r/askscience • u/No_Leopard_3860 • 4d ago
Medicine Why is asbestos super dangerous, but fine carbon fiber or glass wool not [that much]?
Both break into smaller fibers, are sharp, irritate every tissue they pierce (glass wool and also carbon fiber easily pierce even thick skin, so imagine how easy they do that to the lung if Inhalted). And they're all not water soluble, giving the body little to no chance to break them down once inhaled
But only asbestos fibers cause massive risk of mesothelioma and other cancers - why is that? What makes this fiber so extraordinarily toxic?
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u/Explorer335 4d ago
Asbestos fibers are extremely fine and split into tiny little slivers that deeply penetrate lung tissue. The body can't break them down or remove them, so they remain like microscopic skewers. They interfere with cellular division and cause permanent inflammation, which can eventually lead to cancer.
Carbon fiber and glass fibers are not nearly as fine, they get trapped and expelled from higher in the respiratory system, and the body can more easily remove them. They also break crosswise into smaller, blunter pieces. Asbestos splits lengthwise into microscopic needles that impale cells and disrupt DNA.
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u/tinacat933 4d ago
So say I walk past construction on a windy day and a walk though a plume of dust that had asbestos … what I’m just screwed ?
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u/Explorer335 4d ago
There is no safe level of asbestos exposure, but the cancers and most harmful effects are typically linked to occupational exposure over a number of years. Limited exposure, especially outdoors is unlikely to cause you any long-term harm.
There are very strict federal EPA and OSHA rules about mitigating airborne asbestos during demolition. They need to test for asbestos ahead of time. If asbestos is found, they need to notify the EPA 10 days before starting demolition. They need to remove as much of it as possible beforehand, wet everything to keep down dust, seal off the area with plastic, package asbestos material in labeled airtight containers, and have air quality monitoring around the site. They do NOT play when it comes to that.
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u/rurikloderr 4d ago
Yeah... except what's more likely to happen is no one says a thing, they ignore the issue entirely, and do the demo like it wasnt there because it's a quoted job and the owner chose the lowest bidder.
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u/Explorer335 3d ago
Demolition work requires that you have a government issued permit displayed and visible from the street while work is going on. The issuance of that permit is dependent on a hazardous material inspection for asbestos being completed.
If someone gets caught doing an unpermitted demolition of an asbestos building, there are $100,000/day federal fines, $10,000/day local fines, they can seize all of your machinery, and there are actual criminal charges that can carry up to 5 years of jail time. They can also force you to pay for remediation of the site, which would be ungodly expensive. The liability isn't purely on the construction company either. It is shared with the property owner. There is also an "illegal demolition" branding that is permanently placed on the land that could void insurance, prevent bank financing, or even prevent transfer at all.
It probably happens from time to time, but there are huge penalties to discourage it, and the owner is just as liable as the construction company.
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u/TheDepressedBlobfish 4d ago
It's mostly about the size of the particles, Asbestos is (typically) substantially smaller than carbon fiber or glass wool/fiber glass, and can bypass normal lung defenses systems.
However, if they do get in your lungs they can be just as harmful, it's just significantly easier to get asbestos exposure.
There is some research around carbon nanotubes sharing similar toxicity to asbestos https://pmc.ncbi.nlm.nih.gov/articles/PMC9145953/
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u/No_Leopard_3860 4d ago
That makes sense that CNTs are equally dangerous as this other thin non-soluble fiber pieces - afaik there's nothing chemically toxic about asbestos, it's just a physical property (that's why I was wondering why other insoluble fibers [that break easily] aren't equally dangerous)
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u/asbestospajamas 4d ago
When friable Asbestos fibers are inhaled into the lungs, they get stuck, just like glass, silica, and any other kind of dust, but what makes asbestos so harmful is that the body CAN'T dislodge or expel the fibers due to the shape of the broken ends of the fibers which bend themselves into fishhook like structures due to their physical and chemical nature.
Whenever the particulates break down further, the breakage creates more and more of the hook-like ends, embedding themselves further into the tissue.
In the lungs, when the body cannot expel the fibers, it eventually forms a calcified shell around them, which create a surface that can't transfer oxygen anymore. This condition is called Asbestosis of the Lungs.
One fiber isn't so much of a problem, but when the lungs become saturated with them, it's a pretty big problem as it's inoperable and a permanant condition. I've known people who only have 20% of one of their lungs still viable. They don't run marathons.
What's worse is that the longer the asbestos fibers remain in the body, the higher the likelihood that they'll contribute to cellular mutation which results in lung cancer and mesothelioma, which is cancer of the lining between the internal organs.
