Mercury poisoning

Introduction

Introduction to mercury poisoning Mercury poisoning is more common in chronic conditions, mainly in production activities, caused by long-term inhalation of mercury vapor and mercury compound dust. Psycho-neural abnormalities, gingivitis, and tremor are the main symptoms. Mercury is a silvery white liquid metal that evaporates at room temperature. Acute mercury poisoning occurs when high-dose mercury vapor inhalation or ingestion of mercury compounds occurs. Those who are allergic to mercury may be poisoned even if they are partially coated with a mercury oil base. Mercury mining, amalgam smelting, gold and silver extraction, mercury rectifiers, as well as vacuum pumps, lamps, gauges, thermometers, amalgams, mercury, pigments, pharmaceuticals, nuclear reactor coolants and anti-atoms In the production workers of radiation materials, organic mercury compounds used to be mainly used as agricultural fungicides, but they are highly toxic and are no longer produced and used in China. basic knowledge The proportion of illness: 0.003% Susceptible people: no specific population Mode of infection: non-infectious Complications: renal failure

Cause

Causes of mercury poisoning

Occupational factors (35%)

Mercury poisoning is a common occupational poisoning because mercury is rich in fluidity and easily evaporates at room temperature. Mainly occurs in the production of long-term inhalation of mercury vapor or mercury compound dust. Productive poisoning is found in production workers such as mercury mining, amalgam smelting, gold and silver extraction, vacuum mercury, lighting, instrumentation, thermometers, fillings, mercury, pigments, pharmaceuticals, nuclear reactor coolants and atomic radiation protection materials.

Environmental factors (30%)

Mercury is widely found in nature. Various natural phenomena can make mercury continuously circulate from the surface through the atmosphere, rain and snow, and can be absorbed by animals and plants. Human production activities can significantly increase the pollution of mercury to the environment. Although the proportion of such artificial pollution is not large, but the concentration is concentrated, the damage is far more serious than natural pollution. The pollution of rivers, lakes and seas by mercury-containing sewage can cause pollution diseases such as waterlogging.

Mistake factor (10%)

Short-term (>3~5 hours) inhalation of high concentration of mercury vapor (>1.0mg/m3) and oral administration of large amounts of inorganic mercury can cause acute mercury poisoning; taking or applying mercury-containing remedies can cause subacute mercury poisoning; occupational exposure to mercury vapor Often caused by chronic mercury poisoning.

Pathogenesis:

Mercury ions are easily combined with sulfhydryl groups, which inactivate cytochrome oxidase, pyruvate kinase, succinate dehydrogenase, etc., which are related to sulfhydryl groups. Mercury also binds to amino groups, carboxyl groups, and phosphoryl groups to affect the activity of functional groups. The activity of enzymes and functional groups is affected, which hinders the biological activity and normal metabolism of cells, and ultimately leads to cell degeneration and necrosis. In recent years, it has been found that mercury damages the kidneys, mainly renal proximal tubular epithelial cells, and mercury can also cause immunity. Dysfunction, production of autoantibodies, nephrotic syndrome or glomerulonephritis.

Prevention

Mercury poisoning prevention

Mercury poisoning can be treated with drugs such as sodium dimercaptopropane sulfonate or sodium dimercaptosuccinate. Mild chronic mercury poisoning can be cured, and patients do not have to worry about it. Prevention should use comprehensive preventive measures to replace mercury with non-toxic or low-toxic materials, such as replacing mercury meters with electronic meters, replacing mercury thermometers with alcohol thermometers, and venting or sealing devices to avoid smelting or injecting mercury. Mercury vapor escapes. Timely removal and recovery of mercury remaining on the table, floor, and walls. The concentration of mercury in the air of the workshop is measured periodically. Mercury workers should be physically examined once a year to detect mercury absorption and early mercury poisoning patients for early treatment. Mercury-containing waste gas, wastewater, and waste residue should be disposed of after treatment.

In the case of household mercury leakage, if there is liquid, the sulfur powder should be sprinkled on it to allow it to react; if it has been volatilized, pay attention to indoor ventilation, and do not directly touch mercury with hands. Mercury may cause skin irritation.

Metallic mercury adheres to the surface of the object for a long time and continues to evaporate at normal temperature. Therefore, the surface of the wall, floor and console of the mercury workshop should be smooth and free of cracks, which is convenient for cleaning and detoxification. The temperature of the workshop should not exceed 15~16 °C. The maximum allowable concentration of mercury in the air of the workshop is set at 0.001 mg/m3.

