연 흡수에 의한 δ-aminolevulinic acid 탈수효소 활성치의 변동 = δ-Aminolevulinic acid Dehydratase Activity as an indication of Lead Absorption

다국어 초록 (Multilingual Abstract)

This study was conducted in an attempt to clarify the interrelationship among blood lead level, erythrocyte δ-aminolevulinic acid dehydratase (δ-ALAD) activity and urinary δ-aminolevulinic acid (δ-ALA) excretion as an indication of lead absorption in lead workers in Korea.
Blood lead level, δ-ALAD activity and urinary δ-ALA excretion were measured with samples obtained from 37 lead workers and 33 non-lead workers (coal miners) as a control group.
Analytical methods used for this study were atomic spectrophotometric method using Jarrel-Ash 82-500 atomic absorption spectrophotometer (Fisher Scientific Co.) by Hessel's method (1968) for blood lead level, Bonsignore's method modified by Weissberg (1971) for erythrocyte δ-ALAD activity, and Mauzerall and Granick's method modified by Wada et al (1969) for urinary δ-ALA excretion.
Erythrocyte δ-ALAD activity in relation to blood lead level and urinary δ-ALA excretion was discussed as a measure of lead absorption.
The following results were obtained:
1. There was no difference in blood lead level among workers of different age groups, and on the other hand, there was a definite tendency of increase in blood lead level with duration of working years at lead workplaces.
2. Mean erythrocyte δ-ALAD activity was 70.9±12.00 units for the non-lead workers and the value decreased sharply to 45.6±14.25 units and to 19.6±9.00 units as the blood lead levels increased to 10-19 ㎍% and 20-39 ㎍%, respectively. The rate of decrease of the erythrocyte δ-ALAD activity was lessened when the blood lead level increased higher than 40 ㎍%.
3. Mean urinary δ-ALA excretion amounted to 2.6±1.36 ㎎/g creatinine on an average in non-lead workers, and increased proportionally with blood lead level showing linear regressional relationship of urinary δ-ALA excretion (Y: ㎎/g creatinine) on blood lead level (X: ㎍%) expressed by equation: Y=0.3627 X-0.3974 (r=0.8853).
4. Regressional relationship of erythrocyte δ-ALAD activity (Y: unit) on blood lead level (X: ㎍%) was expressed by the equation log Y=log226-0.689 logX (r=-0.8257), and that of erythrocyte δ-ALAD activity (Y: unit) on urinary δ-ALA excretion (X: ㎎/g creatinine) by logY=log109-0.728 logX (r=-0.7003).