Serum Lead and Micronutrients Levels in Public Transport Drivers in Osogbo, Nigeria

Background of Study: Toxic exposure to lead (Pb) in humans occurs through environmental and occupational sources like leaded gasoline. Despite the ban on the use of leaded gasoline by many regulatory authorities due to its adverse health effects, Nigeria remains among nations using leaded fuel.

Aim: The study aimed to determine toxic lead exposure to gasoline fumes and its impact on plasma levels of micronutrients (zinc [Zn], copper [Cu], and calcium [Ca]) in public transport drivers in Nigeria.

Materials and Methods: The case-control study, compared serum micronutrient levels of 40 occupational lead exposed public transport drivers with physically matched 40 non-occupational lead exposed civil servicemen. The concentrations of Pb, Zn, Cu and Ca in the serum of the study subjects were determined by atomic absorption spectrometry.

Results: Results analyzed with the t-test showed that mean serum lead level in public transport drivers was significantly (P=0.000) high compared to the control group. Also, micronutrient levels were significantly (P=0.000) lower in occupational than non-occupational lead-exposed men. Pearson correlation analysis results showed significant positive correlation between Cu and Ca (r=0.481, P=0.002), Zn and Cu (r=0.635, P=0.000), Zn and Ca (r=0.456, P=0.003). Whereas an inverse but non-significant correlation between lead and Cu (r=-0.275), lead and Ca (r=-0.130), lead and Zn (r=-0.121) was observed at the 0.05 level.

Conclusion: In conclusion, the study results indicate that exposure to lead can significantly decrease serum zinc, copper, and calcium. The decrease in micronutrient level in the drivers could be through renal loss, mediated by the nephrotoxic effect of lead.