Feces mercury

Exposure is also affected by absorption. Even though we may come into contact with an agent, if little is taken up into the body (or absorbed), there is little effect. For example, the metallic mercury from a broken thermometer, if swallowed, is very poorly absorbed by the gut and will be excreted in the feces. However, if this same amount of mercury were allowed to evaporate and be inhaled, there would be very serious health consequences. This example shows that metabolism and excretion modify absorption. What is not absorbed (and even some of what is absorbed) may be excreted from the body by various routes, including the urine, feces, and sweat or through exhalation. Excretion reduces the effect because it lowers the amount of toxicant in the body, thus reducing exposure to sensitive organs. 

Mercury Elemental mercury Respiratory tract Soft tissues, especially kidney, CNS CNS tremor, behavioral (erethism) gingivostomatitis peripheral neuropathy acrodynia pneumonitis (high-dose) Inhibits enzymes alters membranes Elemental Hg converted to Hg2+. Urine (major) feces (minor)... 

Mercury is eliminated from the body in the urine and feces, with the latter being the major route. Thus, with methyl mercury, 90% is excreted into the feces. Methyl mercury is secreted into the bile as a cysteine conjugate and undergoes extensive enterohepatic recirculation. 

Excretion of inorganic mercury occurs through the urine and feces. The mechanisms by which excretion occurs are not well understood. 

Mercury leaves the body mostly through the urine and feces. One of the worst-known cases of mercury poisoning occurred at Minamata, Japan, when methylmercury compounds formed during the manufacture of a paint solvent were discharged into Minamata Bay. Local people who ate a large amount of fish began... 

Mercury is the bane of all metals, even of all things, for he eats away and devours the vessels all things immersed in him swim to the surface, except gold which, however, he attracts to himself and purifies. He conducts the feces with himself through the strainer, and leaves the gold pure. 

CORPUSCULE — The whole of the great and sublime operation of the Philosophers is performed with a single corpuscule or little body, which contains, so to speak, only feces, dross, abominations, and from which there is extracted a certain dark and mercurial moisture, which includes in itself all that is necessary to the Philosopher. For he seeks only the true Mercury. The Mercury which he should use is not that which is found in the earth, but that which is extracted from bodies. Common Mercury does not contain a sufficient quantity of Sulphur, and, consequently, we must work upon a body created by nature, in which Sulphur and Mercury are united, that is, the male and female principles, which the artist should separate. He should then purify them and afterwards join them anew. The resulting substance is the Rude Stone, Chaos, Piaster, Hyle. 

Gregus and Klaassen carried out a comparative study of fecal and urinary excretion and tissue distribution of eighteen metals in rats after intravenous injection. Total (fecal + urinary) excretion was relatively rapid (over 50% of the dose in 4 days) for cobalt, silver and manganese between 50 and 20% for copper, thallium, bismuth, lead, cesium, gold, zinc, mercury, selenium and chromium and below 20% for arsenic, cadmium, iron, methylmercury and tin. Feces was the predominant route of excretion for silver, manganese, copper, thallium, lead, zinc, cadmium, iron and methylmercury whereas urine was the predominant route of excretion of cobalt, cesium, gold, selenium, arsenic and tin. Most of the metals reached the highest concentration in liver and kidney. However, there was no... 

The metabolite is eliminated mainly in urine and feces it is also excreted in milk. In humans, inorganic mercury compounds have two elimination half-lives one lasts for days or weeks and the other much longer. 

Saliva is not an important route of excretion since most of the chemicals present in saliva will eventually reach the gastrointestinal tract to be reabsorbed or eliminated in the feces. The unbound fraction of several therapeutic drugs may diffuse passively from plasma into saliva. This provides a noninvasive means of indirectly monitoring plasma concentrations of drugs like lithium, phenytoin, and theophylline. Metals like lead, cadmium, and mercury are also present in saliva. 

