Lead--the toxic metal to stay with human.
Lead has been known to be toxic to most living things at high dose. It is found naturally in earth and present in almost all parts of the environment, such as foods, air, water, dust, soil, paint, and tissues of living organisms including human. This metal is being used in various aspects including the manufacturing of storage batteries, production of chemicals, paints and gasoline additives. It is also used to make various metal products, e.g. sheet lead, solder, and pipes. Human exposure to lead is mainly from foods and other environments. However, it is expected that exposure to environmental lead is normally excessive and produces toxic effects. The well-known and excessive environmental exposures are air of industrial and heavy traffic areas. Use of leaded gasoline has caused the main lead pollution for years in almost every big city. Therefore, city inhabitants normally exposed to lead much more than those who live in the rural area. The most vulnerable groups at risk to lead exposure are fetuses and preschool age children. Young children in the 2-3 year-old age may be the most at risk for exposure to contaminated soil. Adults are affected when exposure is excessive in the working place and causing lead poisoning. Toxicities are mainly on heme biosynthesis, neurological effects including encepharopathy, peripheral neuropathy, and most importantly on I.Q. deficits. It also affects renal tissues to produce acute and chronic nephropathy and elevated blood pressure. There are studies of lead exposure of various means and the effects on human health, both in children and adults. Lead in environment and human exposure are expected to stay with us for long to come, due the still required lead use in many fields, particularly the use of lead in storage batteries and others. The magnitude of exposure will depend solely on the control of use by not allowing the contamination of lead in our environment to be excessive.
Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
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Srianujata
D000740:Anemia / Q000139:chemically induced; D004781:Environmental Exposure; D006801:Humans; D007360:Intelligence / Q000187:drug effects; D007855:Lead Poisoning / Q000150:complications* / Q000209:etiology / Q000517:prevention & control; D016273:Occupational Exposure