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Facing the Dangers of Nanotech
bethr writes "Technology Review has a Q&A with Andrew Maynard, the science advisor for the Woodrow Wilson International Center's nanotechnology project regarding the dangers of nanomaterials and why we have to act now." From the article: "Individual experiments have indicated that if you develop materials with a nanostructure, they do behave differently in the body and in the environment. We know from animal studies that very, very fine particles, particles with high surface area, lead to a greater inflammatory response than the same amount of larger particles. We also know that they can enter the lining of the lungs and get through to the blood and enter other organs. There is some evidence that nanoparticles can move into the brain along the olfactory nerve, so this is completely circumventing the blood-brain barrier."
Arrrgh! help! they're in my brain!
Nanotech: The Asbestos of the Future.
As Mork would say, "Nano, Nano!"
try { do() || do_not(); } catch (JediException err) { yoda(err); }
Yes, and having one of those enter your brain along your olfactory nerve can cause serious health issues.
OMG! The three-quarteres of the Earth is covered in very deep bodies of liquid nanoparticles! Even worse, the atmosphere now consists almost entirely of nanoparticles! We inhale huge amounts of them with every breath!
WE'RE ALL GONNA DIE!
"You know your god is man-made when he hates all the same people you do."
Nature is replete with examples where scale matters. Insect-scale airfoils don't work particularly well. Jumbo jet-scale insects wouldn't fly, either. At the molecular level, flagella give great propulsion in fluids, but the same wouldn't hold at the macroscopic level.
The same is true in biology. I remember having read a study done at NASA on the effect of iron nanoparticles in lungs. (Alas, I can't seem to find the link anymore.) They concluded that at the nano scale, the iron particles could escape the normal protections and remain in the lungs (in the interstitium and cells themselves), where they could collect and have a toxic effect, including diminished lung function. (The test rats became lethargic, etc.) All this at exposure levels that wouldn't be considered toxic at other scales.
I've seen similar research on sunscreen. Zinc oxide particles are great protecting at UVA and UVB. However, at large scale, they're quite visible and hard to blend in. Make them smaller, and that problem goes away, but they get absorbed deeper into the skin. Make them smaller still, and it's quite possible that they'll be absorbed into the cells themselves, leading to new potential health effects. (e.g., does zinc oxide become carcinogenic when they remain in the cells for too long? Does the motion into the cells increase the likelihood of reactive oxygen species (free radicals) accumlating inside the cells, rather than outside?)
I'm not a biochemist or a biologist (I'm a biomathematician), so I don't have the answers to these questions. But it's clear that scale really does matter, and it needs to be considered. Is the danger overhyped? Possibly, or maybe not. That's why it needs to be studied. But it's going to be important to understand these effects when we move from the low levels that occur naturally to the high levels that will occur in human-made materials and products. -- Paul
OpenSource.MathCancer.org: open source comp bio
I played a thought experiment with a very smart fellow. The goal of the experiment was to come up with a safe way to create self replicating nanites that could cure cancer. We had 1 nanite that would cure cancer, but it was, of course, slow. The goal was to create enough to heal an entire body.
.001% mutation that's still 100,000 self replicating mistakes. If even one of those 100,000 mistakes is a mutation that just doesn't turn off self replication you now have a very bad problem.
So the best way to make more nanites is to have the nanites make more of themselves. Seems pretty straight forward... only everytime we go about doing it we run into this little problem.
Mutations.
So we build these guys to start replicating and to stop replicating when we want them to... but when you make a billion of something you end up with some odd mutations. Even if you are talking about
Released, this nanite could theoretically convert the earth (see "grey goo") into a giant ball of itself.
Now I know this thread is going to be long, because so many of you very smart people will have so many smart ideas about how to make this safe. I'm glad you have these ideas and I'm glad you're voicing them. Some of them might even work.
What scares the hell out of me is that you're not the people working on this.
So essentially your argument is:
There exists some molecules that already enter the blood-brain barrier without problems. Therefor all molecules entering the blood-brain barrier have no problems. One could prove anything (including known falsehoods) using that kind of logic.
What I read in the article was that when we create very very fine particles out of substances they behave differently in biological organisms than they do when they aren't in very very small particles. We really have no information on how these very fine particles might behave in biological organisms, so we really should be more cautious in including them in food products, or anything else people might injest since they really haven't been tested yet.
AccountKiller
No, this is not FUD. Forget gasses and liquids, this is about solids. Solids come in non-molecular chunks. Out bodies (and the bodies of every other living thing out there) are accustomed to encountering solids that are in fairly large sized chunks. If you can find a way to process those solids into much smaller chunks then you have a nano-material. This is the stuff that's dangerous. It's true of non-nano tech too. For example if I had a large piece of asbestos, that's not really dangerous, but if I pulverize it into dust it is. These new nano materials open up the possibility that alot more materials could be dangerous.
....it'll pass. What if I swallowed something that contained a quarter shredded into pieces no larger than 100nm, will that pass? Or will large amounts get trapped in various nooks and corners in my guts, and what effect will it have if those bits stay there for 30 years? What if I breathe it into my lungs? Will it do something like asbestos dust?
A TIONS.htm for cosmetics and foot powder containing Iron Oxide and Zinc Oxide nano materials that you can easily ingest or breathe.
If I swallow a quarter,
See http://www.kemcointernational.com/NANOPHASEAPPLIC
> We're all gonna die!
Correct.