, from a core drilled 1646 feet deep, was dated to roughly 10,000 years old (placing it in the Neolithic Stone Age). According to Murr et al (2004b), the average diameter of the aggregates was <1 µm. These findings show that MWCNTs and other carbonaceous nanoparticles were present in airborne respirable dust aggregates in the prehistoric environment.…”

Section: Multiwall Carbon Nanotubes Were Combustion Products Of Anciementioning

confidence: 99%

“…However, if carbon atoms can be stripped off from ethylene/pyrene during pyrolysis that produced MWCNTs (Che et al, 1998), and from methane and propane during natural-gas combustion that generated MWCNTs, fullerenes, and other carbon nanoparticles (Bang et al, 2004;Murr et al, 2004aMurr et al, , 2004b, one could speculate that some of the carbon atoms formed in the automotive combustion chamber from gasoline (which contains mainly octane and other hydrocarbons) could form MWCNTs. One may speculate that MWCNTs are present in the soot of automotive exhaust.…”

Section: Multiwall Carbon Nanotubes In Fine Particulate Matter and Thmentioning

confidence: 99%

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A Review of Carbon Nanotube Toxicity and Assessment of Potential Occupational and Environmental Health Risks

Lam

James

McCluskey

et al. 2006

Critical Reviews in Toxicology

1,085

654

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Nanotechnology has emerged at the forefront of science research and technology development. Carbon nanotubes (CNTs) are major building blocks of this new technology. They possess unique electrical, mechanical, and thermal properties, with potential wide applications in the electronics, computer, aerospace, and other industries. CNTs exist in two forms, single-wall (SWCNTs) and multi-wall (MWCNTs). They are manufactured predominately by electrical arc discharge, laser ablation and chemical vapor deposition processes; these processes involve thermally stripping carbon atoms off from carbon-bearing compounds. SWCNT formation requires catalytic metals. There has been a great concern that if CNTs, which are very light, enter the working environment as suspended particulate matter (PM) of respirable sizes, they could pose an occupational inhalation exposure hazard. Very recently, MWCNTs and other carbonaceous nanoparticles in fine (<2.5 µm) PM aggregates have been found in combustion streams of methane, propane, and natural-gas flames of typical stoves; indoor and outdoor fine PM samples were reported to contain significant fractions of MWCNTs. Here we review several rodent studies in which test dusts were administered intratracheally or intrapharyngeally to assess the pulmonary toxicity of manufactured CNTs, and a few in vitro studies to assess biomarkers of toxicity released in CNT-treated skin cell cultures. The results of the rodent studies collectively showed that regardless of the process by which CNTs were synthesized and the types and amounts of metals they contained, CNTs were capable of producing inflammation, epithelioid granulomas (microscopic nodules), fibrosis, and biochemical/toxicological changes in the lungs. Comparative toxicity studies in which mice were given equal weights of test materials showed that SWCNTs were more toxic than quartz, which is considered a serious occupational health hazard if it is chronically inhaled; ultrafine carbon black was shown to produce minimal lung responses. The differences in opinions of the investigators about the potential hazards of exposures to CNTs are discussed here. Presented here are also the possible mechanisms of CNT pathogenesis in the lung and the impact of residual metals and other impurities on the toxicological manifestations. The toxicological hazard assessment of potential human exposures to airborne CNTs and occupational exposure limits for these novel compounds are discussed Address correspondence to Chiu-wing Lam, JSC Toxicology Group, Space Life Sciences, NASA Johnson Space Center, SF23/Wyle, Houston, TX 77058, USA. E-mail: Chiu-wing. 189This document is a U.S. government work and is not subject to copyright in the United States. 190C.-W. LAM ET AL. in detail. Environmental fine PM is known to form mainly from combustion of fuels, and has been reported to be a major contributor to the induction of cardiopulmonary diseases by pollutants. Given that manufactured SWCNTs and MWCNTs were found to elicit pathological changes in the lungs, and SWCNTs...

