9300. Mercury

Mercury is a toxic heavy metal capable of accumulating in the body and causing systemic toxicity. The test is performed to quantitatively determine the concentration of mercury in the blood for the purpose of detecting acute or chronic poisoning and monitoring occupational or domestic exposure.

Mercury is the only metal that is in a liquid state at room temperature. Sources of mercury entering the atmosphere include its natural evaporation from the Earth’s crust, industrial pollution (chlorine and alkali production, the electrical engineering industry, pharmaceutical manufacturing, pulp and paper production), and the burning of coal.

Mercury is used in medicine and cosmetology (ointments, creams, disinfectant solutions), in dentistry (amalgam fillings), and mercury compounds are used as fungicides for seed treatment. Elemental metallic mercury is of low toxicity. During conversion to the ionized (inorganic) form, it becomes toxic. Some microorganisms convert inorganic mercury into organic mercury (methylmercury). Methylmercury is lipophilic and binds with high affinity to lipid-rich nervous tissue. Methylation of mercury occurs in the bottom sediments of seas, lakes, and bodies of water. Consumption of certain species of fish and shellfish may be dangerous to humans (Minamata disease). Another source of methylmercury poisoning may be the consumption of game from areas where mercury-containing fungicides have been used. Metallic mercury is readily absorbed when its vapors are inhaled; in the gastrointestinal tract, it is hardly absorbed. Inorganic mercury is very readily absorbed from the lungs and gastrointestinal tract. In the blood, more than 90% of mercury binds to erythrocytes (hemoglobin). Inorganic mercury is excreted in the urine, while organic mercury is secreted into the bile, enters the gastrointestinal tract, and is then reabsorbed into the bloodstream.

The toxic properties of mercury are due to the fact that its ions readily bind to sulfhydryl groups of proteins. This changes their structure and properties. Acute mercury poisoning is usually associated with the absorption of inorganic mercury compounds, which damage the gastrointestinal tract and renal tubules. Chronic poisoning is usually associated with inhalation or absorption of small amounts of mercury. This may cause gingivitis, stomatitis, increased excitability, tremor, nephrotoxic syndrome, colitis, anemia, and, in children, acrodynia (Pink disease).

Occupational poisoning with mercury vapors — mercurialism — is caused by the fact that mercury is a thiol poison. The poisoning manifests as nephropathy and hepatopathy. Organic mercury intoxication manifests as fatigue, headache, memory impairment, apathy, emotional instability, changes in sensation, impaired coordination of movements, speech, vision, and hearing. In severe cases, poisoning may lead to coma and death.

• In cases of suspected acute or chronic mercury poisoning, which may occur as a result of accidental or intentional exposure, as well as occupational exposure (for example, in workers in the chemical industry and in the manufacture of medical devices).
• In the presence of symptoms that may be associated with mercury poisoning, such as tremor, mood changes, memory problems, impaired coordination, numbness of the extremities, and kidney problems.
• To monitor mercury levels in workers who have occupational exposure to this substance as part of periodic medical examinations.
• In cases of suspected environmental exposure to mercury, for example, following the consumption of fish with a high mercury content (for residents of certain regions).
• As prescribed by a physician – when there are clinical indications for assessing the level of this toxic metal in the body.

• Venous blood

In order to exclude factors that may affect the test results, we recommend to follow the preparation rules: