Jor
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The POTENCY of carcinogens.
As I work with nickel compounds, chromium compounds, and also sometimes with CHCl3/CCl4, I was really interested in the potency of these materials
carcinogen. There's all carcinogens, but the how powerful of a carcinogen a material is, that'what interests me.
I found this.
http://www.springerlink.com/content/p85680g33770047k/fulltex...
This gives a table (table 4), wich gives a median relatlive potency, with dimethylnitrosoamine as reference (=1).
However, arsenic, chromium and some others are missing.
Does nayone have another table? I have been looking on google for quite some time now, and it;s hard to find a good wich gives the potency for these
materials, and not just : 'it's very potent'.
I'm surprised that benzene, CHCl3 and CCl4 aren't as badass carcinogens as I initially thought. They are quite weak actually, one of the weakest of
the list.
I'm also surprised that cadmium is one of the strongest carcinogens, it's extremely potent! TCDD (the famous dioxin) is incredible.
Due to my lack of Engish, I do not understand what the numers on the right in table are. Hydrazine has a very high number, 2200. What does this say?
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497
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Interesting data. It leads me to wonder why people get so freaked out about stuff like benzene and CCl4 when the are apparently very low on the list.
Hell, they're only ~10-20 times higher that saccharine! Maybe the potential for chronic exposure to them increases the risk?
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Formatik
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Some time I came upon a compound called propane sultone which is said to be an extremely potent carcinogen: http://linkinghub.elsevier.com/retrieve/pii/S037842740400083... I wonder how it would fare against any of those.
| Quote: | | Originally posted by Jor Due to my lack of Engish, I do not understand what the numers on the right in table are. Hydrazine has a very high
number, 2200. What does this say? |
That is the interquartile range. Statistics. Shortly put, the middlespread: http://en.wikipedia.org/wiki/Interquartile_range They are saying this is for the activity profile. To which: "The range of relative potency values
represent the "activity profile" for the test compound relative to the reference compounds".
[Edited on 9-12-2008 by Formatik]
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Jor
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Yes, it seems that benzene and CCl4 are indeed not so strongly carcinogenic. I read before that people only really get cancer on working for long
times with this chemical.
Please remember that CCl4 is still a very strong liver toxin.
You also indeed have the very potent carcinogens, and I too have come across propane sultone. This one has caused tumors in laboratory animals after a
single exposure. I would guess things like TCDD and cadmium could do the same.
I also found out that solubility of compounds doesn't say much on the potential carcinogenity. For example, of all Cr(VI)-compounds, the soluble ones
ar emore carcinogenic than insoluble, but slightly soluble ones are the worst. Zinc chromate is the strongest carcinogen used in industry, followed by
strontium chromate AFAIK.
For nicke-compounds it's the opposite. I read yesterday in a very long article, that insoluble nickel's are much more carcinogenic than soluble ones,
due to their higher bioavalbility (I wonder why, maybe only inhalation?).
Saccharine is somethign else than saccharose! It's and articifial stweetener, found to be carcinogenic in humans.
Anotehr parameter for the potency is the TD50 of a chemical, wich is the dose in mg/kg/day for a long period wich causes cancer in 50% of the
laboratory animals.
EDIT: I'm scared to hell. Chromium is said to be more than 30 times as potent as cadmium and 5000 times more potent than benzene. 
And when I waking K3CrO8, I think I have inhaled some small droplets of hexavalent chromium. Am I at high risk now?
http://74.125.77.132/search?q=cache:avInsSpog58J:ftp://ftp.arb.ca.gov/carbis/board/books/2006/092806/06-8-3pres.pdf+extremely+potent+carcinogen&hl
=nl&ct=clnk&cd=14&gl=nl
page 7
[Edited on 10-12-2008 by Jor]
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DrP
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| Quote: | Originally posted by Jor
Yes, it seems that benzene and CCl4 are indeed not so strongly carcinogenic. I read before that people only really get cancer on working for long
times with this chemical.
Please remember that CCl4 is still a very strong liver toxin.
[Edited on 10-12-2008 by Jor] |
Our chemistry teacher told us that CCCl4 was used as a hand wash for coal miners. Apparently they started to get skin cancer on their hands after
long periods of time working with the stuff. Makes me think whether it was the CCl4 or the coal dust itself that was doing the harm though. Probably
both at the end of the day.
