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The Dangers of Dimethylmercury (2019)
- jonpalmisc 5y agoChubbyEmu’s video [1] on this was quite good. (As is the rest of his channel, if this kind of stuff interests you.) [1] https://m.youtube.com/watch?v=NJ7M01jV058 https://m.youtube.com/watch?v=NJ7M01jV058
- chrisbrandow 5y agoI still remember this event when it happened. I was getting my PhD at the time. I think about it regularly.
- throwawayboise 5y agoI wonder if the outcome would have been differnt if she had just immediately changed her gloves (or maybe she did? The story doesn't really say, but implies that she just continued the experiment).
- deleted 5y ago[deleted]
- DrAwdeOccarim 5y agoI started my chem grad school about a decade later and all the changes were well accepted and the field was still mourning her loss. What a tragedy.
- julienchastang 5y agoNote the time between initial exposure and death -- almost a year. Terrifying.
- brazzy 5y agoAnd about 5 month before any symptoms showed up, then comatose within 3 weeks. I once asked a biochemist how that's even possible. Apparently it irretrievably destroys a part of the body's metabolism that is necessary to repair nerve cells.
- trutannus 5y agoWorked with a professor who knew this person. He talked about this not infrequently. All the grad students knew of the story as well, and would talk about it. Her death really shook up the NMR community. It was the reason we never use DEM in our lab, and why many try to avoid it at all costs even now. If I remember properly, and this was over 10 years ago, the reason its commonly used is to calibrate the spectrometers, so in some areas it gets hard to avoid. Also, the article mentions you need nitrile gloves to protect yourself from it. This is not sufficient and is dangerously misinformed. You need silver shield gloves to protect yourself from it.
- kibwen 5y agoThe article mentions it: "The bulletin also urged that, aside from wearing a face shield, anyone working with dimethylmercury should wear Silver Shield laminate gloves beneath abrasion-resistant outer gloves. [...] Sugden points out that, when dealing with toxic substances, labs have shifted from latex gloves to nitrile gloves, which are less porous"
- rotifer 5y ago> Also, the article mentions you need nitrile gloves to protect yourself from it. I don't see that. With respect to an OSHA bulletin, the article says: The bulletin also urged that, aside from wearing a face shield, anyone working with dimethylmercury should wear Silver Shield laminate gloves beneath abrasion-resistant outer gloves. The mention of nitrile gloves is in a more general context: Sugden points out that, when dealing with toxic substances, labs have shifted from latex gloves to nitrile gloves, [...]
- crdrost 5y agoYeah I wouldn't even want nitrile gloves on with the stuff. It is worth explaining just what is wrong with it. Mercury of course is a toxic compound, but kids used to crack mercury thermometers in their mouths and suffer no consequences. Pressure gauges came with exposed tubs of mercury and you would get some on your hands and it was fine, even kind of fun to play around with. Felters famously felt symptoms after careers of using it, usually blamed on long term inhalation, but it required a long time and lots of exposure to get to that point. Many people received dental amalgams with mercury bases and while there has always been a conspiracy theory about it, it has never been acutely toxic enough to be mainstream—the shift to other composites has instead been driven by comfort (metal fillings conduct heat and cold at an unnatural rate) and aesthetics (the new composites are white instead of silvery). The basic reason is that the body does not eat metal and does not know what to do with it largely. Even with the metals that the body uses, like cobalt, it wraps every atom of cobalt in a big old ring of carbon and that's Vitamin B12. Dimethyl mercury, is different from normal mercury, in a similar way. The methyl groups are organic groups that your body is much more willing to absorb and process. So the latex is not protecting you nearly as much because latex is this organic natural filter that lets things through... But also your skin is not protecting you because this stuff can seep into your skin via those methyl groups, your cells are just like “oh you look interesting I can take you into my chemistry.” So yeah, milligrams are all it takes, tiny trace amounts: but the reason that you don't think of it being quite that dangerous is that your exposure to the liquid metal version is an exposure to a form that your body is uniquely unsuited to process or absorb. Water off a duck's back. Even though the water contains neurotoxin, it just rolls right off. Even, in our case, when ingested. But add these little methyl groups, methylmercury and dimethylmercury and really any organic mercury molecule, it gets real bad real fast because it's no longer rolling off our backs, it's soaking into our feathers.
