• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.2
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• pp.111-117
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• 2001

A cross-sectional study was performed to evaluate associations between lead biomarkers, lead-related symptoms, and ${\delta}$-aminolevulinic acid dehydratase (ALAD) genotype among 598 lead workers and 144 control office workers in storage battery industries, secondary smelting and litharge making industries. Lead inhibits the second enzymes, ALAD, in the heme synthesis pathway. ALAD gene, which codes for one of three isozymic proteins (termed ALAD1-1, ALAD1-2, and ALAD2-2), seems to modify the toxicokinetics of lead. The result as follows; The percents of total workers whose genotype of ALAD1-1 and ALAD1-2 were 88.4% and 11.6%, respectively. The zinc protoporphyrin in blood (ZPP) and ${\delta}$-aminolevulinic acid in urine (ALAU) of lead workers with ALAD1-2 were significantly lower than those of lead workers with ALAD1-1, but there were no significant difference between two genotype for blood lead, age, and work duration. The proportion of ALAD1-2 genotype in control office workers was 13.2%. The proportions of ALAD1-2 genotype of lead workers were 14.0%(their mean air lead level below $0.024mg/m^3$), 10.4%($0.025-0.049mg/m^3$), 11.8%($0.050-0.099mg/m^3$), and 9.4%(above $0.100mg/m^3$), respectively. In the logistic analysis of 15 lead related symptoms, 'arthralgia'(S7) symptom of ALAD1-2 was significantly lower (OR=0.481; 95% CI=0.248-0.932) than that of ALAD1-1, but 'feeling of irritation'(S11) of ALAD1-2 was significantly higher(OR=1.636; 95% CI=1.035-2.586) than that of ALAD1-1 after controlling possible confounder (blood lead, work duration, smoking and drinking habit).

• Korean Journal of Community Nutrition
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• v.11 no.6
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• pp.771-778
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• 2006

Previous studies have suggested that delta-aminolevulinic acid dehydratase (ALAD) phenotype differently affect mineral metabolism. The objective of this study was to determine the effectiveness of 6-month iron supplementation as syrup of NaFeEDTA in improvement of iron status according to ALAD genotype. One hundred thirty adult women living in rural areas of Asan were provided NaFeEDTA syrup once a week for 6 months at the dose of 64mg Fe/week. Three hundred control subjects were observed during the study period. Fasting blood was obtained for analyzing hemoglobin (Hb) and zinc protophorphyrin (ZPP) and serum was analyzed for ferritin, iron and total iron capacity (TIBC) levels before and after iron supplementation. Ninety percent of ALAD 1-1 (ALAD1) and 10% of ALAD 1-2 (ALAD2) genotype were observed in the control group. However in the intervention group, 98% showed ALAD1 while only 2% was ALAD2, which is significantly lower proportions of ALAD2 compared to the control group (p<0.01). The iron status of Intervention group significantly improved except for ferritin and TIBC regardless or ALAD genotype, while the control group did not show any changes in iron status except for ZPP. ZPP concentration of the control group significantly increased in both ALAD1 and 2 while the intervention group showed significantly decreased ZPP after supplementation in ALAD1. Iron supplementation in the form of NaFeEDTA seems to be effective in reduction of ZPP levels although ALAD2 did not show significant changes due to the small number. However, it is difficult to make a conclusion from these results, and more specified further investigation is needed with more participants.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.2
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• pp.152-160
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• 2006

Genotype of ALAD and VDR yields two alleles, respectively and it has been implicated in susceptibility to lead toxicity. Also genotype known to variety by race. To evaluate the genetic susceptibility of ALAD and VDR gene on health effect of lead exposure, this study was done with new workers who entered lead industries from 1992 to 2001. Among database of lead industries of Soonchunhyang University Institute of Industrial Medicine, only new workers were selected for this study. The total of eligible workers for this category was 3,540 workers including non lead exposed workers of same lead industries. Genotype of ALAD and VDR were measured from stored blood in specimen bank of Soonchunhyang University, blood lead and other relevant information were obtained from database of each workers which were gathered at their first year of employment. Among 3,540 new employed study subjects during period of 1992-2001, 3204 workers(90.5%) had ALAD genotype 1-1; whereas 336 workers(9.5%) had variant type of ALAD (1-2 or 2-2). Lead exposed workers, 9.8%(n=243) male and 8.1%(n=16) female were heterozygous for the ALAD allele. Also non lead exposed workers, 8.9%(n=67) male and 9.3%(n=10) female were heterozygous for the ALAD allele. For VDR genotype, 2,903 workers(89.7%) out of total tested 3,238 workers were belonged to type bb and 335 workers(10.3%) were type bB or BB. Lead exposed workers, 10.4%(n=235) male and 12.2%(n=24) female were heterozygous for the VDR allele. Also non lead exposed workers, 9.2%(n=64) male and 12.5%(n=12) female were heterozygous for the VDR allele. No significant differences were seen in mean blood lead levels by ALAD and VDR genotype, nor was significantly associated with blood lead except age in multiple regression analysis.