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Can Asbestos Help Us Understand Nanotoxicity?
Roland Piquepaille writes "Occupational Hazards is running an interesting article about how using our knowledge of asbestos could help us to assess the risks from nanoparticles, or their nanotoxicity. Today, it's unknown if nanomaterials under development are dangerous to human beings or to our environment. Some people think that nanoparticles can move to our lungs or our brains, presenting a significant threat to our health. Other scientists think there is no danger because we have been exposed to nanoparticles for thousands of years, such as ashes from volcanic eruptions. For example, nanotubes which are now used for many industrial developments, have similar shapes as fibers like asbestos, being long and extremely thin. And like nanomaterials today, asbestos was considered as harmless when humans were exposed to it. While the comparison has some merit, more research needs to be done before drawing any conclusion."
Boihazard == Bad
Nanotoxins == Bad
What part of dead are you having trouble understanding?
Weird, occupationalhazards.com isn't registered to Roland Piquepaille. What's the catch?
This looks to be the second article in a row from the esteemed Monsieur Piquepaille that doesn't link to an article in his blog. Check out his story posting history:
Can asbestos help us understand nanotoxicity? Wed Oct 19, '05 12:23 PM
Pillows Dangerous for Your Health Sat Oct 15, '05 12:28 PM
Molecular Gastronomy, The Science of Cooking Mon Aug 29, '05 11:32 AM
The Eyes of the Space Shuttle Wed Aug 03, '05 12:58 PM
BIG gap between the two latest non-self-referential stories, and the weekly shameless self-promotion that used to be his trademark.
I suspect that somebody either gave Mr. P a stern talking-to, or more likely the editors just quit accepting his stories. Now, he's back, chastened and better for it. You've got to admit, the guy has an eye for science stories. He's just got to have confidence that if he posts good stuff, the click-throughs to his main page (linked appropriately to his name) will follow in time.
I'm all for shameless self-promotion, of course, but I'm content with the URL link in the post heading. Well, mostly...
Stressed? Me? Of course not. Stress is what a rubber band feels before it breaks, silly.
The chances are minute.
"Other scientists think there is no danger because we have been exposed to nanoparticles for thousands of years, such as ashes from volcanic eruptions. " /sarcasm on/ /sarcasm off/
And humans haven't had ANY as of yet unexplained health problems over those thousands of years either.
I think it was a bloody shame that the EPA declared New York's air safe to breath after the attack on the World Trade Center, when trillions of nano-toxins were released into the air for cleanup and emergency crews to inhale. We're going to see more of New York Lung, in the years to come.
Saskboy's blog is good. 9 out of 10 dentists agree.
Plasticisers, stabilizing agents, enzymes, catalysts and all these wonderful pharmecuticals that we consume and then pee into the environment are also nanomachines, just ones built with bulk chemistry rather than direct nanoscale assembly.
:v)
Didn't we ought to focus on what they do in the environment, rather than propagate scare stories about future nanomachines that can be pre-programmed to safely degrade?
Vik
I'm not sure if asbestos is an appropriate analog for nano-based respiratory hazards. When Dr. Irving J. Seilkoff published his report on the link between asbestos and respiratory ailments, there was already an abundant record of impairment in the form of asbestosis. Asbestosis is a scarring and sedimentation of the lung due to particulate inhalation. It is in a general family of respiratory ailments known as pneumoconiosis. That group includes silicosis (affects quarry workers) and black lung (coal miners). The link that Seilkoff is credited with is the connection of asbestos to lung cancer, which is has only one known asbestiform species in direct connection: crocidolite. This blue amphibole was used in ship construction and in homes in and around Australia (sorry mates!). This asbestiform mineral has been directly connected to one of the most virulent forms of lung cancer, mesothelioma. This cancer of the plural lining is fatal within months of diagnosis.
Connections between other asbestiform minerals and cancer is more complex. Tremolite and serpentenite have also been linked to lung cancer, but the connection is much more tenuous. Another factor that would complicate the study of asbestos as an analog is the size: an asbestos fiber is counted for toxicological purposes only when it fits a 5:1 aspect ratio and is >5 micron in length. That is the geometry that is most likely to fit into the alveoli. This deep penetration of asbestos into the tissues of the lung is presumed to be the mechanism that leads to cancer. Plaques form around the embedded spines of asbestos as microphages attack and envelope the fibers. This process leads to a general lessening of the effective surface area for gas transfer leading to shortness of breath. The mechanics leading to cancer, however, are dubious and have plagued researchers for more than two decades.
I can't see how the study of asbestos can illuminate any area of occupational health. I can, however, see how injury claims attorneys would use the experience of asbestos litigation in any future attack on the nano-industry.
"Rocky Rococo, at your cervix!"
The real question comes in why asbestos causes harm. Is the the morphology (shape) of it that is the key? Or is it the chemical properties? Or is it both?
I must plead my ignorance when I say I don't know if that question has been fully answered yet. I do know that from certain Taconite mining operations they have found non-asbestos minerals that have a similar shape to asbestos, and have found higher rates of rare cancers, of the kind known that asbestos can cause, in the region around the mines. That might suggest the shape itself is important. You can find an example in this article.
Nay, those are the very Sacred Properties of His Noodly Appendage. Carbon Nanotubes are merely the newest Tower Of Babel - a feeble attempt to use puny "science" to achieve Sublime Pastaness.
Carbon... pah! It's carbohydrates that are pure and holy!
Don't disappoint your bird dog. Go to the range.
If I recall coreectly, people working on the space elevator (Lawrence Livermore Labs) were creating long strings of bucky balls (carbon nanotubes) as it is a very strong, very light material. The problem that they discovered (this was a few years ago) was that if you put 0.5 parts per billion of buckyballs into a fish tank (500 gallon aquarium), within 3 days, 20% of the fish start exhibiting signs of mental retardation. Within 5 days, the number soars to 80%, accompanied by 10% of the most severely affected fish dying. Within one week, all of the fish are either showing signs of extreme mental retardation, or have died. The part that they found most troubling was that if predatory fish ate those dead or dying fish, then they too would experience the same symptoms, and die in exactly the same way and in the same length of time. Preliminary disections showed that the carbon nanotubes could get past the membrane that surrounds the brain. Once they got in, they tended to cause severe damage to the brain. At least one report is here: http://www.newscientist.com/article.ns?id=dn4825
Are nanotubes and like materials dangerous?
Yes.
So... don't go around breathing in nanotubes. I hope we've learned from our past health failings enough to use these materials responsibly. Who am I kidding though?
People are not going to understand that the cancer probe or glucose sensor made of nanotubes is actually safe, while the nanotube sweaters may be a bad idea.
is that (at least with buckyballs and nanotubes) they're non-biodegradable (in this they're similar to asbestos). I recall watching the photo of a macrophage destroyed because it tried to swallow an asbestos particle.
The questions to be asked are:
Can the nanoparticles destroy the human cells, or alter their DNA as a side effect?
Can they clutter in the bloodstream or inside the organs?
While I am sure there are risks to nano technology, I think the real force driving all this "concern" is plan and simple greed.
Nano technology is what's called a "disruptive" technology. That means that it will enable people to do things for pennies on the dollar that used to cost billions. Because of this it threatens what is called "barriers to entry" for many large corporations. According to business 101, the most profitable businesses have high barriers to entry that help keep competitors out and lock profits in.
The only problem is that when a company can't compete off of it's "natural" barriers to entry, then it's only option is to compete off of "regulatory" barriers to entry. Hence the strong incentives and financial pressure to make sure nano technology is a super overregulated industry before it even exits the starting gate.
So now all the other "concerns" about nano technology that keep poping up should be far more clear.
Nanotoxicity? If you ask me, anyone stupid enough to eat their iPod deserves what they get.
"In a 32-bit world, you're a 2-bit user. You've got your own newsgroup, alt.total.loser." -Weird Al
That study is somewhat old hat. Have a look here and you'll see that the mechanism is now understood.
:v)
In short, you can make toxic, or non-toxic buckyballs. The more bits you dangle on the outside of the buckyballs, the less toxic they become. Nanomachine designers will be aware of this and act accordingly.
Vik
I work for the EPA and happen to know a couple people looking into the health effects (in mice) of fine particulates and are just starting a new project to look at diesel particles. My fellow postdoc friend has been smelling like diesel a lot lately. The odor is really quite a nice accompanyment to lunch :)
The problem with abating diesel particulate pollution is that a lot of people will likely bitch loudly about the cost of prevention or switching to a less polluting technology. It is a lot easier to study the potential effects of a new technology before it gains widespread adoption rather than trying to put the genie back in the bottle.
I live in NYC, and I don't trust the EPA to tell me that nanoparticles are safe. They lied to us after 9/11/2001 about the poisonous air. They lied to the heroic volunteers and police/fire/EMTs who could have worn masks while digging in the rubble. Instead thousands of people are walking testimonials to the EPA's lies about air pollution. I see them every day. The EPA's got a lot of work to recover its credibility. And I haven't seen anything to convince me that they're on that path.
