Eating Carbon Nanotubes
by mitch on Feb 23 2010 (14837 Views)
Fathi Moussa
Lon Wilson
Last year I covered Khodakovskaya et al.'s paper regarding the benefits of growing tomatoes in carbon nanotubes (CNT).[CB] At the time I was concerned with the potential health risks associated from eating carbon nanotubes, but today in ACS Nano my concerns are alleviated. A paper from Lon Wilson's and Fathi Moussa's research groups discusses the effects from administering oral doses of carbon nanotubes (concentrations as high as 1g of CNT per kg body weight) to Swiss mice.[ACS Nano] The authors summarize their work the best.
CNT materials did not induce any abnormalities in the pathological examination. Thus, under these conditions, the lowest lethal dose (LDLo) is greater than 1000 mg/kg b.w. in Swiss mice.
So feel free to eat all the CNTs you want in lab, assuming they are not functionalized, you do it only once, and you limit yourself to single walled carbon nanotubes. I think partly because the results of the oral administration of CNTs went without any interesting side effects to present, the authors also looked into what happens when you inject CNTs into the peritoneal cavity of mice.
The image on the left is the control while the image on the right is 14 days after injecting mice with CNTs at a concentration of 1g CNT per kg of mouse. Although it looks sickly, the mice injected with the high concentration of CNTs did not die. Well..., not from the CNTs anyways.
Link to paper: In Vivo Behavior of Large Doses of Ultrashort and Full-Length Single-Walled Carbon Nanotubes after Oral and Intraperitoneal Administration to Swiss Mice (ACS Nano)
Mitch
NanoPoo?
The Wilson paper doesn't really tell us anything practical about the safety of carbon nanotube ingestion. There need to be long term animal studies about more types of nanotubes, like we would actually use in the real world.
I just had a course where we worked with this stuff, and we were strongly warned not to ingest or inhale any of it. We worked with it under fumehoods, but my breathing still stopped reflexively whenever i got near.
The TA cited some studies done on rats, but i cant be arsed to dig them up now.
I always understood the scientific pursuit of knowledge as not needing immediate use for whatever knowledge is gained, since this is an unknown at the time. I am in no way a supporter of PETA or any animal rights group, am all for animal testing and research, and a firm believer in supporting the sciences, but I still find myself morally confused after reading about this study involving injecting mice with high amounts of CNT just to see what would happen. I have no illusions that this method or worse methods of testing are rare; this is simply the first I've heard of a study that made me question where I actually stand as far as the treatment of animals in research.
This article made me think, which is a good thing, even if the topic itself wasn't what I thought about. Thanks for sharing.
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