What is lead poisoning? What are the symptoms?

Acute lead poisoning is mostly caused by taking lead acetate, lead carbonate, lead chromate and tetraethyl lead by mistake, breathing their dust or smoke, steam, skin absorption or taking their solvents orally. Excessive contact, inhalation of lead compounds or lead-containing Chinese medicines, such as calcined lead, calcined black tin, Yangdianfeng pills, and the use of lead-containing cosmetics can also cause poisoning. The poisoning mechanism of acute lead poisoning is that lead and its lead compounds can combine with Ryukyu group of enzyme after entering cells and inhibit the function of enzyme. At the same time, the damage to the central nervous system is particularly obvious, which can interfere with the enzymes that synthesize hemoglobin and cause abnormal porphyrin metabolism. Lead acting on cell membrane can cause hemolysis, resulting in a series of symptoms such as hematopoiesis, nervous system, digestion and urinary system. The clinical manifestation of acute lead poisoning is 1. The digestive system is characterized by nausea, vomiting, loss of appetite, metallic taste in the mouth, salivation, abdominal distension, constipation, bloody stool, abdominal cramps and tenderness, as well as hepatomegaly, jaundice and decreased liver function. 2. The nervous system is characterized by headache, dizziness, anxiety, insomnia, lethargy and excitability. In severe cases, delirium, convulsions, convulsions and coma may occur, and even brain edema and peripheral neuritis may occur. 3. The blood system shows anemia symptoms, such as pallor, palpitation and shortness of breath. 4. Urinary symptoms include low back pain, edema, proteinuria, hematuria, renal tubular urine, and severe renal failure. First aid for acute lead poisoning: 1. For oral poisoning, you can immediately give a lot of strong tea or warm water to stimulate the pharynx to induce vomiting, and then give milk, egg white and soybean milk to protect the gastric mucosa. 2. Symptomatic first aid. Abdominal pain can be treated by hot compress or oral atropine 0.5- 1.0 mg; For coma patients, foreign bodies in the oral cavity should be removed in time to keep the respiratory tract unobstructed, so as to avoid suffocation caused by foreign bodies entering the trachea or respiratory tract by mistake. 3. After the above-mentioned on-site first aid, the patient should be sent to the hospital for emergency treatment immediately, so as not to delay time and endanger the patient's life.

Adult lead poisoning often appears: fatigue, depression, heart failure, abdominal pain, kidney deficiency, hypertension, joint pain, reproductive disorders, anemia and other symptoms. After lead poisoning in pregnant women, there will be serious consequences such as abortion, low birth weight, stillbirth and infant dysplasia. Children often have symptoms such as loss of appetite, stomachache, insomnia, learning disabilities, constipation, nausea, diarrhea, fatigue, low IQ and anemia.

The harm of lead poisoning is mainly manifested in the lifelong damage to nervous system, blood system, cardiovascular system and skeletal system:

Lead has a direct toxic effect on specific nerve structures of multiple central and peripheral nervous systems. In the central nervous system, the cerebral cortex and cerebellum are the main target tissues of lead toxicity; In the peripheral nervous system, motor axons are the main target tissues of lead poisoning. Among them, the toxicity of lead to the nervous system is mainly manifested in the following four aspects: (1) It changes the psychology of patients with lead poisoning. Adults show depression, irritability and personality changes, while children show hyperactivity. (2) Lead poisoning can lead to mental decline, especially for children with learning disabilities. It is reported that the IQ of children with high lead is 4-6 points lower than that of children with low lead. (3) Lead poisoning can lead to sensory dysfunction. For example, many patients with lead poisoning will have visual dysfunction: retinal edema, retrobulbar optic neuritis, blind spots, abductor paralysis, optic atrophy, eye movement disorder, abnormal pupil accommodation, amblyopia or visual field changes; Or smell, taste disorders, etc. (4) The main effect of lead on peripheral nervous system is to reduce motor function and nerve conduction velocity, and muscle injury is one of the typical proofs of severe lead poisoning.

Lead has two main effects on the blood system, one is to inhibit the synthesis of hemoglobin, the other is to shorten the life of circulating red blood cells, which will eventually lead to anemia.

The damage of lead to cardiovascular system is mainly manifested in: (1) The mortality of cardiovascular diseases is closely related to the excessive lead in arteries, and the blood lead and 24-hour urine lead levels of patients with cardiovascular diseases are significantly higher than those of patients without cardiovascular diseases. (2) Lead exposure can cause hypertension. (3) Lead exposure can cause heart diseases and changes in heart function.

Bone is an important target organ system of lead toxicity. On the one hand, lead indirectly affects bone function and bone mineral metabolism by damaging endocrine organs; On the other hand, it directly interferes with the function of bone cells by poisoning cells, interfering with basic cell processes and enzyme functions, changing the coupling relationship between osteoblasts and osteoclasts, and affecting the calcium system.

This shows that the harm of lead poisoning is serious, so the prevention and detection work becomes very important. However, the symptoms after lead poisoning are often very hidden and difficult to find, so the most reliable method at present is blood test.

The harm of lead poisoning is mainly manifested in the lifelong damage to nervous system, blood system, cardiovascular system and skeletal system:

Lead has two main effects on the blood system, one is to inhibit the synthesis of hemoglobin, the other is to shorten the life of circulating red blood cells, which will eventually lead to anemia.

Bone is an important target organ system of lead toxicity. On the one hand, lead indirectly affects bone function and bone mineral metabolism by damaging endocrine organs; On the other hand, it poisons cells, interferes with basic cell processes and enzyme functions, changes the coupling relationship between osteoblasts and osteoclasts, affects the calcium system, and directly interferes with the function of bone cells.