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Section: Multiwall Carbon Nanotubes In the Outdoor Environmentmentioning

confidence: 71%

Section: Multiwall Carbon Nanotubes Were Combustion Products Of Anciementioning

confidence: 96%

Section: Formation Of Multiwall Carbon Nanotubesmentioning

confidence: 99%

Section: Multiwall Carbon Nanotubes Were Combustion Products Of Anciementioning

confidence: 99%

Section: Multiwall Carbon Nanotubes In Fine Particulate Matter and Thmentioning

confidence: 99%

See 3 more Smart Citations

A Review of Carbon Nanotube Toxicity and Assessment of Potential Occupational and Environmental Health Risks

Lam

James

McCluskey

et al. 2006

Critical Reviews in Toxicology

1,085

654

View full text Add to dashboard Cite

show abstract

Toxicity of Carbon Nanotubes and its Implications for Occupational and Environmental Health

Lam

James

McCluskey

et al. 2003

Nanotechnologies for the Life Sciences

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The sections in this article are Introduction Overview General Background Carbon Nanotubes and Nanotechnology Manufactured Carbon Nanotubes: Their Synthesis, Properties, and Potential Applications Discovery and Synthesis Physical and Chemical Properties Applications Occurrence of Carbon Nanotubes in the Environment Potential Occupational Exposures and Environmental Impact of Manufactured Carbon Nanotubes Combustion‐generated Carbon Nanotubes in the Environment MWCNT Formation from Natural Gas Combustion Indoors MWCNTs in Metropolitan Outdoor Air MWCNTs in Ancient Ice Concern about Combustion‐generated MWCNTs in the Environment Comparison of Physical Structures of Manufactured and Non‐manufactured Carbon Nanotubes Toxicological Studies and Toxicity of Manufactured CNTs Study of SWCNTs in Guinea Pigs by Huczko et al. of Warsaw University Study of SWCNTs in Mice by Lam et al. of NASA ‐ JSC Toxicology Laboratory Study of SWCNTs in Rats by Warheit et al. of DuPont Company Study of SWCNTs in Mice by Shvedova et al. of NIOSH Study of MWCNTs by Muller et al. of Belgium Health Risk Implications Toxicity Summary of CNTs and Occupational Exposure Risk Impact of SWCNTs on Environmental Health Toxicity of MWCNTs and Impact on Environmental Health Acknowledgment

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Morphology, chemical composition and nanostructure of single carbon-rich particles studied by transmission electron microscopy: source apportionment in workroom air of aluminium smelters

Weinbruch

Benker²,

Kandler³

et al. 2015

Anal Bioanal Chem

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Sources of C-rich particles at work places in two aluminium smelters in Norway were studied by transmission electron microscopy and energy-dispersive X-ray microanalysis. Based on morphology, nanostructure and chemistry, three different types of C-rich particles are distinguished: (a) chain-like agglomerates (70-100% by number, relative to the sum of C-rich particles) consisting of primary particles with typical onion-shell structure of graphene layers, (b) multi-walled carbon nanotube particles (≈3%) and (c) spheres or agglomerates of amorphous C-rich particles (0-30%). Chain-like agglomerates are interpreted as diesel soot in accordance with literature data on primary particle diameter, chemical composition and nanostructure of primary particles. The source of the observed multi-walled carbon nanotubes is not known. The amorphous C-rich particles most likely consist of organic carbon species which cannot be characterized further by X-ray microanalysis. Unaltered graphitic electrode material was not found among the C-rich particles. The high fraction of diesel soot particles indicates that elemental carbon is generally suited as proxy for diesel soot in aluminium smelters. However, due to the presence of carbon nanotubes and amorphous C-rich particles, detailed characterization of sources of carbon-rich particles by electron microscopy is recommended for accurate assessment of adverse health effects.

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Carbon nanotubes and nanocrystals in methane combustion and the environmental implications

Cited by 23 publications

References 12 publications

A Review of Carbon Nanotube Toxicity and Assessment of Potential Occupational and Environmental Health Risks

A Review of Carbon Nanotube Toxicity and Assessment of Potential Occupational and Environmental Health Risks

Toxicity of Carbon Nanotubes and its Implications for Occupational and Environmental Health

Morphology, chemical composition and nanostructure of single carbon-rich particles studied by transmission electron microscopy: source apportionment in workroom air of aluminium smelters

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