CureZone   Log On   Join
Mercury is NOT the 2nd most deadly biological toxin
 
White Shark Views: 8,766
Published: 11 years ago
 
This is a reply to # 1,120,057

Mercury is NOT the 2nd most deadly biological toxin


The most toxic chemicals known to men can be million times more toxic then the most dangerous mercury compound, dimethyl mercury.

Dimethyl mercury, the most dangerous mercury compound, is not considered as toxic (by experts), as the top 10 most toxic chemicals known to men.

That doesn't mean dimethylmercury is not toxic ... it only means it is not as toxic as some other compounds created by some bacteria or viruses.

Dimethyl mercury is extremely toxic, but is not considered the 2nd most deadly biological toxin by any expert in chemistry.


The problem with messages on CureZone is that people keep spreading myths or half truths. By doing so, they take away from the credibility of the complete message.


If one part of a message is clearly wrong (there are hard facts proving it being wrong) ... how can we be sure that the rest of a message is not as wrong too?


When you say mercury, in chemistry, physics and in most sciences that means "elemental mercury".

Elemental mercury is not even close to the top 50 most toxic substances known to men.


The most dangerous mercury compound, dimethyl mercury, is so toxic that even a few micro-liters (few milligrams) spilled on the skin, or even a latex glove, can cause death. Dimethylmercury can be fatal within hours or less.

In case of the most toxic chemicals, it is enough with a few nanograms. (nanogram = 1000 times less then micro-gram = million times less then milligram)



(1 micro-liter of Dimethylmercury =~ 1 milligram Dimethylmercury = 1000 micrograms)



Compounds of mercury tend to be much more toxic than the element itself, and organic compounds of mercury are often extremely toxic and have been implicated in causing brain and liver damage.

Through bioaccumulation in the environment, methyl mercury works its way up the food chain, reaching high concentrations among populations of some species. Larger species of fish, such as tuna or swordfish, are usually of greater concern than smaller species.

There is no evidence that moderate consumption of fish in the U.S. poses a significant health hazard. One recent Harvard Medical School study of mothers and their infants suggests that the nutritional benefits of eating fish outweighs the potential drawbacks of methylmercury.


Ethylmercury is a breakdown product of the antibacteriological agent thimerosal which has effects similar but not identical to methyl mercury.






Here's a list of the most poisonous chemicals known to men.



Toxicity varies from one species to another (i.e., what may be poisonous for a mouse may be more/less poisonous to a human) and within a species (i.e., age, sex, genetics all affect susceptibility to a toxin).


#1 tetanus
1 nanogram/kg
mouse, human

#2 botulinal neurotoxin (bacteria)
1 nanogram/kg
mouse, human

#3 shigella (bacteria)
1 nanogram/kg
monkey, human

#3 palytoxin (coral)
60 nanogram/kg
dog (iv)

#4 diphtheria (bacteria)
100 nanogram/kg
human

#5 ricin (from castor beans)
1 microgram/kg
human


#6 aflatoxins (mold which grows on nuts, legumes, seeds)
1-784 micrograms, depending on type of aflatoxin
duckling (oral)


#7 shigella (bacteria)
1 microgram/kg
mouse



#8 saxitoxin (shellfish)
3-5 micrograms
mouse (iv), about 50x higher dose orally



#9 tetrodotoxin (fugu pufferfish)
10 micrograms
mouse (ip)



#10 diphtheria (bacteria)
1.6 milligram/kg
mouse




Sources:

Merck Index, 11th Ed., S. Budavari et al. (editors), Merck (1989) ISBN 911910-28-X

McGraw-Hill Concise Encyclopedia of Science and Technology, 2nd Ed., McGraw Hill (1989) ISBN 0-07-045512-0, CD-ROM




http://en.wikipedia.org/wiki/Mercury_poisoning


Elemental mercury (pure mercury) is readily absorbed through the skin. However, because mercury has a very high surface tension at room temperature, it does not wet the skin (as water would) and the contact area is therefore limited (reducing absorption rates). Materials with high surface tensions tend to form near spherical droplets which do not conform fully to topologically complex surfaces like skin (the mercury touches the papillary ridges, not the grooves). Nonetheless, handling mercury with unprotected hands has resulted in cases of severe mercury poisoning.



Mercury vapour is rapidly absorbed into the body through the respiratory tract during inhalation. Chronic exposure, even at low concentrations in the range 0.7–42 μg/m3, has been shown in case control studies to cause effects such as tremors, impaired cognitive skills, and sleep disturbance in workers.

Mercury is only poorly absorbed through the gastrointestinal tract.



