Why the element mercury is toxic when breathed

Liquid mercury is nowhere near as toxic when swallowed as it is when the vapors are inhaled. However, some of the mercury in the digestive tract can be converted into soluble salts, which then damage the kidneys. Until the end of the 19th century, mercury was used to treat syphilis. The mercury was mixed with lard, petroleum jelly, lanolin or olive oil and applied to the skin as an ointment. In the case of an intestinal obstruction, a patient even had to drink the liquid metal by the liter. However, not all patients survived this procedure. The literature also reports cases of people drinking liquid mercury or injecting the liquid metal into their veins with suicidal intent. The Margrave of Brandenburg is said to have drank a sip of mercury on his wedding night in 1515 without being harmed. A nurse survived after injecting herself with 27 grams of mercury intravenously. She died of tuberculosis many years later. The autopsy found globules of mercury in her body, but she hadn't died from it. Lit [55] Suicide worked for others, and after a few weeks they died in great agony.

The English King Charles II had a great weakness for alchemy. In his own laboratory he tried to make gold together with assistants. From 1684 the king began to show symptoms that, according to today's knowledge, indicated mercury poisoning. He became irritable and felt more and more unwell. Karl died on February 6th. It was initially believed that he had suffered a stroke. The autopsy showed that the outer brain regions were filled with blood. Lit [55] E. Holmes investigated in 2003 (in his book The Sickly Stuarts) the case of Charles again and came to the conclusion that the king must have probably inhaled the vapors in large quantities while distilling mercury. Lit [56]

Mercury vapors can form if, for example, an old clinical thermometer breaks and the small balls get stuck in cracks on the floor. In one documented case, a ten-year-old brought 250 milliliters of mercury home from school. Lit [55] He played with it and then poured the metal onto the furniture and carpets. After the whole family developed symptoms of intoxication, the doctor diagnosed acrodynia. Symmetrical reddening of the skin appeared due to chronic mercury poisoning. The Swiss doctor Dr. Emil Feer first described the disease in detail in 1923. Gaseous mercury is particularly easily absorbed by the lungs. The metal crosses the blood-brain barrier and is deposited in the brain. Acute poisoning can lead to pneumonia with fatal outcome. Regular absorption of the vapors in small quantities results in chronic clinical pictures that manifest themselves in fatigue, headache and pain in the limbs, inflammation in the oral mucosa and gums, the formation of dark lines on the gums, tremors, poor memory and massive disorders in the central nervous system.

Inorganic and water-soluble mercury compounds such as mercury (II) oxide or mercury (II) chloride can be absorbed particularly easily when they come into contact with the skin. There is an acute danger to life here. As little as 200 milligrams of these substances can be fatal if eaten. The main attack in acute poisoning by inorganic mercury salts is on the kidneys. In contrast, the water-insoluble mercury sulfide used as pigment (cinnabar) is not as toxic.

In the 1950s, residents of Minimata Bay in Japan were mass poisoned by the residents because they had eaten fish that were contaminated with organic mercury compounds for years. Many people suffered from headaches and body aches, symptoms of paralysis or psychosis. Around 3,000 people died and 17,000 suffered from symptoms of intoxication. The sewage from a chemical factory was later found to be the cause. Microorganisms in the water convert the inorganic mercury compounds into organic methyl mercury. This substance accumulates in the fish via the food chain. Most affected are the final users of the food chain, predatory fish and humans. Tuna or cod (cod) have particularly high concentrations of mercury when they live in polluted waters. Methylmercury can be absorbed particularly easily by the human organism; it does less damage to the kidneys, but it massively attacks the central nervous system. It can also harm the fetus as it easily crosses the placental barrier. Lit [37]

The amalgam fillings in the teeth have also come under discussion. A study by the University of Tübingen in 1996 showed that the mercury concentration in saliva increases significantly as the number of amalgam fillings increases. Lit [40] Of 18,000 test persons examined, 44% exceeded the ADI (Acceptable Daily Intake) limit of the World Health Organization of 43 micrograms (= 43 millionths of a gram) of mercury intake per day. This value takes into account the total daily intake of mercury from all sources.


Mercury pollution from amalgam fillings


 
The more amalgam fillings there are in the teeth, the higher the mercury concentration in the saliva.
 

How much of the mercury in saliva is actually absorbed by the human body and causes damage is controversial. Electrochemical corrosion can dissolve mercury ions from the dental alloy in the mouth if different metals have been used. Chronic clinical pictures are described in the literature and some patients report an improvement with professional removal of the amalgam. How dangerous amalgam really is in teeth has not yet been conclusively clarified. Hardly any other toxicology topic has had so much discussion in the past. Lit [29] In March 2017, the European Parliament passed an amalgam ban in the EU from July 2018 for children under 15 years of age and for pregnant and breastfeeding women. Lit [105]