1.What is lead? Lead is a heavy metal element widely found in nature, soft and silver-gray, low melting point, corrosion resistance, and its compounds can show pink, yellow and other colors. It is widely used in batteries, power electronics, printing, petrochemicals, paints, pigments, plastics, rubber, and even the food industry. Lead is a kind of toxin for our body, once it enters the body, it will have toxic effects on all systems and organs of the body. At present, in developing countries, the average annual use of lead in all walks of life up to 500,000 tons. Therefore, if the environmental protection is not properly done, the lead will pollute our daily life with industrial waste gas, waste water, waste residue and other ways, which will jeopardize every one of us. At present, lead poisoning is one of the important public health problems in developing countries (the period of lead pollution in developed countries occurred before the 1970s and has passed). Children are a special group of people who are in the period of growth and development and are more sensitive to the toxicity of lead than adults, so lead poisoning is more harmful to children, and the toxic damage can affect their whole life, which should be emphasized. Therefore, lead is indispensable to many industries, and it can be said that lead is necessary to our daily life. While bringing us benefits, it also pollutes the environment we live in and brings harm to our health. 2. Occurrence and prevalence of children’s lead poisoning According to the international standard of lead poisoning, i.e. blood lead is equal to or greater than 100mg/L. According to the results of the national children’s lead poisoning survey in 2004, the average incidence rate of children’s lead poisoning in China is about 10%, and the average value of blood lead is about 60mg/L, which is a significant decrease compared with that of 10 years ago. The incidence rate varies in different areas due to different degrees of environmental pollution, but the difference is not significant. Currently, the incidence of lead poisoning among children in the United States is 4.4%. In fact, the problem of lead pollution in the U.S. also experienced a very serious period, in the 1960s and 1970s, the incidence of lead poisoning among children aged 1-5 was 85-97%, which was very high. After the efforts of the government and health departments to intervene and prohibit the use of leaded gasoline and paint, the problem of lead poisoning in the 1990s has been under significant control and has dropped to the current level of 4.4%. 3, the harm of lead to children and the characteristics of clinical performance Once lead enters into the body, it first combines with red blood cells, and then transfers to the bones and is deposited, 80%-90% of the lead in the body is stored in the bones, while the lead in the blood reaches every system and organ of the body with the blood flow, such as the brain, liver, kidneys, immune system organs and so on, which will cause damages. There is a wide range of symptoms. For children, the common symptoms are mainly in the nervous system and growth and development: inattention, hyperactivity, and poor or declining academic performance. There is a negative correlation between blood lead levels and IQ, with a 2-3 point drop in IQ for every 10 μg/dl increase in blood lead levels. Some children will show temperament and behavioral problems, short temper, tantrums, gnawing fingers, truancy, absenteeism and so on. Some children show physical growth and development is affected (not long, thin), zinc, calcium, iron and other trace elements deficiency. Some show susceptibility to colds, low immunity, abdominal pain, leg pain, and so on. More serious manifestations such as kidney damage, encephalopathy (coma), and multiple organ failure are rare in children, and are mainly seen in lead workers. Diagnosis of children’s lead poisoning The diagnosis of children’s lead poisoning is based on the above mentioned symptoms and manifestations, and the blood lead test is carried out. Generally speaking, if the blood lead is ≥10μg/dl, it is considered as lead poisoning, regardless of whether there are corresponding clinical manifestations or biochemical changes. This is an internationally standardized criterion that applies to both adults and children. Lead poisoning can be categorized into the following 4 grades: –Mild lead poisoning: blood lead level is 10–24.9 μg/dl. Clinical manifestations include inattention, hyperactivity, deficiencies of trace elements and minerals such as calcium and zinc. –Moderate lead poisoning: blood lead level is 25-44.9μg/dl, clinical manifestations include inattention, hyperactivity, learning difficulties, temper tantrums, decreased IQ, deficiencies of trace elements and minerals such as calcium and zinc, anemia, unexplained abdominal pain, growth and developmental delays, and immune deficiency. –Severe lead poisoning: blood lead level is 45–69.9μg/dl. Clinical manifestations include temper tantrums, irritability, aggression, headache, mental retardation, abdominal colic, deficiencies of trace elements and minerals such as calcium and zinc, anemia, impaired vision and hearing, high blood pressure, cardiac arrhythmia, and so on. –Extremely severe lead poisoning: blood lead level ≥70μg/dl. Clinical manifestations include liver, kidney, heart and other organs damage, lead encephalopathy, and even death. If the blood lead is between 10 – 19 μg/dl, follow-up within 1-3 months; if the blood lead is between 20 – 44.9 μg/dl, follow-up within 1 week to 1 month is needed; if the blood lead is above 