Lead
Lead is a chemical element with symbol (PB) and atomic number 82
Lead is a heavy metal with a high density and is normally found in a bluish-silver color, which quickly loses its luster to a dark gray color when exposed to air.
Lead is included in the composition of a number of alloys. It is also a soft, malleable metal that can be drawn and malleable. It is also a stable metal and three of its isotopes are located at the end of the decay chain of radioactive heavy elements.
Lead is extracted from its ores easily, and since ancient times, people in the ancient world have been able to obtain it, especially from the metal galena, which is the main source for extracting lead, since silver often accompanies lead in its ores, so the quest to obtain silver was the reason for the knowledge of lead and its use in daily life. In ancient Rome. In 2014, global lead production reached about 10 million tons, and more than 50% of it was obtained from recycling lead-containing waste.
The distinctive properties of lead, including its high density, relatively low melting point, and chemical inertness to oxidation, in addition to its high relative abundance and low price, helped lead to its use in many applications that included, for example, construction, radiation protection, plumbing, the manufacture of batteries, bullets, projectiles, weights, and various alloys such as soldering alloys, pewter alloys, and alloys. It is easy to melt (smelting), in addition to its previous use in the field of paints and its addition to automobile fuel (in the form of tetraethyl lead).
Lead is a toxic metal
Which led to limiting its applications in most countries after discovering its toxicity.
Lead has a negative effect on biological organisms, as its effect is similar to neurotoxins in terms of its ability to harm the nervous system and disrupt the functional performance of some vital enzymes, causing nervous and motor disorders.
Lead poisoning is a type of metal poisoning caused by the accumulation of lead in the body. The brain is considered the most sensitive organ to lead. Symptoms of poisoning may include abdominal pain, constipation, headache, irritability, memory problems, inability to have children, infertility, and tingling in the hands and feet. Lead poisoning causes approximately 10% of cases of mental retardation that occur for unknown reasons, otherwise This can lead to behavioral problems. Lead poisoning leaves some lasting effects and, in severe cases, anemia, seizures, coma, or death may occur. One can be exposed to lead through polluted air, dust, food, or consumer products. Children are at greater risk because they are more likely to pick up objects from the floor and put them in their mouths, such as those containing lead paint, and they absorb a much greater proportion of the lead they eat than adults. Exposure at work is a common cause of lead poisoning in adults who work in certain occupations with a risk of exposure to lead.
Diagnosis is usually made by measuring the level of lead in the blood. The United States Disease Control Centers have set the upper limit for the level of lead in the blood of adults at 10 µg/dL (10 µg/100 g) and for children at 5 µg/dL.
High lead can also be detected by detecting changes in red blood cells or the dense lines that appear in children's bones as they appear on X-rays.
Lead poisoning can be prevented, and this includes some individual efforts, such as removing lead-containing items from the home, and efforts made in the workplace, such as improving ventilation and continuous follow-up of cases. This can also be done through national policies, such as issuing laws that prohibit the use of lead in products such as paint and gasoline, and laws. Which provides for the cleaning of contaminated soil.
Treatment depends mainly on removing the source of lead and using medications that bind to lead so that the body can get rid of it. Lead is thought to have led to 853,000 deaths in 2013, occurring mostly in the developing world, especially among the poor, who are most at risk. Lead is believed to be responsible for 0.6% of the world's disease burden. People have been mining and using lead for thousands of years. Lead poisoning has been described since at least 2000 BC, while the first efforts to reduce lead use date back to at least the 16th century. Concerns about low exposure levels began in the 1970s, with no minimum safe level of exposure to lead