Impaired Antioxidant-Defence Status in Nigerian Children with Elevated Blood Lead Levels: A Possible Predisposing Factor to Chronic Diseases.

Background: Lead, a prime environmental toxicant and multi-organ poison, exerts its toxicity through interaction with essential metals and the generation of free radicals. Aim and Objectives: To explore and elucidate possible interaction dynamics between lead and the antioxidant-defence status in apparently healthy children with Elevated Blood Lead Level (EBLL) in Ibadan, South-West, Nigeria. Material and Methods: Three-hundred-and-nine apparently healthy, public primary school children were grouped into 169 children with EBLL (BLL > 5µg/dL) and 140 control (BLL= 5µg/dL). Blood lead (Pb), plasma enzymatic antioxidants [Superoxide Dismutase (SOD) and Glutathione Peroxidase (GPx) activities], antioxidant metals [Copper (Cu), Zinc (Zn), Selenium (Se)], and oxidative stress parameters [Total Antioxidant Potential (TAP), Total Plasma Peroxide (TPP) and Oxidative Stress Index (OSI)] were determined. Results: Levels of Pb, Zn, Se, TPP and OSI increased while SOD, GPx and TAP decreased in children with EBLL compared with control (p<0.05). No difference was observed in Cu levels between the two groups (p > 0.05). Lead associated positively with Se, TPP and OSI (p<0.05), negatively with TAP, SOD and GPx (p<0.05) but showed no association with Zn and Cu (p>0.05). Conclusion: There was impaired antioxidant-defence status in children with EBLLs which may predispose them to chronic diseases if unresolved. [ABSTRACT FROM AUTHOR]