Re: [rp-ml] Nano/fabber politics

From: Brock Hinzmann (bhinzmann@sric-bi.com)
Date: Tue Aug 09 2005 - 23:48:36 EEST


This is certainly something that the RP community can understand. I have
been including this in my nanotech presentations for a couple of years
(although these scientific studies Bob's reference cites are more
recent) and I always use RP as an example. Remember how in early days
everyone said they didn't know of any health risks associated with
sterolithography materials, but then some people began developing bad
allergies a couple years after handling the stuff? The same will
undoubtedly happen with some nanomaterials. Ironically, the excitement
around nanomaterials is that, as particle sizes become smaller, the
atoms become constrained and the physical properties change. That change
creates other physical, electrical, optical, and other properites that
are different at the nanoscale than they are in the same elements as a
bulk material. No one knows what those properties will be or what the
health and environmental impacts will be. Most nanomaterials will likely
be benign, but odds are, some will have unintentioned effects. And, like
the RP allergy problem, some of those effects won't show up for a couple
years or only after intense exposure. Also, if some material that we are
not using in high volumes or exposure rates today, and which we assume
to be safe, may increase in use as we discover new uses and might have
toxicities that we didn't test for previously.

Brock Hinzmann

Rose & Crangle, Ltd. wrote:

>Fascinating thread. By the way, Susan Gaidos in the August 1 issue of
>The Scientist had an article on a nano issue we do not usually consider.
>I reproduce parts of it below.
>
>Bob Crangle
>Rose & Crangle, Ltd
>117 N. 4th Street, PO Box 285
>Lincoln, KS 67455
>785 524 5050 (fax 3130)
>
>Volume 19 | Issue 15 | Page 29 | Aug. 1, 2005 The Scientist
>
>Conventional approaches to risk assessment, toxicity screening, and ADME
>(absorption, distribution, metabolism, and excretion) modeling don't
>necessarily apply to nanoscale materials. Even nomenclature is a
>problem: Existing measures for regulating new chemical substances
>distinguish materials by name, not size. Thus, the Toxic Substances
>Control Act (TSCA) inventory, a listing of the more than 80,000
>industrial chemicals currently produced or imported into the United
>States, classifies carbon nanotubes as a material chemically identical
>to diamond.
>
>Yet nanoparticles (those smaller than 100 nanometers in diameter) often
>acquire properties absent from their macroscale counterparts; they may
>become stronger, lighter, more heat-resistant, or better electrical
>conductors, for instance. But they also can be more toxic, being readily
>inhaled into the lungs, absorbed through the skin, or transported across
>cell membranes. And nobody knows how long such materials may linger in
>or be cleared from the environment.
>
>"While there is concern that the nanostructure-dependent properties of
>many engineered nanomaterials may lead to them being hazardous, the
>direct risk they present to human health will depend on the probability
>of exposures occurring, and the extent to which materials entering the
>body exhibit behavior associated with their nanostructure," says Julie
>W. Fitzpatrick, a scientist with the International Life Sciences
>Institute, who is developing toxicity screening strategies.
>
>Too few studies have been completed, says Kristin Kulinowski, executive
>director for education and public policy for the National Science
>Foundation-funded Center for Biological and Environmental Nanotechnology
>(CBEN) at Rice University. "What we do know is that what may be true for
>one particular nanoparticle in one form or one application, may not be
>true for another," she says. "There have been some studies that have
>pointed out particular effects of nanoparticles on certain systems, such
>as cells in culture, fish, and rodents. But they have been pretty
>limited, and there are still many gaps in our knowledge about
>nanoparticle safety."
>
>In one widely publicized 2004 report, Southern Methodist University
>researcher Eva Oberdörster found that nanoparticles called buckyballs
>can cause brain damage in fish.1 Later that year, Vicki Colvin and
>Christy Sayes at CBEN found that buckyballs are also toxic in vitro,
>causing 50% of cultured human cells to die at a concentration of 20
>parts per billion.2 "The findings from those [CBEN] experiments were
>interesting in that they showed that the toxicity varied dramatically,
>according to what was happening at the surface of those particles," says
>Kulinowski.
>
>Similarly, Mark Banaszak Holl of the University of Michigan has found
>that a particle's surface chemistry can govern whether a particle works
>well for biomedical applications.3 And North Carolina State University
>toxicologist Nancy Monteiro-Riviere showed that, depending on how
>they're made, some nanoscale materials that may otherwise irritate the
>skin can be rendered nontoxic.4 Her group is now studying quantum dots,
>carbon fullerenes, and iron oxide nanocrystals to see if these
>nanomaterials can also penetrate to the dermis.
>
>While participants generally lauded the group's effort, some said its
>proposal doesn't go far enough. In a report statement presented at the
>meeting, a coalition of 17 environmental and health advocacy groups,
>including the Natural Resources Defense Council, the Sierra Club, and
>the Breast Cancer Fund, proposed classifying nanomaterials as "new"
>chemical substances under TSCA, because they are new organic or
>inorganic substances of a particular molecular identity.
>
>The coalition backed recommendations from the Royal Society and the
>Royal Academy of Engineering, that nanoparticle release into the
>environment be minimized until more is known about how they would affect
>ecosystems.
>
>The EPA is now formulating its strategy, and preliminary plans for the
>voluntary reporting scheme could arrive later this year. Charles Auer,
>director of the EPA's Office of Prevention, Pesticides, and Toxic
>Substances, says, "When we will have all these issues resolved, I don't
>know. There are a lot of wrinkles here to be sorted through, but there's
>a lot of work underway."
>
>
>-----Original Message-----
>From: owner-rp-ml@rapid.lpt.fi [mailto:owner-rp-ml@rapid.lpt.fi] On
>Behalf Of Adrian Bowyer
>Sent: Tuesday, August 09, 2005 12:52 PM
>To: rp-ml@rapid.lpt.fi
>Subject: RE: [rp-ml] Nano/fabber politics
>
>Quoting "David K. Leigh" <dkleigh@harvest-tech.com>:
>
>
>
>>Now we're talkin' politics - origin of the species. This oughta get
>>
>>
>good
>
>
>>now. :)
>>
>>
>
>Eh?
>
>Oh - One of the things we Europeans can forget completely is that there
>are any
>politics at all in Darwinian evolution. It feels a bit as if you were
>to say,
>"Well, if we do the orbital calculations assuming the Earth takes 365.25
>days
>to go round the Sun..." and an engineer at the back interrupts to say,
>"Earth
>go round the Sun! That's blasphemy."
>
>You'd blink a bit, wouldn't you...
>
>Yours
>
>Adrian
>
>http://staff.bath.ac.uk/ensab
>http://reprap.org
>
>
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>
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