Crude lead: What is the danger to human body?

　　Crude lead: Lead is a corrosion-resistant heavy non-ferrous metal material with the advantages of low melting point, high corrosion resistance, not easily penetrated by X-rays and rays, and good plasticity. It is often processed into plates and tubes, which are widely used in chemical, cable, battery, radioactive protection and other industrial fields. So what is the danger of crude lead to human body?

　　Crude lead: What is the danger to human body?

　　Crude lead: lead is one of the three major heavy metal pollutants, and is a heavy metal element that seriously endangers human health. The ideal level of lead in human body is zero. The human body takes lead into the body through eating and drinking tap water. 90% of the lead entering the human body is stored in the bones, and 10% is distributed to all tissues and organs of the body with blood circulation, affecting the functions of red blood cells, brain, kidney and nervous system. Especially for infants and children, after absorbing lead, more than 30% of lead will remain in their bodies, which will affect the growth and intellectual development of infants and children.

　　Because lead is cumulative poisoning, only when the lead content in human body reaches a certain level, it will cause physical discomfort. After long-term intake of lead, it will cause serious damage to human blood system and nervous system, especially to children's health and intelligence.

　　Neurosis is one of the early and common symptoms of lead poisoning, which is manifested as dizziness, headache, general weakness, memory loss, sleep disorder, and excessive dreaming. Polyneuropathy can be divided into sensory, motor and mixed types: sensory type manifests as numbness in the limbs and glove-sock type sensory disorder in the limbs; motor manifests as muscle weakness and muscle paralysis. Toxic encephalopathy is rare and is the most severe form of lead poisoning, manifesting as headache, nausea, vomiting, high fever, irritability, convulsions, drowsiness, mental disturbance, coma and other symptoms. Mild symptoms of the digestive system can be manifested as metallic taste in the mouth, loss of appetite, epigastric distention and discomfort; severe abdominal cramps. The blood system is mainly lead, which interferes with the synthesis of hemoglobin and causes anemia. Generally speaking, lead poisoning can be recovered quickly after lead expulsion treatment, and there are few after-effects except lead poisoning encephalopathy.

　　Crude lead: What are the applications of lead?

　　Crude lead: Lead is a raw material for manufacturing batteries and cables, and an additive for gasoline. Lead compounds are used as raw materials for pigments, glass, plastics and rubber. Metallic lead is widely used in the manufacture of chemical and metallurgical equipment because of its excellent resistance to acid and alkali corrosion. Lead alloys are used as bearings, movable gold and solder, etc. In addition, lead has opened up some new uses.

　　Lead is one of the earliest metals extracted by human beings. The earliest discovery in China is a lead block excavated from the Erlitou site in Yanshui, Henan Province, about 3500 to 4000 years ago. Lead jars, money, zun, ding and gao were excavated from Shang and Western Zhou tombs. The lead content in the Western Zhou period (11th century B.C.-771 B.C.) was 99.75 percent. Lead did not become more common in Palestine until the 15th century BC. However, it was not until the 17th-18th centuries that lead began to be produced on a large scale. The main lead-producing countries are the United States, the former Soviet Union, Japan, Germany, England, and China.