What is Mercury Poisoning?

Mercury is a silver-white liquid metal that evaporates at room temperature. Mercury poisoning is more common in chronic conditions, which mainly occur during production activities and are caused by long-term inhalation of mercury vapor and mercury compound dust. The main symptoms are psycho-nerve abnormalities, gingivitis, and tremor. Acute mercury poisoning occurs when large doses of mercury vapor are inhaled or mercury compounds are ingested. For people who are allergic to mercury, poisoning can occur even when topical application of a mercury oil base preparation.

Basic Information

Also known as

Occupational mercury poisoning

English name

mercurypoisoning

Visiting department

Emergency Department

Common causes

Long-term inhalation of mercury vapor and mercury compound dust

Common symptoms

Psycho-nerve disorders, gingivitis, tremor

Causes of Mercury Poisoning

Mercury poisoning is a common occupational poisoning because mercury is rich in fluidity and easy to evaporate at normal temperature. It mainly occurs during long-term inhalation of mercury vapor or mercury compound dust during production. Productive poisoning is found in production workers such as mercury mining, amalgam smelting, gold and silver extraction, vacuum mercury, lamps, meters, thermometers, dental fillings, thunder mercury, pigments, pharmaceuticals, nuclear reactor coolants, and anti-radiation materials.

Mercury exists widely in nature. Various natural phenomena can make mercury continuously circulate from the ground through the atmosphere, rain and snow, and can be absorbed by plants and animals. Human production activities can significantly aggravate the pollution of mercury to the environment. Although the proportion of such anthropogenic pollution is not large, but the emissions are concentrated, it is far more serious than natural pollution. Pollution of rivers, lakes, and seas caused by mercury-containing sewage can cause public hazards, such as Minamata disease.

Short-term (> 3 to 5 hours) inhalation of high-concentration mercury vapor (> 1.0mg / m ³ ) and oral administration of large amounts of inorganic mercury can cause acute mercury poisoning; taking or smearing mercury-containing prescriptions can cause subacute mercury poisoning; occupational exposure to mercury Vapors often cause chronic mercury poisoning.

Clinical manifestations of mercury poisoning

The clinical manifestation of mercury poisoning is closely related to the form, route, dose and time of mercury in human body.

Acute mercury poisoning

(1) Systemic symptoms Metallic taste in the mouth, headache, dizziness, nausea, vomiting, abdominal pain, diarrhea, fatigue, general soreness, chills, fever (38-39 ° C), severe cases are emotionally agitated, restless, insomnia, or even have convulsions, coma or Mental disorder.

(2) Respiratory tract manifestations Cough, sputum, chest pain, dyspnea, cyanosis, auscultation can be heard on both lungs, with varying degrees of dry and wet rales or respiratory sounds weakened.

(3) Gastrointestinal manifestations Gingival swelling and pain, erosion, bleeding, oral mucosal ulceration, loose teeth, salivation, "mercurialline", lip and buccal mucosal ulcers, abnormal liver function and liver enlargement. Oral poisoning can cause general abdominal pain, diarrhea, mucus discharge, or bloody stools. In severe cases, generalized peritonitis may be caused by gastrointestinal perforation, shock may occur due to dehydration, and liver damage may occur in some cases.

(4) Toxic nephropathy Due to necrosis of renal tubular epithelial cells, oral administration of mercury salts for several hours, inhalation of high-concentration mercury vapor, edema, anuria, azotemia, hyperkalemia, acidosis, and uremia Wait until acute renal failure and life-threatening. Hematuria, eosinophilia, and systemic allergic symptoms can occur in people who are allergic to mercury. Some patients can develop acute glomerulonephritis. In severe cases, hematuria, proteinuria, hypertension, and acute renal failure (ARF) can occur.

(5) Skin manifestation is more than 2 to 3 days after poisoning, and it is red maculopapular rash. It appears early on the extremities and head and face, and then on the whole body. It can fuse into flaky or ulcerated infections with enlarged lymph nodes throughout the body. In severe cases, exfoliative dermatitis may occur.

2. Subacute mercury poisoning

Common cases of oral and smeared mercury-containing remedies and inhaled mercury vapor concentrations are not very high (0.5 to 1.0 mg / m ³ ), and often develop after 1 to 4 weeks of exposure to mercury. The clinical manifestations are similar to acute mercury poisoning, and to a lesser extent. But it can be seen that hair loss, insomnia, dreaming, triple tremor (eyelid, tongue, fingers) and other performance. It is usually cured after several weeks of disengagement and treatment.

3. Chronic mercury poisoning

(1) Neuropsychiatric symptoms include dizziness, headache, insomnia, dreaminess, forgetfulness, fatigue, lack of appetite, and other symptoms of mental weakness, often palpitations, sweating, positive skin scratch test, hyposexuality, menstrual disorders (female), and then appear Emotions and personality changes, manifestations of irritability, moodiness, irritability, crying, timidity, shyness, depression, loneliness, suspicion, inattention, and even mental symptoms such as hallucinations and delusions

(2) Stomatitis Early swelling of the gums, soreness, easy bleeding, oral mucosal ulcers, enlarged salivary glands, increased saliva, bad breath, followed by gingival atrophy, loose teeth, and loss of teeth. Poor oral hygiene may have "mercury lines" (secreted by the salivary glands) Mercury is combined with hydrogen sulfide produced by the decay of oral residues to generate a blue-black line of about 1 mm formed by mercury sulfide deposited under the gingival mucosa).

