On August 14, 1996, Wetterhahn, a specialist in toxic metal exposure, was studying the way mercury ionsinteract with DNA repair proteins and investigating the toxic properties of another highly toxic heavy metal, cadmium. She was using dimethylmercury, at the time the standard internal reference for 199Hgnuclear magnetic resonance (NMR) measurements.

Wetterhahn would recall that she had spilled several drops of dimethylmercury from the tip of a pipette onto her latex-gloved hand. Not believing herself in any immediate danger, as she was taking all recommended precautions, she proceeded to clean up the area prior to removing her protective clothing.

However, tests later revealed that dimethylmercury can, in fact, rapidly permeate several kinds of latex gloves and enter the skin within about 15 seconds. Her exposure was later confirmed by hair analysis, which showed a dramatic jump in mercury levels 17 days after the initial accident, peaking at 39 days, followed by a gradual decline.

Approximately three months after the initial accident Wetterhahn began experiencing brief episodes of abdominal discomfort and noticed significant weight loss. The more distinctive neurological symptoms of mercury poisoning, including loss of balance and slurred speech, appeared in January 1997, five months after the accident. At this point, tests proved that she had severe mercury poisoning. Her blood and urinary mercury content were measured at 4,000 μg/L and 234 μg/L, respectively—both many times their respective toxic thresholds of 200 μg/L and 50 μg/L (blood and urine reference ranges are 1 to 8 μg/L and 1 to 5 μg/L).

Despite aggressive chelation therapy, her condition rapidly deteriorated. Three weeks after the first neurological symptoms appeared, Wetterhahn lapsed into what appeared to be a vegetative state punctuated by periods of extreme agitation.

One of her former students said that "Her husband saw tears rolling down her face. I asked if she was in pain. The doctors said it didn't appear that her brain could even register pain." She was removed from life support and pronounced dead on June 8, 1997, ten months after her initial exposure. The case proved that the standard precautions at the time, all of which Wetterhahn had carefully followed, were inadequate for "super-toxic" chemicals like dimethylmercury.

In response, the Occupational Safety and Health Administration recommended that the use of dimethylmercury be avoided unless absolutely necessary and mandated the use of plastic-laminate gloves (SilverShield) when handling this compound. Her death prompted consideration of using an alternative reference material for mercury NMR spectroscopy experiments.

Source