Karen Wetterhahn (KW) was a chemistry professor who researched toxic metal exposure. She had an influential career at a prestigious . institution and there were few- maybe none- in the world who knew mercury toxicity better than her. And yet…
She accidentally spilled 2 drops of dimethyl mercury on her gloved hand… and subsequently died in agony.
Now it’s important you take note this is dimethyl mercury, which is NOTORIOUSLY dangerous. Methyl mercury, which caused the outbreak of Minamata Disease in Japan in the 1960s and 70s was METHYL mercury, not DIMETHYL mercury. We all saw the horrible picture of young kids from the city if Minamata, twitching and jerking in wheelchairs, as they slowly died.
Well, dimethyl mercury is ten times as deadly.* It’s horrible!
KW turned up in ER five months after her accidental exposure. She was sure that she had not touched the chemical. She apparently followed the full detox procedure at the time (she was a professional, after all). But…
This is what happened to her: she noticed progressive deterioration in balance, gait, and speech; she has lost 15 pounds in the 2 months leading up to her admission, and experienced several brief episodes of nausea and abdominal discomfort.
She started walking into walls and assumed she had not been paying proper attention. Then, one day, she almost got into a car accident. She started asking her husband to drive her to university. Maybe she hadn’t slept well, she thought.
When examined, she had a condition called “dysmetria” (“dys-” meaning wrong, and “-metria” meaning length). She was mis-estimating distances and how close or far away things were, which made her extremely clumsy.
Similarly, she had ataxic gait, meaning her walk was awkward, imbalanced, and disorderly. Both of these were combined with lousy handwriting and slurred speech, all of which amounted to severe neurodegeneration, with mercury as the likely culprit.
She was a skilled professional and she knew what all this meant. She was right to be concerned about her condition.
As the days continued, KW reports that she has a tingling in her fingers that’s getting stronger. She sees brief flashes of light in both eyes. She introduces the concept of white background noise that begins to wash away her normal hearing in both ears. Her gait becomes even more ataxic. Her speech becomes more slurred; her field of vision, more narrow.
A blood test revealed that her blood mercury levels were over 4,000 mcg/L. Thats 4,000 times greater than the upper limit of normal. Obviously, mercury poisoning was THE cause of her condition.
But the sad part of the story is that she did not show any signs of recovery, many weeks after leaving the lab. Where was the mercury hiding? It was clearly not being excreted. 95% of her “dose” was unaccounted for.
In fact it ended up in the nervous system. Remember, she was not poisoned by mercury metal but the dimethyl form, which has a strong affinity for fatty tissue. What’s the fattiest organ in the body?
The brain! it’s over . 60% fat.
So a near-lethal dose of organic mercury is transferred to her brain and nervous tissues. She was in big trouble.
The problem with dimethlymercury is that, in the liver, it’s broken down to methylmecury, which still dissolved strongly in fatty tissue (hence Minamata Disease). Even worse, it’s known to bing to tissue and cause free radical damage and oxidative stress, and form complexes that accelerate cell death.
The best solution here is to trap the mercury inside a molecule that’s water-soluble on the outside, so that it will grab the mercury but still dissolve in water and be excreted by the kidneys. We call this “chelation”, from the Latin word for a crab’s claw!
But it was too late. A week later a neuropsychiatric consultant found severe cognitive deficits. She’s losing touch. Her husband tries to speak to her, but she would stare blankly into a void.
At 3 weeks’ time after initially presenting to the emergency room, KW becomes unresponsive to verbal, visual, and touch stimuli. From the depths of her coma, she is sometimes found yawning spontaneously with brief episodes of agitation, screaming, crying, and unpromted sudden, jerky limb movements. There’s someone inside, but that person is trapped in a prison of her own comatose body.
There continued to be some debate whether her condition was caused by steady accumulation of mercury from her work. But a hair analysis showed that was not the case.
The amount of free mercury found in her body halved every 75 days, with a maximum excretion recorded roughly 150 days before presenting to the emergency room: the time she was subject to the spill in the lab.
Working, backwards, it became obvious that she had absorbed a MASSIVE quantity of demethylmercury, four times the lethal dose. She was as good as dead from the moment of the spill. In fact at one point her blood mercury levels were likely to be 16,000 times the upper limit of normal, it was calculated.
It was discovered later the dimethylmercury does, in fact, diffuse through the type of disposable latex gloves KW wore that day, and it does so within seconds. The small exposure, equivalent to a few drops absorbed into her skin, embedded into her body and caused delayed onset of cerebral disease.
In view of the dismal prognosis and after more than three months of trying everything they could do to saver her, the patient’s advance directives were followed, and she was left to die peacefully on June 8, 1997, 298 days after exposure.
Before she lapsed into a vegetative state, the patient requested that her case be presented to the general medical community, to scientists working with mercury, and to toxicologists, in the hope of improving the recognition, treatment, and prevention of future cases of mercury poisoning.
Only three other cases of dimethylmercury poisoning have been documented in history. In 1865, two lab assistants who were synthesizing it for the first time passed away several weeks after doing so. In the 1960s, another lab worker was exposed to it and he too suffered a delayed neurologic decline in the same fashion as KW.
In general, it’s a good rule to not touch things if you don’t know what they are. Be cognizant of what comes in contact with your skin. Unless you’re a chemist, you probably won’t come into direct contact with dimethylmercury the way that KW did. And don’t worry, you would have to eat 65,000kg of fresh Atlantic salmon in one sitting to get you to where she was.
It is important to understand that methyl and dimethylmercury are ORGANIC forms of mercury, not the same as thiomersol at all (mis-spelled by Americans as thimersal).
I don’t think it is appropriate to illustrate this story with an image of the patient. But if you want to watch a YouTube video about this famous case, go here:
A gloomy story, And of course it poses the obvious question: why would they want to put ANY form of mercury into babies? Teething powders resulted in deadly “pink disease”, back in the 1940s and 50s. Then it was used in vaccines. Duh! now we have to worry about polluted fish (from coal burning and other industrial waste). As a general rule, smaller fish, like squid, scallops, sardines, contain less mercury than larger varieties such as tune and swordfish, which are higher up the food chain.
Also- a good idea: get yourself a copy of the Monterey Aquarium phone app. Check the quality of fish you are eating!
Prof. Keith Scott-Mumby
The Official Alternative Doctor
- A figure of speech only.
1. Medpage Today
2. June 4, 1998. N Engl J Med 1998; 338:1672-1676 doi: 10.1056/NEJM199806043382305