Blood lead and plasma homocysteine in petrol pump workers in Karachi: Role of vitamins B6, B12, folate and C

Mohsin Yakub, Mohammad Perwaiziqbal, Naseema Mehboob Ali, Ghulam Haider, Iqbal Azam

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


Vehicle population in Karachi has increased significantly. Therefore, workers at petrolpumps would be at a risk of developing lead poisoning. Present study was undertaken to determine if petrol-pump workers in Karachi have high levels of blood lead and plasma homocysteine, and to find out the role of vitamins-folate, B12, B6 and C in influencing levels of blood lead and homocysteine in study population. In a comparative pilot study, 35 males working at petrol-pumps and SO age-matched males working in the Aga Khan University (AKU) were enrolled. Fasting blood was analyzed for lead, while plasma/serum was analyzed for homocysteine, folate, vitamin-B12, pyridoxal phosphate (PLP, coenzymic form of vitamin-B6) and vitamin-C. Mean levels of blood lead and plasma homocysteine in petrol-pump workers and AKU-employees were not found to be significantly different (12.9 ± 3.7 μg/d1, 25.35 ± 17 μmol/l, 14.5 ± 6.1 μg/d1, 23.8 ± 18 μmol/1, respectively). Vitamin-C and folate levels in serum of petrol-pump workers were, however, found to be significantly decreased compared to AKU employees (P = 0.018 for vitamin-C and P = 0.009 for folate). Percent deficiencies of folate, vitamin-B12, PLP and vitamin-C in the study population were found to be 22.4 %, 16.4 %, 29.4 % and 10.2 %, respectively. Correlation analysis of the data revealed a moderate positive association between blood lead and plasma homocysteine (Pearson's r = 0.24; P = 0.01) and an inverse relationship between blood lead and serum folate (Pearson's r =-0.300; P = 0.006). Folate deficiency and moderately elevated levels of lead could be contributing to hyperhomocysteinemia in Karachi population. Introduction of unleaded petrol might have decreased blood lead in this population.

Original languageEnglish
Pages (from-to)319-323
Number of pages5
JournalJournal of the Chemical Society of Pakistan
Issue number2
Publication statusPublished - Apr 2009


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