45 μg/dl, follow-up within 48 hours or immediately with venous blood is needed. Parents should pay attention to their children to see if they have any symptoms such as inattention in class, hyperactivity, change in temperament, lack of growth, thinness, etc. If so, they should take their children for blood lead test. One more point is that some children’s blood lead has exceeded the standard, but the performance is often not obvious, or the parents failed to detect it because of insufficient observation. Therefore, even if there is no obvious clinical manifestation, if possible, we should give the children regular blood lead test, usually every half a year to once a year. 5. Blood lead greater than or equal to 10μg/dl is the limit for diagnosing lead poisoning, so is it safe to have a blood lead level below 10μg/dl? Strictly speaking, the ideal blood lead level should be close to 0μg/dl, but the fact is that we live in a lead-contaminated environment, and it is impossible to maintain 0μg/dl blood lead. Studies have shown that even if blood lead is below 10μg/dl, there is also damage at the tissue, cellular and even genetic levels, only with mild clinical manifestations. However, it has also been shown that an increase in blood lead from 0 μg/dl to 10 μg/dl has a greater effect on a child’s IQ (5-6 point drop in IQ) than an increase from 10 μg/dl to 20 μg/dl (2-3 point drop in IQ). For maternal blood lead below 10 μg/dl, it can also affect fetal development and predispose to miscarriage. Therefore, there is no ideal blood lead threshold below which there is no harm to the body. Currently, the average blood lead level of children in the U.S. is 2.7μg/dl. Therefore, it is generally believed that the ideal blood lead level for children should be controlled below 5μg/dl in order to minimize the damage. 6. Detection methods of lead poisoning Blood lead test is usually used. Blood lead test methods can be divided into direct and indirect methods: the more sensitive and accurate direct methods are atomic absorption graphite furnace method and anodic dissolution voltammetry (ADV), with ADV being the most accurate. Indirect method is mainly erythrocyte zinc protoporphyrin (ZPP) determination, blood lead is high when the erythrocyte zinc protoporphyrin tends to rise, so it can be indirectly reflected in the blood lead level through the determination of zinc protoporphyrin, because of the influence of many factors, inaccurate, this method has basically given up the use of. In addition to blood lead, hair lead, urine lead, bone lead and dental lead can also be measured, but some of these methods are complicated, time-consuming, and some have poor accuracy, so they cannot be widely used. At present, the more recognized test method for diagnosing lead poisoning is blood lead. 7. Causes and Risk Factors of Lead Poisoning in Children Lead in children’s bodies mainly comes from polluted air in their living environment, daily contact with lead-containing articles and food. * Polluted air includes the whole atmosphere polluted by automobile exhaust and the small indoor air environment polluted by home decoration materials, and the lead dust floating in the air is taken into the body through the respiratory tract. *Children’s daily contact with items containing high levels of lead are mainly toys and school supplies with paint, batteries, newspapers, books and other printed materials, and children have a characteristic of more hand-to-mouth movements or biting these things directly with their mouths, and thus lead enters the body. *Through food and diet is also a way of lead intake, food containing lead in the high main eggs, pesticide-contaminated vegetables and fruits, canned food, popcorn popped by the old-fashioned iron stove, and puffed food. Some crystal and patterned ceramic tableware often contain lead, which is released into food when exposed to heat and acid. Drinking water contamination is also noteworthy. *For infants under 1 year old, there is another source of lead in the body, which is the mother’s body, mainly through the placenta during pregnancy and the mother’s breast milk after birth. Therefore, if you pay attention to and prevent these links above, you can reduce the intake of lead and effectively avoid the occurrence of lead poisoning. Treatment of lead poisoning in children The treatment program of lead poisoning in children should be determined according to the blood lead level, and different treatment measures should be taken for different levels. The basic principle of treating children’s lead poisoning is: prevention first, nutritional intervention. Regardless of the level of lead poisoning, the first step is to provide health education, improve the environment, wash hands frequently, avoid foods with high lead content, and eat a balanced diet. Mild-moderate lead poisoning: health education and environmental intervention should be the main focus, so as to wash hands diligently and get out of the lead-polluted environment; at the same time, nutritional intervention should be carried out to treat the disease, and calcium, zinc and other minerals and trace elements and vitamins should be supplemented when necessary. Regular review. Severe and very severe lead poisoning: lead repellent drugs such as calcium disodium edetate (CaNa2EDTA), dimercaptosuccinic acid (DMSA), dimercaptopropanol (BAL) should be applied. Note that the side effects of these drugs are large, and they have damaging effects on the heart, liver, kidney and other organs, and also cause disorders of minerals, trace elements and water electrolytes, therefore, hospitalization