Lead was mined for the first time, in Turkey, around 6500 B.C.; and its toxicity was recognized and recorded by 2000 B.C. This metal has been an active ingredient in paints, lead-glazed ceramic ware, water pipes, gasoline, metal jewelry, batteries, solder, and cosmetics. During the seventies, the usage of this metal was curtailed to some extent, through legislation.
Lead poisoning occurs due to the increased level of this metal in the blood. This happens when the human body absorbs this metal, through breathing or swallowing. Sometimes, even small amounts of lead can be toxic, especially for children. The condition can result in severe mental and physical disorders in small children. Even though, the toxicity of this metal affects both adults and kids, lead poisoning in children below the age of six, is more severe and frequent. Lead poisoning may occur all of a sudden, when exposed to a large amount of lead. Long-term exposure to small amounts of this metal, may also cause this condition.
Normally, a very small amount of lead is present in the human body. If the lead content is higher than normal, it can damage almost every organ; but the kidneys, the brain and other parts of the nervous system, are more susceptible. In kids, a blood lead level of 10 ug/dL (micro grams per deciliter) or higher, is a cause for concern. This can lead to mental retardation and other cognitive and behavioral problems. A blood lead level of 80 ug/dL and above, is fatal for adults. However, a blood lead level of 25 to 80 ug/dL may also cause health problems.
Chronic lead poisoning leads to neurological disorders, like reduced cognitive abilities (perception, learning and reasoning). The peripheral and the central nervous system are mainly affected by this metal. High blood lead level can result in peripheral neuropathy (nerve disorders of the peripheral nervous system), which is characterized by wrist drop - weakness of the extensor muscles of the hand. Low levels are associated with impairment of the neuro-cognitive function. In children, even a low blood lead level can cause permanently reduced cognitive capacity (intelligence).
Lead poisoning may also cause insomnia, impotence, chest pain, headache, excess fatigue or hyperactivity, irritability, coma and sometimes death. It may also cause symptoms, like nausea, abdominal pain, constipation, vomiting, diarrhea, weight loss, anemia, kidney problems, blue lines along the gums, and high blood pressure. Children may experience slow growth, hearing problems, staggering, behavior problems, learning problems, headaches, convulsions, drowsiness and confusion. Severe and life-threatening symptoms develop in case of exposure to toxic doses of lead.
Lead is present in the Earth's crust in a very small quantity. Human activities, like mining and use of leaded gasoline, have resulted in the widespread prevalence of lead poisoning. Regular usage of substances with a high lead content can lead to this condition. It could be due to absorption of very low doses of lead over a stretch of time, or high doses over a short period.
Adults, who work as welders, potters and metal smelters, are at a greater risk of lead poisoning. Hobbies, like shooting, working with stained glass and building lead-based models, can also result in exposure to lead. Even tap water can be contaminated with lead, if the water pipes are made of this metal, or if you are using brass plumbing fixtures and copper pipes soldered with lead. Even though, paints with lead are banned in the U.S., older homes and buildings have lead-based paint that can cause lead poisoning.
Imported toys and pottery may also contain this metal. Soil contaminated with lead from gasoline and paint, is another reason for lead poisoning. While household dust is a common source, some imported canned foods may also contain lead. It has also been found that traditional medicines of some regions contain high levels of this metal. Cosmetics, like 'kohl' may also have a high lead content.
In order to curtail the risk of lead poisoning, avoid exposure to this metal. Don't allow your children to ingest paint flakes or soil. A little precaution can save you from this condition and help you lead a healthful life.