Karen Wetterhahn
Encyclopedia
Karen Wetterhahn was a well-known professor of chemistry
at Dartmouth College
, New Hampshire, who specialized in toxic metal exposure. She made national headlines when mercury poisoning claimed her life at the age of 48 due to accidental exposure to the organic mercury
compound dimethylmercury
(Hg(CH3)2). She was the Albert Bradley Third Century Professor in the Sciences at Dartmouth College.
measurements.
Wetterhahn, a specialist in toxic metals, was accidentally poisoned in her lab by a few drops of the toxic, colorless compound, which penetrated her protective glove; Dimethylmercury is a synthetic compound used almost exclusively as a reference standard in a particular type of specialized chemical analysis. Wetterhahn was investigating the toxic properties of another highly toxic heavy metal, cadmium, and was using dimethylmercury as a point of reference.
The accidental spill occurred on August 14, 1996 but symptoms of her mercury poisoning were not detected until six months later, at which time the poisoning was irreversible. Wetterhahn suddenly became very ill in January of 1997 and was hospitalized; she then went into a coma which lasted until she died in June.
Wetterhahn recalled that she had spilled several drops of dimethylmercury from the tip of the pipette onto her latex gloved hand. Tests later showed that this can rapidly permeate different kinds of latex gloves and enter the skin within about 15 seconds.
Five months after the exposure, it became evident that some initial serious neurological symptoms such as loss of balance and slurred speech were the result of a very serious debilitating mercury intoxication. She was admitted to the hospital, where it was discovered that the single exposure to dimethylmercury had raised her blood mercury level to 4,000 micrograms per liter, or 80 times the toxic threshold. Her urinary mercury content had risen to 234 µg per liter; its normal range is 1 to 5 and the toxic level is > 50 μg/L.
Despite aggressive chelation therapy
, her condition rapidly deteriorated and three weeks after first symptoms appeared she fell into a coma described by one of her former students as not being "... the kind of coma I'd expected... She was thrashing about. 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." Wetterhahn died a few months later, less than a year after her initial exposure.
There had been previous documented cases of death due to dimethylmercury poisoning. In 1865, two English laboratory assistants died several weeks after helping to synthesize dimethylmercury for the first time. In 1972, a 28 year old Czech chemist in Czechoslovakia had suffered the same symptoms as Wetterhahn after synthesizing 6kg of the compound.
, and adherence to standard safety procedures. After Wetterhahn's mercury poisoning was discovered, her colleagues tested various safety gloves against dimethylmercury
and found that the small, apolar molecule diffuses through most of them in seconds, much faster than expected. As a result, it is nowadays recommended to wear highly resistant, flexible, plastic-laminate gloves when handling dimethylmercury and other equally dangerous substances. For increased protection, such thin gloves can be worn under long-cuffed, heavy-duty outer gloves made of, for example, neoprene.
At the time, dimethylmercury was the common calibration standard for 199Hg
NMR spectroscopy
because it has certain advantages over the alternatives that exist. As a consequence of Wetterhahn's accident, recommendations and MSDS sheets have been revised, and the use of dimethylmercury has been highly discouraged.
Dartmouth College has since established an award in Wetterhahn's name to encourage other women to pursue careers in science. Whenever possible, preference is given to a woman in granting the award. The National Institute of Environmental Health Sciences
also maintains an annual award, for a graduate student or post-doctoral researcher, in honor of Karen Wetterhahn.
Wetterhahn helped establish Dartmouth College’s Women in Science Project (WISP), which helped to raise the share of women science majors from 13 to 25 percent at Dartmouth College and has become a national model.
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
at Dartmouth College
Dartmouth College
Dartmouth College is a private, Ivy League university in Hanover, New Hampshire, United States. The institution comprises a liberal arts college, Dartmouth Medical School, Thayer School of Engineering, and the Tuck School of Business, as well as 19 graduate programs in the arts and sciences...
, New Hampshire, who specialized in toxic metal exposure. She made national headlines when mercury poisoning claimed her life at the age of 48 due to accidental exposure to the organic mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...
compound dimethylmercury
Dimethylmercury
Dimethylmercury is an organomercury compound. This colorless liquid is one of the strongest known neurotoxins. It is described as having a slightly sweet smell, although inhaling enough vapor to detect its odor would be hazardous....
(Hg(CH3)2). She was the Albert Bradley Third Century Professor in the Sciences at Dartmouth College.
Accident
On August 14th, 1996, Wetterhahn was studying the way mercury ions interact with DNA repair proteins and was using dimethylmercury as a standard reference material for 199Hg NMRNuclear magnetic resonance
Nuclear magnetic resonance is a physical phenomenon in which magnetic nuclei in a magnetic field absorb and re-emit electromagnetic radiation...
measurements.
