P-365 Analysis of Heavy Metals Interference in Blood Delta-Aminolevulinic Acid Dehydratase (Δ-Alad) Activity

Introduction Lead may alter δ-ALAD activity, the enzymes involved in the heme synthesis pathway. In the occupational setting, lead exposure rarely appears alone but occurs together with other heavy metal. This study aims to analyze the relationship of multiple heavy metals exposure with the δ-ALAD activity. Methods We conducted a cross-sectional study in Java Island, Indonesia. A total of 71 participants were consecutively recruited from 3 locations. The questionnaire, physical examinations, and blood samples were taken from all subjects. Blood δ-ALAD activity was measured using NMAM 8000 method, while heavy metals levels were measured using ICPMS. 25-OH vitamin D was measured using ECLIA method. Results We identify that several occupational activities were the sources of heavy metals exposure. The median (min-max) of the blood δ-ALAD activity was 22.16 (2.88-36.98) unit/g hematocrit. The median (min-max) concentrations of lead, chromium, cadmium and 25-OH vitamin D levels were 6.97 (1.17-43.94) μg/dL, 9.26 (0.05-66.95) μg/L, 1.0 (0.01-6.43) μg/L and 21 (11-36) ng/mL, respectively. The δ-ALAD activity was found to be significantly correlated with blood lead, chromium, and cadmium level, as well as with the ratio of Pb/Mn, Cd/Mn, Cd/vitamin D, and Pb/vitamin D. Discussion Our findings indicated that some heavy metals may contribute to the catalysis activity of the δ-ALAD enzyme. Conclusion Blood δ-ALAD activity can be interfered with by lead, chromium, and cadmium. The health impacts mitigation efforts due to lead exposure need to pay attention to the potential involvement of co-exposure to other heavy metals.