Comments on: Asbestos-like toxicity of some carbon nanotubes

By: Phillip Huggan

Phillip Huggan — Wed, 28 May 2008 21:23:27 +0000

My first instincts were to suggest longer dimensioned phagocytes as the long-term cure, then to suggest some sort of larger-than-20-micron-CNT buckling mechanism. Both are silly. It shouldn’t be too hard to engineer a 3D filter of some sort, that captures most/all CNTs larger than 20 microns.

Sucks that being a CNT researcher exposes one to the same hazards as being a housing demolition labourer. But not that much, given the latter paid $7.50/hr in 2004.

By: Richard Jones

Richard Jones — Wed, 28 May 2008 07:44:03 +0000

David, I wonder if you’ve read the paper in full. The assay the authors used was specific for the particular pathologies induced by long fibres, rather than for detecting any non-specific mutagenic effect, and they directly compared long-fibre nanotubes with short fibre nanotubes and with nanoparticulate carbon, finding this pathogenic effect only with the long nanotubes. Do you know the details of the synthesis routes of the nanotubes the authors looked at?

I don’t think it’s either helpful or wise to try and discredit a paper like this by suggesting that it’s been “written for publicity”.

By: David Lashmore

David Lashmore — Mon, 26 May 2008 20:33:22 +0000

The authors of this study did not remove the nickel or cobalt contained in every one of their tubes! Since these metals are known mutagens when injected in mice, it is difficult understand how they arrived at the conclusions that the tubes were responsible for the observed effects and not the metal catalysts.

Further it is known that tubes contain high molecular weight hydrocarbons adsorbed on their surface. Some of these are also known mutagens (benzene for example).

This paper seems to be written for the publicity not for the science.

By: Richard Jones

Richard Jones — Sat, 24 May 2008 08:41:18 +0000

Many branches of experimental research use some potentially very dangerous chemicals, so, no, one doesn’t necessarily stop research because the materials maybe harmful; instead one uses the precautions that are appropriate. In the UK and the rest of the EU this is a legal requirement. Certainly the labs I know about that have been making long nanotubes have been aware of the potential risks for a while, and are already using equipment and working practices that minimise the dangers to researchers.

By: M Q

M Q — Sat, 24 May 2008 01:21:35 +0000

If we invest in lab automation with isolated chambers then researchers would have less exposure to harmful materials because there would be no need to put fingers on samples or breath air from them.

Would you stop your research if I prove to you that your sample materials cause cancer in mice? Yes or No?

By: Richard Jones

Richard Jones — Wed, 21 May 2008 07:33:31 +0000

Thanks, Kristen - for other readers, the ICON backgrounder is here.

By: Kristen Kulinowski

Kristen Kulinowski — Tue, 20 May 2008 21:41:53 +0000

Dear Dr. Jones,
ICON has produced some backgrounder materials on this subject which may be of interest to your readers. To add to your excellent synopsis of the findings of this paper we have commentaries by the authors of this and a related prior publication, as well as several other stakeholders. We also have a modest graphic that attempts to show the successful vs frustrated phagocytosis that occurs upon exposure to the short, tangled and long straight nanotubes.