(3) Tremors At first, needle trembling when writing needles, writing, and chopsticks, the position is inaccurate, intentional, and gradually developed to the limbs. The patient's diet, clothing, travel, cycling, and ascent were affected, and pronunciation and vomiting were impaired. The tremor is relatively reduced when doing habitual work or not being noticed. Electromyography may have peripheral nerve damage.

(4) Renal manifestations are generally insignificant, and a few may appear with low back pain, proteinuria, and red blood cells on uroscopy. Clinical cases of renal tubular nephritis, glomerulonephritis, and nephrotic syndrome are rare. Generally it can be recovered from mercury and treated. Some patients may have enlarged liver and abnormal liver function.

Mercury poisoning check

1. Determination of urine mercury and blood mercury

To some extent, it reflects the amount of mercury absorbed in the body, but it is often not parallel to the clinical symptoms and severity of mercury poisoning.

2. Patients with chronic mercury poisoning

May have changes in EEG amplitude and rhythmic electrical activity, slower peripheral nerve conduction, increased a ₂ globulin and reduced glutathione in the blood, and lysosomal enzymes, erythrocyte cholinesterase, and serum sulfhydryl groups in the blood And so on.

3.X-ray chest radiograph

It can be seen that the two lungs have extensive irregular shadows, and most of them merge into dots, flakes, or ground-glass-like interstitial changes.

Diagnosis of mercury poisoning

According to the history and typical symptoms and signs, the diagnosis of acute mercury poisoning is not difficult; the significant increase in urine mercury has important diagnostic value. The diagnosis of chronic mercury poisoning must have a clear history of long-term mercury exposure; it can be divided into three levels: light, medium and severe according to the diagnostic criteria. Mild poisoning has the typical clinical characteristics of mercury poisoning, such as neurasthenia, stomatitis, tremor, etc., to a lesser extent; if the above symptoms are aggravated, and there are mental and personality changes, it can be diagnosed as moderate poisoning; Toxic encephalopathy can be diagnosed as severe poisoning. Urinary mercury is not parallel to symptoms and signs, and can only be used as a basis for excessive mercury exposure. If urine mercury is not high, a mercury drive test can be performed to facilitate diagnosis.

Differential diagnosis of mercury poisoning

Acute mercury poisoning needs to be distinguished from acute upper respiratory infections, infectious pneumonia, drug allergies, and infectious diseases; chronic mercury poisoning should be distinguished from neurasthenia, Parkinson's, and chronic alcoholism.

Mercury Poisoning Treatment

Emergency treatment

Those who are poisoned by oral mercury and its compounds should immediately wash the stomach with sodium bicarbonate or warm water to induce vomiting, and then take raw egg white, milk or soybean milk orally, absorb the poison, and then use magnesium sulfate to diarrhea. Those who inhale mercury poisoning should immediately evacuate the site and change clothes.

2. Mercury drive treatment

For acute mercury poisoning, a 5% sodium dimercaptopropanesulfonate solution can be injected intramuscularly; after that, once every 4 to 6 hours, and once a day after 1 to 2 days, the general treatment is about 1 week. Dimercaptobutane or dimercaptopropanol can also be selected. If the patient develops acute renal failure during treatment, the mercury drive should be suspended, and renal failure should be the main treatment; or a small dose of mercury drive should be used in conjunction with hemodialysis. The common drug used in the treatment of chronic mercury poisoning and mercury flooding is 5% sodium dimercaptopropanesulfate solution, intramuscular injection, once a day for 3 consecutive days, and 4 days of withdrawal as a course of treatment. The number of treatment sessions is determined according to the condition and the condition of mercury drive.

3. Symptomatic supportive treatment

Rehydration, correction of water and electrolyte disorders, oral care, and application of glucocorticoids to improve the condition. When contact dermatitis occurs, 3% boric acid can be used for wet compress.

Once the history of exposure to organic mercury is established, mercury removal therapy should be performed with or without symptoms. The method is the same as that of chronic mercury poisoning, but it should be treated as acute mercury poisoning in the first week; oral poisoning should be done in time. Symptomatic supportive therapy is particularly important for organic mercury poisoning, which is mainly used to protect the functions of important organs, especially the nervous system, because simply driving mercury can not stop the development of neuropsychiatric symptoms.

Mercury poisoning prevention

1. Replace mercury with non-toxic or low-toxic raw materials, such as electronic instruments instead of mercury instruments, and alcohol thermometers instead of metal mercury thermometers.

2. When smelting or pouring mercury, an exhaust hood or a closed device shall be provided to prevent mercury vapor from escaping, and the mercury concentration in the air of the workshop shall be determined periodically. The surfaces of the walls, floor and operating table of the mercury workshop should be smooth and free of cracks, which is convenient for cleaning and detoxification. Workshop temperature should not exceed 15 ~ 16 . The maximum allowable concentration of mercury in the air of the workshop is set to 0.001 mg / m ³ .

3. Mercury workers should have a physical examination once a year to detect mercury absorption and early mercury poisoning patients in time for early treatment. Mercury-containing waste gas, waste water and waste residue should be discharged after treatment.

4. The treatment method for household mercury leakage is: if there is still liquid, sprinkle sulfur powder on it and let it react; if it is volatilized, pay attention to indoor ventilation, and do not directly touch the mercury with your hands to avoid skin allergies.