--
make install -not war
Too much coal dust will kill you. Too much radiation will kill you. Too much Vitamin A will kill you. Too much tylenol will kill you. A large bale of marijuana will kill you, if dropped from sufficient height. And varying amounts of above substances can make you sick. We need to know safe acceptable limits whenever the population en masse will be exposed to new substances. Lots of tricky details to sort out, and no simple answers.
Be heard || Be herd
The dangers of asbestos were actualy knowns since as early as 1898, when Lucy Dean, one of the first women inspectors for factories in the UK wrote about asbestos work as one of the top four dusty occupations which came under observation that year 'on account of their easily demonstrated danger to the health of workers and because of ascertained cases of injury of brinchial tubes and lungs'.
o rt_2001_22/en/issue-22-part-05.pdf for more informations about asbestos and the problems it's use created.
Similar observations followed in the years 1909 and 1910 and were widly circulated amongst policy-makers and politicans. By 1918 insurance companies in Canada and the United States declined insurance cover for asbestos workers 'due to the assumed injourious conditions in the industry'.
I repeat; the danger of asbestos was known from the very beginning and shorty thereafter insurance companies decliend to cover asbestos damage. That was in the 1920s. Asbestos was however used into the 1980 as a cheap and fire resistant material.
I think we should learn from the mistakes in the past and try not to repeat them.
Read this http://reports.eea.eu.int/environmental_issue_rep
Nanotubes disintegrate in water. (Humans are bags of mostly water.) So you'll have to look elsewhere for your asbetos-like lung-daggers.
I'm a politician in a parks & rec district that recently underwent national media attention on asbestos, and have had some opportunity to do some research on this - as well as get squeezed in a battle between the EPA and our county govt. on this asbestos issue - primarily over the perceived threat to property values (and taxes collected from it).
My seat of the pants analysis of this is based somewhat on a 2003 conference held in San Francisco with attendance by a worldwide collection of asbestos related experts.
Bottom line - not much has improved in studies for asbestos related health risks. How much is safe? What is the correlation between exposure, longevity, lifestyle, etc? It seems that Chrysotile forms of asbestos are "more safe" due to their curly shape, and apparent expectorability from the lungs via natural processes (breathing, coughing, philial movement, encapsulation in other materials produced by your body, etc.)
However, Amphibole types seem to be much more dangerous - needle-like, long fibers. Easily "stuck" into tiny spaces in the lungs and not expectorated. Macrophages in the lungs apparently envelope these fibers and work to eventually break them down, but for some reason, they don't encapsulate the entire length of the fibers (if you can imagine a pig-in-a-blanket dough/hotdog analogy). Not much is understood of this area, and due to the location, is not an area for easy testing. Combine that with the longevity for detection, it's difficult to do tests on any factors leading to, or progression of any asbestos related illnesses.
What the EPA is certain in saying is that there appears to be a 5X incidence of mesothelioma among smokers (in an occupational setting - somewhat difficult to compare to a park setting with occasional possible exposure). However, ATSDR says there isn't a way to distinguish smokers related illnesses against mesothelioma, which leads me to believe as another poster suggested that asbestos interferes with some portion of the lungs or biological process/byproduct with close proximity to the lungs that allows greater incidence of mesothelioma amongst smokers.
Testing has been somewhat difficult under existing standards. Spiked samples of asbestos have come back with 0 fibers/cm^3 readings from labs, clean samples have come back with readings. Then there are some tests conducted by labs that violate friability standards - by crushing the rock and then looking for asbestos. This is not a realistic exposure model.
As a result of the screwball results, the EPA was unwilling to admit that the soil samples were bad, preferring to use only air samples that were collected via activity based testing and comparing the results ot nearby stationary air samplers. Apparently there is some consistency seen using such methods.
HOWEVER, the EPA left town, wanting to wash their hands of some of this debacle. We still have a fence up near a field, and have conducted further tests by a certified hazardous materials expert. The results are coming back 0 (preliminary tests). That's a cause of consternation on the part of the EPA as well as by our parks & rec dept. How do we reconcile the differences and does the EPA end up having a tarnished image from even the new testing methodology? How do we instill confidence in parents whose kids play on the field, or in a nearby tot-lot where the EPA said there were elevated levels of asbestos? (Our community has asbestos running through it, but this field has a totally different type of asbestos apparently (from EPA, not our own subsequent testing) which was brought in as a replaced field mix.
This is an area where there is not much glory for this type of research, and is fraught with VERY long periods of time before any possible correlated illness is even detected (usually by death - but was it by THIS exposure?)
I suppose that in the area of nano-technology, it will be a good thing to at least be open to this area of study, but may also prove to show causation.
Me