Lead poisoning is characterized by weakness of limbs, abdominal pain, metallic taste in the mouth, loss of appetite, nausea, vomiting and hepatomegaly. In severe cases, headache, convulsion, coma, respiratory paralysis and wrist droop may occur. Babies and pregnant women are most affected by lead pollution. Because the protective structure of the baby's organs is not fully developed, it can't resist the impact of lead; The absorption rate of lead in infants' intestines and stomach is also 5 ~ 8 times higher than that in adults. Babies' kidneys don't excrete lead as effectively as adults, so the retention time of lead in infants is five times that of adults. On the other hand, through the placenta, the lead in the mother's blood can be transferred to the fetal blood and fetal brain.
Chronic low-level lead harm not only affects the intellectual development of infants, but also affects the development process of nervous system in many aspects such as learning behavior and hearing, and its impact may be long-term. Medical research has found that the neurotoxicity of lead to infants is also related to the imperfect performance of blood-brain barrier. The neurotoxicity of lead mainly affects the formation of cerebral cortex, axons, dendrites and synapses, especially in hippocampus, which is the center to control learning and memory activities.
Lead can enter our bodies in many ways. In addition to the so-called "disease from the mouth", some lead-containing compounds can also penetrate into the body through breathing and skin.
The study found that after excluding the influence of intelligence factors, the possibility of dropping out of primary school in infants and children with lead content above 20 mg/kg increased by 7.4 times; With a small vocabulary, the possibility of reading difficulties is 5.8 times greater; Other aspects closely related to learning ability, such as hand-eye coordination and response speed to stimuli, are poor. Lead will not only destroy the synthesis of hemoglobin red blood cells, affect the life span of red blood cells, and cause the "illusion" of iron deficiency anemia, but also enter the central nervous system, affecting children's intellectual development. Every time blood lead rises 10 microgram, the IQ quality will drop by 6 ~ 7 points.
According to the results of epidemiological investigation in China in recent ten years 1 1 provinces and cities 18, it is found that the average level of infant blood lead in urban industrial areas is mostly between 20 and 40 μ g/dl, and the prevalence rate of infant lead poisoning is above 85%, which is much higher than that in western developed countries. Even in ordinary urban areas without obvious industrial pollution, the blood lead level of infants is around 1 0 μ g/dl, especially in big cities. For example, the blood lead level of 37.8% infants in Shanghai is 10 μ g/dl, while that in Beijing is as high as 68.7%.
If your child has some abnormal behaviors, maybe the doctor will advise you to check your blood lead. In children's hospital, doctors screen children by drawing blood, and the general cost is about 20 ~ 30 yuan, and the blood lead content of children can be known in about 3 days.
How to prevent infant lead poisoning
Go to crowded places less, such as on both sides of the road; Go to lead-polluted areas, such as battery factories and paint factories.
Don't eat food containing lead, such as preserved eggs with lead, popcorn and food with pigments. Prevent the deficiency of protein, calcium, iron and zinc, because the deficiency of trace elements can increase the absorption of lead in the intestine and increase the blood lead level.
Pregnant women living in areas with serious lead pollution should have their blood lead tested regularly.
Eat more foods that can drive lead, such as milk. Protein contained in milk can combine with lead to form insoluble compounds, which can prevent the absorption of lead. Calcium contained in milk can replace lead deposited on bones and be excreted with urine.
In addition to milk, the following foods can also drive lead:
Kelp: Kelp contains ingredients that can promote the excretion of lead in the body and prevent constipation.
Carrots: Carrots contain a lot of pectin, which can reduce the toxicity of lead in the body, reduce the absorption of lead and prevent constipation caused by lead poisoning.
Shrimp skin: the calcium content of shrimp skin is high. Eating shrimp skin often can relieve the symptoms of lead poisoning and accelerate the excretion of lead.
Tea: Tea contains condensed acids and other substances, which can be combined with lead invading the body to form soluble substances and excreted with urine.
Garlic and eggs: These two substances have high sulfur content and can dissolve lead poisoning.