Effect of Pb-exposure and B vitamin deficiencies on δ-aminolevulinic acid dehydratase activity among workers from Pb recycling plants.

Previous studies reported that Pb exposure causes a negative association with delta-aminolevulinic acid dehydratase activity (δ-ALAD), but the impact of Pb exposure (dose and time), B vitamin deficiencies, and lifestyle factors needs to be explored. In this study, the impact of Pb exposure, B vitamin deficiencies, and lifestyle factors on δ-ALAD activity among workers exposed to Pb from the Pb-recycling process was evaluated. Blood lead levels (BLLs), B vitamins (B6, B9, and B12), hematological factors (Hb% and HCT), lifestyle factors, and δ-ALAD activity was assessed in 170 male Pb-exposed workers engaged in the Pb recycling process. BLLs are estimated using the ICP-OES method. B vitamins in serum samples from workers were determined using the ELISA method. The δ-ALAD activity in whole blood samples was determined using the spectrophotometer method. The lifestyle factors were collected using a standard questionnaire. The δ-ALAD activity was significantly decreased in workers with the habits of alcohol use, tobacco consumption, hematocrit < 41%, mild and moderate categories of anemia, vitamin B6 and B12 deficiency, and BLL categories of 10-30, 30-50, and > 50 µg/dL. Multiple regression analysis revealed that the independent variables of alcohol consumption (β = - 0.170; P = 0.025), BLLs (β = - 0.589; P = 0.001) and Hb% (β = 0.183; P = 0.001) significantly influenced the δ-ALAD activity with 44.2% (R 2  = 0.442). Among the workers exposed to Pb from the Pb recycling plant, δ-ALAD activity was considerably reduced by Pb exposure, B vitamin deficiency, hematological parameters, and lifestyle factors.