is necessary when applying these drugs, and the changes of liver and kidney functions, electrocardiogram, water electrolytes and trace elements should be monitored, and attention should be paid to the protection of the liver, kidney and heart functions, timely correction of water and electrolyte disorders, and supplementation of minerals and trace elements, such as calcium, zinc, and iron. Supplement calcium, zinc, iron and other minerals and trace elements. Dietary and nutritional intervention treatment of lead poisoning in children ① Health care lead repellent food and nutritional medicine Professional and targeted lead repellent health food is only available in recent years, and its main ingredients are also amino acids, vitamins, minerals, trace elements, pectin, cellulose, etc., which are extracted from food or wild plants. The main ingredients are also extracted from food or wild plants, such as amino acids, vitamins, minerals, trace elements, pectin, fiber, etc. The purpose of lead repellent is achieved by preventing the intestinal absorption of lead, the replacement of lead in the tissues, and the antioxidant effect. Zinc, calcium, iron and other minerals and trace elements, like lead, are divalent cations, antagonistic and inhibitory to each other in absorption and function, lead poisoning is often accompanied by the lack of these elements, so some trace element preparations can also be used as a lead-expelling treatment. Note: There is no scientific evidence for the use of traditional Chinese medicine, please use with caution. ②How to treat lead poisoning with diet? The purpose of dietary treatment is to regulate the intake of fats, proteins, minerals, vitamins and other nutrients to achieve the purpose of lead repellent treatment. Increased fat intake can promote the absorption of lead; protein can be combined with lead, lead replacement from the tissues to reduce the toxic effects of lead; vitamins C, E, B, etc. can fight against the oxidative damage of lead; cellulose and pectin in the intestinal tract can be combined with the lead to form a gel, inhibit the absorption of the minerals – zinc, calcium, etc. can be in the process of intestinal absorption as well as post-absorption with the lead antagonism and replacement, inhibit the absorption of lead and the replacement of lead, and inhibit the absorption of lead and the absorption of lead. Zinc and calcium can antagonize and displace lead during and after absorption, inhibiting the absorption and toxic effects of lead. Therefore, for children with lead poisoning, the first thing to do is to have a balanced diet. Eat less fatty meat, fried and greasy food, and increase the intake of protein and vitamins as appropriate. Eat more protein-rich foods (such as milk, soy products, fish, lean meat, beef, etc.), fresh vegetables and fruits, hard-shelled nuts (walnuts, peanuts, pistachios, etc.), and black fungus. However, it is important to note that vegetables and fruits should be washed and fruits should be peeled, as pesticides often contain lead. At the same time, drink more water to promote the excretion of lead. Lead poisoning prevention Lead poisoning in children is completely preventable and can be prevented at two levels, i.e. primary prevention and secondary prevention. Primary prevention is mainly to carry out health education, develop good hygienic habits, wash hands frequently, avoid contacting objects with high lead content, avoid eating foods with high lead content, and at the same time, eat balanced meals every day without any partiality, which has been talked about in the previous section. If parents are engaged in lead-related industries, they should take a shower and change out of their work clothes at the end of the day before going home so as not to bring lead home. In addition, home decoration should also take care to avoid using materials with high lead content such as paints and pigments. What is more important is for the whole society to strengthen its awareness of environmental protection so that the environment we live in can be kept clean. Secondary prevention mainly involves regular blood lead testing for children, which can be included in routine medical checkups. This is conducive to early detection of lead poisoning and early treatment to minimize the damage to health. In addition, for couples who are planning to have a child, blood lead should be measured before pregnancy, and both couples should do it, because if the father has high lead, the quality of sperm will be affected; if the mother has high lead, the lead can be transmitted to the fetus through the placenta during pregnancy, and after birth, the mother’s lead can be transmitted to the baby through breast milk, which will cause the baby’s blood lead to be elevated. Therefore, you should have your blood lead tested before getting pregnant, and if your blood lead is high, you should wait until it is lowered before getting pregnant, and you should not use cosmetics or hair dyes. Given the high incidence of lead poisoning in children, it should be taken seriously by parents, but there is no need to panic. Lead poisoning can be avoided or alleviated if good hygiene habits are practiced in daily life, hand washing is done diligently, the environment is improved, foods high in lead are avoided, and meals are balanced and not partial, then lead poisoning can be avoided or alleviated. Of course the most fundamental way to prevent lead poisoning is environmental protection, production and use of green products, which requires the participation of many departments and the formulation of relevant regulations.