Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Carbon nanotubes that look like asbestos, behave like asbestos

21.05.2008
New study shows inhaling long, thin carbon nanotubes may result in asbestos-related disease

A major study published today in Nature Nanotechnology suggests some forms of carbon nanotubes – a poster child for the “nanotechnology revolution” – could be as harmful as asbestos if inhaled in sufficient quantities.

The study used established methods to see if specific types of nanotubes have the potential to cause mesothelioma — a cancer of the lung lining that can take 30-40 years to appear following exposure. The results show that long, thin multi-walled carbon nanotubes that look like asbestos fibers, behave like asbestos fibers.

Discovered nearly 20 years ago, carbon nanotubes have been described as the wonder material of the 21st Century. Light as plastic and stronger that steel, they are being developed for use in new drugs, energy-efficient batteries and futuristic electronics. But since their discovery, questions have been raised about whether some of these nanoscale materials may cause harm and undermine a nascent market for all types of carbon nanotubes, including multi- and single-walled carbon nanotubes. Leading forecasting firms say sales of all nanotubes could reach $2 billion annually within the next four to seven years, according to an article in the U.S. publication Chemical & Engineering News.

“This study is exactly the kind of strategic, highly focused research needed to ensure the safe and responsible development of nanotechnology,” says Andrew Maynard, Chief Science Advisor to the Project on Emerging Nanotechnologies and a co-author on the paper. “It looks at a specific nanoscale material expected to have widespread commercial applications and asks specific questions about a specific health hazard. Even though scientists have been raising concerns about the safety of long, thin carbon nanotubes for over a decade, none of the research needs in the current U.S. federal nanotechnology environment, health and safety risk research strategy address this question.”

Widespread exposure to asbestos has been described as the worst occupational health disaster in U.S. history and the cost of asbestos-related disease is expected to exceed $200 billion, according to major U.S. think tank RAND Corporation.

Anthony Seaton, MD, a co-author on the paper and a professor emeritus at the University of Aberdeen in the United Kingdom, says, “The toll of asbestos-related cancer, first noticed in the 1950s and 1960s, is likely to continue for several more decades even though usage reduced rapidly some 25 years ago. While there are reasons to suppose that nanotubes can be used safely, this will depend on appropriate steps being taken to prevent them from being inhaled in the places they are manufactured, used and ultimately disposed of. Such steps should be based on research into exposure and risk prevention, leading to regulation of their use. Following this study, the results of which were foreseen by the Royal Society in the U.K. in 2004, we can no longer delay investing in such research.”

Researchers, led by Professor Kenneth Donaldson at the University of Edinburgh in the United Kingdom, examined the potential for long and short carbon nanotubes, long and short asbestos fibers, and carbon black to cause pathological responses known to be precursors of mesothelioma. Material was injected into the abdominal cavity of mice — a sensitive predictor of long fiber response in the lung lining.

“The results were clear,” says Donaldson. “Long, thin carbon nanotubes showed the same effects as long, thin asbestos fibers.”

Asbestos fibers are harmful because they are thin enough to penetrate deep into the lungs, but sufficiently long to confound the lungs’ built-in clearance mechanisms for getting rid of particles.

Donaldson stresses there are still pieces of the puzzle to fill in. “We still don’t know whether carbon nanotubes will become airborne and be inhaled, or whether, if they do reach the lungs, they can work their way to the sensitive outer lining. But if they do get there in sufficient quantity, there is a chance that some people will develop cancer—perhaps decades after breathing the stuff,” states Donaldson.

There is a silver lining to this research. According to Donaldson, “Short or curly carbon nanotubes did not behave like asbestos, and by knowing the possible dangers of long, thin carbon nanotubes, we can work to control them. It’s a good news story, not a bad one. It shows that carbon nanotubes and their products could be made to be safe.”

But Donaldson added that the present study only tested for fiber-like behavior and did not exonerate carbon nanotubes from damaging the lungs in other ways. “More research is still needed if we are to understand how to use these materials as safely as possible,” he notes.

Carbon nanotubes are atom-thick sheets of graphite formed into cylinders. They may be formed from a single layer of graphite or they may consist of multiple concentric layers of graphite, resulting in multi-walled carbon nanotubes. While the diameter of a nanotube can vary from a few nanometers up to tens of nanometers, they can be hundreds or even thousands of nanometers long. Carbon nanotubes come in many forms, with different shapes, different atomic arrangements, and varying amounts and types of added chemicals—all of which affect their properties and might influence their impact on human health and the environment.

“This is a wakeup call for nanotechnology in general and carbon nanotubes in particular,” says Maynard. “As a society, we cannot afford not to exploit this incredible material, but neither can we afford to get it wrong—as we did with asbestos.”

Colin Finan | EurekAlert!
Further information:
http://www.wilsoncenter.org
http://www.cir.med.ed.ac.uk/

More articles from Studies and Analyses:

nachricht Study relating to materials testing Detecting damages in non-magnetic steel through magnetism
23.07.2018 | Technische Universität Kaiserslautern

nachricht Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Metamolds: Molding a mold

20.08.2018 | Information Technology

It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

20.08.2018 | Power and Electrical Engineering

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>