Complication

Mercury poisoning complications Complications, renal failure

Chronic mercury poisoning patients may have changes in EEG amplitude and rhythm electrical activity, peripheral nerve conduction velocity slows, blood a2 globulin and reduced glutathione increase, and blood lysosomal enzyme, erythrocyte cholinesterase And serum sulfhydryl groups are reduced.

Symptom

Mercury poisoning symptoms Common symptoms Abdominal pain

First, acute mercury poisoning

Mainly caused by mercury compounds such as oral mercury, patients with acute corrosive stomatitis and gastroenteritis after a few minutes to tens of minutes after taking the patient, the patient complained of burning in the mouth and throat, and have nausea, vomiting, abdominal pain, followed by Diarrhea, vomit and feces often have bloody mucus and shedding necrotic tissue. Patients often have peripheral circulatory failure and gastrointestinal perforation. Acute renal failure can occur after 3 to 4 days (seriously within 24 hours). At the same time, there may be liver damage.

Inhalation of high concentrations of mercury vapor can cause fever, chemical tracheobronchitis and pneumonia, respiratory failure, and acute renal failure.

Skin contact with mercury and its compounds can cause contact dermatitis, which has allergic properties. The rash is erythematous papules, which can be fused into tablets or form blisters, and pigmentation is followed.

Second, chronic mercury poisoning

Often caused by occupational inhalation of mercury vapor, a small number of patients may also be caused by the application of mercury preparations, psychotic and neurological symptoms may first have dizziness, headache, insomnia, multiple dreams, followed by emotional or depression, anxiety and timidity and autonomic nerves Symptoms such as blushing, sweating, skin scratches, etc. Muscle tremors are first seen in the fingers, eyelids and tongues, and later involve the arms, lower limbs and head, and even the whole body; more noticeable when being noticed and excited, oral Symptoms mainly include mucosal congestion, ulceration, swelling and bleeding of the gums, loosening and falling off of the teeth, and poor oral hygiene. The blue-black mercury sulfide fine particles are arranged in rows of mercury lines, which is a marker of mercury absorption. Initially subclinical renal tubular dysfunction, low molecular proteinuria, etc., nephritis and nephrotic syndrome may also occur. Kidney damage is expected to recover after exposure to mercury. Chronic poisoning patients may still have weight loss and sexual dysfunction. Women with menstrual disorders or miscarriage and hyperthyroidism, peripheral neuropathy, brown light reflection in the anterior chamber of the lens, considered to be The "mercury lenticular inflammation" caused by mercury sequestration, which persists after the symptoms of poisoning disappear or come out of contact with mercury, is another indicator of mercury absorption.

Examine

Mercury poisoning inspection

Urinary mercury and hematuria reflect the absorption of mercury in the body to a certain extent, but it is often not related to the clinical symptoms and severity of mercury poisoning. The normal value of urinary mercury varies from region to region, and the normal upper limit of domestic urinary mercury is dithizone. The thermal nitrification method generally does not exceed 0.25 mol/L (0.05 mg/L) or the atomic energy absorption method does not exceed 0.1 mol/L (0.02 mg/L), and the normal upper limit of blood mercury is 1.5 mol/L (0.03 mg/dl). .

Chronic mercury poisoning patients may have changes in EEG amplitude and rhythm electrical activity, peripheral nerve conduction velocity slows, blood a2 globulin and reduced glutathione increase, and blood lysosomal enzyme, erythrocyte cholinesterase And serum sulfhydryl groups are reduced.

Diagnosis

Diagnosis and identification of mercury poisoning

The diagnosis of acute mercury poisoning is mainly based on occupational history or history of toxic ingestion, combined with clinical manifestations and urinary mercury or blood mercury determination (increased increase). The diagnosis of chronic mercury poisoning should emphasize the history of exposure and clinical psycho-neuro symptoms. Stomatitis and tremor are the main manifestations, and need to exclude similar clinical manifestations caused by other causes. Increased urinary mercury and blood mercury levels are helpful for diagnosis. Mercury-suppressing tests can be performed with 0.25 g of sodium dimercaptosulfonate, orally; or Bismuthine disodium 0.5g, intravenous injection; such as urinary mercury discharge significantly increased, can be used as an important auxiliary diagnostic basis.

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