Methylmercury is rapidly and nearly completely absorbed from the gastrointestinal tract 90-100% absorption is estimated. Methylmercury is somewhat lipophilic, allowing it to pass through lipid membranes of cells and facilitating its distribution to all tissues, and it binds readily to proteins. Methylmercury binds to amino acids in fish muscle tissue. The highest methylmercury levels in humans generally are found in the kidneys. Methylmercury in the body is considered to be relatively stable and is only slowly transformed to other forms of mercury. Methylmercury readily crosses the placental and blood/brain barriers. Its estimated half-life in the human body ranges from 44 to 80 days. Excretion of methylmercury is via the feces, urine, and breast milk. Methylmercury is also distributed to human hair and to the fur and feathers of wildlife measurement of mercury in hair and these other tissues has served as a useful biomonitor of contamination levels. 

Gastrointestinal absorption of mercuric chloride from food is less than 15% in mice and 7% in a study of human volunteers. In humans and other mammals, the kidneys are the primary targets where mercuric ions accumulate. Renal uptake and accumulation of mercury in vivo are rapid. As much as 50% of low dose of mercuric chloride (0.5pmolkg ) has been shown to be present in the kidney of rats within a few hours after exposure. Within the kidney it accumulates primarily in the cortex and outer stripe of outer medulla. Mercuric chloride does not readily cross the blood-brain barrier but will accumulate in the placenta. Urinary and fecal excretion of mercury is the principal means by which humans and other mammals eliminate the different forms of mercury from the body. Under most circumstances, a greater fraction of a dose of mercury is excreted in the feces than in the urine early after exposure to a nonne-phrotoxic dose of mercuric chloride. 

Mercury will cross the placental barrier. In mammalian tissue, organic mercury, especially alkyl mercury, is converted to inorganic forms but not vice versa. Inorganic forms of mercury (not organic forms) induce a metallothionein. Inorganic mercury concentrates mainly in the kidney. Organic mercury compounds, being lipid soluble, concentrate in adipose tissue and the brain. Elimination is primarily in the urine and the feces, with small amounts in breath, sweat, and saliva. 

Following exposure to metallic mercury, the elimination of mercury can occur via the urine, feces, and expired air. Following exposure to inorganic mercury (mercuric), mercury is eliminated in the urine and feces. Organic mercury compounds are excreted predominantly via the feces in humans. In animals, methylmercury is excreted in the feces, and phenylmercury compounds are initially excreted in the feces and then in the urine. Organic mercury compounds are excreted predominantly in the inorganic form. Both inorganic mercury and methylmercury are excreted in breast milk. 

Metallic and Inorganic Mercury. The urine and feces are the main excretory pathways of metallic and inorganic mercury in humans, with a body burden half-life of approximately 1-2 months (Clarkson 1989). In a study of former chloralkali workers exposed to metallic mercury vapor for 2-18 years (median, 5 years), Sallsten et al. (1995) found that the elimination of mercury in urine was well characterized by a one-compartment model, which estimated a half-life of 55 days. There was a tendency toward longer half-lives with shorter duration exposures than with long-term exposure, when uptake and... 

Organic Mercury. The fecal (biliary) pathway is the predominant excretory route for methylmercury, with less than one-third of the total mercury excretion occurring through the urine, following oral and inhalation exposure (Norseth and Clarkson 1970). In humans, nearly all of the total mercury in the feces after organic mercury administration is in the inorganic form. The conversion of methylmercury to inorganic mercury is a major step that is dependent on the duration of exposure and/or the duration after cessation of exposure. 

During the first few days after intravenous dosing, phenylmercury compounds are also eliminated primarily in the feces as a result of biliary secretion and its concentration in the gastrointestinal tract (mucosa and lumen) (Berlin and Ullberg 1963). The initial urinary excretion of phenylmercury represents primarily the parent compound (Gage 1964). Several days after exposure, however, elimination is primarily in the urine, which contains predominantly inorganic mercury (Gotelli et al. 1985). 

Bjorkman L, Sandborgh-Englund G, Ekstrand J. 1997. Mercury in salvia and feces after removal of amalgam fillings. Toxicol Appl Pharmacol 144 156-162. 

Nakamura I, Hosokawa K, Tamra H, et al. 1977. Reduced mercury excretion with feces in germffee mice after oral administration of methylmercury chloride. Bull Environ Contain Toxicol 17 528-533. 

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