\"It\'s a man\'s obligation to stick his boneration in a women\'s separation; this sort of penetration will increase the population of the younger
generation\" - Eric Cartman
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harrydrez
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| Quote: |
I'm scared to hell. Chromium is said to be more than 30 times as potent as cadmium and 5000 times more potent than benzene. And when I waking K3CrO8, I think I have inhaled some small droplets of hexavalent
chromium. Am I at high risk now? |
Just try to be more careful, work in a hood if you think the solution will splash.
They are useful compounds, but yes they are quite toxic. On the other hand, we're exposed to all kinds of carcinogens everyday. I think you'll be ok,
just try and be more careful with potentially toxic compounds. Try and understand the hazards of said chemicals before you work with them.
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woelen
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Jor, you still must put things in perspective. The article you posted is talking about probabilities like 100 out of 1000.000, which is just 0.01%
after low-level exposures, which lasted for years.
Your exposure will however be MUCH lower than what this article is about (workers in chrome processing industries). I once had a talk with a chemist,
who is working here in a lab near where I live. He compares working with hexavalent chromium with smoking cigarettes. Each experiment you do, which is
not carried out that carefully (e.g. inhaling some droplets with dissolved dichromate) can be regarded as smoking a cigarette. This is not good, but
you also understand that all those persons smoking several cigarettes, every day, run a much higer risk of getting cancer.
The point is, your hobby imposes some risk, just like someone else's hobby imposes other risks. ALL activities in life impose some risk. It is our
responsibility to reduce risks as much as possible, but we cannot eliminate risk and at the same time have fun in our life  . We do many things which impose risks. Drinking a few beers or wines can be a
pleasant experience, but I'm quite sure that this also introduces a certain risk of cancer (formation of acetaldehyde in the body). I still do accept
that risk.
In your case, doing the K3CrO8 experiment every day would be a serious risk, but your one-time or two-times experiment is not a problem at all. Just
work cleanly next time and try not to panic.
Many carcinogens have linear probability profiles for getting cancer. E.g. when exposure to 0.001 mg every day for 5 years results in a chance of
0.01%, then exposure to 0.001 mg for only 1 out of 10 days for 5 years results in a chance of 0.001%.
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harrydrez
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| Quote: |
Many carcinogens have linear probability profiles for getting cancer. E.g. when exposure to 0.001 mg every day for 5 years results in a chance of
0.01%, then exposure to 0.001 mg for only 1 out of 10 days for 5 years results in a chance of 0.001%. |
Carcinogens are funny that way, It's not so black and white. It's a more complex system. Some people can work with cancer causing chemicals for years
and have no issues, others aren't so lucky. Our bodies do have ways to mitigate damage to our DNA (DNA damage happens all the time). Hell, sometimes
things go wrong without over exposure to chemicals. So perhaps life can be called a carcinogen as well.
There are some studies I tend to take with a grain of salt, like showing a chemical causes cancer by exposing cancer prone mice to ludicrous levels.
Without any evidence it actually causes problems in humans.
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a_bab
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Related to hexavalent chromium, I just read an article about a female worker that has been expozed to potassium dichromate for like 20 years, and she
got a chronical disease that perforated the septum from the interior due to the airborn particles of K2Cr2O7. Now that's an exposure! It looks like
this is a common disease for the people who would work with K2Cr2O7, sort of what "phossy jaw" is to WP.
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a_bab
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Jut found this: http://potency.berkeley.edu/index.html
It looks like an interesting read.
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sparkgap
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I will merely note that propane sultone has functionality similar to some of the NCI Standard Agents, in particular busulfan and Yoshi-864. Very good leaving groups, them alkylsulfonates...
sparky (~_~)
"What's UTFSE? I keep hearing about it, but I can't be arsed to search for the answer..."
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Fluorite
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Can someone tell me what's the safest way to concentrate 4L sodium chromate? Made by reacting stainless steel with acid and then NaOCl?
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Fyndium
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Everything that is not either having water as only volatile compound or the volume of harmless liquid is very low to evaporate, I always use closed
distillation apparatus to concentrate stuff. This is probably the most common and safest method for any use. If volatile, toxic, malodorous or
otherwise harmful stuff is distilled, put a tube into inverted funnel large enough for the purpose into a scrubbing liquid proper for the purpose, or
alternatively just exhaust it to suction line that goes outdoors, or lead a long enough tube to outdoors. Some people scrub gases through the toilet
water lock by just putting the tube through it.
For the carcinogens, most common stuff that is considered health hazard is designated for occupational point of view. Minor or single exposure few
times during a life is generally of no issue unless dealing with bioaccumulative or extreme stuff, but people working with them can literally rinse
their hands multiple times a day with something an consider it a good practice, hence the exposure is just absolutely enormous. I don't stress minor
stuff like toluene at all, because I handle them so little and even then I may get an occasional whiff of the already extremely low odor treshold.