Wetterhahn, a specialist in toxic metals, was accidentally poisoned in her lab by a few drops of the toxic, colorless compound, which penetrated her protective glove; Dimethylmercury is a synthetic compound used almost exclusively as a reference standard in a particular type of specialized chemical analysis. Wetterhahn was investigating the toxic properties of another highly toxic heavy metal, cadmium, and was using dimethylmercury as a point of reference.
The accidental spill occurred on August 14, 1996 but symptoms of her mercury poisoning were not detected until six months later, at which time the poisoning was irreversible. Wetterhahn suddenly became very ill in January of 1997 and was hospitalized; she then went into a coma which lasted until she died in June.
Wetterhahn recalled that she had spilled several drops of dimethylmercury from the tip of the pipette onto her latex gloved hand. Tests later showed that this can rapidly permeate different kinds of latex gloves and enter the skin within about 15 seconds.
Five months after the exposure, it became evident that some initial serious neurological symptoms such as loss of balance and slurred speech were the result of a very serious debilitating mercury intoxication. She was admitted to the hospital, where it was discovered that the single exposure to dimethylmercury had raised her blood mercury level to 4,000 micrograms per liter, or 80 times the toxic threshold. Her urinary mercury content had risen to 234 µg per liter; its normal range is 1 to 5 and the toxic level is > 50 μg/L.
Despite aggressive chelation therapy
Chelation therapy
Chelation therapy is the administration of chelating agents to remove heavy metals from the body. For the most common forms of heavy metal intoxication—those involving lead, arsenic or mercury—the standard of care in the United States dictates the use of dimercaptosuccinic acid...
, her condition rapidly deteriorated and three weeks after first symptoms appeared she fell into a coma described by one of her former students as not being "... the kind of coma I'd expected... She was thrashing about. 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." Wetterhahn died a few months later, less than a year after her initial exposure.
There had been previous documented cases of death due to dimethylmercury poisoning. In 1865, two English laboratory assistants died several weeks after helping to synthesize dimethylmercury for the first time. In 1972, a 28 year old Czech chemist in Czechoslovakia had suffered the same symptoms as Wetterhahn after synthesizing 6kg of the compound.
Legacy
Karen Wetterhahn's death shocked not only the entire chemistry department but even regulatory agencies, as the accidental exposure occurred despite having taken all required measures known at that time. These included the use of latex gloves, a fume hoodFume hood
A fume hood or fume cupboard is a type of local ventilation device that is designed to limit exposure to hazardous or noxious fumes, vapors or dusts. A fume hood is typically a large piece of equipment enclosing five sides of a work area, the bottom of which is most commonly located at a standing...
, and adherence to standard safety procedures. After Wetterhahn's mercury poisoning was discovered, her colleagues tested various safety gloves against dimethylmercury
Dimethylmercury
Dimethylmercury is an organomercury compound. This colorless liquid is one of the strongest known neurotoxins. It is described as having a slightly sweet smell, although inhaling enough vapor to detect its odor would be hazardous....
and found that the small, apolar molecule diffuses through most of them in seconds, much faster than expected. As a result, it is nowadays recommended to wear highly resistant, flexible, plastic-laminate gloves when handling dimethylmercury and other equally dangerous substances. For increased protection, such thin gloves can be worn under long-cuffed, heavy-duty outer gloves made of, for example, neoprene.
At the time, dimethylmercury was the common calibration standard for 199Hg
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...
NMR spectroscopy
NMR spectroscopy
Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy, is a research technique that exploits the magnetic properties of certain atomic nuclei to determine physical and chemical properties of atoms or the molecules in which they are contained...
because it has certain advantages over the alternatives that exist. As a consequence of Wetterhahn's accident, recommendations and MSDS sheets have been revised, and the use of dimethylmercury has been highly discouraged.
Dartmouth College has since established an award in Wetterhahn's name to encourage other women to pursue careers in science. Whenever possible, preference is given to a woman in granting the award. The National Institute of Environmental Health Sciences
National Institute of Environmental Health Sciences
The National Institute of Environmental Health Sciences is a part of the National Institutes of Health , which is in turn a part of the Department of Health and Human Services ....
also maintains an annual award, for a graduate student or post-doctoral researcher, in honor of Karen Wetterhahn.
Wetterhahn helped establish Dartmouth College’s Women in Science Project (WISP), which helped to raise the share of women science majors from 13 to 25 percent at Dartmouth College and has become a national model.