1.Lead poisoning: When the content of lead in children’s blood exceeds about 100 micrograms per liter (μg/L), it is childhood lead poisoning, about 30% in China and about 20% in children aged 3-5 years old. 2.Mild lead poisoning: Blood lead content between 100 and 199 micrograms per liter is mild lead poisoning; 3.Moderate lead poisoning: 200 to 449 micrograms is moderate lead poisoning (domestic higher than 250 micrograms No more than 5%); 4. Severe lead poisoning: it is severe lead poisoning when it is greater than or equal to 450 micrograms (where >700 micrograms/liter is extremely severe). Lead is indeed more harmful to children than adults. Industrial pollution, exhaust gas pollution containing leaded gasoline, environmental pollution, home decoration, pipes of PVC profiles (including doors and windows) and other reasons may lead to lead poisoning in children. Children have higher absorption rate of blood lead and less excretion; children sucking fingers and biting pencil tips are easy to bring lead into the digestive tract; lead generally accumulates more in the atmosphere about 1 meter above the ground, which is just the range of children’s breathing; children also inhale more lead per unit volume. But lead poisoning is not terrible, the key is that we need to know how to prevent it and keep lead away from children, the state has specialized agencies responsible for it. Special reminder: There is a period of time when “lead poisoning”, “lead overload”, “lead exorcism”, “lead magic”, “lead The words “lead detoxification” and “blood lead screening” flooded the media, and in some big cities, there are dozens of free lead testing outlets to promote lead detoxification health products, and a course of treatment is expensive and business is booming. Some manufacturers and medical institutions create lead panic, talk nonsense and make unjust money: 1. nonsense that children’s “hyperactivity” is due to lead poisoning; 2. nonsense testing, what “hair lead”, “urine lead”, “one drop blood test”, “one lead test” and “one lead test”. 2. indiscriminate tests, such as “lead hair”, “urine lead”, “one drop of blood” zinc porphyrin measurement and so on. In fact, only venous blood measurement of lead has practical significance, and lead poisoning can be considered only when it exceeds 100 micrograms/liter. 3. Indiscriminately changing the diagnostic criteria of lead poisoning, saying that anything over 30 micrograms/liter is over the limit and lead must be driven away, and even proposing to fight a war to drive away lead, which is simply too foolish to parents, I always tell parents that I hope we believe in science.