Problem description:

I have used freckle cream with excessive mercury. It is reported that cosmetics with excessive mercury content are harmful to kidneys, lungs and other organs. How big is this harm, how long will it last, how to remedy it, and will it affect the pregnancy in the next year?

Analysis:

(1) absorption

Metal mercury and its compounds mainly enter the human body through the respiratory tract in the form of steam or dust, and can also invade through the digestive tract and skin mucosa.

1. Metal mercury in respiratory tract mainly enters human body through respiratory tract, which has strong evaporation, dispersion and solubility. Once inhaled, it can quickly diffuse through alveolar membrane and be absorbed within a few minutes, accounting for 75 ~ 85% of inhaled mercury. Inhalation of mercury vapor with concentration of 1 ~ 3 mg/m3 for several hours can cause acute poisoning. Mercury compounds enter the respiratory tract in the form of dust or aerosol.

2. The amount of metallic mercury absorbed by digestive tract is very small, while alkyl mercury and mercuric chloride can be absorbed by digestive tract quickly. Hg2+ is more easily absorbed than Hg+.

3. Mercury or mercury compounds in the skin mucosa can also be absorbed through the skin mucosa, such as using drugs such as mercury-containing suppositories and mercury-containing ointments.

(2) Distribution

After mercury enters the blood, 50% of inorganic mercury combines with plasma protein. 90% of organic mercury is bound to red blood cells and then distributed to brain and kidney, followed by liver, intestinal wall, heart, lung, respiratory mucosa and skin. About 80% of absorbed mercury compounds accumulate in renal proximal convoluted tubules. Testis, thyroid gland, hair and nails can also contain a certain amount.

(3) Emissions

Inorganic mercury is mainly excreted through urine, and methylmercury is mainly excreted through intestine. Mercury vapor can also be exhaled by breathing, and a small amount of mercury is excreted with saliva, milk and sweat. Metal mercury is oxidized into divalent mercury ions in blood, and then combined with plasma protein and hemoglobin to form bound mercury. It can also combine with low-molecular-weight sulfhydryl compounds such as cysteine, reduced glutathione, coenzyme A and anions in body fluids to form diffused mercury. Metal mercury can also affect fetal development through the placental barrier. Both mercury can be distributed in tissues and organs with blood flow, and gradually transferred to the kidneys. Metallothionein in kidney tissue combines with mercury and plays a major role in the accumulation of mercury in kidney. When mercury binds to protein, hapten can become antigen, causing allergic reaction and nephrotic syndrome. Repeated exposure to mercury will increase metallothionein (MT) in kidney and urine mercury. If this protein is exhausted by combining with mercury, renal damage will occur.

Fourth, the performance of toxic effects.

Occupational acute poisoning is extremely rare. More common in accidents. If metal is smelted in a well-ventilated small room, a large amount of metallic mercury will escape in the form of mercury vapor. It mainly causes respiratory symptoms, and in severe cases it can cause chemical pneumonia. Acute poisoning caused by mercury compounds is partly caused by intentional suicide or ingestion of bivalent mercury (HgCL2). It mainly causes gastrointestinal necrosis, circulatory failure and severe renal failure. The lethal dose is about 1g mercury salt.

Chronic poisoning is caused by long-term inhalation of mercury vapor, and its main target organ is the central nervous system, which is often accompanied by autonomic nervous dysfunction. There are three main symptoms: increased excitability, tremor and stomatitis. It is manifested as emotional irritability, irritability, timidity, inattention, memory loss, insomnia and so on. Tremors are mostly intentional, first appearing in the muscles of eyelids, tongue and fingers, and then developing to limbs. I trembled when I was heavier. The main manifestations of stomatitis are gingivitis, swelling of oral mucosa, ulcer, erosion, loose teeth and easy to fall off.

Other manifestations are nephrotic syndrome and glomerulonephritis, which are relatively rare.

The subclinical manifestations of chronic poisoning can cause weight loss, anorexia, mild tremor and insomnia when the air concentration is lower than 0. 1mg/m3 for a long time. Mercury is also common when cleaning mucous membranes with mercury preparations, smearing skin or treating certain diseases with mercury-containing drugs.

The most prominent symptom of organic mercury poisoning is neuropsychiatric symptoms, which are manifested as neurasthenia syndrome in the early stage, and the symptoms of a few serious cases continue to develop and worsen, showing mental disorders. In severe cases, mental disorder, delirium and coma may occur. The nervous system can also be involved, and the extrapyramidal system is seriously damaged. When the cerebellum is damaged, there may be ataxia such as clumsy gait and dysgraphia. Brain nerve injury, centripetal field of vision narrowing, hearing loss, etc. Others may also show symptoms of digestive tract and kidney damage, as well as heart and liver damage. Minamata disease is a chronic organic mercury poisoning in Japan. At first, the patient had slurred speech, unsteady gait and facial dementia, and later he was deaf and blind, and his whole body was numb. Finally, he went insane and his condition further developed to death.

Verb (abbreviation of verb) diagnosis

The diagnosis of mercury poisoning should be based on the occupational exposure history, clinical symptoms and signs and the determination of mercury in biological materials.

Acute mercury poisoning is easy to increase urinary mercury, and it is not difficult to diagnose combined with contact history.

Chronic mercury poisoning can be divided into three grades: mild, moderate and severe according to 1974: issued by the Ministry of Health. Mild poisoning is characterized by neurasthenia syndrome, stomatitis and slight tremor of fingers, tongue and eyelids, and urine mercury often exceeds normal values. In addition to the above symptoms and signs, moderate poisoning also has excitability, obvious tremor of fingers and increased urine mercury. Severe poisoning is characterized by toxic encephalopathy; The mental character is obviously changed, the hands and feet and the whole body are rough and trembling, the limbs are ataxia, and the urine mercury is increased or normal. Because urine mercury fluctuates greatly, it should be comprehensively analyzed according to the results of multiple tests.

Urine mercury absorption is higher than normal, and there is no obvious poisoning symptom.

At present, the normal upper limit of urine mercury is 250 nmol/L (0.0 mg/L) (dithizone method), 100nmol/L(0.02mg/L) (cold atomic absorption method) or 50nmol/L(0.0 1mg/L) (protein precipitation method).

Six, the principle of treatment

Patients should be out of contact with mercury and be treated with mercury repellent and symptomatic treatment.

Patients who take mercury salt by mistake should be given egg white, milk or soybean milk immediately, which is helpful to delay the absorption of mercury and protect the stomach wall. 0.2% ~ 0.5% activated carbon can also be used for gastric lavage. At the same time, 40 ml of 50% magnesium sulfate can be given for catharsis and detoxification.

At present, sodium dimercaptopropane and sodium dimercaptosuccinate are the first choice drugs to drive mercury, followed by penicillamine. The first two are sulfhydryl complexing agents, which can protect human sulfhydryl enzymes from being damaged by mercury, and can also restore enzymes that have lost their activity for a short time under the action of mercury. Once the sulfhydryl group is combined with mercury, it can be excreted through the kidney.