Mercury (element)

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Mercury (Hg) is a heavy metal element of considerable use and potential for human toxicity.

It is very important in the history of medicine with the term quack being able to be related to the german word for mercury or quicksilver — quacksalber. (An alternative explanation for quack is that it comes from Dutch, someone who promotes their salves for curing things.)

Once upon a time some mercury compounds were used as diuretics. The alternative was clearly worse, but subsequent generations should appreciate the development of less toxic alternatives thiazides and compounds like furosemide greatly. Even before this Jacob Carpensic is reported to have used in 1502 mercury in syphilis allowing Paracelsus to proclaim it a specific and the only specific for syphilis in 1636. Arab physicians used mercurial ointment in the treatment of itching, and certainly if caused by scabies this should have worked. Indeed, its use seems to have been widespread to treat every possible illness before its full toxicity was characterised.

The mercury sphygmomanometer is a fairly accurate and useful device for measuring blood pressure, so much so that it is the standard - although, because of the toxicity of mercury, it might be banned at some future date.[1]

Contents

Mercury in Medicines

QuotationMarkLeft.png Mercurial Pills 1809

Pilulae Hydrargyri 1787

Pilulae mercuriales 1745

Take of purified mercury by weight, two drachms. Confection of red roses, three drachms. Liquorice root powdered, a drachm. Rub the mercury with the confection, until the globules disappear; then add the liquorice root, and beat the whole together until they are thoroughly incorporated.

The mercurial pill, often from its colour called the blue pill, is one of the established forms which it has not been thought proper to alter in any way...  QuotationMarkRight.pngLondon Pharmacopoeia Royal College of Physicians 1809

The only medicines currently or recently containing any mercury by design or as a result of manufacture are some vaccines, some of which have included the preservative thiomersal (thimerosal in some countries)

While this is a matter of enormous furore in the USA with a clash between evidence based medicine and public extrapolation of the general toxicity issues with mercury[2], presentations of vaccines in the UK appear to have been formulated with no, or reduced levels of thiomersal early on, partly due to the absence of need for it in single dose vaccines, which replaced multi-dose vials earlier here.

Thiomersal is still used in the manufacture of some vaccines, at intermediate stages, and although none is intended to reach the finished product it will be presumed that there are at least detectable numbers of molecules in them. Given other sources of mercury this is probably not our largest problem.

It is common ground that thiomersal and any other preservatives will be removed from vaccine formulations where and as soon as possible, and likely that where this process is not complete it will remain for some time marginally better than the alternative.

Mercury in Food

Fish

Carnivorous fish - top predators - such as Swordfish or Tuna concentrate Hg in their bodies. When eaten by the ultimate top predator, we get it. Suggestions of maximum amounts of these fish to eat - which are very similar to suggestions of the minimum amount of oily and other fish to eat - have been made, based on a combination of measurements, professional judgement and the precautionary principle. In the US, the current levels were set by a federal judge who over-ruled the FDA in their desire to prevent a consignment of tinned swordfish reaching the public, ruling in favour of the manufacturers. To be fair, the judge examined the evidence presented, and advice in the US also stresses prudence in the amount of such fish consumed.

Minamata Bay, and the toponymous Minamata disease, are the classic case of mercury poisoning of a whole population, as well as a good illustration of the unacceptable face not only of capitalism but of any system of organising industry.

Mercury in Teeth

In the first decade of the 21st century crematoria are to equip themselves to reclaim Hg from flue gasses - recalling Brave New World.

Teeth are dental, as are fillings, and an opinion may be obtained from a dental colleague if the question of Hg in amalgam fillings arises.

Metallic mercury ingestion

Swallowed mercury tends to pass through (and contribute to hazards somewhere well downstream). Some few people have injected mercury intravenously[3][4]. Embolisation of small globules occurs. Expect some disturbance of lung function which is likely to resolve. Mercury was noted to be present in a granuloma at an injection site, and it seems worth removing these as this may remove a significant amount of mercury.

Mercury toxicity

Mercury is toxic in its elemental form,[5] and more so in some of its compounds.

Mercury spills

From recent paper:[6]

"In the event of spillages of mercury from barometers, thermometers or other sources, members of the public should seek advice on clean up from their local Environmental Health Officer, insurance company or local Health Protection Unit. In summary, they should be advised:

  • not to vacuum, as contaminated vacuum cleaners will be a persistent source of mercury vapour and may require disposal as contaminated waste,
  • not to wash potentially contaminated clothes in their clothes washer as this will be a persistent source of vapour and may require disposal as contaminated waste,
  • that kitchen gloves should be worn as mercury can be absorbed through the skin and may form amalgams with gold rings,
  • that affected areas of carpet and soft furnishings are likely to require professional removal,
  • that all contaminated materials should be placed in plastic bags and sealed,
  • that specialist waste disposal contractors should be contacted to arrange for safe disposal."

Investigating a case of industrial mercury poisoning in Dundee, Ide[7] described a somewhat Dickensian workshop in which mercury sphygmomanometers were repaired. Metallic mercury was visible in floor cracks. The level of mercury in the air of the room was well above that recommended.

See Also

Almost nothing about Mercury intake and effect on the World Wide Web is to be trusted, in particular assertions about Thiomersal/Thimerosal.

External links

References

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