ENVIRONMENTAL LEAD-EXPOSURE INDUCES CHANGES IN THE HEME BIOSYNTHETIC-PATHWAY

Lead is ubiquitous in the environment today, Lead enters our body from a variety of sources such as urban environments and food. All humans have lead in their bodies primarily as a result of exposure to man-mad e sources. Children show a greater sensitivity to lead's effects than adults do. In this study, the concentration of metabolites of heme bio synthesis in school children from a group of volunteers with various b lood lead contents and a group of lead-intoxicated children were repor ted. Also, the measurement of free erythrocyte porphyrins (FEP) as a m icroscreening test for lead toxicity was performed, and the blood lead levels of the school children were determined as well. The results sh ow that the concentrations of the metabolites of heme biosynthesis are affected by the blood lead level. FEP level shows a small change as t he blood lead level slightly increases. Elevation of blood lead level and the increase of the metabolite concentration are a good indication of lead-induced heme metabolic changes. FEP is an excellent screening test for the heme metabolic imbalances. Because of differences in ind ividual susceptibility, symptoms of lead intoxication and their onset may vary. With increasing exposure, the severity of symptoms can be ex pected to change with varying degrees of lead toxicity. (C) 1997 by Jo hn Wiley & Sons, Inc.