- supernova87a 5y agoI think every blackboard organic chemistry class should be required to be taught with multiple repeated asides about the dangers of organometallic reagents. And other dangerous materials too. It's not just pushing electrons around, it's fucking with your life potentially. And they send you into lab with only folk-story level preparation if you're lucky enough to have gotten that info from others, and one day there is in front of you a bottle of organo-tin looking not too dissimilar from any other less harmful reagent. Only saved from danger by some slightly older grad student saying, "be careful around that stuff" (again, if you're lucky). I myself only knew about, for example, the dangers of ether bottles left for a long time, because of my own interest in happening to read about it. Not a single person in my entire undergrad/grad career mentioned it. Hydrofluoric acid. Other nasty stuff, etc. It's a major oversight for student education -- to be taught the dangers of the subject you're about to be exposed to in real life.
- ashtonkem 5y agoEven as a lay person I know that most fluorine molecules are not to be messed with.
- dheera 5y agoUh, except the stuff you shove on your toothbrush? The high-dimensional surface of "threat to life" vs. molecule structure is super, super, non-convex. Like H2O -> yay, H2O2 -> die, H2 + O2 -> fire Like methanol -> die, ethanol -> fun, propanol -> die, butanol -> die, heptanol -> die, octanol -> die
- verisimi 5y ago[flagged]
- kwohlfahrt 5y agoEthylmercury is used insted of (di-)methylmercury, because it is cleared from the body faster: https://www.cdc.gov/vaccinesafety/concerns/thimerosal/index.html https://www.cdc.gov/vaccinesafety/concerns/thimerosal/index....
- ncmncm 5y agoBut not nearly so fast as we are invited to believe.
- bogota 5y agoNo its not as you pointed out but didn’t clarify. Ethylmercury is not the same as methylmercury.
- hammock 5y agoIt is not. The mercury in (some, but not all or even most, these days) vaccines is ethyl mercury. Here is an article that explains a bit more of the similarity with dimethyl mercury, though - they are both organic mercurials: >Both ethyl mercury and Hg2+ are very neuro toxic compounds. However, ethyl mercury is more rapidly partitioned into the hydrophobic (fatty) tissues of the central nervous system and is a more potent neuro toxin than Hg2+ based on this “partitioning factor”. It is this partitioning factor that makes organic mercurials such as dimethyl mercury so neuro toxically lethal (this is the compound that caused the death of a Dartmouth University chemistry professor after she was exposed to a drop or two on her gloved hand). >The concern with organic mercurials, such as thimerosal, is that such compounds can be perceived as “pro toxicants” just as certain pharmaceuticals can be classified as “pro drugs”. This means that the original compound, e.g. thimerosal, is less reactive giving the compound time to partition into certain areas of the body before it breaks down releasing the ethyl mercury and then further releasing Hg2+. However, while attaching ethyl mercury to thiolsalicylate makes the ethyl mercury less reactive it most likely allows increased partitioning into the central nervous system before the ethyl mercury is released and thereby, increases the neuro toxicity per unit ethyl mercury involved https://vaccinechoicecanada.com/vaccine-ingredients/thimerosal-containing-vaccines-and-neurodevelopment-outcomes/ https://vaccinechoicecanada.com/vaccine-ingredients/thimeros...
- JoeyBananas 5y ago> OSHA fined Dartmouth $9,000 (£6890) for what it considered the institution’s failure to provide adequate caution, particularly about the shortcomings of disposable latex gloves. I would think that PhD. chemists would be responsible for buying their own PPE. Also $9,000 is such a weirdly small number
- michaelcampbell 5y ago> I would think that PhD. chemists would be responsible for buying their own PPE. I wouldn't; why would you?
- masklinn 5y agoGuessing / hoping they meant the chemists would be responsible for determining / ordering PPE suiting what they’re working on, not that they’re supposed to pay for it out of pocket. Though from what I’ve heard about solid through sand buckets, and pitted face-shields, and contents of lab fridges, I’d think GP a bit optimistic.
- michaelcampbell 5y ago> Guessing / hoping they meant the chemists would be responsible for determining / ordering PPE suiting what they’re working on, not that they’re supposed to pay for it out of pocket. That makes more sense, thanks.
