A good general rule of thumb in chemistry is to avoid touching, licking, or taking a good deep inhale of whatever you’re studying.
I mean unless you’re studying cocaine in grad school. I’m not the boss of you.
Then there are utterly monstrous chemicals that don’t respect the rules. They don’t burn you, choke you, or give you a single warning sign that anything’s wrong. Before you realize what’s happened but long after you can do anything about it, they’ve signed away your grim fate.
Today’s Moment of Science… Dimethylmercury and the death of Dr. Karen Wetterhahn.
Many types of heavy metals can cause toxicity, and the symptoms vary element to cranky little element. Lead, manganese, aluminum, and of course mercury have been shown to be neurotoxic. Different forms of the substances can be worse for you than others. Mercury in its elemental, ‘quicksilver’ state or in the form of an inorganic salt aren’t exactly full of sunshine and vitamin C, but they’re not an instant death sentence.
Organic mercury compounds, though? Fucking yikes. Dimethylmercury is one of the planet’s deadlier chemical compounds. In a 150lb human, 3mgs could easily be fatal.
For perspective, one drop weighs about 50mgs. You’ve got somewhere between zero and fuck all room for error.
Dr. Karen Wetterhahn was an expert on exactly goddamn this. A chemistry professor at Dartmouth specializing in toxic metal exposure, she knew as well as anybody on the planet how to handle this monster. On August 14, 1996, she was conducting an experiment that used dimethylmercury, and all safety precautions were in order. Chemicals were being handled in the fume hood. She donned the appropriate lab coat, face shield, and gloves.
Two drops.
She got a mere two drops of it on her latex protective glove, but the glove held up and she didn’t think too much of it. Just like anybody else who was a preeminent expert in the field at the time would have, she thought that glove was enough to protect her. After she tidied up the area, she changed those soiled gloves, promptly forgetting about this absolute non-incident and went back about her business of researching super deadly shit.
Then the symptoms started.
Three months down the road, she started dealing with abdominal pain, vomiting, and significant weight loss. By January of 1997 she was exhibiting neurological symptoms, slurring her speech and losing balance. She saw flashes of lights in her eyes, her fingers tingled, and her ears filled with noise. When she went to the hospital for testing, they asked if there was anyone who might have wanted to poison her. The level of mercury in her blood was 4,000 µg/L, hundreds of times higher than normal. They had to consult her lab notes in conjunction with charting the levels of mercury in her system to determine the date of the accident and put together what happened.
By the time they started chelation therapy on her, the dimethylmercury had been coursing through her system, wreaking havoc on her brain for 168 days. Just eight days later, she would be virtually unresponsive to stimuli.
Though the numbers indicated that they were successfully removing the mercury from her body, Wetterhahn grew sicker. Her abilities to speak, walk, and hear were gradually taken from her. Her visual field started shrinking. Her husband would be talking to her and he’d notice she’d just start starting off, blankly.
She slipped into a persistent vegetative state, and died on June 8th, 1997.
It would eventually be determined that dimethylmercury could permeate latex gloves in a matter of seconds.
In the wake of Dr. Karen Wetterhahn’s death, the way we handle extremely toxic substances like these had to change. For starters, she wasn’t even studying dimethylmercury that day; it was being used as an internal reference standard to study another compound. We now frown upon using super ultra fuck up your day chemicals when there’s goddamn anything else that could possibly do the job. More appropriate gloves to handle the chemical were researched. And you can be damn sure that if someone gets even a droplet of this on them, they’ll have a change of gloves ready to go.
Dartmouth was fined by OSHA for “failing to provide training on the limitations of disposable gloves.”
This has been your daily Moment of Science, just letting you know it would take about 65,000kg of salmon to imbibe much mercury.
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there is a blog by Derek Lowe called ‘in the pipeline’ which has a section called ‘things i won’t work with’ which has lots more of these types of chemical mixtures. it’s worth a read.
I <3 D-Lowe.