Mercury occurs inorganically as salts such as mercury chloride. Mercury salts primarily affect the gastrointestinal tract and the kidneys, and can cause severe kidney damage; however, as they can not cross the blood-brain barrier easily, mercury salts inflict little neurological damage without continuous or heavy exposure.


As two oxidation states of mercury form salts (Hg+1 and Hg+2), mercury salts occur in both mercury(I) (or mercurous) and mercury(II) (mercuric) forms.

Mercury(II) salts are usually more toxic than their mercury(I) counterparts because their solubility in water is greater; thus, they are more readily absorbed from the gastrointestinal tract.


Occurrences of mercury poisoning

The phrase mad as a hatter is likely a reference to mercury poisoning, as mercury-based compounds were once used in the manufacture of felt hats in the 18th and 19th century. (The Mad Hatter character of Alice in Wonderland was almost certainly inspired by an eccentric furniture dealer, not by a victim of mercury poisoning.)

An early scientific study of mercury poisoning was in 1923-6 by the German inorganic chemist, Alfred Stock, who himself became poisoned, together with his colleagues, by breathing mercury vapour that was being released by his laboratory equipment — diffusion pumps, float valves, and manometers — all of which contained mercury, and also from mercury that had been accidentally spilt and remained in cracks in the linoleum floor covering. He published a number of papers on mercury poisoning, founded a committee in Berlin to study cases of possible mercury poisoning, and introduced the term micromercurialism.[25]


The term Hunter-Russell syndrome derives from a study of mercury poisoning among workers in a seed packing factory in England in the late 1930s who breathed methylmercury that was being used as a seed disinfectant and preservative.[26]
From 1932 to 1968 methyl mercury was released into the sea around the city of Minamata in Kumamoto prefecture, Japan. The toxin bioaccumulated in fish, which when eaten by the local population caused the largest case of mercury poisoning known. Minamata disease caused the deaths of over 1000 people and permanently disabled a great many more.

Widespread mercury poisoning occurred in rural Iraq in 1971-1972, when grain treated with a methyl mercury-based fungicide that was intended for planting only was used by the rural population to make bread, causing at least 6530 cases of mercury poisoning and at least 459 deaths (see Basra poison grain disaster).[27]
On August 14, 1996, Karen Wetterhahn, a chemistry professor working at Dartmouth College, spilled a small amount of dimethylmercury on her latex glove. She began experiencing the symptoms of mercury poisoning five months later and, despite aggressive chelation therapy, died a few months later from brain malfunction due to mercury intoxication.[18][19]


In April of 2000, Alan Chmurny attempted to kill a former employee, Marta Bradley, by pouring mercury into the ventilation system of her car.[28]
The first emperor of unified China, Qin Shi Huang Di, was driven insane and killed by mercury pills intended to give him eternal life.



Acrodynia epidemic

Acrodynia is a type of mercury poisoning in children characterized by pain and pink discoloration of the hands and feet. The word is derived from the Greek, where ακρος means high (as in:in an extremity) and οδυνη means pain. As such, it might be (erroneously) used to indicate that a patient has pain in the hands or feet. However, acrodynia is a disease rather than a symptom.[2] Also known as pink disease, erythredema, Selter's disease, or Swift-Feer disease, acrodynia was relatively commonplace amongst children in the first half of the 20th century.[29] Initially, the cause of the acrodynia epidemic among infants and young children was unknown; however, mercury poisoning, primarily from calomel in teething powders, began to be widely accepted as its cause in the 1950s and 60s.[29] The prevalence of acrodynia decreased greatly after calomel was excluded from most teething powders in 1954.[29]



Medical procedures


Because elemental mercury often passes through the GI tract without being absorbed, it was used medically for various purposes until the dangers of mercury poisoning became known. For example, elemental mercury was used to mechanically clear intestinal obstructions (due to its great weight and fluidity), and it was a key ingredient in various medicines throughout history, such as blue mass. The toxic effects often were either not noticed at all, or so subtle or generic that they were attributed to other causes and were not recognized as poisoning caused by mercury. While the usage of mercury in medicine has declined, mercury-containing compounds are still used medically in vaccines and dental amalgam, both of which have been the subject of controversy regarding their potential for mercury poisoning.



http://en.wikipedia.org/wiki/Mercury_poisoning



White Shark
 

 
Printer-friendly version of this page Email this message to a friend

This Forum message belongs to a larger discussion thread. See the complete thread below. You can reply to this message!


 

Donate to CureZone


CureZone Newsletter is distributed in partnership with https://www.netatlantic.com


Contact Us - Advertise - Stats

Copyright 1999 - 2019  www.curezone.org

0.469 sec, (6)