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Title: Delta-aminolevulinic acid dehydratase (ALAD) polymorphism in lead exposed Bangladeshi children and its effect on urinary aminolevulinic acid (ALA)

Background and objective: Lead has long been recognized as a harmful environmental pollutant. People in developing countries like Bangladesh still have a higher risk of lead exposure. Previous research has suggested that the delta-aminolevulinic acid dehydratase (ALAD) genotype can modify lead toxicity and individual susceptibility. As children are more susceptible to lead-induced toxicity, this study investigated whether the ALAD genotype influenced urinary excretion of delta-aminolevulinic acid (U-ALA) among children exposed to environmental lead in Bangladesh. Methods: Subjects were elementary schoolchildren from a semi-urban industrialized area in Bangladesh. A total of 222 children were studied. Blood and urine were collected to determine ALAD genotypes, blood lead levels and urinary aminolevulinic acid (U-ALA). Results: The mean BPb level was 9.7 µg/dl for the study children. BPb was significantly positively correlated with hemoglobin (p<0.01). In total, allele frequency for ALAD 1 and 2 was 0.83 and 0.17 respectively. The mean U-ALA concentration was lower in ALAD1-2/2-2 carriers than ALAD1-1 carriers for boys (p=0.001). But for girls, U-ALA did not differ significantly by genotype (p=0.26). When U-ALA was compared by genotype at the same exposure level in a multiple linear regression analysis, boys who were ALAD1-2/2-2 carriers still had a lower level of U-ALAmore » compared to ALAD1-1carriers. Conclusion: This study provides information about the influence of ALAD polymorphism and its association with U-ALA in Bangladeshi children. Our results indicate that the ALAD1-2/2-2 genotype may have a protective effect in terms of U-ALA for environmentally lead exposed boys. - Highlights: • High blood lead level for the environmentally exposed schoolchildren. • BPb was significantly correlated with U-ALA and Hb. • Effect of ALAD genotype on U-ALA is differed by sex. • Lower U-ALA in ALAD2 than ALAD1 carriers only for boys at same exposure.« less
Authors:
 [1] ;  [1] ;  [2] ;  [3] ;  [1]
  1. Department of Human Ecology, School of International Health, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)
  2. Department of Occupational and Environmental Health, Bangladesh Institute of Health Sciences, 125/1, Darus Salam, Mirpur, Dhaka 1216 (Bangladesh)
  3. Department of Public Health, State University of Bangladesh, 77 Satmasjid Road, Dhanmondi, Dhaka 1205 (Bangladesh)
Publication Date:
OSTI Identifier:
22447569
Resource Type:
Journal Article
Resource Relation:
Journal Name: Environmental Research; Journal Volume: 136; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; AMINOLEVULINIC ACID; BANGLADESH; BLOOD; CARRIERS; CHILDREN; CONCENTRATION RATIO; ECOLOGICAL CONCENTRATION; EXCRETION; GENOTYPE; HEMOGLOBIN; HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY; HUMAN POPULATIONS; ICP MASS SPECTROSCOPY; LEAD; LENGTH; POLLUTANTS; POLYMERASE CHAIN REACTION; REGRESSION ANALYSIS; TOXICITY; URINE