Some individuals may be surprised to learn that lead pencils do not contain lead. The "lead" is actually a blend of graphite and clay; the greater the proportion of graphite, the softer and darker the point.
Lead has many important uses in industry and technology that cannot be replaced by alternatives. For example, it is used as an additive for steel castings and for brassware because it increases hardness and durability. It is also used in ammunition, paint, medicine, and some chemicals. Lead is dangerous because it can leach into food or water that someone else comes in contact with. Young people especially are at risk for lead poisoning because their brains and bodies are still developing cells that will later bind with lead. Lead can also damage organs such as the kidneys, brain, and lungs.
Children's access to lead-based paints needs to be prevented through education about the dangers of lead and through the replacement of those materials where possible. Lead pipes used to deliver drinking water to homes with older plumbing systems should be replaced because the lead in them can leach into the water. Lead dust is also harmful if it enters through the airways or is ingested. Employees working with lead or its products need to avoid exposure by using protective equipment such as masks, gloves, and boots.
Here's a myth buster: pencils contain no lead. Rather, the core is constructed of graphite, a non-toxic material. However, when you grind down the end of the pencil, some of that graphite may become exposed inside the tip of the pen.
Lead has many names including galena, plumbago, and white gold. It is a silver-gray metal that is malleable at room temperature and has an iron oxide color. It is soft and ductile and can be cut with a knife. Lead is toxic if ingested so please use caution not to eat it. The main source of lead exposure for people is through eating contaminated food or drinking water containing lead. Other sources include inhalation of lead dust or ingestion of lead in objects such as paint or solder.
In animals, lead affects the brain, kidneys, muscles, and blood cells. In humans, it can cause aggression, anxiety, appetite loss, confusion, depression, hallucinations, memory problems, nausea, pain in joints, bones, or teeth, seizures, tingling hands or feet, urinary problems, and vision changes. Although very rare, it can be fatal if not treated promptly.
False. Lead pencils are made of graphite (a kind of carbon), not lead. Pencils were not created the way they are now at the time of the Cumbria discovery. Instead, graphite blocks were sawed into sticks to be utilized as writing instruments. These early sticks of wood-carbon were called "chalk" and were actually used before coal was discovered as a source of heat. The name "pencil" came later when hemp or bamboo was used instead. Today, most pencils are made from petroleum products such as wax and asphalt. However, there are pencils that are made from trees, such as oak and maple. These pencils are known as "woodblock" pencils.
Lead has many useful properties that make it attractive for use in tools. It is hard, lightweight, and relatively inert. Although lead is toxic if ingested, it is less so than either copper or zinc. Lead compounds have been used for centuries in medicine and dentistry as treatments for infections caused by bacteria that tend to resist antibiotics. They also have been used to treat heavy menstrual bleeding, relieve pain, and prevent migraines. Modern studies have shown that exposures to low levels of lead may affect human behavior, cognitive development, immune function, and reproductive biology. But since the majority of modern lead exposure comes from sources other than traditional lead pipes and paint, these effects are likely under greater public concern than previous generations of lead workers.