Environmental lead exposure induces changes in the heme biosynthetic pathway

Abstract

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-made sources. Children show a greater sensitivity to lead's effects than adults do. In this study, the concentration of metabolites of heme biosynthesis in school children from a group of volunteers with various blood lead contents and a group of lead-intoxicated children were reported. Also, the measurement of free erythrocyte porphyrins (FEP) as a microscreening test for lead toxicity was performed, and the blood lead levels of the school children were determined as well. The results show that the concentrations of the metabolites of heme biosynthesis are affected by the blood lead level. FEP level shows a small change as the 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 individual susceptibility, symptoms of lead intoxication and their onset may vary. With increasing exposure, the severity of symptoms can be expected to change with varying degrees of lead toxicity. ©1997 by John Wiley & Sons, Inc. Environ Toxicol Water Qual 12: 245–248, 1997