- throwawayboise 5y agoI'd expect standard PPE to be purchased by the chemistry department for all labs (charged back to individual research grants or just part of the "overhead" percentage they take out of all grant funding). Anything specialty is probably specified by the researcher, and ordered and paid for by the staff person handling grant administration.
- JoeyBananas 5y agoWho else is supposed to know how chemicals are supposed to be handled?
- pmoriarty 5y agoThis reminds me of the tragic case (involving a different compound) of Sheri Sangji[1], a research assistant at UCLA who spilled a pyrophoric substance on her highly flammable synthetic sweater that she was wearing instead of a lab coat. [1] - https://en.wikipedia.org/wiki/Sheri_Sangji_case https://en.wikipedia.org/wiki/Sheri_Sangji_case
- praptak 5y agoThis stuff is scary when you think it could be used in Putin-style assassinations.
- pumnikol 5y agoIt is now assumed that this already happened, in 2011, in a Bulgarian umbrella attack in Germany's crime capital, Hanover. My somewhat unfounded guess is that the perpetrator himself perished not too long after the victim, which would explain why the case is still unsolved.
- vmception 5y agoThe assassins are too scared to handle it too Coupled with the year long gap before death Its probably not an ideal choice
- tagoregrtst 5y agoExcept for the most pressing assassinations, I imagine lag is a feature, not a bug.
- stevespang 5y ago
- Nextgrid 5y agoIt seems like it's easily detected though? Is there any legitimate reason in today's world for someone to have ~80x above mercury's human toxicity limit, besides those actually working with the stuff in the industry?
- ngcc_hk 5y agoWhilst it becomes political now, lab accidents and lab protection even for known risk is still happened. If you study something intensively and it will leak out with more probabilities.
- mahkeiro 5y agoWhen I was studying chemistry, latex gloves were not allowed in org chemistry lab as too many thing can go through them and they provide a false sense of security.
- throwawayboise 5y agoI didn't take chemistry past freshman general chem, but we didn't use gloves at all. Eye protection, yes.
- fabian2k 5y agoChemists get trained to work with dangerous substances, that's a core part of the job. But Dimethylmercury is something else, it's far more dangerous than anything else someone in that field would ever encounter. NMR is usually a pretty boring field in terms of stuff killing you. The most you can usually expect is someone sealing an NMR tube with something still reactive inside, which might blow up the glass tube at a later point. That tends to annoy the people managing the NMR spectrometers, so there are usually rules and procedures that should eliminate that risk. Of course you examine all kinds of substances by NMR, so my previous statement is kinda wrong. If you work with really toxic substances, you also want to analyze them and put them into an NMR spectrometer. A huge difference here is whether you're regularly working with really dangerous substances or not. Many substances in chemistry are dangerous, but they're the kind of dangerous that every chemist is supposed to be trained for. But there is an enormous differences between a regular dangerous chemical and something like Dimethylmercury where a few drops through a nitrile glove can kill you. That needs an entirely different level of precautions than the ones you usually have in the lab. And it's the kind of danger that simply isn't worth it for most cases. If you're used to work with truly dangerous substances you can probably handle somethign like this safely, but the real danger is when people used to working with medium dangerous substances handle a truly dangerous substance like this without being really aware of the extent of the danger. That chemical is simply far too dangerous to be a calibration standard, and that's why it isn't anymore.
- pyuser583 5y agoHow much if this is the fact that the folks dealing with this are used to “medium dangerous” chemicals? I know some lab workers who deal with nuclear materials. They have insane security and safety protocols. And they’re pretty non chalant about it. I also know some industrial workers who deal with conventional metals at very high temperatures. Is this weird mercury really more dangerous than molten steel? I suppose you could survive “a few drops” of molten steel on your hand, but you wouldn’t have a hand anymore.
- adhesive_wombat 5y agoAn equivalent size droplet of molten steel wouldn't take your hand off, unless the burn gets infected later. Also, molten steel radiates IR and glows obviously, so you can usually tell when it's about, and doesn't stay molten and remain a silent, persistent danger.
- userbinator 5y agoAfter all, she had adhered to the safety regulations involving dimethylmercury. Within weeks of Wetterhahn’s death, Chemical & Engineering News ran a letter on her lethal accident and the alarming results of a dimethylmercury test on the type of gloves she had worn. It's interesting that no one ever tested them before that.