I'm extra careful with bioaccumulative stuff though, as single exposure will take decade to leave your body.
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outer_limits
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What do you mean by closed distillation apparatus? Apparatus can't be closed during distillation as it can be disassembled in a violent and quick way.
Traps and leading the fumes outside is good option when there is no fume hood available.
For benzene and similar carcinogens - it's not that bad, single exposure is not likely to do the harm. But there is also a seriously nasty stuff but
it definitely shouldn't be messed with without appropriate infrastructure.
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Fyndium
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Closed apparatus means behind a water lock or some other dynamic phase barrier, like I described. Not an actual closed setup, of course. This is
supposedly only appliciable when protecting passive reagents from air, or if intentionally creating a pressurized vessel.
Open apparatus is something that is freely accessible to surrounding air. A distillation setup with bare vacuum outlet is what I also consider open
device, or at least semi-open, as any fumes can freely escape.
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Jome
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Cigarette equivalents could be a useful comparison unit, or perhaps for the more potent carcinogens "average smoker weeks/months/years"
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Dr.Bob
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I still have scads of old books on cancer and mutagenicity, toxicology and more. If you have specific topics, contact me and I can see if I have any
books on any topics you want. I likely have some books on Chromium toxicity, but they are pretty dry reading, I will warn.
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TriiodideFrog
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Is naphthalene a carcinogen? Some sources say it is while others say it's not.
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VeritasC&E
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The original link seems to be dead, does anyone maybe have the paper?
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zed
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Asbestos, Smoking Cigarettes, UV, HPV, DES, Beta-Napthtalamine....
Liver Viruses. Alcoholism.
There are lots of carcinogens. But some are potent, common, and especially famous.
Wear gloves. Wear a respirator. Exercise caution.
[Edited on 9-7-2021 by zed]
[Edited on 9-7-2021 by zed]
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VeritasC&E
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does anyone have the paper?
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ArbuzToWoda
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Since the link is dead and for some reason no one uploaded the paper to this time, here it is.
[Edited on 27-9-2021 by ArbuzToWoda]
Attachment: glass1991.pdf (841kB)
This file has been downloaded 304 times
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CharlieA
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This is just my personal take on this thread as a whole. as one who worked in an organic lab, for several years, and smoked (~pack a day for ca. 50
years), and is now a 19 year cancer survivor of squamous cell carcinoma or the head and neck
My cancer surgeon and radiation oncologist who worked well together (and obviously on me) have different opinions: one thinks my cancer was caused by
smoking, and the other thinks that is from my exposure to various solvents and other chemicals over the years. Of course I suppose that the cancer
could have come from a cell mutation.
But my bottom line is: it really doesn't matter what causes any cancer; it just matters how successful the treatment(s) is(are). My first chemical
company boss had a favorite saying (you have to imagine his thick German accent): We all have 20-20 hindsight! In hindsight, I should have availed
myself of more PPE, and not done stupid things like pipetting (just about anything) by mouth. My only (ignorant) defense is that this all occurred
50-60 years ago.
Just my 2 cents. Thanks for "listening".
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VeritasC&E
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Quote: Originally posted by ArbuzToWoda  | Since the link is dead and for some reason no one uploaded the paper to this time, here it is.
[Edited on 27-9-2021 by ArbuzToWoda] |
Thanks a lot ArbuzToWoda!! (due to the delay in between our messages I just saw this now) It's a useful list.
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VeritasC&E
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| Quote: Originally posted by CharlieA |
But my bottom line is: it really doesn't matter what causes any cancer; it just matters how successful the treatment(s) is(are).
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No it does matter. Because whatever is carcinogenic (apart from targeted / incisive gene/translation/folding editing/interference) generally insults
the genetic and epigenetic stability/conformity of cells throughout your body, and thus the performance of different tissues/organs at what they are
supposed to do. In other words, cancer is the result of a sum of issues. Avoiding death from cancer certainly doesn't erase those accumulated issues
in your body.
What can ultimately lead to cancer CERTAINLY slowly makes all your organs less potent and healthy over the course of time; all the more so as aberrant
function of some cells / organ accelerates damage to all other cells/organs: As your immune system becomes senescent all cells of your body suffer
from increased viral insult to their genome; increased oxidative stress due to less effective antibody response to infections; etc. As your
hepatocytes become senescent you get longer and higher exposure to mutagens normally routinely quickly cleared from your body by a healthy liver. And
so it goes for each and every organ.
[Edited on 18-8-2022 by VeritasC&E]
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