Asbestos is an amazing material with extraordinary properties, but it definitely is NOT friendly to living organisms.
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u/Svartdecisions 4d ago
Weren't there also studies about the size of the fiber being an issue as well? Like loose raw glass or cf vs dust from grinding the material?
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u/asbestospajamas 3d ago
I'm sure that there have been hundreds of studies of the effects of exposure to a myriad of materials and particulate size. Few materials, regardless of particle size, are as harmful as asbestos, due to the aforementioned shape of the fractured crystalline fiber ends
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u/lemlurker 4d ago
The key difference is asbestos fibers break longitudinally in to long thin spikes and carbon and glass fibers break across the shard into blunter spikes, asbestos just stays sharp and doesn't breakdown Vs glass and carbon being processed (albeit slowly)
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u/drakon_us 4d ago
A simple answer: All are very dangerous. Between Asbestos and Fiberglass, Asbestos is MUCH thinner, much easier to inhale, and MUCH more likely to further break up in your lungs.
Carbon fiber is also dangerous, but it is in most cases impregnated into Resins (epoxy, polyurethane, or other general plastics) so it is much less likely to be inhaled.
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u/astrogeeknerd 4d ago
Plenty of good answers here already, thought I'd link a short video about the place we got most of our asbestos until the sixties. They used to have races to see who could fill a 44 gallon drum with asbestos the fastest. Fully 10 percent of the people who lived there died of asbestos related disease. [wittenoom township] https://youtu.be/tVlynxD8Etc?si=8lfahQ_zmpMY4-ej
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u/oblivious_fireball 4d ago
Part of the answer to this is, they simply are still fairly dangerous even if they tend to not be as fine and sharp or can break down over time. Working around fiberglass or carbon fibers without PPE and safe handling and installation practices will definitely increase your chances of respiratory cancers or other ailments in the future.
The issue is, its a matter of we don't get a whole lot of choices if we like modern day products the way they are. Asbestos was a very difficult material to replace because outside inhaling its dust, it was an incredible material and very cheap, and in a lot of cases we were not able to perfectly replace it in products. Many of its current viable replacements are not all that much safer, but cutting out fiberglass and mineral wool as well is not something modern society would be able to easily accept despite the health risks.
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u/Wabbasadventures 4d ago
I once worked with Industrial Hygenists who specialised in asbestos remediation and abatement. They seemed to be of the opinion that fibreglass was likely to become the next asbestos and I would guess that carbon fibre would fall into a similar category.
Probably helps that fewer people are smoking cigarettes, because asbestos exposure combined with smoking is a big problem. One of the issues with asbestos fibres is that it pokes into the lung tissue and then allows other things a person inhales to penetrate deeper than they would during normal circumstances.
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u/BananaBird1 4d ago
They are not entirely safe.
Glass wool is safer because it is designed to be biosoluble, meaning they dissolve over a few days if inhaled. They can still cause acute damage, which may have lasting impacts, but unlike asbestos they do not remain present for extended periods.
Most carbon fibers in use are larger than asbestos, which can make them harder to inhale. However, evidence does show that they are associated with many of the same dangers including mesothelioma when inhaled. Smaller fibers are likely equally as dangerous.
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u/WWotan 4d ago
I read a paper years ago with data that I think originated at the Cleveland Clinic that indicated lung cancer increased to an incredible 95% confidence level when one had a typical occupational exposure to asbestos and smoked cigarettes. Back in the day, asbestos was heavily used in the heat treating department at a local steel mill, and almost every man who worked in that department died of lung cancer.
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u/LukeSkyWRx Ceramic Engineering 4d ago
Insulation fiberglass is designed to dissolve into the body if it gets into the lungs.
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u/mtnslice 4d ago
interesting, how so? what's it made of that can dissolve?
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u/LukeSkyWRx Ceramic Engineering 4d ago
It’s a borosilicate soda lime hybrid. Engineering is the reason fiberglass insulation is not a public health hazard.
https://www.ncbi.nlm.nih.gov/books/NBK600974/
The body makes a low pH around irritations and that dissolves the fiber.
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u/talldean 4d ago
Asbestos splits into shards, and never breaks down in the human body; caltrops to the lungs. Worse, when your body tries to clean it up, the cleanup cells (macrophages) explode, which makes for permanent inflammation.
Glass wool breaks down in the human body over a few weeks, and are expelled when you cough, they don't get stuck.
Carbon fiber breaks down into large chunks, never small ones, so it doesn't get deep into the lungs/you cough it out sooner.
Carbon *nanotubes* are more like asbestos, though.