Lead toxicity update. A brief review.

Lead is a metal which has been associated with human activities for thelast 6000 years. In ancient civilizations, uses of lead included the manufacture of kitchen utensils,trays, and other decorative articles. However, lead is also toxic to humans, with the most deleteriouseffects on the hemopoietic, nervous, reproductive systems and the urinary tract. The main sources oflead exposure are paints, water, food, dust, soil, kitchen utensils, and leaded gasoline. The majorityof cases of lead poisoning are due to oral ingestion and absorption through the gut. Lead poisoning inadults occurs more frequently during exposure in the workplace and primarily involves the central nervoussystem. Symptoms of hemopoietic system involvement include microcytic, hypochromic anemia with basophilicstippling of the erythrocytes. Hyperactivity, anorexia, decreased play activity, low intelligence quotient,and poor school performance have been observed in children with high lead levels. Lead crosses the placentaduring pregnancy and has been associated with intrauterine death, prematurity, and low birth weight.In 1991, the Centers for Disease Control and Prevention in the USA redefined elevated blood lead levelsas those > or = 10 microg/dl and recommended a new set of guidelines for the treatment of lead levels> or =15 microg/dl.

Keywords: Chelating Agents - therapeutic use, Adult, Child, Lead - toxicity, Lead Poisoning - physiopathology, Pregnancy